Prometheus monitoring for GitLab Pages

This starts of the prometheus monitoring for GitLab Pages, and
resolves gitlab-org/gitlab-pages#42

Point to check:
- Are the metric names good, keeping Prometheus' conventions in mind?
- Golang, general style etc
- Shouldn't I do some voodoo magic to import this in the library?

137 files changed, 25556 insertions, 3472 deletions

diff --git a/Godeps/Godeps.json b/Godeps/Godeps.json
index a3ef6478..ca81fa69 100644
--- a/Godeps/Godeps.json
+++ b/Godeps/Godeps.json
@@ -1,15 +1,60 @@
 {
 	"ImportPath": "gitlab.com/gitlab-org/gitlab-pages",
-	"GoVersion": "go1.5",
+	"GoVersion": "go1.7",
+	"GodepVersion": "v77",
 	"Packages": [
 		"./..."
 	],
 	"Deps": [
 		{
+			"ImportPath": "github.com/beorn7/perks/quantile",
+			"Rev": "4c0e84591b9aa9e6dcfdf3e020114cd81f89d5f9"
+		},
+		{
+			"ImportPath": "github.com/golang/protobuf/proto",
+			"Rev": "f592bd283e9ef86337a432eb50e592278c3d534d"
+		},
+		{
 			"ImportPath": "github.com/kardianos/osext",
 			"Rev": "efacde03154693404c65e7aa7d461ac9014acd0c"
 		},
 		{
+			"ImportPath": "github.com/matttproud/golang_protobuf_extensions/pbutil",
+			"Comment": "v1.0.0-2-gc12348c",
+			"Rev": "c12348ce28de40eed0136aa2b644d0ee0650e56c"
+		},
+		{
+			"ImportPath": "github.com/prometheus/client_golang/prometheus",
+			"Comment": "v0.8.0-9-g334af01",
+			"Rev": "334af0119a8f8fb6af5bb950d535c482cac7f836"
+		},
+		{
+			"ImportPath": "github.com/prometheus/client_golang/prometheus/promhttp",
+			"Comment": "v0.8.0-9-g334af01",
+			"Rev": "334af0119a8f8fb6af5bb950d535c482cac7f836"
+		},
+		{
+			"ImportPath": "github.com/prometheus/client_model/go",
+			"Comment": "model-0.0.2-12-gfa8ad6f",
+			"Rev": "fa8ad6fec33561be4280a8f0514318c79d7f6cb6"
+		},
+		{
+			"ImportPath": "github.com/prometheus/common/expfmt",
+			"Rev": "ebdfc6da46522d58825777cf1f90490a5b1ef1d8"
+		},
+		{
+			"ImportPath": "github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg",
+			"Rev": "ebdfc6da46522d58825777cf1f90490a5b1ef1d8"
+		},
+		{
+			"ImportPath": "github.com/prometheus/common/model",
+			"Rev": "ebdfc6da46522d58825777cf1f90490a5b1ef1d8"
+		},
+		{
+			"ImportPath": "github.com/prometheus/procfs",
+			"Rev": "abf152e5f3e97f2fafac028d2cc06c1feb87ffa5"
+		},
+		{
 			"ImportPath": "github.com/stretchr/testify/assert",
 			"Rev": "1297dc01ed0a819ff634c89707081a4df43baf6b"
 		},
@@ -18,12 +63,16 @@
 			"Rev": "1297dc01ed0a819ff634c89707081a4df43baf6b"
 		},
 		{
-			"ImportPath": "golang.org/x/crypto/ssh/terminal",
-			"Rev": "1351f936d976c60a0a48d728281922cf63eafb8d"
+			"ImportPath": "golang.org/x/net/http2",
+			"Rev": "07b51741c1d6423d4a6abab1c49940ec09cb1aaf"
+		},
+		{
+			"ImportPath": "golang.org/x/net/http2/hpack",
+			"Rev": "07b51741c1d6423d4a6abab1c49940ec09cb1aaf"
 		},
 		{
-			"ImportPath": "golang.org/x/net/http2",
-			"Rev": "b4e17d61b15679caf2335da776c614169a1b4643"
+			"ImportPath": "golang.org/x/net/lex/httplex",
+			"Rev": "07b51741c1d6423d4a6abab1c49940ec09cb1aaf"
 		}
 	]
 }
diff --git a/README.md b/README.md
index 087a2152..1f5bf7b5 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ In large environment it can be time consuming to list all directories, and CNAME
 4. Periodically (every second) it checks the `pages-root/.update` file and reads its content to verify if there was update.
 
 To force route refresh, reload of configs fill the `pages-root/.update` with random content.
-The reload will be done asynchronously, and it will not interrupt the current requests. 
+The reload will be done asynchronously, and it will not interrupt the current requests.
 
 ### How it serves content
 
diff --git a/acceptance_test.go b/acceptance_test.go
index 2e36acd1..e603e392 100644
--- a/acceptance_test.go
+++ b/acceptance_test.go
@@ -2,9 +2,13 @@ package main
 
 import (
 	"flag"
-	"github.com/stretchr/testify/assert"
+	"fmt"
+	"io/ioutil"
 	"net/http"
+	"regexp"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 var shouldRun = flag.Bool("run-acceptance-tests", false, "Run the acceptance tests?")
@@ -33,7 +37,7 @@ func skipUnlessEnabled(t *testing.T) {
 
 func TestUnknownHostReturnsNotFound(t *testing.T) {
 	skipUnlessEnabled(t)
-	teardown := RunPagesProcess(t, *pagesBinary, listeners)
+	teardown := RunPagesProcess(t, *pagesBinary, listeners, "")
 	defer teardown()
 
 	for _, spec := range listeners {
@@ -48,7 +52,7 @@ func TestUnknownHostReturnsNotFound(t *testing.T) {
 
 func TestKnownHostReturns200(t *testing.T) {
 	skipUnlessEnabled(t)
-	teardown := RunPagesProcess(t, *pagesBinary, listeners)
+	teardown := RunPagesProcess(t, *pagesBinary, listeners, "")
 	defer teardown()
 
 	for _, spec := range listeners {
@@ -60,3 +64,20 @@ func TestKnownHostReturns200(t *testing.T) {
 		}
 	}
 }
+
+func TestPrometheusMetricsCanBeScraped(t *testing.T) {
+	skipUnlessEnabled(t)
+	listener := []ListenSpec{{"http", "127.0.0.1", "37003"}}
+	fmt.Println("Start pages process")
+	teardown := RunPagesProcess(t, *pagesBinary, listener, ":42345")
+	defer teardown()
+
+	resp, err := http.Get("http://localhost:42345/metrics")
+
+	if assert.NoError(t, err) {
+		defer resp.Body.Close()
+		body, _ := ioutil.ReadAll(resp.Body)
+
+		assert.Regexp(t, regexp.MustCompile("gitlab_pages_http_sessions_active 0"), string(body))
+	}
+}
diff --git a/app.go b/app.go
index 35b661cc..ffe7bc24 100644
--- a/app.go
+++ b/app.go
@@ -4,9 +4,12 @@ import (
 	"crypto/tls"
 	"log"
 	"net/http"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 const xForwardedProto = "X-Forwarded-Proto"
@@ -43,6 +46,9 @@ func (a *theApp) serveContent(ww http.ResponseWriter, r *http.Request, https boo
 	w := newLoggingResponseWriter(ww)
 	defer w.Log(r)
 
+	sessionsActive.Inc()
+	defer sessionsActive.Dec()
+
 	// Add auto redirect
 	if https && !a.RedirectHTTP {
 		u := *r.URL
@@ -62,6 +68,7 @@ func (a *theApp) serveContent(ww http.ResponseWriter, r *http.Request, https boo
 
 	// Serve static file
 	domain.ServeHTTP(&w, r)
+	processedRequests.WithLabelValues(strconv.Itoa(w.status), r.Method).Inc()
 }
 
 func (a *theApp) ServeHTTP(ww http.ResponseWriter, r *http.Request) {
@@ -121,6 +128,14 @@ func (a *theApp) Run() {
 		}(fd)
 	}
 
+	// Serve metrics for Prometheus
+	if a.MetricsAddress != "" {
+		go func() {
+			http.Handle("/metrics", promhttp.Handler())
+			log.Fatal(http.ListenAndServe(a.MetricsAddress, nil))
+		}()
+	}
+
 	go watchDomains(a.Domain, a.UpdateDomains, time.Second)
 
 	wg.Wait()
diff --git a/app_config.go b/app_config.go
index 7ffa1e76..8220bb87 100644
--- a/app_config.go
+++ b/app_config.go
@@ -6,9 +6,10 @@ type appConfig struct {
 	RootCertificate []byte
 	RootKey         []byte
 
-	ListenHTTP  []uintptr
-	ListenHTTPS []uintptr
-	ListenProxy []uintptr
+	ListenHTTP     []uintptr
+	ListenHTTPS    []uintptr
+	ListenProxy    []uintptr
+	MetricsAddress string
 
 	HTTP2        bool
 	RedirectHTTP bool
diff --git a/domains.go b/domains.go
index de038f5e..91a9cd1d 100644
--- a/domains.go
+++ b/domains.go
@@ -30,6 +30,8 @@ func (d domains) addDomain(rootDomain, group, project string, config *domainConf
 	}
 	domainName = strings.ToLower(domainName)
 	d[domainName] = newDomain
+
+	domainsServed.Inc()
 	return nil
 }
 
@@ -147,6 +149,12 @@ func watchDomains(rootDomain string, updater domainsUpdater, interval time.Durat
 		if updater != nil {
 			updater(domains)
 		}
+
+		// Update prometheus metrics
+		domainLastUpdateTime.Set(float64(time.Now().UTC().Unix()))
+		domainsServed.Set(float64(len(domains)))
+		domainUpdates.Inc()
+
 		time.Sleep(interval)
 	}
 }
diff --git a/helpers_test.go b/helpers_test.go
index 3bab08e0..4e5c3d93 100644
--- a/helpers_test.go
+++ b/helpers_test.go
@@ -124,7 +124,7 @@ func (l ListenSpec) JoinHostPort() string {
 // GetPageFromProcess to do a HTTP GET against a listener.
 //
 // If run as root via sudo, the gitlab-pages process will drop privileges
-func RunPagesProcess(t *testing.T, pagesPath string, listeners []ListenSpec) (teardown func()) {
+func RunPagesProcess(t *testing.T, pagesPath string, listeners []ListenSpec, promPort string) (teardown func()) {
 	var tempfiles []string
 	var args []string
 	var hasHTTPS bool
@@ -146,14 +146,18 @@ func RunPagesProcess(t *testing.T, pagesPath string, listeners []ListenSpec) (te
 		args = append(args, "-root-key", key, "-root-cert", cert)
 	}
 
+	if promPort != "" {
+		args = append(args, "-metrics-address", promPort)
+	}
+
 	if os.Geteuid() == 0 && os.Getenv("SUDO_UID") != "" && os.Getenv("SUDO_GID") != "" {
 		t.Log("Pages process will drop privileges")
 		args = append(args, "-daemon-uid", os.Getenv("SUDO_UID"), "-daemon-gid", os.Getenv("SUDO_GID"))
 	}
 
 	cmd := exec.Command(pagesPath, args...)
-	t.Logf("Running %s %v", pagesPath, args)
 	cmd.Start()
+	fmt.Println("Running %s %v", pagesPath, args)
 
 	// Wait for all TCP servers to be open. Even with this, gitlab-pages
 	// will sometimes return 404 if a HTTP request comes in before it has
diff --git a/main.go b/main.go
index 62d28e0e..6238e6eb 100644
--- a/main.go
+++ b/main.go
@@ -27,6 +27,7 @@ func appMain() {
 	var useHTTP2 = flag.Bool("use-http2", true, "Enable HTTP2 support")
 	var pagesRoot = flag.String("pages-root", "shared/pages", "The directory where pages are stored")
 	var pagesDomain = flag.String("pages-domain", "gitlab-example.com", "The domain to serve static pages")
+	var metricsAdress = flag.String("metrics-address", "", "The adress to server metrics to")
 	var daemonUID = flag.Uint("daemon-uid", 0, "Drop privileges to this user")
 	var daemonGID = flag.Uint("daemon-gid", 0, "Drop privileges to this group")
 
@@ -46,6 +47,7 @@ func appMain() {
 	config.Domain = strings.ToLower(*pagesDomain)
 	config.RedirectHTTP = *redirectHTTP
 	config.HTTP2 = *useHTTP2
+	config.MetricsAddress = *metricsAdress
 
 	if *pagesRootCert != "" {
 		config.RootCertificate = readFile(*pagesRootCert)
diff --git a/metrics.go b/metrics.go
new file mode 100644
index 00000000..8250fe3f
--- /dev/null
+++ b/metrics.go
@@ -0,0 +1,42 @@
+package main
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	domainsServed = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "gitlab_pages_domains_served_total",
+		Help: "The total number of sites served by this Pages app",
+	})
+
+	domainUpdates = prometheus.NewCounter(prometheus.CounterOpts{
+		Name: "gitlab_pages_domains_updated_total",
+		Help: "The total number of site updates processed since daemon start",
+	})
+
+	domainLastUpdateTime = prometheus.NewCounter(prometheus.CounterOpts{
+		Name: "gitlab_pages_last_domain_update_seconds",
+		Help: "Seconds since Unix Epoc to the last update for all domains served",
+	})
+
+	processedRequests = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Name: "gitlab_pages_http_requests_total",
+		Help: "Total number of HTTP requests done serving",
+	},
+		[]string{"code", "method"},
+	)
+
+	sessionsActive = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "gitlab_pages_http_sessions_active",
+		Help: "The number of HTTP requests currently being processed",
+	})
+)
+
+func init() {
+	prometheus.MustRegister(domainsServed)
+	prometheus.MustRegister(domainUpdates)
+	prometheus.MustRegister(domainLastUpdateTime)
+	prometheus.MustRegister(processedRequests)
+	prometheus.MustRegister(sessionsActive)
+}
diff --git a/vendor/github.com/beorn7/perks/LICENSE b/vendor/github.com/beorn7/perks/LICENSE
new file mode 100644
index 00000000..339177be
--- /dev/null
+++ b/vendor/github.com/beorn7/perks/LICENSE
@@ -0,0 +1,20 @@
+Copyright (C) 2013 Blake Mizerany
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/vendor/github.com/beorn7/perks/quantile/exampledata.txt b/vendor/github.com/beorn7/perks/quantile/exampledata.txt
new file mode 100644
index 00000000..1602287d
--- /dev/null
+++ b/vendor/github.com/beorn7/perks/quantile/exampledata.txt
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diff --git a/vendor/github.com/beorn7/perks/quantile/stream.go b/vendor/github.com/beorn7/perks/quantile/stream.go
new file mode 100644
index 00000000..f4cabd66
--- /dev/null
+++ b/vendor/github.com/beorn7/perks/quantile/stream.go
@@ -0,0 +1,292 @@
+// Package quantile computes approximate quantiles over an unbounded data
+// stream within low memory and CPU bounds.
+//
+// A small amount of accuracy is traded to achieve the above properties.
+//
+// Multiple streams can be merged before calling Query to generate a single set
+// of results. This is meaningful when the streams represent the same type of
+// data. See Merge and Samples.
+//
+// For more detailed information about the algorithm used, see:
+//
+// Effective Computation of Biased Quantiles over Data Streams
+//
+// http://www.cs.rutgers.edu/~muthu/bquant.pdf
+package quantile
+
+import (
+	"math"
+	"sort"
+)
+
+// Sample holds an observed value and meta information for compression. JSON
+// tags have been added for convenience.
+type Sample struct {
+	Value float64 `json:",string"`
+	Width float64 `json:",string"`
+	Delta float64 `json:",string"`
+}
+
+// Samples represents a slice of samples. It implements sort.Interface.
+type Samples []Sample
+
+func (a Samples) Len() int           { return len(a) }
+func (a Samples) Less(i, j int) bool { return a[i].Value < a[j].Value }
+func (a Samples) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+
+type invariant func(s *stream, r float64) float64
+
+// NewLowBiased returns an initialized Stream for low-biased quantiles
+// (e.g. 0.01, 0.1, 0.5) where the needed quantiles are not known a priori, but
+// error guarantees can still be given even for the lower ranks of the data
+// distribution.
+//
+// The provided epsilon is a relative error, i.e. the true quantile of a value
+// returned by a query is guaranteed to be within (1±Epsilon)*Quantile.
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error
+// properties.
+func NewLowBiased(epsilon float64) *Stream {
+	ƒ := func(s *stream, r float64) float64 {
+		return 2 * epsilon * r
+	}
+	return newStream(ƒ)
+}
+
+// NewHighBiased returns an initialized Stream for high-biased quantiles
+// (e.g. 0.01, 0.1, 0.5) where the needed quantiles are not known a priori, but
+// error guarantees can still be given even for the higher ranks of the data
+// distribution.
+//
+// The provided epsilon is a relative error, i.e. the true quantile of a value
+// returned by a query is guaranteed to be within 1-(1±Epsilon)*(1-Quantile).
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error
+// properties.
+func NewHighBiased(epsilon float64) *Stream {
+	ƒ := func(s *stream, r float64) float64 {
+		return 2 * epsilon * (s.n - r)
+	}
+	return newStream(ƒ)
+}
+
+// NewTargeted returns an initialized Stream concerned with a particular set of
+// quantile values that are supplied a priori. Knowing these a priori reduces
+// space and computation time. The targets map maps the desired quantiles to
+// their absolute errors, i.e. the true quantile of a value returned by a query
+// is guaranteed to be within (Quantile±Epsilon).
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error properties.
+func NewTargeted(targets map[float64]float64) *Stream {
+	ƒ := func(s *stream, r float64) float64 {
+		var m = math.MaxFloat64
+		var f float64
+		for quantile, epsilon := range targets {
+			if quantile*s.n <= r {
+				f = (2 * epsilon * r) / quantile
+			} else {
+				f = (2 * epsilon * (s.n - r)) / (1 - quantile)
+			}
+			if f < m {
+				m = f
+			}
+		}
+		return m
+	}
+	return newStream(ƒ)
+}
+
+// Stream computes quantiles for a stream of float64s. It is not thread-safe by
+// design. Take care when using across multiple goroutines.
+type Stream struct {
+	*stream
+	b      Samples
+	sorted bool
+}
+
+func newStream(ƒ invariant) *Stream {
+	x := &stream{ƒ: ƒ}
+	return &Stream{x, make(Samples, 0, 500), true}
+}
+
+// Insert inserts v into the stream.
+func (s *Stream) Insert(v float64) {
+	s.insert(Sample{Value: v, Width: 1})
+}
+
+func (s *Stream) insert(sample Sample) {
+	s.b = append(s.b, sample)
+	s.sorted = false
+	if len(s.b) == cap(s.b) {
+		s.flush()
+	}
+}
+
+// Query returns the computed qth percentiles value. If s was created with
+// NewTargeted, and q is not in the set of quantiles provided a priori, Query
+// will return an unspecified result.
+func (s *Stream) Query(q float64) float64 {
+	if !s.flushed() {
+		// Fast path when there hasn't been enough data for a flush;
+		// this also yields better accuracy for small sets of data.
+		l := len(s.b)
+		if l == 0 {
+			return 0
+		}
+		i := int(math.Ceil(float64(l) * q))
+		if i > 0 {
+			i -= 1
+		}
+		s.maybeSort()
+		return s.b[i].Value
+	}
+	s.flush()
+	return s.stream.query(q)
+}
+
+// Merge merges samples into the underlying streams samples. This is handy when
+// merging multiple streams from separate threads, database shards, etc.
+//
+// ATTENTION: This method is broken and does not yield correct results. The
+// underlying algorithm is not capable of merging streams correctly.
+func (s *Stream) Merge(samples Samples) {
+	sort.Sort(samples)
+	s.stream.merge(samples)
+}
+
+// Reset reinitializes and clears the list reusing the samples buffer memory.
+func (s *Stream) Reset() {
+	s.stream.reset()
+	s.b = s.b[:0]
+}
+
+// Samples returns stream samples held by s.
+func (s *Stream) Samples() Samples {
+	if !s.flushed() {
+		return s.b
+	}
+	s.flush()
+	return s.stream.samples()
+}
+
+// Count returns the total number of samples observed in the stream
+// since initialization.
+func (s *Stream) Count() int {
+	return len(s.b) + s.stream.count()
+}
+
+func (s *Stream) flush() {
+	s.maybeSort()
+	s.stream.merge(s.b)
+	s.b = s.b[:0]
+}
+
+func (s *Stream) maybeSort() {
+	if !s.sorted {
+		s.sorted = true
+		sort.Sort(s.b)
+	}
+}
+
+func (s *Stream) flushed() bool {
+	return len(s.stream.l) > 0
+}
+
+type stream struct {
+	n float64
+	l []Sample
+	ƒ invariant
+}
+
+func (s *stream) reset() {
+	s.l = s.l[:0]
+	s.n = 0
+}
+
+func (s *stream) insert(v float64) {
+	s.merge(Samples{{v, 1, 0}})
+}
+
+func (s *stream) merge(samples Samples) {
+	// TODO(beorn7): This tries to merge not only individual samples, but
+	// whole summaries. The paper doesn't mention merging summaries at
+	// all. Unittests show that the merging is inaccurate. Find out how to
+	// do merges properly.
+	var r float64
+	i := 0
+	for _, sample := range samples {
+		for ; i < len(s.l); i++ {
+			c := s.l[i]
+			if c.Value > sample.Value {
+				// Insert at position i.
+				s.l = append(s.l, Sample{})
+				copy(s.l[i+1:], s.l[i:])
+				s.l[i] = Sample{
+					sample.Value,
+					sample.Width,
+					math.Max(sample.Delta, math.Floor(s.ƒ(s, r))-1),
+					// TODO(beorn7): How to calculate delta correctly?
+				}
+				i++
+				goto inserted
+			}
+			r += c.Width
+		}
+		s.l = append(s.l, Sample{sample.Value, sample.Width, 0})
+		i++
+	inserted:
+		s.n += sample.Width
+		r += sample.Width
+	}
+	s.compress()
+}
+
+func (s *stream) count() int {
+	return int(s.n)
+}
+
+func (s *stream) query(q float64) float64 {
+	t := math.Ceil(q * s.n)
+	t += math.Ceil(s.ƒ(s, t) / 2)
+	p := s.l[0]
+	var r float64
+	for _, c := range s.l[1:] {
+		r += p.Width
+		if r+c.Width+c.Delta > t {
+			return p.Value
+		}
+		p = c
+	}
+	return p.Value
+}
+
+func (s *stream) compress() {
+	if len(s.l) < 2 {
+		return
+	}
+	x := s.l[len(s.l)-1]
+	xi := len(s.l) - 1
+	r := s.n - 1 - x.Width
+
+	for i := len(s.l) - 2; i >= 0; i-- {
+		c := s.l[i]
+		if c.Width+x.Width+x.Delta <= s.ƒ(s, r) {
+			x.Width += c.Width
+			s.l[xi] = x
+			// Remove element at i.
+			copy(s.l[i:], s.l[i+1:])
+			s.l = s.l[:len(s.l)-1]
+			xi -= 1
+		} else {
+			x = c
+			xi = i
+		}
+		r -= c.Width
+	}
+}
+
+func (s *stream) samples() Samples {
+	samples := make(Samples, len(s.l))
+	copy(samples, s.l)
+	return samples
+}
diff --git a/vendor/github.com/golang/protobuf/AUTHORS b/vendor/github.com/golang/protobuf/AUTHORS
new file mode 100644
index 00000000..15167cd7
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/AUTHORS
@@ -0,0 +1,3 @@
+# This source code refers to The Go Authors for copyright purposes.
+# The master list of authors is in the main Go distribution,
+# visible at http://tip.golang.org/AUTHORS.
diff --git a/vendor/github.com/golang/protobuf/CONTRIBUTORS b/vendor/github.com/golang/protobuf/CONTRIBUTORS
new file mode 100644
index 00000000..1c4577e9
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/CONTRIBUTORS
@@ -0,0 +1,3 @@
+# This source code was written by the Go contributors.
+# The master list of contributors is in the main Go distribution,
+# visible at http://tip.golang.org/CONTRIBUTORS.
diff --git a/vendor/github.com/golang/protobuf/LICENSE b/vendor/github.com/golang/protobuf/LICENSE
new file mode 100644
index 00000000..1b1b1921
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/LICENSE
@@ -0,0 +1,31 @@
+Go support for Protocol Buffers - Google's data interchange format
+
+Copyright 2010 The Go Authors.  All rights reserved.
+https://github.com/golang/protobuf
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+    * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
diff --git a/vendor/github.com/golang/protobuf/proto/Makefile b/vendor/github.com/golang/protobuf/proto/Makefile
new file mode 100644
index 00000000..e2e0651a
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/Makefile
@@ -0,0 +1,43 @@
+# Go support for Protocol Buffers - Google's data interchange format
+#
+# Copyright 2010 The Go Authors.  All rights reserved.
+# https://github.com/golang/protobuf
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+install:
+	go install
+
+test: install generate-test-pbs
+	go test
+
+
+generate-test-pbs:
+	make install
+	make -C testdata
+	protoc --go_out=Mtestdata/test.proto=github.com/golang/protobuf/proto/testdata,Mgoogle/protobuf/any.proto=github.com/golang/protobuf/ptypes/any:. proto3_proto/proto3.proto
+	make
diff --git a/vendor/github.com/golang/protobuf/proto/clone.go b/vendor/github.com/golang/protobuf/proto/clone.go
new file mode 100644
index 00000000..e392575b
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/clone.go
@@ -0,0 +1,229 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2011 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Protocol buffer deep copy and merge.
+// TODO: RawMessage.
+
+package proto
+
+import (
+	"log"
+	"reflect"
+	"strings"
+)
+
+// Clone returns a deep copy of a protocol buffer.
+func Clone(pb Message) Message {
+	in := reflect.ValueOf(pb)
+	if in.IsNil() {
+		return pb
+	}
+
+	out := reflect.New(in.Type().Elem())
+	// out is empty so a merge is a deep copy.
+	mergeStruct(out.Elem(), in.Elem())
+	return out.Interface().(Message)
+}
+
+// Merge merges src into dst.
+// Required and optional fields that are set in src will be set to that value in dst.
+// Elements of repeated fields will be appended.
+// Merge panics if src and dst are not the same type, or if dst is nil.
+func Merge(dst, src Message) {
+	in := reflect.ValueOf(src)
+	out := reflect.ValueOf(dst)
+	if out.IsNil() {
+		panic("proto: nil destination")
+	}
+	if in.Type() != out.Type() {
+		// Explicit test prior to mergeStruct so that mistyped nils will fail
+		panic("proto: type mismatch")
+	}
+	if in.IsNil() {
+		// Merging nil into non-nil is a quiet no-op
+		return
+	}
+	mergeStruct(out.Elem(), in.Elem())
+}
+
+func mergeStruct(out, in reflect.Value) {
+	sprop := GetProperties(in.Type())
+	for i := 0; i < in.NumField(); i++ {
+		f := in.Type().Field(i)
+		if strings.HasPrefix(f.Name, "XXX_") {
+			continue
+		}
+		mergeAny(out.Field(i), in.Field(i), false, sprop.Prop[i])
+	}
+
+	if emIn, ok := extendable(in.Addr().Interface()); ok {
+		emOut, _ := extendable(out.Addr().Interface())
+		mIn, muIn := emIn.extensionsRead()
+		if mIn != nil {
+			mOut := emOut.extensionsWrite()
+			muIn.Lock()
+			mergeExtension(mOut, mIn)
+			muIn.Unlock()
+		}
+	}
+
+	uf := in.FieldByName("XXX_unrecognized")
+	if !uf.IsValid() {
+		return
+	}
+	uin := uf.Bytes()
+	if len(uin) > 0 {
+		out.FieldByName("XXX_unrecognized").SetBytes(append([]byte(nil), uin...))
+	}
+}
+
+// mergeAny performs a merge between two values of the same type.
+// viaPtr indicates whether the values were indirected through a pointer (implying proto2).
+// prop is set if this is a struct field (it may be nil).
+func mergeAny(out, in reflect.Value, viaPtr bool, prop *Properties) {
+	if in.Type() == protoMessageType {
+		if !in.IsNil() {
+			if out.IsNil() {
+				out.Set(reflect.ValueOf(Clone(in.Interface().(Message))))
+			} else {
+				Merge(out.Interface().(Message), in.Interface().(Message))
+			}
+		}
+		return
+	}
+	switch in.Kind() {
+	case reflect.Bool, reflect.Float32, reflect.Float64, reflect.Int32, reflect.Int64,
+		reflect.String, reflect.Uint32, reflect.Uint64:
+		if !viaPtr && isProto3Zero(in) {
+			return
+		}
+		out.Set(in)
+	case reflect.Interface:
+		// Probably a oneof field; copy non-nil values.
+		if in.IsNil() {
+			return
+		}
+		// Allocate destination if it is not set, or set to a different type.
+		// Otherwise we will merge as normal.
+		if out.IsNil() || out.Elem().Type() != in.Elem().Type() {
+			out.Set(reflect.New(in.Elem().Elem().Type())) // interface -> *T -> T -> new(T)
+		}
+		mergeAny(out.Elem(), in.Elem(), false, nil)
+	case reflect.Map:
+		if in.Len() == 0 {
+			return
+		}
+		if out.IsNil() {
+			out.Set(reflect.MakeMap(in.Type()))
+		}
+		// For maps with value types of *T or []byte we need to deep copy each value.
+		elemKind := in.Type().Elem().Kind()
+		for _, key := range in.MapKeys() {
+			var val reflect.Value
+			switch elemKind {
+			case reflect.Ptr:
+				val = reflect.New(in.Type().Elem().Elem())
+				mergeAny(val, in.MapIndex(key), false, nil)
+			case reflect.Slice:
+				val = in.MapIndex(key)
+				val = reflect.ValueOf(append([]byte{}, val.Bytes()...))
+			default:
+				val = in.MapIndex(key)
+			}
+			out.SetMapIndex(key, val)
+		}
+	case reflect.Ptr:
+		if in.IsNil() {
+			return
+		}
+		if out.IsNil() {
+			out.Set(reflect.New(in.Elem().Type()))
+		}
+		mergeAny(out.Elem(), in.Elem(), true, nil)
+	case reflect.Slice:
+		if in.IsNil() {
+			return
+		}
+		if in.Type().Elem().Kind() == reflect.Uint8 {
+			// []byte is a scalar bytes field, not a repeated field.
+
+			// Edge case: if this is in a proto3 message, a zero length
+			// bytes field is considered the zero value, and should not
+			// be merged.
+			if prop != nil && prop.proto3 && in.Len() == 0 {
+				return
+			}
+
+			// Make a deep copy.
+			// Append to []byte{} instead of []byte(nil) so that we never end up
+			// with a nil result.
+			out.SetBytes(append([]byte{}, in.Bytes()...))
+			return
+		}
+		n := in.Len()
+		if out.IsNil() {
+			out.Set(reflect.MakeSlice(in.Type(), 0, n))
+		}
+		switch in.Type().Elem().Kind() {
+		case reflect.Bool, reflect.Float32, reflect.Float64, reflect.Int32, reflect.Int64,
+			reflect.String, reflect.Uint32, reflect.Uint64:
+			out.Set(reflect.AppendSlice(out, in))
+		default:
+			for i := 0; i < n; i++ {
+				x := reflect.Indirect(reflect.New(in.Type().Elem()))
+				mergeAny(x, in.Index(i), false, nil)
+				out.Set(reflect.Append(out, x))
+			}
+		}
+	case reflect.Struct:
+		mergeStruct(out, in)
+	default:
+		// unknown type, so not a protocol buffer
+		log.Printf("proto: don't know how to copy %v", in)
+	}
+}
+
+func mergeExtension(out, in map[int32]Extension) {
+	for extNum, eIn := range in {
+		eOut := Extension{desc: eIn.desc}
+		if eIn.value != nil {
+			v := reflect.New(reflect.TypeOf(eIn.value)).Elem()
+			mergeAny(v, reflect.ValueOf(eIn.value), false, nil)
+			eOut.value = v.Interface()
+		}
+		if eIn.enc != nil {
+			eOut.enc = make([]byte, len(eIn.enc))
+			copy(eOut.enc, eIn.enc)
+		}
+
+		out[extNum] = eOut
+	}
+}
diff --git a/vendor/github.com/golang/protobuf/proto/decode.go b/vendor/github.com/golang/protobuf/proto/decode.go
new file mode 100644
index 00000000..04dcb881
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/decode.go
@@ -0,0 +1,874 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+/*
+ * Routines for decoding protocol buffer data to construct in-memory representations.
+ */
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"reflect"
+)
+
+// errOverflow is returned when an integer is too large to be represented.
+var errOverflow = errors.New("proto: integer overflow")
+
+// ErrInternalBadWireType is returned by generated code when an incorrect
+// wire type is encountered. It does not get returned to user code.
+var ErrInternalBadWireType = errors.New("proto: internal error: bad wiretype for oneof")
+
+// The fundamental decoders that interpret bytes on the wire.
+// Those that take integer types all return uint64 and are
+// therefore of type valueDecoder.
+
+// DecodeVarint reads a varint-encoded integer from the slice.
+// It returns the integer and the number of bytes consumed, or
+// zero if there is not enough.
+// This is the format for the
+// int32, int64, uint32, uint64, bool, and enum
+// protocol buffer types.
+func DecodeVarint(buf []byte) (x uint64, n int) {
+	// x, n already 0
+	for shift := uint(0); shift < 64; shift += 7 {
+		if n >= len(buf) {
+			return 0, 0
+		}
+		b := uint64(buf[n])
+		n++
+		x |= (b & 0x7F) << shift
+		if (b & 0x80) == 0 {
+			return x, n
+		}
+	}
+
+	// The number is too large to represent in a 64-bit value.
+	return 0, 0
+}
+
+// DecodeVarint reads a varint-encoded integer from the Buffer.
+// This is the format for the
+// int32, int64, uint32, uint64, bool, and enum
+// protocol buffer types.
+func (p *Buffer) DecodeVarint() (x uint64, err error) {
+	// x, err already 0
+
+	i := p.index
+	l := len(p.buf)
+
+	for shift := uint(0); shift < 64; shift += 7 {
+		if i >= l {
+			err = io.ErrUnexpectedEOF
+			return
+		}
+		b := p.buf[i]
+		i++
+		x |= (uint64(b) & 0x7F) << shift
+		if b < 0x80 {
+			p.index = i
+			return
+		}
+	}
+
+	// The number is too large to represent in a 64-bit value.
+	err = errOverflow
+	return
+}
+
+// DecodeFixed64 reads a 64-bit integer from the Buffer.
+// This is the format for the
+// fixed64, sfixed64, and double protocol buffer types.
+func (p *Buffer) DecodeFixed64() (x uint64, err error) {
+	// x, err already 0
+	i := p.index + 8
+	if i < 0 || i > len(p.buf) {
+		err = io.ErrUnexpectedEOF
+		return
+	}
+	p.index = i
+
+	x = uint64(p.buf[i-8])
+	x |= uint64(p.buf[i-7]) << 8
+	x |= uint64(p.buf[i-6]) << 16
+	x |= uint64(p.buf[i-5]) << 24
+	x |= uint64(p.buf[i-4]) << 32
+	x |= uint64(p.buf[i-3]) << 40
+	x |= uint64(p.buf[i-2]) << 48
+	x |= uint64(p.buf[i-1]) << 56
+	return
+}
+
+// DecodeFixed32 reads a 32-bit integer from the Buffer.
+// This is the format for the
+// fixed32, sfixed32, and float protocol buffer types.
+func (p *Buffer) DecodeFixed32() (x uint64, err error) {
+	// x, err already 0
+	i := p.index + 4
+	if i < 0 || i > len(p.buf) {
+		err = io.ErrUnexpectedEOF
+		return
+	}
+	p.index = i
+
+	x = uint64(p.buf[i-4])
+	x |= uint64(p.buf[i-3]) << 8
+	x |= uint64(p.buf[i-2]) << 16
+	x |= uint64(p.buf[i-1]) << 24
+	return
+}
+
+// DecodeZigzag64 reads a zigzag-encoded 64-bit integer
+// from the Buffer.
+// This is the format used for the sint64 protocol buffer type.
+func (p *Buffer) DecodeZigzag64() (x uint64, err error) {
+	x, err = p.DecodeVarint()
+	if err != nil {
+		return
+	}
+	x = (x >> 1) ^ uint64((int64(x&1)<<63)>>63)
+	return
+}
+
+// DecodeZigzag32 reads a zigzag-encoded 32-bit integer
+// from  the Buffer.
+// This is the format used for the sint32 protocol buffer type.
+func (p *Buffer) DecodeZigzag32() (x uint64, err error) {
+	x, err = p.DecodeVarint()
+	if err != nil {
+		return
+	}
+	x = uint64((uint32(x) >> 1) ^ uint32((int32(x&1)<<31)>>31))
+	return
+}
+
+// These are not ValueDecoders: they produce an array of bytes or a string.
+// bytes, embedded messages
+
+// DecodeRawBytes reads a count-delimited byte buffer from the Buffer.
+// This is the format used for the bytes protocol buffer
+// type and for embedded messages.
+func (p *Buffer) DecodeRawBytes(alloc bool) (buf []byte, err error) {
+	n, err := p.DecodeVarint()
+	if err != nil {
+		return nil, err
+	}
+
+	nb := int(n)
+	if nb < 0 {
+		return nil, fmt.Errorf("proto: bad byte length %d", nb)
+	}
+	end := p.index + nb
+	if end < p.index || end > len(p.buf) {
+		return nil, io.ErrUnexpectedEOF
+	}
+
+	if !alloc {
+		// todo: check if can get more uses of alloc=false
+		buf = p.buf[p.index:end]
+		p.index += nb
+		return
+	}
+
+	buf = make([]byte, nb)
+	copy(buf, p.buf[p.index:])
+	p.index += nb
+	return
+}
+
+// DecodeStringBytes reads an encoded string from the Buffer.
+// This is the format used for the proto2 string type.
+func (p *Buffer) DecodeStringBytes() (s string, err error) {
+	buf, err := p.DecodeRawBytes(false)
+	if err != nil {
+		return
+	}
+	return string(buf), nil
+}
+
+// Skip the next item in the buffer. Its wire type is decoded and presented as an argument.
+// If the protocol buffer has extensions, and the field matches, add it as an extension.
+// Otherwise, if the XXX_unrecognized field exists, append the skipped data there.
+func (o *Buffer) skipAndSave(t reflect.Type, tag, wire int, base structPointer, unrecField field) error {
+	oi := o.index
+
+	err := o.skip(t, tag, wire)
+	if err != nil {
+		return err
+	}
+
+	if !unrecField.IsValid() {
+		return nil
+	}
+
+	ptr := structPointer_Bytes(base, unrecField)
+
+	// Add the skipped field to struct field
+	obuf := o.buf
+
+	o.buf = *ptr
+	o.EncodeVarint(uint64(tag<<3 | wire))
+	*ptr = append(o.buf, obuf[oi:o.index]...)
+
+	o.buf = obuf
+
+	return nil
+}
+
+// Skip the next item in the buffer. Its wire type is decoded and presented as an argument.
+func (o *Buffer) skip(t reflect.Type, tag, wire int) error {
+
+	var u uint64
+	var err error
+
+	switch wire {
+	case WireVarint:
+		_, err = o.DecodeVarint()
+	case WireFixed64:
+		_, err = o.DecodeFixed64()
+	case WireBytes:
+		_, err = o.DecodeRawBytes(false)
+	case WireFixed32:
+		_, err = o.DecodeFixed32()
+	case WireStartGroup:
+		for {
+			u, err = o.DecodeVarint()
+			if err != nil {
+				break
+			}
+			fwire := int(u & 0x7)
+			if fwire == WireEndGroup {
+				break
+			}
+			ftag := int(u >> 3)
+			err = o.skip(t, ftag, fwire)
+			if err != nil {
+				break
+			}
+		}
+	default:
+		err = fmt.Errorf("proto: can't skip unknown wire type %d for %s", wire, t)
+	}
+	return err
+}
+
+// Unmarshaler is the interface representing objects that can
+// unmarshal themselves.  The method should reset the receiver before
+// decoding starts.  The argument points to data that may be
+// overwritten, so implementations should not keep references to the
+// buffer.
+type Unmarshaler interface {
+	Unmarshal([]byte) error
+}
+
+// Unmarshal parses the protocol buffer representation in buf and places the
+// decoded result in pb.  If the struct underlying pb does not match
+// the data in buf, the results can be unpredictable.
+//
+// Unmarshal resets pb before starting to unmarshal, so any
+// existing data in pb is always removed. Use UnmarshalMerge
+// to preserve and append to existing data.
+func Unmarshal(buf []byte, pb Message) error {
+	pb.Reset()
+	return UnmarshalMerge(buf, pb)
+}
+
+// UnmarshalMerge parses the protocol buffer representation in buf and
+// writes the decoded result to pb.  If the struct underlying pb does not match
+// the data in buf, the results can be unpredictable.
+//
+// UnmarshalMerge merges into existing data in pb.
+// Most code should use Unmarshal instead.
+func UnmarshalMerge(buf []byte, pb Message) error {
+	// If the object can unmarshal itself, let it.
+	if u, ok := pb.(Unmarshaler); ok {
+		return u.Unmarshal(buf)
+	}
+	return NewBuffer(buf).Unmarshal(pb)
+}
+
+// DecodeMessage reads a count-delimited message from the Buffer.
+func (p *Buffer) DecodeMessage(pb Message) error {
+	enc, err := p.DecodeRawBytes(false)
+	if err != nil {
+		return err
+	}
+	return NewBuffer(enc).Unmarshal(pb)
+}
+
+// DecodeGroup reads a tag-delimited group from the Buffer.
+func (p *Buffer) DecodeGroup(pb Message) error {
+	typ, base, err := getbase(pb)
+	if err != nil {
+		return err
+	}
+	return p.unmarshalType(typ.Elem(), GetProperties(typ.Elem()), true, base)
+}
+
+// Unmarshal parses the protocol buffer representation in the
+// Buffer and places the decoded result in pb.  If the struct
+// underlying pb does not match the data in the buffer, the results can be
+// unpredictable.
+func (p *Buffer) Unmarshal(pb Message) error {
+	// If the object can unmarshal itself, let it.
+	if u, ok := pb.(Unmarshaler); ok {
+		err := u.Unmarshal(p.buf[p.index:])
+		p.index = len(p.buf)
+		return err
+	}
+
+	typ, base, err := getbase(pb)
+	if err != nil {
+		return err
+	}
+
+	err = p.unmarshalType(typ.Elem(), GetProperties(typ.Elem()), false, base)
+
+	if collectStats {
+		stats.Decode++
+	}
+
+	return err
+}
+
+// unmarshalType does the work of unmarshaling a structure.
+func (o *Buffer) unmarshalType(st reflect.Type, prop *StructProperties, is_group bool, base structPointer) error {
+	var state errorState
+	required, reqFields := prop.reqCount, uint64(0)
+
+	var err error
+	for err == nil && o.index < len(o.buf) {
+		oi := o.index
+		var u uint64
+		u, err = o.DecodeVarint()
+		if err != nil {
+			break
+		}
+		wire := int(u & 0x7)
+		if wire == WireEndGroup {
+			if is_group {
+				if required > 0 {
+					// Not enough information to determine the exact field.
+					// (See below.)
+					return &RequiredNotSetError{"{Unknown}"}
+				}
+				return nil // input is satisfied
+			}
+			return fmt.Errorf("proto: %s: wiretype end group for non-group", st)
+		}
+		tag := int(u >> 3)
+		if tag <= 0 {
+			return fmt.Errorf("proto: %s: illegal tag %d (wire type %d)", st, tag, wire)
+		}
+		fieldnum, ok := prop.decoderTags.get(tag)
+		if !ok {
+			// Maybe it's an extension?
+			if prop.extendable {
+				if e, _ := extendable(structPointer_Interface(base, st)); isExtensionField(e, int32(tag)) {
+					if err = o.skip(st, tag, wire); err == nil {
+						extmap := e.extensionsWrite()
+						ext := extmap[int32(tag)] // may be missing
+						ext.enc = append(ext.enc, o.buf[oi:o.index]...)
+						extmap[int32(tag)] = ext
+					}
+					continue
+				}
+			}
+			// Maybe it's a oneof?
+			if prop.oneofUnmarshaler != nil {
+				m := structPointer_Interface(base, st).(Message)
+				// First return value indicates whether tag is a oneof field.
+				ok, err = prop.oneofUnmarshaler(m, tag, wire, o)
+				if err == ErrInternalBadWireType {
+					// Map the error to something more descriptive.
+					// Do the formatting here to save generated code space.
+					err = fmt.Errorf("bad wiretype for oneof field in %T", m)
+				}
+				if ok {
+					continue
+				}
+			}
+			err = o.skipAndSave(st, tag, wire, base, prop.unrecField)
+			continue
+		}
+		p := prop.Prop[fieldnum]
+
+		if p.dec == nil {
+			fmt.Fprintf(os.Stderr, "proto: no protobuf decoder for %s.%s\n", st, st.Field(fieldnum).Name)
+			continue
+		}
+		dec := p.dec
+		if wire != WireStartGroup && wire != p.WireType {
+			if wire == WireBytes && p.packedDec != nil {
+				// a packable field
+				dec = p.packedDec
+			} else {
+				err = fmt.Errorf("proto: bad wiretype for field %s.%s: got wiretype %d, want %d", st, st.Field(fieldnum).Name, wire, p.WireType)
+				continue
+			}
+		}
+		decErr := dec(o, p, base)
+		if decErr != nil && !state.shouldContinue(decErr, p) {
+			err = decErr
+		}
+		if err == nil && p.Required {
+			// Successfully decoded a required field.
+			if tag <= 64 {
+				// use bitmap for fields 1-64 to catch field reuse.
+				var mask uint64 = 1 << uint64(tag-1)
+				if reqFields&mask == 0 {
+					// new required field
+					reqFields |= mask
+					required--
+				}
+			} else {
+				// This is imprecise. It can be fooled by a required field
+				// with a tag > 64 that is encoded twice; that's very rare.
+				// A fully correct implementation would require allocating
+				// a data structure, which we would like to avoid.
+				required--
+			}
+		}
+	}
+	if err == nil {
+		if is_group {
+			return io.ErrUnexpectedEOF
+		}
+		if state.err != nil {
+			return state.err
+		}
+		if required > 0 {
+			// Not enough information to determine the exact field. If we use extra
+			// CPU, we could determine the field only if the missing required field
+			// has a tag <= 64 and we check reqFields.
+			return &RequiredNotSetError{"{Unknown}"}
+		}
+	}
+	return err
+}
+
+// Individual type decoders
+// For each,
+//	u is the decoded value,
+//	v is a pointer to the field (pointer) in the struct
+
+// Sizes of the pools to allocate inside the Buffer.
+// The goal is modest amortization and allocation
+// on at least 16-byte boundaries.
+const (
+	boolPoolSize   = 16
+	uint32PoolSize = 8
+	uint64PoolSize = 4
+)
+
+// Decode a bool.
+func (o *Buffer) dec_bool(p *Properties, base structPointer) error {
+	u, err := p.valDec(o)
+	if err != nil {
+		return err
+	}
+	if len(o.bools) == 0 {
+		o.bools = make([]bool, boolPoolSize)
+	}
+	o.bools[0] = u != 0
+	*structPointer_Bool(base, p.field) = &o.bools[0]
+	o.bools = o.bools[1:]
+	return nil
+}
+
+func (o *Buffer) dec_proto3_bool(p *Properties, base structPointer) error {
+	u, err := p.valDec(o)
+	if err != nil {
+		return err
+	}
+	*structPointer_BoolVal(base, p.field) = u != 0
+	return nil
+}
+
+// Decode an int32.
+func (o *Buffer) dec_int32(p *Properties, base structPointer) error {
+	u, err := p.valDec(o)
+	if err != nil {
+		return err
+	}
+	word32_Set(structPointer_Word32(base, p.field), o, uint32(u))
+	return nil
+}
+
+func (o *Buffer) dec_proto3_int32(p *Properties, base structPointer) error {
+	u, err := p.valDec(o)
+	if err != nil {
+		return err
+	}
+	word32Val_Set(structPointer_Word32Val(base, p.field), uint32(u))
+	return nil
+}
+
+// Decode an int64.
+func (o *Buffer) dec_int64(p *Properties, base structPointer) error {
+	u, err := p.valDec(o)
+	if err != nil {
+		return err
+	}
+	word64_Set(structPointer_Word64(base, p.field), o, u)
+	return nil
+}
+
+func (o *Buffer) dec_proto3_int64(p *Properties, base structPointer) error {
+	u, err := p.valDec(o)
+	if err != nil {
+		return err
+	}
+	word64Val_Set(structPointer_Word64Val(base, p.field), o, u)
+	return nil
+}
+
+// Decode a string.
+func (o *Buffer) dec_string(p *Properties, base structPointer) error {
+	s, err := o.DecodeStringBytes()
+	if err != nil {
+		return err
+	}
+	*structPointer_String(base, p.field) = &s
+	return nil
+}
+
+func (o *Buffer) dec_proto3_string(p *Properties, base structPointer) error {
+	s, err := o.DecodeStringBytes()
+	if err != nil {
+		return err
+	}
+	*structPointer_StringVal(base, p.field) = s
+	return nil
+}
+
+// Decode a slice of bytes ([]byte).
+func (o *Buffer) dec_slice_byte(p *Properties, base structPointer) error {
+	b, err := o.DecodeRawBytes(true)
+	if err != nil {
+		return err
+	}
+	*structPointer_Bytes(base, p.field) = b
+	return nil
+}
+
+// Decode a slice of bools ([]bool).
+func (o *Buffer) dec_slice_bool(p *Properties, base structPointer) error {
+	u, err := p.valDec(o)
+	if err != nil {
+		return err
+	}
+	v := structPointer_BoolSlice(base, p.field)
+	*v = append(*v, u != 0)
+	return nil
+}
+
+// Decode a slice of bools ([]bool) in packed format.
+func (o *Buffer) dec_slice_packed_bool(p *Properties, base structPointer) error {
+	v := structPointer_BoolSlice(base, p.field)
+
+	nn, err := o.DecodeVarint()
+	if err != nil {
+		return err
+	}
+	nb := int(nn) // number of bytes of encoded bools
+	fin := o.index + nb
+	if fin < o.index {
+		return errOverflow
+	}
+
+	y := *v
+	for o.index < fin {
+		u, err := p.valDec(o)
+		if err != nil {
+			return err
+		}
+		y = append(y, u != 0)
+	}
+
+	*v = y
+	return nil
+}
+
+// Decode a slice of int32s ([]int32).
+func (o *Buffer) dec_slice_int32(p *Properties, base structPointer) error {
+	u, err := p.valDec(o)
+	if err != nil {
+		return err
+	}
+	structPointer_Word32Slice(base, p.field).Append(uint32(u))
+	return nil
+}
+
+// Decode a slice of int32s ([]int32) in packed format.
+func (o *Buffer) dec_slice_packed_int32(p *Properties, base structPointer) error {
+	v := structPointer_Word32Slice(base, p.field)
+
+	nn, err := o.DecodeVarint()
+	if err != nil {
+		return err
+	}
+	nb := int(nn) // number of bytes of encoded int32s
+
+	fin := o.index + nb
+	if fin < o.index {
+		return errOverflow
+	}
+	for o.index < fin {
+		u, err := p.valDec(o)
+		if err != nil {
+			return err
+		}
+		v.Append(uint32(u))
+	}
+	return nil
+}
+
+// Decode a slice of int64s ([]int64).
+func (o *Buffer) dec_slice_int64(p *Properties, base structPointer) error {
+	u, err := p.valDec(o)
+	if err != nil {
+		return err
+	}
+
+	structPointer_Word64Slice(base, p.field).Append(u)
+	return nil
+}
+
+// Decode a slice of int64s ([]int64) in packed format.
+func (o *Buffer) dec_slice_packed_int64(p *Properties, base structPointer) error {
+	v := structPointer_Word64Slice(base, p.field)
+
+	nn, err := o.DecodeVarint()
+	if err != nil {
+		return err
+	}
+	nb := int(nn) // number of bytes of encoded int64s
+
+	fin := o.index + nb
+	if fin < o.index {
+		return errOverflow
+	}
+	for o.index < fin {
+		u, err := p.valDec(o)
+		if err != nil {
+			return err
+		}
+		v.Append(u)
+	}
+	return nil
+}
+
+// Decode a slice of strings ([]string).
+func (o *Buffer) dec_slice_string(p *Properties, base structPointer) error {
+	s, err := o.DecodeStringBytes()
+	if err != nil {
+		return err
+	}
+	v := structPointer_StringSlice(base, p.field)
+	*v = append(*v, s)
+	return nil
+}
+
+// Decode a slice of slice of bytes ([][]byte).
+func (o *Buffer) dec_slice_slice_byte(p *Properties, base structPointer) error {
+	b, err := o.DecodeRawBytes(true)
+	if err != nil {
+		return err
+	}
+	v := structPointer_BytesSlice(base, p.field)
+	*v = append(*v, b)
+	return nil
+}
+
+// Decode a map field.
+func (o *Buffer) dec_new_map(p *Properties, base structPointer) error {
+	raw, err := o.DecodeRawBytes(false)
+	if err != nil {
+		return err
+	}
+	oi := o.index       // index at the end of this map entry
+	o.index -= len(raw) // move buffer back to start of map entry
+
+	mptr := structPointer_NewAt(base, p.field, p.mtype) // *map[K]V
+	if mptr.Elem().IsNil() {
+		mptr.Elem().Set(reflect.MakeMap(mptr.Type().Elem()))
+	}
+	v := mptr.Elem() // map[K]V
+
+	// Prepare addressable doubly-indirect placeholders for the key and value types.
+	// See enc_new_map for why.
+	keyptr := reflect.New(reflect.PtrTo(p.mtype.Key())).Elem() // addressable *K
+	keybase := toStructPointer(keyptr.Addr())                  // **K
+
+	var valbase structPointer
+	var valptr reflect.Value
+	switch p.mtype.Elem().Kind() {
+	case reflect.Slice:
+		// []byte
+		var dummy []byte
+		valptr = reflect.ValueOf(&dummy)  // *[]byte
+		valbase = toStructPointer(valptr) // *[]byte
+	case reflect.Ptr:
+		// message; valptr is **Msg; need to allocate the intermediate pointer
+		valptr = reflect.New(reflect.PtrTo(p.mtype.Elem())).Elem() // addressable *V
+		valptr.Set(reflect.New(valptr.Type().Elem()))
+		valbase = toStructPointer(valptr)
+	default:
+		// everything else
+		valptr = reflect.New(reflect.PtrTo(p.mtype.Elem())).Elem() // addressable *V
+		valbase = toStructPointer(valptr.Addr())                   // **V
+	}
+
+	// Decode.
+	// This parses a restricted wire format, namely the encoding of a message
+	// with two fields. See enc_new_map for the format.
+	for o.index < oi {
+		// tagcode for key and value properties are always a single byte
+		// because they have tags 1 and 2.
+		tagcode := o.buf[o.index]
+		o.index++
+		switch tagcode {
+		case p.mkeyprop.tagcode[0]:
+			if err := p.mkeyprop.dec(o, p.mkeyprop, keybase); err != nil {
+				return err
+			}
+		case p.mvalprop.tagcode[0]:
+			if err := p.mvalprop.dec(o, p.mvalprop, valbase); err != nil {
+				return err
+			}
+		default:
+			// TODO: Should we silently skip this instead?
+			return fmt.Errorf("proto: bad map data tag %d", raw[0])
+		}
+	}
+	keyelem, valelem := keyptr.Elem(), valptr.Elem()
+	if !keyelem.IsValid() {
+		keyelem = reflect.Zero(p.mtype.Key())
+	}
+	if !valelem.IsValid() {
+		valelem = reflect.Zero(p.mtype.Elem())
+	}
+
+	v.SetMapIndex(keyelem, valelem)
+	return nil
+}
+
+// Decode a group.
+func (o *Buffer) dec_struct_group(p *Properties, base structPointer) error {
+	bas := structPointer_GetStructPointer(base, p.field)
+	if structPointer_IsNil(bas) {
+		// allocate new nested message
+		bas = toStructPointer(reflect.New(p.stype))
+		structPointer_SetStructPointer(base, p.field, bas)
+	}
+	return o.unmarshalType(p.stype, p.sprop, true, bas)
+}
+
+// Decode an embedded message.
+func (o *Buffer) dec_struct_message(p *Properties, base structPointer) (err error) {
+	raw, e := o.DecodeRawBytes(false)
+	if e != nil {
+		return e
+	}
+
+	bas := structPointer_GetStructPointer(base, p.field)
+	if structPointer_IsNil(bas) {
+		// allocate new nested message
+		bas = toStructPointer(reflect.New(p.stype))
+		structPointer_SetStructPointer(base, p.field, bas)
+	}
+
+	// If the object can unmarshal itself, let it.
+	if p.isUnmarshaler {
+		iv := structPointer_Interface(bas, p.stype)
+		return iv.(Unmarshaler).Unmarshal(raw)
+	}
+
+	obuf := o.buf
+	oi := o.index
+	o.buf = raw
+	o.index = 0
+
+	err = o.unmarshalType(p.stype, p.sprop, false, bas)
+	o.buf = obuf
+	o.index = oi
+
+	return err
+}
+
+// Decode a slice of embedded messages.
+func (o *Buffer) dec_slice_struct_message(p *Properties, base structPointer) error {
+	return o.dec_slice_struct(p, false, base)
+}
+
+// Decode a slice of embedded groups.
+func (o *Buffer) dec_slice_struct_group(p *Properties, base structPointer) error {
+	return o.dec_slice_struct(p, true, base)
+}
+
+// Decode a slice of structs ([]*struct).
+func (o *Buffer) dec_slice_struct(p *Properties, is_group bool, base structPointer) error {
+	v := reflect.New(p.stype)
+	bas := toStructPointer(v)
+	structPointer_StructPointerSlice(base, p.field).Append(bas)
+
+	if is_group {
+		err := o.unmarshalType(p.stype, p.sprop, is_group, bas)
+		return err
+	}
+
+	raw, err := o.DecodeRawBytes(false)
+	if err != nil {
+		return err
+	}
+
+	// If the object can unmarshal itself, let it.
+	if p.isUnmarshaler {
+		iv := v.Interface()
+		return iv.(Unmarshaler).Unmarshal(raw)
+	}
+
+	obuf := o.buf
+	oi := o.index
+	o.buf = raw
+	o.index = 0
+
+	err = o.unmarshalType(p.stype, p.sprop, is_group, bas)
+
+	o.buf = obuf
+	o.index = oi
+
+	return err
+}
diff --git a/vendor/github.com/golang/protobuf/proto/encode.go b/vendor/github.com/golang/protobuf/proto/encode.go
new file mode 100644
index 00000000..8c1b8fd1
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/encode.go
@@ -0,0 +1,1363 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+/*
+ * Routines for encoding data into the wire format for protocol buffers.
+ */
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"sort"
+)
+
+// RequiredNotSetError is the error returned if Marshal is called with
+// a protocol buffer struct whose required fields have not
+// all been initialized. It is also the error returned if Unmarshal is
+// called with an encoded protocol buffer that does not include all the
+// required fields.
+//
+// When printed, RequiredNotSetError reports the first unset required field in a
+// message. If the field cannot be precisely determined, it is reported as
+// "{Unknown}".
+type RequiredNotSetError struct {
+	field string
+}
+
+func (e *RequiredNotSetError) Error() string {
+	return fmt.Sprintf("proto: required field %q not set", e.field)
+}
+
+var (
+	// errRepeatedHasNil is the error returned if Marshal is called with
+	// a struct with a repeated field containing a nil element.
+	errRepeatedHasNil = errors.New("proto: repeated field has nil element")
+
+	// errOneofHasNil is the error returned if Marshal is called with
+	// a struct with a oneof field containing a nil element.
+	errOneofHasNil = errors.New("proto: oneof field has nil value")
+
+	// ErrNil is the error returned if Marshal is called with nil.
+	ErrNil = errors.New("proto: Marshal called with nil")
+
+	// ErrTooLarge is the error returned if Marshal is called with a
+	// message that encodes to >2GB.
+	ErrTooLarge = errors.New("proto: message encodes to over 2 GB")
+)
+
+// The fundamental encoders that put bytes on the wire.
+// Those that take integer types all accept uint64 and are
+// therefore of type valueEncoder.
+
+const maxVarintBytes = 10 // maximum length of a varint
+
+// maxMarshalSize is the largest allowed size of an encoded protobuf,
+// since C++ and Java use signed int32s for the size.
+const maxMarshalSize = 1<<31 - 1
+
+// EncodeVarint returns the varint encoding of x.
+// This is the format for the
+// int32, int64, uint32, uint64, bool, and enum
+// protocol buffer types.
+// Not used by the package itself, but helpful to clients
+// wishing to use the same encoding.
+func EncodeVarint(x uint64) []byte {
+	var buf [maxVarintBytes]byte
+	var n int
+	for n = 0; x > 127; n++ {
+		buf[n] = 0x80 | uint8(x&0x7F)
+		x >>= 7
+	}
+	buf[n] = uint8(x)
+	n++
+	return buf[0:n]
+}
+
+// EncodeVarint writes a varint-encoded integer to the Buffer.
+// This is the format for the
+// int32, int64, uint32, uint64, bool, and enum
+// protocol buffer types.
+func (p *Buffer) EncodeVarint(x uint64) error {
+	for x >= 1<<7 {
+		p.buf = append(p.buf, uint8(x&0x7f|0x80))
+		x >>= 7
+	}
+	p.buf = append(p.buf, uint8(x))
+	return nil
+}
+
+// SizeVarint returns the varint encoding size of an integer.
+func SizeVarint(x uint64) int {
+	return sizeVarint(x)
+}
+
+func sizeVarint(x uint64) (n int) {
+	for {
+		n++
+		x >>= 7
+		if x == 0 {
+			break
+		}
+	}
+	return n
+}
+
+// EncodeFixed64 writes a 64-bit integer to the Buffer.
+// This is the format for the
+// fixed64, sfixed64, and double protocol buffer types.
+func (p *Buffer) EncodeFixed64(x uint64) error {
+	p.buf = append(p.buf,
+		uint8(x),
+		uint8(x>>8),
+		uint8(x>>16),
+		uint8(x>>24),
+		uint8(x>>32),
+		uint8(x>>40),
+		uint8(x>>48),
+		uint8(x>>56))
+	return nil
+}
+
+func sizeFixed64(x uint64) int {
+	return 8
+}
+
+// EncodeFixed32 writes a 32-bit integer to the Buffer.
+// This is the format for the
+// fixed32, sfixed32, and float protocol buffer types.
+func (p *Buffer) EncodeFixed32(x uint64) error {
+	p.buf = append(p.buf,
+		uint8(x),
+		uint8(x>>8),
+		uint8(x>>16),
+		uint8(x>>24))
+	return nil
+}
+
+func sizeFixed32(x uint64) int {
+	return 4
+}
+
+// EncodeZigzag64 writes a zigzag-encoded 64-bit integer
+// to the Buffer.
+// This is the format used for the sint64 protocol buffer type.
+func (p *Buffer) EncodeZigzag64(x uint64) error {
+	// use signed number to get arithmetic right shift.
+	return p.EncodeVarint(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+
+func sizeZigzag64(x uint64) int {
+	return sizeVarint(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+
+// EncodeZigzag32 writes a zigzag-encoded 32-bit integer
+// to the Buffer.
+// This is the format used for the sint32 protocol buffer type.
+func (p *Buffer) EncodeZigzag32(x uint64) error {
+	// use signed number to get arithmetic right shift.
+	return p.EncodeVarint(uint64((uint32(x) << 1) ^ uint32((int32(x) >> 31))))
+}
+
+func sizeZigzag32(x uint64) int {
+	return sizeVarint(uint64((uint32(x) << 1) ^ uint32((int32(x) >> 31))))
+}
+
+// EncodeRawBytes writes a count-delimited byte buffer to the Buffer.
+// This is the format used for the bytes protocol buffer
+// type and for embedded messages.
+func (p *Buffer) EncodeRawBytes(b []byte) error {
+	p.EncodeVarint(uint64(len(b)))
+	p.buf = append(p.buf, b...)
+	return nil
+}
+
+func sizeRawBytes(b []byte) int {
+	return sizeVarint(uint64(len(b))) +
+		len(b)
+}
+
+// EncodeStringBytes writes an encoded string to the Buffer.
+// This is the format used for the proto2 string type.
+func (p *Buffer) EncodeStringBytes(s string) error {
+	p.EncodeVarint(uint64(len(s)))
+	p.buf = append(p.buf, s...)
+	return nil
+}
+
+func sizeStringBytes(s string) int {
+	return sizeVarint(uint64(len(s))) +
+		len(s)
+}
+
+// Marshaler is the interface representing objects that can marshal themselves.
+type Marshaler interface {
+	Marshal() ([]byte, error)
+}
+
+// Marshal takes the protocol buffer
+// and encodes it into the wire format, returning the data.
+func Marshal(pb Message) ([]byte, error) {
+	// Can the object marshal itself?
+	if m, ok := pb.(Marshaler); ok {
+		return m.Marshal()
+	}
+	p := NewBuffer(nil)
+	err := p.Marshal(pb)
+	var state errorState
+	if err != nil && !state.shouldContinue(err, nil) {
+		return nil, err
+	}
+	if p.buf == nil && err == nil {
+		// Return a non-nil slice on success.
+		return []byte{}, nil
+	}
+	return p.buf, err
+}
+
+// EncodeMessage writes the protocol buffer to the Buffer,
+// prefixed by a varint-encoded length.
+func (p *Buffer) EncodeMessage(pb Message) error {
+	t, base, err := getbase(pb)
+	if structPointer_IsNil(base) {
+		return ErrNil
+	}
+	if err == nil {
+		var state errorState
+		err = p.enc_len_struct(GetProperties(t.Elem()), base, &state)
+	}
+	return err
+}
+
+// Marshal takes the protocol buffer
+// and encodes it into the wire format, writing the result to the
+// Buffer.
+func (p *Buffer) Marshal(pb Message) error {
+	// Can the object marshal itself?
+	if m, ok := pb.(Marshaler); ok {
+		data, err := m.Marshal()
+		if err != nil {
+			return err
+		}
+		p.buf = append(p.buf, data...)
+		return nil
+	}
+
+	t, base, err := getbase(pb)
+	if structPointer_IsNil(base) {
+		return ErrNil
+	}
+	if err == nil {
+		err = p.enc_struct(GetProperties(t.Elem()), base)
+	}
+
+	if collectStats {
+		stats.Encode++
+	}
+
+	if len(p.buf) > maxMarshalSize {
+		return ErrTooLarge
+	}
+	return err
+}
+
+// Size returns the encoded size of a protocol buffer.
+func Size(pb Message) (n int) {
+	// Can the object marshal itself?  If so, Size is slow.
+	// TODO: add Size to Marshaler, or add a Sizer interface.
+	if m, ok := pb.(Marshaler); ok {
+		b, _ := m.Marshal()
+		return len(b)
+	}
+
+	t, base, err := getbase(pb)
+	if structPointer_IsNil(base) {
+		return 0
+	}
+	if err == nil {
+		n = size_struct(GetProperties(t.Elem()), base)
+	}
+
+	if collectStats {
+		stats.Size++
+	}
+
+	return
+}
+
+// Individual type encoders.
+
+// Encode a bool.
+func (o *Buffer) enc_bool(p *Properties, base structPointer) error {
+	v := *structPointer_Bool(base, p.field)
+	if v == nil {
+		return ErrNil
+	}
+	x := 0
+	if *v {
+		x = 1
+	}
+	o.buf = append(o.buf, p.tagcode...)
+	p.valEnc(o, uint64(x))
+	return nil
+}
+
+func (o *Buffer) enc_proto3_bool(p *Properties, base structPointer) error {
+	v := *structPointer_BoolVal(base, p.field)
+	if !v {
+		return ErrNil
+	}
+	o.buf = append(o.buf, p.tagcode...)
+	p.valEnc(o, 1)
+	return nil
+}
+
+func size_bool(p *Properties, base structPointer) int {
+	v := *structPointer_Bool(base, p.field)
+	if v == nil {
+		return 0
+	}
+	return len(p.tagcode) + 1 // each bool takes exactly one byte
+}
+
+func size_proto3_bool(p *Properties, base structPointer) int {
+	v := *structPointer_BoolVal(base, p.field)
+	if !v && !p.oneof {
+		return 0
+	}
+	return len(p.tagcode) + 1 // each bool takes exactly one byte
+}
+
+// Encode an int32.
+func (o *Buffer) enc_int32(p *Properties, base structPointer) error {
+	v := structPointer_Word32(base, p.field)
+	if word32_IsNil(v) {
+		return ErrNil
+	}
+	x := int32(word32_Get(v)) // permit sign extension to use full 64-bit range
+	o.buf = append(o.buf, p.tagcode...)
+	p.valEnc(o, uint64(x))
+	return nil
+}
+
+func (o *Buffer) enc_proto3_int32(p *Properties, base structPointer) error {
+	v := structPointer_Word32Val(base, p.field)
+	x := int32(word32Val_Get(v)) // permit sign extension to use full 64-bit range
+	if x == 0 {
+		return ErrNil
+	}
+	o.buf = append(o.buf, p.tagcode...)
+	p.valEnc(o, uint64(x))
+	return nil
+}
+
+func size_int32(p *Properties, base structPointer) (n int) {
+	v := structPointer_Word32(base, p.field)
+	if word32_IsNil(v) {
+		return 0
+	}
+	x := int32(word32_Get(v)) // permit sign extension to use full 64-bit range
+	n += len(p.tagcode)
+	n += p.valSize(uint64(x))
+	return
+}
+
+func size_proto3_int32(p *Properties, base structPointer) (n int) {
+	v := structPointer_Word32Val(base, p.field)
+	x := int32(word32Val_Get(v)) // permit sign extension to use full 64-bit range
+	if x == 0 && !p.oneof {
+		return 0
+	}
+	n += len(p.tagcode)
+	n += p.valSize(uint64(x))
+	return
+}
+
+// Encode a uint32.
+// Exactly the same as int32, except for no sign extension.
+func (o *Buffer) enc_uint32(p *Properties, base structPointer) error {
+	v := structPointer_Word32(base, p.field)
+	if word32_IsNil(v) {
+		return ErrNil
+	}
+	x := word32_Get(v)
+	o.buf = append(o.buf, p.tagcode...)
+	p.valEnc(o, uint64(x))
+	return nil
+}
+
+func (o *Buffer) enc_proto3_uint32(p *Properties, base structPointer) error {
+	v := structPointer_Word32Val(base, p.field)
+	x := word32Val_Get(v)
+	if x == 0 {
+		return ErrNil
+	}
+	o.buf = append(o.buf, p.tagcode...)
+	p.valEnc(o, uint64(x))
+	return nil
+}
+
+func size_uint32(p *Properties, base structPointer) (n int) {
+	v := structPointer_Word32(base, p.field)
+	if word32_IsNil(v) {
+		return 0
+	}
+	x := word32_Get(v)
+	n += len(p.tagcode)
+	n += p.valSize(uint64(x))
+	return
+}
+
+func size_proto3_uint32(p *Properties, base structPointer) (n int) {
+	v := structPointer_Word32Val(base, p.field)
+	x := word32Val_Get(v)
+	if x == 0 && !p.oneof {
+		return 0
+	}
+	n += len(p.tagcode)
+	n += p.valSize(uint64(x))
+	return
+}
+
+// Encode an int64.
+func (o *Buffer) enc_int64(p *Properties, base structPointer) error {
+	v := structPointer_Word64(base, p.field)
+	if word64_IsNil(v) {
+		return ErrNil
+	}
+	x := word64_Get(v)
+	o.buf = append(o.buf, p.tagcode...)
+	p.valEnc(o, x)
+	return nil
+}
+
+func (o *Buffer) enc_proto3_int64(p *Properties, base structPointer) error {
+	v := structPointer_Word64Val(base, p.field)
+	x := word64Val_Get(v)
+	if x == 0 {
+		return ErrNil
+	}
+	o.buf = append(o.buf, p.tagcode...)
+	p.valEnc(o, x)
+	return nil
+}
+
+func size_int64(p *Properties, base structPointer) (n int) {
+	v := structPointer_Word64(base, p.field)
+	if word64_IsNil(v) {
+		return 0
+	}
+	x := word64_Get(v)
+	n += len(p.tagcode)
+	n += p.valSize(x)
+	return
+}
+
+func size_proto3_int64(p *Properties, base structPointer) (n int) {
+	v := structPointer_Word64Val(base, p.field)
+	x := word64Val_Get(v)
+	if x == 0 && !p.oneof {
+		return 0
+	}
+	n += len(p.tagcode)
+	n += p.valSize(x)
+	return
+}
+
+// Encode a string.
+func (o *Buffer) enc_string(p *Properties, base structPointer) error {
+	v := *structPointer_String(base, p.field)
+	if v == nil {
+		return ErrNil
+	}
+	x := *v
+	o.buf = append(o.buf, p.tagcode...)
+	o.EncodeStringBytes(x)
+	return nil
+}
+
+func (o *Buffer) enc_proto3_string(p *Properties, base structPointer) error {
+	v := *structPointer_StringVal(base, p.field)
+	if v == "" {
+		return ErrNil
+	}
+	o.buf = append(o.buf, p.tagcode...)
+	o.EncodeStringBytes(v)
+	return nil
+}
+
+func size_string(p *Properties, base structPointer) (n int) {
+	v := *structPointer_String(base, p.field)
+	if v == nil {
+		return 0
+	}
+	x := *v
+	n += len(p.tagcode)
+	n += sizeStringBytes(x)
+	return
+}
+
+func size_proto3_string(p *Properties, base structPointer) (n int) {
+	v := *structPointer_StringVal(base, p.field)
+	if v == "" && !p.oneof {
+		return 0
+	}
+	n += len(p.tagcode)
+	n += sizeStringBytes(v)
+	return
+}
+
+// All protocol buffer fields are nillable, but be careful.
+func isNil(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
+		return v.IsNil()
+	}
+	return false
+}
+
+// Encode a message struct.
+func (o *Buffer) enc_struct_message(p *Properties, base structPointer) error {
+	var state errorState
+	structp := structPointer_GetStructPointer(base, p.field)
+	if structPointer_IsNil(structp) {
+		return ErrNil
+	}
+
+	// Can the object marshal itself?
+	if p.isMarshaler {
+		m := structPointer_Interface(structp, p.stype).(Marshaler)
+		data, err := m.Marshal()
+		if err != nil && !state.shouldContinue(err, nil) {
+			return err
+		}
+		o.buf = append(o.buf, p.tagcode...)
+		o.EncodeRawBytes(data)
+		return state.err
+	}
+
+	o.buf = append(o.buf, p.tagcode...)
+	return o.enc_len_struct(p.sprop, structp, &state)
+}
+
+func size_struct_message(p *Properties, base structPointer) int {
+	structp := structPointer_GetStructPointer(base, p.field)
+	if structPointer_IsNil(structp) {
+		return 0
+	}
+
+	// Can the object marshal itself?
+	if p.isMarshaler {
+		m := structPointer_Interface(structp, p.stype).(Marshaler)
+		data, _ := m.Marshal()
+		n0 := len(p.tagcode)
+		n1 := sizeRawBytes(data)
+		return n0 + n1
+	}
+
+	n0 := len(p.tagcode)
+	n1 := size_struct(p.sprop, structp)
+	n2 := sizeVarint(uint64(n1)) // size of encoded length
+	return n0 + n1 + n2
+}
+
+// Encode a group struct.
+func (o *Buffer) enc_struct_group(p *Properties, base structPointer) error {
+	var state errorState
+	b := structPointer_GetStructPointer(base, p.field)
+	if structPointer_IsNil(b) {
+		return ErrNil
+	}
+
+	o.EncodeVarint(uint64((p.Tag << 3) | WireStartGroup))
+	err := o.enc_struct(p.sprop, b)
+	if err != nil && !state.shouldContinue(err, nil) {
+		return err
+	}
+	o.EncodeVarint(uint64((p.Tag << 3) | WireEndGroup))
+	return state.err
+}
+
+func size_struct_group(p *Properties, base structPointer) (n int) {
+	b := structPointer_GetStructPointer(base, p.field)
+	if structPointer_IsNil(b) {
+		return 0
+	}
+
+	n += sizeVarint(uint64((p.Tag << 3) | WireStartGroup))
+	n += size_struct(p.sprop, b)
+	n += sizeVarint(uint64((p.Tag << 3) | WireEndGroup))
+	return
+}
+
+// Encode a slice of bools ([]bool).
+func (o *Buffer) enc_slice_bool(p *Properties, base structPointer) error {
+	s := *structPointer_BoolSlice(base, p.field)
+	l := len(s)
+	if l == 0 {
+		return ErrNil
+	}
+	for _, x := range s {
+		o.buf = append(o.buf, p.tagcode...)
+		v := uint64(0)
+		if x {
+			v = 1
+		}
+		p.valEnc(o, v)
+	}
+	return nil
+}
+
+func size_slice_bool(p *Properties, base structPointer) int {
+	s := *structPointer_BoolSlice(base, p.field)
+	l := len(s)
+	if l == 0 {
+		return 0
+	}
+	return l * (len(p.tagcode) + 1) // each bool takes exactly one byte
+}
+
+// Encode a slice of bools ([]bool) in packed format.
+func (o *Buffer) enc_slice_packed_bool(p *Properties, base structPointer) error {
+	s := *structPointer_BoolSlice(base, p.field)
+	l := len(s)
+	if l == 0 {
+		return ErrNil
+	}
+	o.buf = append(o.buf, p.tagcode...)
+	o.EncodeVarint(uint64(l)) // each bool takes exactly one byte
+	for _, x := range s {
+		v := uint64(0)
+		if x {
+			v = 1
+		}
+		p.valEnc(o, v)
+	}
+	return nil
+}
+
+func size_slice_packed_bool(p *Properties, base structPointer) (n int) {
+	s := *structPointer_BoolSlice(base, p.field)
+	l := len(s)
+	if l == 0 {
+		return 0
+	}
+	n += len(p.tagcode)
+	n += sizeVarint(uint64(l))
+	n += l // each bool takes exactly one byte
+	return
+}
+
+// Encode a slice of bytes ([]byte).
+func (o *Buffer) enc_slice_byte(p *Properties, base structPointer) error {
+	s := *structPointer_Bytes(base, p.field)
+	if s == nil {
+		return ErrNil
+	}
+	o.buf = append(o.buf, p.tagcode...)
+	o.EncodeRawBytes(s)
+	return nil
+}
+
+func (o *Buffer) enc_proto3_slice_byte(p *Properties, base structPointer) error {
+	s := *structPointer_Bytes(base, p.field)
+	if len(s) == 0 {
+		return ErrNil
+	}
+	o.buf = append(o.buf, p.tagcode...)
+	o.EncodeRawBytes(s)
+	return nil
+}
+
+func size_slice_byte(p *Properties, base structPointer) (n int) {
+	s := *structPointer_Bytes(base, p.field)
+	if s == nil && !p.oneof {
+		return 0
+	}
+	n += len(p.tagcode)
+	n += sizeRawBytes(s)
+	return
+}
+
+func size_proto3_slice_byte(p *Properties, base structPointer) (n int) {
+	s := *structPointer_Bytes(base, p.field)
+	if len(s) == 0 && !p.oneof {
+		return 0
+	}
+	n += len(p.tagcode)
+	n += sizeRawBytes(s)
+	return
+}
+
+// Encode a slice of int32s ([]int32).
+func (o *Buffer) enc_slice_int32(p *Properties, base structPointer) error {
+	s := structPointer_Word32Slice(base, p.field)
+	l := s.Len()
+	if l == 0 {
+		return ErrNil
+	}
+	for i := 0; i < l; i++ {
+		o.buf = append(o.buf, p.tagcode...)
+		x := int32(s.Index(i)) // permit sign extension to use full 64-bit range
+		p.valEnc(o, uint64(x))
+	}
+	return nil
+}
+
+func size_slice_int32(p *Properties, base structPointer) (n int) {
+	s := structPointer_Word32Slice(base, p.field)
+	l := s.Len()
+	if l == 0 {
+		return 0
+	}
+	for i := 0; i < l; i++ {
+		n += len(p.tagcode)
+		x := int32(s.Index(i)) // permit sign extension to use full 64-bit range
+		n += p.valSize(uint64(x))
+	}
+	return
+}
+
+// Encode a slice of int32s ([]int32) in packed format.
+func (o *Buffer) enc_slice_packed_int32(p *Properties, base structPointer) error {
+	s := structPointer_Word32Slice(base, p.field)
+	l := s.Len()
+	if l == 0 {
+		return ErrNil
+	}
+	// TODO: Reuse a Buffer.
+	buf := NewBuffer(nil)
+	for i := 0; i < l; i++ {
+		x := int32(s.Index(i)) // permit sign extension to use full 64-bit range
+		p.valEnc(buf, uint64(x))
+	}
+
+	o.buf = append(o.buf, p.tagcode...)
+	o.EncodeVarint(uint64(len(buf.buf)))
+	o.buf = append(o.buf, buf.buf...)
+	return nil
+}
+
+func size_slice_packed_int32(p *Properties, base structPointer) (n int) {
+	s := structPointer_Word32Slice(base, p.field)
+	l := s.Len()
+	if l == 0 {
+		return 0
+	}
+	var bufSize int
+	for i := 0; i < l; i++ {
+		x := int32(s.Index(i)) // permit sign extension to use full 64-bit range
+		bufSize += p.valSize(uint64(x))
+	}
+
+	n += len(p.tagcode)
+	n += sizeVarint(uint64(bufSize))
+	n += bufSize
+	return
+}
+
+// Encode a slice of uint32s ([]uint32).
+// Exactly the same as int32, except for no sign extension.
+func (o *Buffer) enc_slice_uint32(p *Properties, base structPointer) error {
+	s := structPointer_Word32Slice(base, p.field)
+	l := s.Len()
+	if l == 0 {
+		return ErrNil
+	}
+	for i := 0; i < l; i++ {
+		o.buf = append(o.buf, p.tagcode...)
+		x := s.Index(i)
+		p.valEnc(o, uint64(x))
+	}
+	return nil
+}
+
+func size_slice_uint32(p *Properties, base structPointer) (n int) {
+	s := structPointer_Word32Slice(base, p.field)
+	l := s.Len()
+	if l == 0 {
+		return 0
+	}
+	for i := 0; i < l; i++ {
+		n += len(p.tagcode)
+		x := s.Index(i)
+		n += p.valSize(uint64(x))
+	}
+	return
+}
+
+// Encode a slice of uint32s ([]uint32) in packed format.
+// Exactly the same as int32, except for no sign extension.
+func (o *Buffer) enc_slice_packed_uint32(p *Properties, base structPointer) error {
+	s := structPointer_Word32Slice(base, p.field)
+	l := s.Len()
+	if l == 0 {
+		return ErrNil
+	}
+	// TODO: Reuse a Buffer.
+	buf := NewBuffer(nil)
+	for i := 0; i < l; i++ {
+		p.valEnc(buf, uint64(s.Index(i)))
+	}
+
+	o.buf = append(o.buf, p.tagcode...)
+	o.EncodeVarint(uint64(len(buf.buf)))
+	o.buf = append(o.buf, buf.buf...)
+	return nil
+}
+
+func size_slice_packed_uint32(p *Properties, base structPointer) (n int) {
+	s := structPointer_Word32Slice(base, p.field)
+	l := s.Len()
+	if l == 0 {
+		return 0
+	}
+	var bufSize int
+	for i := 0; i < l; i++ {
+		bufSize += p.valSize(uint64(s.Index(i)))
+	}
+
+	n += len(p.tagcode)
+	n += sizeVarint(uint64(bufSize))
+	n += bufSize
+	return
+}
+
+// Encode a slice of int64s ([]int64).
+func (o *Buffer) enc_slice_int64(p *Properties, base structPointer) error {
+	s := structPointer_Word64Slice(base, p.field)
+	l := s.Len()
+	if l == 0 {
+		return ErrNil
+	}
+	for i := 0; i < l; i++ {
+		o.buf = append(o.buf, p.tagcode...)
+		p.valEnc(o, s.Index(i))
+	}
+	return nil
+}
+
+func size_slice_int64(p *Properties, base structPointer) (n int) {
+	s := structPointer_Word64Slice(base, p.field)
+	l := s.Len()
+	if l == 0 {
+		return 0
+	}
+	for i := 0; i < l; i++ {
+		n += len(p.tagcode)
+		n += p.valSize(s.Index(i))
+	}
+	return
+}
+
+// Encode a slice of int64s ([]int64) in packed format.
+func (o *Buffer) enc_slice_packed_int64(p *Properties, base structPointer) error {
+	s := structPointer_Word64Slice(base, p.field)
+	l := s.Len()
+	if l == 0 {
+		return ErrNil
+	}
+	// TODO: Reuse a Buffer.
+	buf := NewBuffer(nil)
+	for i := 0; i < l; i++ {
+		p.valEnc(buf, s.Index(i))
+	}
+
+	o.buf = append(o.buf, p.tagcode...)
+	o.EncodeVarint(uint64(len(buf.buf)))
+	o.buf = append(o.buf, buf.buf...)
+	return nil
+}
+
+func size_slice_packed_int64(p *Properties, base structPointer) (n int) {
+	s := structPointer_Word64Slice(base, p.field)
+	l := s.Len()
+	if l == 0 {
+		return 0
+	}
+	var bufSize int
+	for i := 0; i < l; i++ {
+		bufSize += p.valSize(s.Index(i))
+	}
+
+	n += len(p.tagcode)
+	n += sizeVarint(uint64(bufSize))
+	n += bufSize
+	return
+}
+
+// Encode a slice of slice of bytes ([][]byte).
+func (o *Buffer) enc_slice_slice_byte(p *Properties, base structPointer) error {
+	ss := *structPointer_BytesSlice(base, p.field)
+	l := len(ss)
+	if l == 0 {
+		return ErrNil
+	}
+	for i := 0; i < l; i++ {
+		o.buf = append(o.buf, p.tagcode...)
+		o.EncodeRawBytes(ss[i])
+	}
+	return nil
+}
+
+func size_slice_slice_byte(p *Properties, base structPointer) (n int) {
+	ss := *structPointer_BytesSlice(base, p.field)
+	l := len(ss)
+	if l == 0 {
+		return 0
+	}
+	n += l * len(p.tagcode)
+	for i := 0; i < l; i++ {
+		n += sizeRawBytes(ss[i])
+	}
+	return
+}
+
+// Encode a slice of strings ([]string).
+func (o *Buffer) enc_slice_string(p *Properties, base structPointer) error {
+	ss := *structPointer_StringSlice(base, p.field)
+	l := len(ss)
+	for i := 0; i < l; i++ {
+		o.buf = append(o.buf, p.tagcode...)
+		o.EncodeStringBytes(ss[i])
+	}
+	return nil
+}
+
+func size_slice_string(p *Properties, base structPointer) (n int) {
+	ss := *structPointer_StringSlice(base, p.field)
+	l := len(ss)
+	n += l * len(p.tagcode)
+	for i := 0; i < l; i++ {
+		n += sizeStringBytes(ss[i])
+	}
+	return
+}
+
+// Encode a slice of message structs ([]*struct).
+func (o *Buffer) enc_slice_struct_message(p *Properties, base structPointer) error {
+	var state errorState
+	s := structPointer_StructPointerSlice(base, p.field)
+	l := s.Len()
+
+	for i := 0; i < l; i++ {
+		structp := s.Index(i)
+		if structPointer_IsNil(structp) {
+			return errRepeatedHasNil
+		}
+
+		// Can the object marshal itself?
+		if p.isMarshaler {
+			m := structPointer_Interface(structp, p.stype).(Marshaler)
+			data, err := m.Marshal()
+			if err != nil && !state.shouldContinue(err, nil) {
+				return err
+			}
+			o.buf = append(o.buf, p.tagcode...)
+			o.EncodeRawBytes(data)
+			continue
+		}
+
+		o.buf = append(o.buf, p.tagcode...)
+		err := o.enc_len_struct(p.sprop, structp, &state)
+		if err != nil && !state.shouldContinue(err, nil) {
+			if err == ErrNil {
+				return errRepeatedHasNil
+			}
+			return err
+		}
+	}
+	return state.err
+}
+
+func size_slice_struct_message(p *Properties, base structPointer) (n int) {
+	s := structPointer_StructPointerSlice(base, p.field)
+	l := s.Len()
+	n += l * len(p.tagcode)
+	for i := 0; i < l; i++ {
+		structp := s.Index(i)
+		if structPointer_IsNil(structp) {
+			return // return the size up to this point
+		}
+
+		// Can the object marshal itself?
+		if p.isMarshaler {
+			m := structPointer_Interface(structp, p.stype).(Marshaler)
+			data, _ := m.Marshal()
+			n += len(p.tagcode)
+			n += sizeRawBytes(data)
+			continue
+		}
+
+		n0 := size_struct(p.sprop, structp)
+		n1 := sizeVarint(uint64(n0)) // size of encoded length
+		n += n0 + n1
+	}
+	return
+}
+
+// Encode a slice of group structs ([]*struct).
+func (o *Buffer) enc_slice_struct_group(p *Properties, base structPointer) error {
+	var state errorState
+	s := structPointer_StructPointerSlice(base, p.field)
+	l := s.Len()
+
+	for i := 0; i < l; i++ {
+		b := s.Index(i)
+		if structPointer_IsNil(b) {
+			return errRepeatedHasNil
+		}
+
+		o.EncodeVarint(uint64((p.Tag << 3) | WireStartGroup))
+
+		err := o.enc_struct(p.sprop, b)
+
+		if err != nil && !state.shouldContinue(err, nil) {
+			if err == ErrNil {
+				return errRepeatedHasNil
+			}
+			return err
+		}
+
+		o.EncodeVarint(uint64((p.Tag << 3) | WireEndGroup))
+	}
+	return state.err
+}
+
+func size_slice_struct_group(p *Properties, base structPointer) (n int) {
+	s := structPointer_StructPointerSlice(base, p.field)
+	l := s.Len()
+
+	n += l * sizeVarint(uint64((p.Tag<<3)|WireStartGroup))
+	n += l * sizeVarint(uint64((p.Tag<<3)|WireEndGroup))
+	for i := 0; i < l; i++ {
+		b := s.Index(i)
+		if structPointer_IsNil(b) {
+			return // return size up to this point
+		}
+
+		n += size_struct(p.sprop, b)
+	}
+	return
+}
+
+// Encode an extension map.
+func (o *Buffer) enc_map(p *Properties, base structPointer) error {
+	exts := structPointer_ExtMap(base, p.field)
+	if err := encodeExtensionsMap(*exts); err != nil {
+		return err
+	}
+
+	return o.enc_map_body(*exts)
+}
+
+func (o *Buffer) enc_exts(p *Properties, base structPointer) error {
+	exts := structPointer_Extensions(base, p.field)
+	if err := encodeExtensions(exts); err != nil {
+		return err
+	}
+	v, _ := exts.extensionsRead()
+
+	return o.enc_map_body(v)
+}
+
+func (o *Buffer) enc_map_body(v map[int32]Extension) error {
+	// Fast-path for common cases: zero or one extensions.
+	if len(v) <= 1 {
+		for _, e := range v {
+			o.buf = append(o.buf, e.enc...)
+		}
+		return nil
+	}
+
+	// Sort keys to provide a deterministic encoding.
+	keys := make([]int, 0, len(v))
+	for k := range v {
+		keys = append(keys, int(k))
+	}
+	sort.Ints(keys)
+
+	for _, k := range keys {
+		o.buf = append(o.buf, v[int32(k)].enc...)
+	}
+	return nil
+}
+
+func size_map(p *Properties, base structPointer) int {
+	v := structPointer_ExtMap(base, p.field)
+	return extensionsMapSize(*v)
+}
+
+func size_exts(p *Properties, base structPointer) int {
+	v := structPointer_Extensions(base, p.field)
+	return extensionsSize(v)
+}
+
+// Encode a map field.
+func (o *Buffer) enc_new_map(p *Properties, base structPointer) error {
+	var state errorState // XXX: or do we need to plumb this through?
+
+	/*
+		A map defined as
+			map<key_type, value_type> map_field = N;
+		is encoded in the same way as
+			message MapFieldEntry {
+				key_type key = 1;
+				value_type value = 2;
+			}
+			repeated MapFieldEntry map_field = N;
+	*/
+
+	v := structPointer_NewAt(base, p.field, p.mtype).Elem() // map[K]V
+	if v.Len() == 0 {
+		return nil
+	}
+
+	keycopy, valcopy, keybase, valbase := mapEncodeScratch(p.mtype)
+
+	enc := func() error {
+		if err := p.mkeyprop.enc(o, p.mkeyprop, keybase); err != nil {
+			return err
+		}
+		if err := p.mvalprop.enc(o, p.mvalprop, valbase); err != nil && err != ErrNil {
+			return err
+		}
+		return nil
+	}
+
+	// Don't sort map keys. It is not required by the spec, and C++ doesn't do it.
+	for _, key := range v.MapKeys() {
+		val := v.MapIndex(key)
+
+		keycopy.Set(key)
+		valcopy.Set(val)
+
+		o.buf = append(o.buf, p.tagcode...)
+		if err := o.enc_len_thing(enc, &state); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func size_new_map(p *Properties, base structPointer) int {
+	v := structPointer_NewAt(base, p.field, p.mtype).Elem() // map[K]V
+
+	keycopy, valcopy, keybase, valbase := mapEncodeScratch(p.mtype)
+
+	n := 0
+	for _, key := range v.MapKeys() {
+		val := v.MapIndex(key)
+		keycopy.Set(key)
+		valcopy.Set(val)
+
+		// Tag codes for key and val are the responsibility of the sub-sizer.
+		keysize := p.mkeyprop.size(p.mkeyprop, keybase)
+		valsize := p.mvalprop.size(p.mvalprop, valbase)
+		entry := keysize + valsize
+		// Add on tag code and length of map entry itself.
+		n += len(p.tagcode) + sizeVarint(uint64(entry)) + entry
+	}
+	return n
+}
+
+// mapEncodeScratch returns a new reflect.Value matching the map's value type,
+// and a structPointer suitable for passing to an encoder or sizer.
+func mapEncodeScratch(mapType reflect.Type) (keycopy, valcopy reflect.Value, keybase, valbase structPointer) {
+	// Prepare addressable doubly-indirect placeholders for the key and value types.
+	// This is needed because the element-type encoders expect **T, but the map iteration produces T.
+
+	keycopy = reflect.New(mapType.Key()).Elem()                 // addressable K
+	keyptr := reflect.New(reflect.PtrTo(keycopy.Type())).Elem() // addressable *K
+	keyptr.Set(keycopy.Addr())                                  //
+	keybase = toStructPointer(keyptr.Addr())                    // **K
+
+	// Value types are more varied and require special handling.
+	switch mapType.Elem().Kind() {
+	case reflect.Slice:
+		// []byte
+		var dummy []byte
+		valcopy = reflect.ValueOf(&dummy).Elem() // addressable []byte
+		valbase = toStructPointer(valcopy.Addr())
+	case reflect.Ptr:
+		// message; the generated field type is map[K]*Msg (so V is *Msg),
+		// so we only need one level of indirection.
+		valcopy = reflect.New(mapType.Elem()).Elem() // addressable V
+		valbase = toStructPointer(valcopy.Addr())
+	default:
+		// everything else
+		valcopy = reflect.New(mapType.Elem()).Elem()                // addressable V
+		valptr := reflect.New(reflect.PtrTo(valcopy.Type())).Elem() // addressable *V
+		valptr.Set(valcopy.Addr())                                  //
+		valbase = toStructPointer(valptr.Addr())                    // **V
+	}
+	return
+}
+
+// Encode a struct.
+func (o *Buffer) enc_struct(prop *StructProperties, base structPointer) error {
+	var state errorState
+	// Encode fields in tag order so that decoders may use optimizations
+	// that depend on the ordering.
+	// https://developers.google.com/protocol-buffers/docs/encoding#order
+	for _, i := range prop.order {
+		p := prop.Prop[i]
+		if p.enc != nil {
+			err := p.enc(o, p, base)
+			if err != nil {
+				if err == ErrNil {
+					if p.Required && state.err == nil {
+						state.err = &RequiredNotSetError{p.Name}
+					}
+				} else if err == errRepeatedHasNil {
+					// Give more context to nil values in repeated fields.
+					return errors.New("repeated field " + p.OrigName + " has nil element")
+				} else if !state.shouldContinue(err, p) {
+					return err
+				}
+			}
+			if len(o.buf) > maxMarshalSize {
+				return ErrTooLarge
+			}
+		}
+	}
+
+	// Do oneof fields.
+	if prop.oneofMarshaler != nil {
+		m := structPointer_Interface(base, prop.stype).(Message)
+		if err := prop.oneofMarshaler(m, o); err == ErrNil {
+			return errOneofHasNil
+		} else if err != nil {
+			return err
+		}
+	}
+
+	// Add unrecognized fields at the end.
+	if prop.unrecField.IsValid() {
+		v := *structPointer_Bytes(base, prop.unrecField)
+		if len(o.buf)+len(v) > maxMarshalSize {
+			return ErrTooLarge
+		}
+		if len(v) > 0 {
+			o.buf = append(o.buf, v...)
+		}
+	}
+
+	return state.err
+}
+
+func size_struct(prop *StructProperties, base structPointer) (n int) {
+	for _, i := range prop.order {
+		p := prop.Prop[i]
+		if p.size != nil {
+			n += p.size(p, base)
+		}
+	}
+
+	// Add unrecognized fields at the end.
+	if prop.unrecField.IsValid() {
+		v := *structPointer_Bytes(base, prop.unrecField)
+		n += len(v)
+	}
+
+	// Factor in any oneof fields.
+	if prop.oneofSizer != nil {
+		m := structPointer_Interface(base, prop.stype).(Message)
+		n += prop.oneofSizer(m)
+	}
+
+	return
+}
+
+var zeroes [20]byte // longer than any conceivable sizeVarint
+
+// Encode a struct, preceded by its encoded length (as a varint).
+func (o *Buffer) enc_len_struct(prop *StructProperties, base structPointer, state *errorState) error {
+	return o.enc_len_thing(func() error { return o.enc_struct(prop, base) }, state)
+}
+
+// Encode something, preceded by its encoded length (as a varint).
+func (o *Buffer) enc_len_thing(enc func() error, state *errorState) error {
+	iLen := len(o.buf)
+	o.buf = append(o.buf, 0, 0, 0, 0) // reserve four bytes for length
+	iMsg := len(o.buf)
+	err := enc()
+	if err != nil && !state.shouldContinue(err, nil) {
+		return err
+	}
+	lMsg := len(o.buf) - iMsg
+	lLen := sizeVarint(uint64(lMsg))
+	switch x := lLen - (iMsg - iLen); {
+	case x > 0: // actual length is x bytes larger than the space we reserved
+		// Move msg x bytes right.
+		o.buf = append(o.buf, zeroes[:x]...)
+		copy(o.buf[iMsg+x:], o.buf[iMsg:iMsg+lMsg])
+	case x < 0: // actual length is x bytes smaller than the space we reserved
+		// Move msg x bytes left.
+		copy(o.buf[iMsg+x:], o.buf[iMsg:iMsg+lMsg])
+		o.buf = o.buf[:len(o.buf)+x] // x is negative
+	}
+	// Encode the length in the reserved space.
+	o.buf = o.buf[:iLen]
+	o.EncodeVarint(uint64(lMsg))
+	o.buf = o.buf[:len(o.buf)+lMsg]
+	return state.err
+}
+
+// errorState maintains the first error that occurs and updates that error
+// with additional context.
+type errorState struct {
+	err error
+}
+
+// shouldContinue reports whether encoding should continue upon encountering the
+// given error. If the error is RequiredNotSetError, shouldContinue returns true
+// and, if this is the first appearance of that error, remembers it for future
+// reporting.
+//
+// If prop is not nil, it may update any error with additional context about the
+// field with the error.
+func (s *errorState) shouldContinue(err error, prop *Properties) bool {
+	// Ignore unset required fields.
+	reqNotSet, ok := err.(*RequiredNotSetError)
+	if !ok {
+		return false
+	}
+	if s.err == nil {
+		if prop != nil {
+			err = &RequiredNotSetError{prop.Name + "." + reqNotSet.field}
+		}
+		s.err = err
+	}
+	return true
+}
diff --git a/vendor/github.com/golang/protobuf/proto/equal.go b/vendor/github.com/golang/protobuf/proto/equal.go
new file mode 100644
index 00000000..8b16f951
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/equal.go
@@ -0,0 +1,296 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2011 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Protocol buffer comparison.
+
+package proto
+
+import (
+	"bytes"
+	"log"
+	"reflect"
+	"strings"
+)
+
+/*
+Equal returns true iff protocol buffers a and b are equal.
+The arguments must both be pointers to protocol buffer structs.
+
+Equality is defined in this way:
+  - Two messages are equal iff they are the same type,
+    corresponding fields are equal, unknown field sets
+    are equal, and extensions sets are equal.
+  - Two set scalar fields are equal iff their values are equal.
+    If the fields are of a floating-point type, remember that
+    NaN != x for all x, including NaN. If the message is defined
+    in a proto3 .proto file, fields are not "set"; specifically,
+    zero length proto3 "bytes" fields are equal (nil == {}).
+  - Two repeated fields are equal iff their lengths are the same,
+    and their corresponding elements are equal (a "bytes" field,
+    although represented by []byte, is not a repeated field)
+  - Two unset fields are equal.
+  - Two unknown field sets are equal if their current
+    encoded state is equal.
+  - Two extension sets are equal iff they have corresponding
+    elements that are pairwise equal.
+  - Every other combination of things are not equal.
+
+The return value is undefined if a and b are not protocol buffers.
+*/
+func Equal(a, b Message) bool {
+	if a == nil || b == nil {
+		return a == b
+	}
+	v1, v2 := reflect.ValueOf(a), reflect.ValueOf(b)
+	if v1.Type() != v2.Type() {
+		return false
+	}
+	if v1.Kind() == reflect.Ptr {
+		if v1.IsNil() {
+			return v2.IsNil()
+		}
+		if v2.IsNil() {
+			return false
+		}
+		v1, v2 = v1.Elem(), v2.Elem()
+	}
+	if v1.Kind() != reflect.Struct {
+		return false
+	}
+	return equalStruct(v1, v2)
+}
+
+// v1 and v2 are known to have the same type.
+func equalStruct(v1, v2 reflect.Value) bool {
+	sprop := GetProperties(v1.Type())
+	for i := 0; i < v1.NumField(); i++ {
+		f := v1.Type().Field(i)
+		if strings.HasPrefix(f.Name, "XXX_") {
+			continue
+		}
+		f1, f2 := v1.Field(i), v2.Field(i)
+		if f.Type.Kind() == reflect.Ptr {
+			if n1, n2 := f1.IsNil(), f2.IsNil(); n1 && n2 {
+				// both unset
+				continue
+			} else if n1 != n2 {
+				// set/unset mismatch
+				return false
+			}
+			b1, ok := f1.Interface().(raw)
+			if ok {
+				b2 := f2.Interface().(raw)
+				// RawMessage
+				if !bytes.Equal(b1.Bytes(), b2.Bytes()) {
+					return false
+				}
+				continue
+			}
+			f1, f2 = f1.Elem(), f2.Elem()
+		}
+		if !equalAny(f1, f2, sprop.Prop[i]) {
+			return false
+		}
+	}
+
+	if em1 := v1.FieldByName("XXX_InternalExtensions"); em1.IsValid() {
+		em2 := v2.FieldByName("XXX_InternalExtensions")
+		if !equalExtensions(v1.Type(), em1.Interface().(XXX_InternalExtensions), em2.Interface().(XXX_InternalExtensions)) {
+			return false
+		}
+	}
+
+	if em1 := v1.FieldByName("XXX_extensions"); em1.IsValid() {
+		em2 := v2.FieldByName("XXX_extensions")
+		if !equalExtMap(v1.Type(), em1.Interface().(map[int32]Extension), em2.Interface().(map[int32]Extension)) {
+			return false
+		}
+	}
+
+	uf := v1.FieldByName("XXX_unrecognized")
+	if !uf.IsValid() {
+		return true
+	}
+
+	u1 := uf.Bytes()
+	u2 := v2.FieldByName("XXX_unrecognized").Bytes()
+	if !bytes.Equal(u1, u2) {
+		return false
+	}
+
+	return true
+}
+
+// v1 and v2 are known to have the same type.
+// prop may be nil.
+func equalAny(v1, v2 reflect.Value, prop *Properties) bool {
+	if v1.Type() == protoMessageType {
+		m1, _ := v1.Interface().(Message)
+		m2, _ := v2.Interface().(Message)
+		return Equal(m1, m2)
+	}
+	switch v1.Kind() {
+	case reflect.Bool:
+		return v1.Bool() == v2.Bool()
+	case reflect.Float32, reflect.Float64:
+		return v1.Float() == v2.Float()
+	case reflect.Int32, reflect.Int64:
+		return v1.Int() == v2.Int()
+	case reflect.Interface:
+		// Probably a oneof field; compare the inner values.
+		n1, n2 := v1.IsNil(), v2.IsNil()
+		if n1 || n2 {
+			return n1 == n2
+		}
+		e1, e2 := v1.Elem(), v2.Elem()
+		if e1.Type() != e2.Type() {
+			return false
+		}
+		return equalAny(e1, e2, nil)
+	case reflect.Map:
+		if v1.Len() != v2.Len() {
+			return false
+		}
+		for _, key := range v1.MapKeys() {
+			val2 := v2.MapIndex(key)
+			if !val2.IsValid() {
+				// This key was not found in the second map.
+				return false
+			}
+			if !equalAny(v1.MapIndex(key), val2, nil) {
+				return false
+			}
+		}
+		return true
+	case reflect.Ptr:
+		// Maps may have nil values in them, so check for nil.
+		if v1.IsNil() && v2.IsNil() {
+			return true
+		}
+		if v1.IsNil() != v2.IsNil() {
+			return false
+		}
+		return equalAny(v1.Elem(), v2.Elem(), prop)
+	case reflect.Slice:
+		if v1.Type().Elem().Kind() == reflect.Uint8 {
+			// short circuit: []byte
+
+			// Edge case: if this is in a proto3 message, a zero length
+			// bytes field is considered the zero value.
+			if prop != nil && prop.proto3 && v1.Len() == 0 && v2.Len() == 0 {
+				return true
+			}
+			if v1.IsNil() != v2.IsNil() {
+				return false
+			}
+			return bytes.Equal(v1.Interface().([]byte), v2.Interface().([]byte))
+		}
+
+		if v1.Len() != v2.Len() {
+			return false
+		}
+		for i := 0; i < v1.Len(); i++ {
+			if !equalAny(v1.Index(i), v2.Index(i), prop) {
+				return false
+			}
+		}
+		return true
+	case reflect.String:
+		return v1.Interface().(string) == v2.Interface().(string)
+	case reflect.Struct:
+		return equalStruct(v1, v2)
+	case reflect.Uint32, reflect.Uint64:
+		return v1.Uint() == v2.Uint()
+	}
+
+	// unknown type, so not a protocol buffer
+	log.Printf("proto: don't know how to compare %v", v1)
+	return false
+}
+
+// base is the struct type that the extensions are based on.
+// x1 and x2 are InternalExtensions.
+func equalExtensions(base reflect.Type, x1, x2 XXX_InternalExtensions) bool {
+	em1, _ := x1.extensionsRead()
+	em2, _ := x2.extensionsRead()
+	return equalExtMap(base, em1, em2)
+}
+
+func equalExtMap(base reflect.Type, em1, em2 map[int32]Extension) bool {
+	if len(em1) != len(em2) {
+		return false
+	}
+
+	for extNum, e1 := range em1 {
+		e2, ok := em2[extNum]
+		if !ok {
+			return false
+		}
+
+		m1, m2 := e1.value, e2.value
+
+		if m1 != nil && m2 != nil {
+			// Both are unencoded.
+			if !equalAny(reflect.ValueOf(m1), reflect.ValueOf(m2), nil) {
+				return false
+			}
+			continue
+		}
+
+		// At least one is encoded. To do a semantically correct comparison
+		// we need to unmarshal them first.
+		var desc *ExtensionDesc
+		if m := extensionMaps[base]; m != nil {
+			desc = m[extNum]
+		}
+		if desc == nil {
+			log.Printf("proto: don't know how to compare extension %d of %v", extNum, base)
+			continue
+		}
+		var err error
+		if m1 == nil {
+			m1, err = decodeExtension(e1.enc, desc)
+		}
+		if m2 == nil && err == nil {
+			m2, err = decodeExtension(e2.enc, desc)
+		}
+		if err != nil {
+			// The encoded form is invalid.
+			log.Printf("proto: badly encoded extension %d of %v: %v", extNum, base, err)
+			return false
+		}
+		if !equalAny(reflect.ValueOf(m1), reflect.ValueOf(m2), nil) {
+			return false
+		}
+	}
+
+	return true
+}
diff --git a/vendor/github.com/golang/protobuf/proto/extensions.go b/vendor/github.com/golang/protobuf/proto/extensions.go
new file mode 100644
index 00000000..6b9b3637
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/extensions.go
@@ -0,0 +1,586 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+/*
+ * Types and routines for supporting protocol buffer extensions.
+ */
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"strconv"
+	"sync"
+)
+
+// ErrMissingExtension is the error returned by GetExtension if the named extension is not in the message.
+var ErrMissingExtension = errors.New("proto: missing extension")
+
+// ExtensionRange represents a range of message extensions for a protocol buffer.
+// Used in code generated by the protocol compiler.
+type ExtensionRange struct {
+	Start, End int32 // both inclusive
+}
+
+// extendableProto is an interface implemented by any protocol buffer generated by the current
+// proto compiler that may be extended.
+type extendableProto interface {
+	Message
+	ExtensionRangeArray() []ExtensionRange
+	extensionsWrite() map[int32]Extension
+	extensionsRead() (map[int32]Extension, sync.Locker)
+}
+
+// extendableProtoV1 is an interface implemented by a protocol buffer generated by the previous
+// version of the proto compiler that may be extended.
+type extendableProtoV1 interface {
+	Message
+	ExtensionRangeArray() []ExtensionRange
+	ExtensionMap() map[int32]Extension
+}
+
+// extensionAdapter is a wrapper around extendableProtoV1 that implements extendableProto.
+type extensionAdapter struct {
+	extendableProtoV1
+}
+
+func (e extensionAdapter) extensionsWrite() map[int32]Extension {
+	return e.ExtensionMap()
+}
+
+func (e extensionAdapter) extensionsRead() (map[int32]Extension, sync.Locker) {
+	return e.ExtensionMap(), notLocker{}
+}
+
+// notLocker is a sync.Locker whose Lock and Unlock methods are nops.
+type notLocker struct{}
+
+func (n notLocker) Lock()   {}
+func (n notLocker) Unlock() {}
+
+// extendable returns the extendableProto interface for the given generated proto message.
+// If the proto message has the old extension format, it returns a wrapper that implements
+// the extendableProto interface.
+func extendable(p interface{}) (extendableProto, bool) {
+	if ep, ok := p.(extendableProto); ok {
+		return ep, ok
+	}
+	if ep, ok := p.(extendableProtoV1); ok {
+		return extensionAdapter{ep}, ok
+	}
+	return nil, false
+}
+
+// XXX_InternalExtensions is an internal representation of proto extensions.
+//
+// Each generated message struct type embeds an anonymous XXX_InternalExtensions field,
+// thus gaining the unexported 'extensions' method, which can be called only from the proto package.
+//
+// The methods of XXX_InternalExtensions are not concurrency safe in general,
+// but calls to logically read-only methods such as has and get may be executed concurrently.
+type XXX_InternalExtensions struct {
+	// The struct must be indirect so that if a user inadvertently copies a
+	// generated message and its embedded XXX_InternalExtensions, they
+	// avoid the mayhem of a copied mutex.
+	//
+	// The mutex serializes all logically read-only operations to p.extensionMap.
+	// It is up to the client to ensure that write operations to p.extensionMap are
+	// mutually exclusive with other accesses.
+	p *struct {
+		mu           sync.Mutex
+		extensionMap map[int32]Extension
+	}
+}
+
+// extensionsWrite returns the extension map, creating it on first use.
+func (e *XXX_InternalExtensions) extensionsWrite() map[int32]Extension {
+	if e.p == nil {
+		e.p = new(struct {
+			mu           sync.Mutex
+			extensionMap map[int32]Extension
+		})
+		e.p.extensionMap = make(map[int32]Extension)
+	}
+	return e.p.extensionMap
+}
+
+// extensionsRead returns the extensions map for read-only use.  It may be nil.
+// The caller must hold the returned mutex's lock when accessing Elements within the map.
+func (e *XXX_InternalExtensions) extensionsRead() (map[int32]Extension, sync.Locker) {
+	if e.p == nil {
+		return nil, nil
+	}
+	return e.p.extensionMap, &e.p.mu
+}
+
+var extendableProtoType = reflect.TypeOf((*extendableProto)(nil)).Elem()
+var extendableProtoV1Type = reflect.TypeOf((*extendableProtoV1)(nil)).Elem()
+
+// ExtensionDesc represents an extension specification.
+// Used in generated code from the protocol compiler.
+type ExtensionDesc struct {
+	ExtendedType  Message     // nil pointer to the type that is being extended
+	ExtensionType interface{} // nil pointer to the extension type
+	Field         int32       // field number
+	Name          string      // fully-qualified name of extension, for text formatting
+	Tag           string      // protobuf tag style
+}
+
+func (ed *ExtensionDesc) repeated() bool {
+	t := reflect.TypeOf(ed.ExtensionType)
+	return t.Kind() == reflect.Slice && t.Elem().Kind() != reflect.Uint8
+}
+
+// Extension represents an extension in a message.
+type Extension struct {
+	// When an extension is stored in a message using SetExtension
+	// only desc and value are set. When the message is marshaled
+	// enc will be set to the encoded form of the message.
+	//
+	// When a message is unmarshaled and contains extensions, each
+	// extension will have only enc set. When such an extension is
+	// accessed using GetExtension (or GetExtensions) desc and value
+	// will be set.
+	desc  *ExtensionDesc
+	value interface{}
+	enc   []byte
+}
+
+// SetRawExtension is for testing only.
+func SetRawExtension(base Message, id int32, b []byte) {
+	epb, ok := extendable(base)
+	if !ok {
+		return
+	}
+	extmap := epb.extensionsWrite()
+	extmap[id] = Extension{enc: b}
+}
+
+// isExtensionField returns true iff the given field number is in an extension range.
+func isExtensionField(pb extendableProto, field int32) bool {
+	for _, er := range pb.ExtensionRangeArray() {
+		if er.Start <= field && field <= er.End {
+			return true
+		}
+	}
+	return false
+}
+
+// checkExtensionTypes checks that the given extension is valid for pb.
+func checkExtensionTypes(pb extendableProto, extension *ExtensionDesc) error {
+	var pbi interface{} = pb
+	// Check the extended type.
+	if ea, ok := pbi.(extensionAdapter); ok {
+		pbi = ea.extendableProtoV1
+	}
+	if a, b := reflect.TypeOf(pbi), reflect.TypeOf(extension.ExtendedType); a != b {
+		return errors.New("proto: bad extended type; " + b.String() + " does not extend " + a.String())
+	}
+	// Check the range.
+	if !isExtensionField(pb, extension.Field) {
+		return errors.New("proto: bad extension number; not in declared ranges")
+	}
+	return nil
+}
+
+// extPropKey is sufficient to uniquely identify an extension.
+type extPropKey struct {
+	base  reflect.Type
+	field int32
+}
+
+var extProp = struct {
+	sync.RWMutex
+	m map[extPropKey]*Properties
+}{
+	m: make(map[extPropKey]*Properties),
+}
+
+func extensionProperties(ed *ExtensionDesc) *Properties {
+	key := extPropKey{base: reflect.TypeOf(ed.ExtendedType), field: ed.Field}
+
+	extProp.RLock()
+	if prop, ok := extProp.m[key]; ok {
+		extProp.RUnlock()
+		return prop
+	}
+	extProp.RUnlock()
+
+	extProp.Lock()
+	defer extProp.Unlock()
+	// Check again.
+	if prop, ok := extProp.m[key]; ok {
+		return prop
+	}
+
+	prop := new(Properties)
+	prop.Init(reflect.TypeOf(ed.ExtensionType), "unknown_name", ed.Tag, nil)
+	extProp.m[key] = prop
+	return prop
+}
+
+// encode encodes any unmarshaled (unencoded) extensions in e.
+func encodeExtensions(e *XXX_InternalExtensions) error {
+	m, mu := e.extensionsRead()
+	if m == nil {
+		return nil // fast path
+	}
+	mu.Lock()
+	defer mu.Unlock()
+	return encodeExtensionsMap(m)
+}
+
+// encode encodes any unmarshaled (unencoded) extensions in e.
+func encodeExtensionsMap(m map[int32]Extension) error {
+	for k, e := range m {
+		if e.value == nil || e.desc == nil {
+			// Extension is only in its encoded form.
+			continue
+		}
+
+		// We don't skip extensions that have an encoded form set,
+		// because the extension value may have been mutated after
+		// the last time this function was called.
+
+		et := reflect.TypeOf(e.desc.ExtensionType)
+		props := extensionProperties(e.desc)
+
+		p := NewBuffer(nil)
+		// If e.value has type T, the encoder expects a *struct{ X T }.
+		// Pass a *T with a zero field and hope it all works out.
+		x := reflect.New(et)
+		x.Elem().Set(reflect.ValueOf(e.value))
+		if err := props.enc(p, props, toStructPointer(x)); err != nil {
+			return err
+		}
+		e.enc = p.buf
+		m[k] = e
+	}
+	return nil
+}
+
+func extensionsSize(e *XXX_InternalExtensions) (n int) {
+	m, mu := e.extensionsRead()
+	if m == nil {
+		return 0
+	}
+	mu.Lock()
+	defer mu.Unlock()
+	return extensionsMapSize(m)
+}
+
+func extensionsMapSize(m map[int32]Extension) (n int) {
+	for _, e := range m {
+		if e.value == nil || e.desc == nil {
+			// Extension is only in its encoded form.
+			n += len(e.enc)
+			continue
+		}
+
+		// We don't skip extensions that have an encoded form set,
+		// because the extension value may have been mutated after
+		// the last time this function was called.
+
+		et := reflect.TypeOf(e.desc.ExtensionType)
+		props := extensionProperties(e.desc)
+
+		// If e.value has type T, the encoder expects a *struct{ X T }.
+		// Pass a *T with a zero field and hope it all works out.
+		x := reflect.New(et)
+		x.Elem().Set(reflect.ValueOf(e.value))
+		n += props.size(props, toStructPointer(x))
+	}
+	return
+}
+
+// HasExtension returns whether the given extension is present in pb.
+func HasExtension(pb Message, extension *ExtensionDesc) bool {
+	// TODO: Check types, field numbers, etc.?
+	epb, ok := extendable(pb)
+	if !ok {
+		return false
+	}
+	extmap, mu := epb.extensionsRead()
+	if extmap == nil {
+		return false
+	}
+	mu.Lock()
+	_, ok = extmap[extension.Field]
+	mu.Unlock()
+	return ok
+}
+
+// ClearExtension removes the given extension from pb.
+func ClearExtension(pb Message, extension *ExtensionDesc) {
+	epb, ok := extendable(pb)
+	if !ok {
+		return
+	}
+	// TODO: Check types, field numbers, etc.?
+	extmap := epb.extensionsWrite()
+	delete(extmap, extension.Field)
+}
+
+// GetExtension parses and returns the given extension of pb.
+// If the extension is not present and has no default value it returns ErrMissingExtension.
+func GetExtension(pb Message, extension *ExtensionDesc) (interface{}, error) {
+	epb, ok := extendable(pb)
+	if !ok {
+		return nil, errors.New("proto: not an extendable proto")
+	}
+
+	if err := checkExtensionTypes(epb, extension); err != nil {
+		return nil, err
+	}
+
+	emap, mu := epb.extensionsRead()
+	if emap == nil {
+		return defaultExtensionValue(extension)
+	}
+	mu.Lock()
+	defer mu.Unlock()
+	e, ok := emap[extension.Field]
+	if !ok {
+		// defaultExtensionValue returns the default value or
+		// ErrMissingExtension if there is no default.
+		return defaultExtensionValue(extension)
+	}
+
+	if e.value != nil {
+		// Already decoded. Check the descriptor, though.
+		if e.desc != extension {
+			// This shouldn't happen. If it does, it means that
+			// GetExtension was called twice with two different
+			// descriptors with the same field number.
+			return nil, errors.New("proto: descriptor conflict")
+		}
+		return e.value, nil
+	}
+
+	v, err := decodeExtension(e.enc, extension)
+	if err != nil {
+		return nil, err
+	}
+
+	// Remember the decoded version and drop the encoded version.
+	// That way it is safe to mutate what we return.
+	e.value = v
+	e.desc = extension
+	e.enc = nil
+	emap[extension.Field] = e
+	return e.value, nil
+}
+
+// defaultExtensionValue returns the default value for extension.
+// If no default for an extension is defined ErrMissingExtension is returned.
+func defaultExtensionValue(extension *ExtensionDesc) (interface{}, error) {
+	t := reflect.TypeOf(extension.ExtensionType)
+	props := extensionProperties(extension)
+
+	sf, _, err := fieldDefault(t, props)
+	if err != nil {
+		return nil, err
+	}
+
+	if sf == nil || sf.value == nil {
+		// There is no default value.
+		return nil, ErrMissingExtension
+	}
+
+	if t.Kind() != reflect.Ptr {
+		// We do not need to return a Ptr, we can directly return sf.value.
+		return sf.value, nil
+	}
+
+	// We need to return an interface{} that is a pointer to sf.value.
+	value := reflect.New(t).Elem()
+	value.Set(reflect.New(value.Type().Elem()))
+	if sf.kind == reflect.Int32 {
+		// We may have an int32 or an enum, but the underlying data is int32.
+		// Since we can't set an int32 into a non int32 reflect.value directly
+		// set it as a int32.
+		value.Elem().SetInt(int64(sf.value.(int32)))
+	} else {
+		value.Elem().Set(reflect.ValueOf(sf.value))
+	}
+	return value.Interface(), nil
+}
+
+// decodeExtension decodes an extension encoded in b.
+func decodeExtension(b []byte, extension *ExtensionDesc) (interface{}, error) {
+	o := NewBuffer(b)
+
+	t := reflect.TypeOf(extension.ExtensionType)
+
+	props := extensionProperties(extension)
+
+	// t is a pointer to a struct, pointer to basic type or a slice.
+	// Allocate a "field" to store the pointer/slice itself; the
+	// pointer/slice will be stored here. We pass
+	// the address of this field to props.dec.
+	// This passes a zero field and a *t and lets props.dec
+	// interpret it as a *struct{ x t }.
+	value := reflect.New(t).Elem()
+
+	for {
+		// Discard wire type and field number varint. It isn't needed.
+		if _, err := o.DecodeVarint(); err != nil {
+			return nil, err
+		}
+
+		if err := props.dec(o, props, toStructPointer(value.Addr())); err != nil {
+			return nil, err
+		}
+
+		if o.index >= len(o.buf) {
+			break
+		}
+	}
+	return value.Interface(), nil
+}
+
+// GetExtensions returns a slice of the extensions present in pb that are also listed in es.
+// The returned slice has the same length as es; missing extensions will appear as nil elements.
+func GetExtensions(pb Message, es []*ExtensionDesc) (extensions []interface{}, err error) {
+	epb, ok := extendable(pb)
+	if !ok {
+		return nil, errors.New("proto: not an extendable proto")
+	}
+	extensions = make([]interface{}, len(es))
+	for i, e := range es {
+		extensions[i], err = GetExtension(epb, e)
+		if err == ErrMissingExtension {
+			err = nil
+		}
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+// ExtensionDescs returns a new slice containing pb's extension descriptors, in undefined order.
+// For non-registered extensions, ExtensionDescs returns an incomplete descriptor containing
+// just the Field field, which defines the extension's field number.
+func ExtensionDescs(pb Message) ([]*ExtensionDesc, error) {
+	epb, ok := extendable(pb)
+	if !ok {
+		return nil, fmt.Errorf("proto: %T is not an extendable proto.Message", pb)
+	}
+	registeredExtensions := RegisteredExtensions(pb)
+
+	emap, mu := epb.extensionsRead()
+	if emap == nil {
+		return nil, nil
+	}
+	mu.Lock()
+	defer mu.Unlock()
+	extensions := make([]*ExtensionDesc, 0, len(emap))
+	for extid, e := range emap {
+		desc := e.desc
+		if desc == nil {
+			desc = registeredExtensions[extid]
+			if desc == nil {
+				desc = &ExtensionDesc{Field: extid}
+			}
+		}
+
+		extensions = append(extensions, desc)
+	}
+	return extensions, nil
+}
+
+// SetExtension sets the specified extension of pb to the specified value.
+func SetExtension(pb Message, extension *ExtensionDesc, value interface{}) error {
+	epb, ok := extendable(pb)
+	if !ok {
+		return errors.New("proto: not an extendable proto")
+	}
+	if err := checkExtensionTypes(epb, extension); err != nil {
+		return err
+	}
+	typ := reflect.TypeOf(extension.ExtensionType)
+	if typ != reflect.TypeOf(value) {
+		return errors.New("proto: bad extension value type")
+	}
+	// nil extension values need to be caught early, because the
+	// encoder can't distinguish an ErrNil due to a nil extension
+	// from an ErrNil due to a missing field. Extensions are
+	// always optional, so the encoder would just swallow the error
+	// and drop all the extensions from the encoded message.
+	if reflect.ValueOf(value).IsNil() {
+		return fmt.Errorf("proto: SetExtension called with nil value of type %T", value)
+	}
+
+	extmap := epb.extensionsWrite()
+	extmap[extension.Field] = Extension{desc: extension, value: value}
+	return nil
+}
+
+// ClearAllExtensions clears all extensions from pb.
+func ClearAllExtensions(pb Message) {
+	epb, ok := extendable(pb)
+	if !ok {
+		return
+	}
+	m := epb.extensionsWrite()
+	for k := range m {
+		delete(m, k)
+	}
+}
+
+// A global registry of extensions.
+// The generated code will register the generated descriptors by calling RegisterExtension.
+
+var extensionMaps = make(map[reflect.Type]map[int32]*ExtensionDesc)
+
+// RegisterExtension is called from the generated code.
+func RegisterExtension(desc *ExtensionDesc) {
+	st := reflect.TypeOf(desc.ExtendedType).Elem()
+	m := extensionMaps[st]
+	if m == nil {
+		m = make(map[int32]*ExtensionDesc)
+		extensionMaps[st] = m
+	}
+	if _, ok := m[desc.Field]; ok {
+		panic("proto: duplicate extension registered: " + st.String() + " " + strconv.Itoa(int(desc.Field)))
+	}
+	m[desc.Field] = desc
+}
+
+// RegisteredExtensions returns a map of the registered extensions of a
+// protocol buffer struct, indexed by the extension number.
+// The argument pb should be a nil pointer to the struct type.
+func RegisteredExtensions(pb Message) map[int32]*ExtensionDesc {
+	return extensionMaps[reflect.TypeOf(pb).Elem()]
+}
diff --git a/vendor/github.com/golang/protobuf/proto/lib.go b/vendor/github.com/golang/protobuf/proto/lib.go
new file mode 100644
index 00000000..ac4ddbc0
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/lib.go
@@ -0,0 +1,898 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+/*
+Package proto converts data structures to and from the wire format of
+protocol buffers.  It works in concert with the Go source code generated
+for .proto files by the protocol compiler.
+
+A summary of the properties of the protocol buffer interface
+for a protocol buffer variable v:
+
+  - Names are turned from camel_case to CamelCase for export.
+  - There are no methods on v to set fields; just treat
+	them as structure fields.
+  - There are getters that return a field's value if set,
+	and return the field's default value if unset.
+	The getters work even if the receiver is a nil message.
+  - The zero value for a struct is its correct initialization state.
+	All desired fields must be set before marshaling.
+  - A Reset() method will restore a protobuf struct to its zero state.
+  - Non-repeated fields are pointers to the values; nil means unset.
+	That is, optional or required field int32 f becomes F *int32.
+  - Repeated fields are slices.
+  - Helper functions are available to aid the setting of fields.
+	msg.Foo = proto.String("hello") // set field
+  - Constants are defined to hold the default values of all fields that
+	have them.  They have the form Default_StructName_FieldName.
+	Because the getter methods handle defaulted values,
+	direct use of these constants should be rare.
+  - Enums are given type names and maps from names to values.
+	Enum values are prefixed by the enclosing message's name, or by the
+	enum's type name if it is a top-level enum. Enum types have a String
+	method, and a Enum method to assist in message construction.
+  - Nested messages, groups and enums have type names prefixed with the name of
+	the surrounding message type.
+  - Extensions are given descriptor names that start with E_,
+	followed by an underscore-delimited list of the nested messages
+	that contain it (if any) followed by the CamelCased name of the
+	extension field itself.  HasExtension, ClearExtension, GetExtension
+	and SetExtension are functions for manipulating extensions.
+  - Oneof field sets are given a single field in their message,
+	with distinguished wrapper types for each possible field value.
+  - Marshal and Unmarshal are functions to encode and decode the wire format.
+
+When the .proto file specifies `syntax="proto3"`, there are some differences:
+
+  - Non-repeated fields of non-message type are values instead of pointers.
+  - Getters are only generated for message and oneof fields.
+  - Enum types do not get an Enum method.
+
+The simplest way to describe this is to see an example.
+Given file test.proto, containing
+
+	package example;
+
+	enum FOO { X = 17; }
+
+	message Test {
+	  required string label = 1;
+	  optional int32 type = 2 [default=77];
+	  repeated int64 reps = 3;
+	  optional group OptionalGroup = 4 {
+	    required string RequiredField = 5;
+	  }
+	  oneof union {
+	    int32 number = 6;
+	    string name = 7;
+	  }
+	}
+
+The resulting file, test.pb.go, is:
+
+	package example
+
+	import proto "github.com/golang/protobuf/proto"
+	import math "math"
+
+	type FOO int32
+	const (
+		FOO_X FOO = 17
+	)
+	var FOO_name = map[int32]string{
+		17: "X",
+	}
+	var FOO_value = map[string]int32{
+		"X": 17,
+	}
+
+	func (x FOO) Enum() *FOO {
+		p := new(FOO)
+		*p = x
+		return p
+	}
+	func (x FOO) String() string {
+		return proto.EnumName(FOO_name, int32(x))
+	}
+	func (x *FOO) UnmarshalJSON(data []byte) error {
+		value, err := proto.UnmarshalJSONEnum(FOO_value, data)
+		if err != nil {
+			return err
+		}
+		*x = FOO(value)
+		return nil
+	}
+
+	type Test struct {
+		Label         *string             `protobuf:"bytes,1,req,name=label" json:"label,omitempty"`
+		Type          *int32              `protobuf:"varint,2,opt,name=type,def=77" json:"type,omitempty"`
+		Reps          []int64             `protobuf:"varint,3,rep,name=reps" json:"reps,omitempty"`
+		Optionalgroup *Test_OptionalGroup `protobuf:"group,4,opt,name=OptionalGroup" json:"optionalgroup,omitempty"`
+		// Types that are valid to be assigned to Union:
+		//	*Test_Number
+		//	*Test_Name
+		Union            isTest_Union `protobuf_oneof:"union"`
+		XXX_unrecognized []byte       `json:"-"`
+	}
+	func (m *Test) Reset()         { *m = Test{} }
+	func (m *Test) String() string { return proto.CompactTextString(m) }
+	func (*Test) ProtoMessage() {}
+
+	type isTest_Union interface {
+		isTest_Union()
+	}
+
+	type Test_Number struct {
+		Number int32 `protobuf:"varint,6,opt,name=number"`
+	}
+	type Test_Name struct {
+		Name string `protobuf:"bytes,7,opt,name=name"`
+	}
+
+	func (*Test_Number) isTest_Union() {}
+	func (*Test_Name) isTest_Union()   {}
+
+	func (m *Test) GetUnion() isTest_Union {
+		if m != nil {
+			return m.Union
+		}
+		return nil
+	}
+	const Default_Test_Type int32 = 77
+
+	func (m *Test) GetLabel() string {
+		if m != nil && m.Label != nil {
+			return *m.Label
+		}
+		return ""
+	}
+
+	func (m *Test) GetType() int32 {
+		if m != nil && m.Type != nil {
+			return *m.Type
+		}
+		return Default_Test_Type
+	}
+
+	func (m *Test) GetOptionalgroup() *Test_OptionalGroup {
+		if m != nil {
+			return m.Optionalgroup
+		}
+		return nil
+	}
+
+	type Test_OptionalGroup struct {
+		RequiredField *string `protobuf:"bytes,5,req" json:"RequiredField,omitempty"`
+	}
+	func (m *Test_OptionalGroup) Reset()         { *m = Test_OptionalGroup{} }
+	func (m *Test_OptionalGroup) String() string { return proto.CompactTextString(m) }
+
+	func (m *Test_OptionalGroup) GetRequiredField() string {
+		if m != nil && m.RequiredField != nil {
+			return *m.RequiredField
+		}
+		return ""
+	}
+
+	func (m *Test) GetNumber() int32 {
+		if x, ok := m.GetUnion().(*Test_Number); ok {
+			return x.Number
+		}
+		return 0
+	}
+
+	func (m *Test) GetName() string {
+		if x, ok := m.GetUnion().(*Test_Name); ok {
+			return x.Name
+		}
+		return ""
+	}
+
+	func init() {
+		proto.RegisterEnum("example.FOO", FOO_name, FOO_value)
+	}
+
+To create and play with a Test object:
+
+	package main
+
+	import (
+		"log"
+
+		"github.com/golang/protobuf/proto"
+		pb "./example.pb"
+	)
+
+	func main() {
+		test := &pb.Test{
+			Label: proto.String("hello"),
+			Type:  proto.Int32(17),
+			Reps:  []int64{1, 2, 3},
+			Optionalgroup: &pb.Test_OptionalGroup{
+				RequiredField: proto.String("good bye"),
+			},
+			Union: &pb.Test_Name{"fred"},
+		}
+		data, err := proto.Marshal(test)
+		if err != nil {
+			log.Fatal("marshaling error: ", err)
+		}
+		newTest := &pb.Test{}
+		err = proto.Unmarshal(data, newTest)
+		if err != nil {
+			log.Fatal("unmarshaling error: ", err)
+		}
+		// Now test and newTest contain the same data.
+		if test.GetLabel() != newTest.GetLabel() {
+			log.Fatalf("data mismatch %q != %q", test.GetLabel(), newTest.GetLabel())
+		}
+		// Use a type switch to determine which oneof was set.
+		switch u := test.Union.(type) {
+		case *pb.Test_Number: // u.Number contains the number.
+		case *pb.Test_Name: // u.Name contains the string.
+		}
+		// etc.
+	}
+*/
+package proto
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"reflect"
+	"sort"
+	"strconv"
+	"sync"
+)
+
+// Message is implemented by generated protocol buffer messages.
+type Message interface {
+	Reset()
+	String() string
+	ProtoMessage()
+}
+
+// Stats records allocation details about the protocol buffer encoders
+// and decoders.  Useful for tuning the library itself.
+type Stats struct {
+	Emalloc uint64 // mallocs in encode
+	Dmalloc uint64 // mallocs in decode
+	Encode  uint64 // number of encodes
+	Decode  uint64 // number of decodes
+	Chit    uint64 // number of cache hits
+	Cmiss   uint64 // number of cache misses
+	Size    uint64 // number of sizes
+}
+
+// Set to true to enable stats collection.
+const collectStats = false
+
+var stats Stats
+
+// GetStats returns a copy of the global Stats structure.
+func GetStats() Stats { return stats }
+
+// A Buffer is a buffer manager for marshaling and unmarshaling
+// protocol buffers.  It may be reused between invocations to
+// reduce memory usage.  It is not necessary to use a Buffer;
+// the global functions Marshal and Unmarshal create a
+// temporary Buffer and are fine for most applications.
+type Buffer struct {
+	buf   []byte // encode/decode byte stream
+	index int    // read point
+
+	// pools of basic types to amortize allocation.
+	bools   []bool
+	uint32s []uint32
+	uint64s []uint64
+
+	// extra pools, only used with pointer_reflect.go
+	int32s   []int32
+	int64s   []int64
+	float32s []float32
+	float64s []float64
+}
+
+// NewBuffer allocates a new Buffer and initializes its internal data to
+// the contents of the argument slice.
+func NewBuffer(e []byte) *Buffer {
+	return &Buffer{buf: e}
+}
+
+// Reset resets the Buffer, ready for marshaling a new protocol buffer.
+func (p *Buffer) Reset() {
+	p.buf = p.buf[0:0] // for reading/writing
+	p.index = 0        // for reading
+}
+
+// SetBuf replaces the internal buffer with the slice,
+// ready for unmarshaling the contents of the slice.
+func (p *Buffer) SetBuf(s []byte) {
+	p.buf = s
+	p.index = 0
+}
+
+// Bytes returns the contents of the Buffer.
+func (p *Buffer) Bytes() []byte { return p.buf }
+
+/*
+ * Helper routines for simplifying the creation of optional fields of basic type.
+ */
+
+// Bool is a helper routine that allocates a new bool value
+// to store v and returns a pointer to it.
+func Bool(v bool) *bool {
+	return &v
+}
+
+// Int32 is a helper routine that allocates a new int32 value
+// to store v and returns a pointer to it.
+func Int32(v int32) *int32 {
+	return &v
+}
+
+// Int is a helper routine that allocates a new int32 value
+// to store v and returns a pointer to it, but unlike Int32
+// its argument value is an int.
+func Int(v int) *int32 {
+	p := new(int32)
+	*p = int32(v)
+	return p
+}
+
+// Int64 is a helper routine that allocates a new int64 value
+// to store v and returns a pointer to it.
+func Int64(v int64) *int64 {
+	return &v
+}
+
+// Float32 is a helper routine that allocates a new float32 value
+// to store v and returns a pointer to it.
+func Float32(v float32) *float32 {
+	return &v
+}
+
+// Float64 is a helper routine that allocates a new float64 value
+// to store v and returns a pointer to it.
+func Float64(v float64) *float64 {
+	return &v
+}
+
+// Uint32 is a helper routine that allocates a new uint32 value
+// to store v and returns a pointer to it.
+func Uint32(v uint32) *uint32 {
+	return &v
+}
+
+// Uint64 is a helper routine that allocates a new uint64 value
+// to store v and returns a pointer to it.
+func Uint64(v uint64) *uint64 {
+	return &v
+}
+
+// String is a helper routine that allocates a new string value
+// to store v and returns a pointer to it.
+func String(v string) *string {
+	return &v
+}
+
+// EnumName is a helper function to simplify printing protocol buffer enums
+// by name.  Given an enum map and a value, it returns a useful string.
+func EnumName(m map[int32]string, v int32) string {
+	s, ok := m[v]
+	if ok {
+		return s
+	}
+	return strconv.Itoa(int(v))
+}
+
+// UnmarshalJSONEnum is a helper function to simplify recovering enum int values
+// from their JSON-encoded representation. Given a map from the enum's symbolic
+// names to its int values, and a byte buffer containing the JSON-encoded
+// value, it returns an int32 that can be cast to the enum type by the caller.
+//
+// The function can deal with both JSON representations, numeric and symbolic.
+func UnmarshalJSONEnum(m map[string]int32, data []byte, enumName string) (int32, error) {
+	if data[0] == '"' {
+		// New style: enums are strings.
+		var repr string
+		if err := json.Unmarshal(data, &repr); err != nil {
+			return -1, err
+		}
+		val, ok := m[repr]
+		if !ok {
+			return 0, fmt.Errorf("unrecognized enum %s value %q", enumName, repr)
+		}
+		return val, nil
+	}
+	// Old style: enums are ints.
+	var val int32
+	if err := json.Unmarshal(data, &val); err != nil {
+		return 0, fmt.Errorf("cannot unmarshal %#q into enum %s", data, enumName)
+	}
+	return val, nil
+}
+
+// DebugPrint dumps the encoded data in b in a debugging format with a header
+// including the string s. Used in testing but made available for general debugging.
+func (p *Buffer) DebugPrint(s string, b []byte) {
+	var u uint64
+
+	obuf := p.buf
+	index := p.index
+	p.buf = b
+	p.index = 0
+	depth := 0
+
+	fmt.Printf("\n--- %s ---\n", s)
+
+out:
+	for {
+		for i := 0; i < depth; i++ {
+			fmt.Print("  ")
+		}
+
+		index := p.index
+		if index == len(p.buf) {
+			break
+		}
+
+		op, err := p.DecodeVarint()
+		if err != nil {
+			fmt.Printf("%3d: fetching op err %v\n", index, err)
+			break out
+		}
+		tag := op >> 3
+		wire := op & 7
+
+		switch wire {
+		default:
+			fmt.Printf("%3d: t=%3d unknown wire=%d\n",
+				index, tag, wire)
+			break out
+
+		case WireBytes:
+			var r []byte
+
+			r, err = p.DecodeRawBytes(false)
+			if err != nil {
+				break out
+			}
+			fmt.Printf("%3d: t=%3d bytes [%d]", index, tag, len(r))
+			if len(r) <= 6 {
+				for i := 0; i < len(r); i++ {
+					fmt.Printf(" %.2x", r[i])
+				}
+			} else {
+				for i := 0; i < 3; i++ {
+					fmt.Printf(" %.2x", r[i])
+				}
+				fmt.Printf(" ..")
+				for i := len(r) - 3; i < len(r); i++ {
+					fmt.Printf(" %.2x", r[i])
+				}
+			}
+			fmt.Printf("\n")
+
+		case WireFixed32:
+			u, err = p.DecodeFixed32()
+			if err != nil {
+				fmt.Printf("%3d: t=%3d fix32 err %v\n", index, tag, err)
+				break out
+			}
+			fmt.Printf("%3d: t=%3d fix32 %d\n", index, tag, u)
+
+		case WireFixed64:
+			u, err = p.DecodeFixed64()
+			if err != nil {
+				fmt.Printf("%3d: t=%3d fix64 err %v\n", index, tag, err)
+				break out
+			}
+			fmt.Printf("%3d: t=%3d fix64 %d\n", index, tag, u)
+
+		case WireVarint:
+			u, err = p.DecodeVarint()
+			if err != nil {
+				fmt.Printf("%3d: t=%3d varint err %v\n", index, tag, err)
+				break out
+			}
+			fmt.Printf("%3d: t=%3d varint %d\n", index, tag, u)
+
+		case WireStartGroup:
+			fmt.Printf("%3d: t=%3d start\n", index, tag)
+			depth++
+
+		case WireEndGroup:
+			depth--
+			fmt.Printf("%3d: t=%3d end\n", index, tag)
+		}
+	}
+
+	if depth != 0 {
+		fmt.Printf("%3d: start-end not balanced %d\n", p.index, depth)
+	}
+	fmt.Printf("\n")
+
+	p.buf = obuf
+	p.index = index
+}
+
+// SetDefaults sets unset protocol buffer fields to their default values.
+// It only modifies fields that are both unset and have defined defaults.
+// It recursively sets default values in any non-nil sub-messages.
+func SetDefaults(pb Message) {
+	setDefaults(reflect.ValueOf(pb), true, false)
+}
+
+// v is a pointer to a struct.
+func setDefaults(v reflect.Value, recur, zeros bool) {
+	v = v.Elem()
+
+	defaultMu.RLock()
+	dm, ok := defaults[v.Type()]
+	defaultMu.RUnlock()
+	if !ok {
+		dm = buildDefaultMessage(v.Type())
+		defaultMu.Lock()
+		defaults[v.Type()] = dm
+		defaultMu.Unlock()
+	}
+
+	for _, sf := range dm.scalars {
+		f := v.Field(sf.index)
+		if !f.IsNil() {
+			// field already set
+			continue
+		}
+		dv := sf.value
+		if dv == nil && !zeros {
+			// no explicit default, and don't want to set zeros
+			continue
+		}
+		fptr := f.Addr().Interface() // **T
+		// TODO: Consider batching the allocations we do here.
+		switch sf.kind {
+		case reflect.Bool:
+			b := new(bool)
+			if dv != nil {
+				*b = dv.(bool)
+			}
+			*(fptr.(**bool)) = b
+		case reflect.Float32:
+			f := new(float32)
+			if dv != nil {
+				*f = dv.(float32)
+			}
+			*(fptr.(**float32)) = f
+		case reflect.Float64:
+			f := new(float64)
+			if dv != nil {
+				*f = dv.(float64)
+			}
+			*(fptr.(**float64)) = f
+		case reflect.Int32:
+			// might be an enum
+			if ft := f.Type(); ft != int32PtrType {
+				// enum
+				f.Set(reflect.New(ft.Elem()))
+				if dv != nil {
+					f.Elem().SetInt(int64(dv.(int32)))
+				}
+			} else {
+				// int32 field
+				i := new(int32)
+				if dv != nil {
+					*i = dv.(int32)
+				}
+				*(fptr.(**int32)) = i
+			}
+		case reflect.Int64:
+			i := new(int64)
+			if dv != nil {
+				*i = dv.(int64)
+			}
+			*(fptr.(**int64)) = i
+		case reflect.String:
+			s := new(string)
+			if dv != nil {
+				*s = dv.(string)
+			}
+			*(fptr.(**string)) = s
+		case reflect.Uint8:
+			// exceptional case: []byte
+			var b []byte
+			if dv != nil {
+				db := dv.([]byte)
+				b = make([]byte, len(db))
+				copy(b, db)
+			} else {
+				b = []byte{}
+			}
+			*(fptr.(*[]byte)) = b
+		case reflect.Uint32:
+			u := new(uint32)
+			if dv != nil {
+				*u = dv.(uint32)
+			}
+			*(fptr.(**uint32)) = u
+		case reflect.Uint64:
+			u := new(uint64)
+			if dv != nil {
+				*u = dv.(uint64)
+			}
+			*(fptr.(**uint64)) = u
+		default:
+			log.Printf("proto: can't set default for field %v (sf.kind=%v)", f, sf.kind)
+		}
+	}
+
+	for _, ni := range dm.nested {
+		f := v.Field(ni)
+		// f is *T or []*T or map[T]*T
+		switch f.Kind() {
+		case reflect.Ptr:
+			if f.IsNil() {
+				continue
+			}
+			setDefaults(f, recur, zeros)
+
+		case reflect.Slice:
+			for i := 0; i < f.Len(); i++ {
+				e := f.Index(i)
+				if e.IsNil() {
+					continue
+				}
+				setDefaults(e, recur, zeros)
+			}
+
+		case reflect.Map:
+			for _, k := range f.MapKeys() {
+				e := f.MapIndex(k)
+				if e.IsNil() {
+					continue
+				}
+				setDefaults(e, recur, zeros)
+			}
+		}
+	}
+}
+
+var (
+	// defaults maps a protocol buffer struct type to a slice of the fields,
+	// with its scalar fields set to their proto-declared non-zero default values.
+	defaultMu sync.RWMutex
+	defaults  = make(map[reflect.Type]defaultMessage)
+
+	int32PtrType = reflect.TypeOf((*int32)(nil))
+)
+
+// defaultMessage represents information about the default values of a message.
+type defaultMessage struct {
+	scalars []scalarField
+	nested  []int // struct field index of nested messages
+}
+
+type scalarField struct {
+	index int          // struct field index
+	kind  reflect.Kind // element type (the T in *T or []T)
+	value interface{}  // the proto-declared default value, or nil
+}
+
+// t is a struct type.
+func buildDefaultMessage(t reflect.Type) (dm defaultMessage) {
+	sprop := GetProperties(t)
+	for _, prop := range sprop.Prop {
+		fi, ok := sprop.decoderTags.get(prop.Tag)
+		if !ok {
+			// XXX_unrecognized
+			continue
+		}
+		ft := t.Field(fi).Type
+
+		sf, nested, err := fieldDefault(ft, prop)
+		switch {
+		case err != nil:
+			log.Print(err)
+		case nested:
+			dm.nested = append(dm.nested, fi)
+		case sf != nil:
+			sf.index = fi
+			dm.scalars = append(dm.scalars, *sf)
+		}
+	}
+
+	return dm
+}
+
+// fieldDefault returns the scalarField for field type ft.
+// sf will be nil if the field can not have a default.
+// nestedMessage will be true if this is a nested message.
+// Note that sf.index is not set on return.
+func fieldDefault(ft reflect.Type, prop *Properties) (sf *scalarField, nestedMessage bool, err error) {
+	var canHaveDefault bool
+	switch ft.Kind() {
+	case reflect.Ptr:
+		if ft.Elem().Kind() == reflect.Struct {
+			nestedMessage = true
+		} else {
+			canHaveDefault = true // proto2 scalar field
+		}
+
+	case reflect.Slice:
+		switch ft.Elem().Kind() {
+		case reflect.Ptr:
+			nestedMessage = true // repeated message
+		case reflect.Uint8:
+			canHaveDefault = true // bytes field
+		}
+
+	case reflect.Map:
+		if ft.Elem().Kind() == reflect.Ptr {
+			nestedMessage = true // map with message values
+		}
+	}
+
+	if !canHaveDefault {
+		if nestedMessage {
+			return nil, true, nil
+		}
+		return nil, false, nil
+	}
+
+	// We now know that ft is a pointer or slice.
+	sf = &scalarField{kind: ft.Elem().Kind()}
+
+	// scalar fields without defaults
+	if !prop.HasDefault {
+		return sf, false, nil
+	}
+
+	// a scalar field: either *T or []byte
+	switch ft.Elem().Kind() {
+	case reflect.Bool:
+		x, err := strconv.ParseBool(prop.Default)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default bool %q: %v", prop.Default, err)
+		}
+		sf.value = x
+	case reflect.Float32:
+		x, err := strconv.ParseFloat(prop.Default, 32)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default float32 %q: %v", prop.Default, err)
+		}
+		sf.value = float32(x)
+	case reflect.Float64:
+		x, err := strconv.ParseFloat(prop.Default, 64)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default float64 %q: %v", prop.Default, err)
+		}
+		sf.value = x
+	case reflect.Int32:
+		x, err := strconv.ParseInt(prop.Default, 10, 32)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default int32 %q: %v", prop.Default, err)
+		}
+		sf.value = int32(x)
+	case reflect.Int64:
+		x, err := strconv.ParseInt(prop.Default, 10, 64)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default int64 %q: %v", prop.Default, err)
+		}
+		sf.value = x
+	case reflect.String:
+		sf.value = prop.Default
+	case reflect.Uint8:
+		// []byte (not *uint8)
+		sf.value = []byte(prop.Default)
+	case reflect.Uint32:
+		x, err := strconv.ParseUint(prop.Default, 10, 32)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default uint32 %q: %v", prop.Default, err)
+		}
+		sf.value = uint32(x)
+	case reflect.Uint64:
+		x, err := strconv.ParseUint(prop.Default, 10, 64)
+		if err != nil {
+			return nil, false, fmt.Errorf("proto: bad default uint64 %q: %v", prop.Default, err)
+		}
+		sf.value = x
+	default:
+		return nil, false, fmt.Errorf("proto: unhandled def kind %v", ft.Elem().Kind())
+	}
+
+	return sf, false, nil
+}
+
+// Map fields may have key types of non-float scalars, strings and enums.
+// The easiest way to sort them in some deterministic order is to use fmt.
+// If this turns out to be inefficient we can always consider other options,
+// such as doing a Schwartzian transform.
+
+func mapKeys(vs []reflect.Value) sort.Interface {
+	s := mapKeySorter{
+		vs: vs,
+		// default Less function: textual comparison
+		less: func(a, b reflect.Value) bool {
+			return fmt.Sprint(a.Interface()) < fmt.Sprint(b.Interface())
+		},
+	}
+
+	// Type specialization per https://developers.google.com/protocol-buffers/docs/proto#maps;
+	// numeric keys are sorted numerically.
+	if len(vs) == 0 {
+		return s
+	}
+	switch vs[0].Kind() {
+	case reflect.Int32, reflect.Int64:
+		s.less = func(a, b reflect.Value) bool { return a.Int() < b.Int() }
+	case reflect.Uint32, reflect.Uint64:
+		s.less = func(a, b reflect.Value) bool { return a.Uint() < b.Uint() }
+	}
+
+	return s
+}
+
+type mapKeySorter struct {
+	vs   []reflect.Value
+	less func(a, b reflect.Value) bool
+}
+
+func (s mapKeySorter) Len() int      { return len(s.vs) }
+func (s mapKeySorter) Swap(i, j int) { s.vs[i], s.vs[j] = s.vs[j], s.vs[i] }
+func (s mapKeySorter) Less(i, j int) bool {
+	return s.less(s.vs[i], s.vs[j])
+}
+
+// isProto3Zero reports whether v is a zero proto3 value.
+func isProto3Zero(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.Bool:
+		return !v.Bool()
+	case reflect.Int32, reflect.Int64:
+		return v.Int() == 0
+	case reflect.Uint32, reflect.Uint64:
+		return v.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return v.Float() == 0
+	case reflect.String:
+		return v.String() == ""
+	}
+	return false
+}
+
+// ProtoPackageIsVersion2 is referenced from generated protocol buffer files
+// to assert that that code is compatible with this version of the proto package.
+const ProtoPackageIsVersion2 = true
+
+// ProtoPackageIsVersion1 is referenced from generated protocol buffer files
+// to assert that that code is compatible with this version of the proto package.
+const ProtoPackageIsVersion1 = true
diff --git a/vendor/github.com/golang/protobuf/proto/message_set.go b/vendor/github.com/golang/protobuf/proto/message_set.go
new file mode 100644
index 00000000..fd982dec
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/message_set.go
@@ -0,0 +1,311 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+/*
+ * Support for message sets.
+ */
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"reflect"
+	"sort"
+)
+
+// errNoMessageTypeID occurs when a protocol buffer does not have a message type ID.
+// A message type ID is required for storing a protocol buffer in a message set.
+var errNoMessageTypeID = errors.New("proto does not have a message type ID")
+
+// The first two types (_MessageSet_Item and messageSet)
+// model what the protocol compiler produces for the following protocol message:
+//   message MessageSet {
+//     repeated group Item = 1 {
+//       required int32 type_id = 2;
+//       required string message = 3;
+//     };
+//   }
+// That is the MessageSet wire format. We can't use a proto to generate these
+// because that would introduce a circular dependency between it and this package.
+
+type _MessageSet_Item struct {
+	TypeId  *int32 `protobuf:"varint,2,req,name=type_id"`
+	Message []byte `protobuf:"bytes,3,req,name=message"`
+}
+
+type messageSet struct {
+	Item             []*_MessageSet_Item `protobuf:"group,1,rep"`
+	XXX_unrecognized []byte
+	// TODO: caching?
+}
+
+// Make sure messageSet is a Message.
+var _ Message = (*messageSet)(nil)
+
+// messageTypeIder is an interface satisfied by a protocol buffer type
+// that may be stored in a MessageSet.
+type messageTypeIder interface {
+	MessageTypeId() int32
+}
+
+func (ms *messageSet) find(pb Message) *_MessageSet_Item {
+	mti, ok := pb.(messageTypeIder)
+	if !ok {
+		return nil
+	}
+	id := mti.MessageTypeId()
+	for _, item := range ms.Item {
+		if *item.TypeId == id {
+			return item
+		}
+	}
+	return nil
+}
+
+func (ms *messageSet) Has(pb Message) bool {
+	if ms.find(pb) != nil {
+		return true
+	}
+	return false
+}
+
+func (ms *messageSet) Unmarshal(pb Message) error {
+	if item := ms.find(pb); item != nil {
+		return Unmarshal(item.Message, pb)
+	}
+	if _, ok := pb.(messageTypeIder); !ok {
+		return errNoMessageTypeID
+	}
+	return nil // TODO: return error instead?
+}
+
+func (ms *messageSet) Marshal(pb Message) error {
+	msg, err := Marshal(pb)
+	if err != nil {
+		return err
+	}
+	if item := ms.find(pb); item != nil {
+		// reuse existing item
+		item.Message = msg
+		return nil
+	}
+
+	mti, ok := pb.(messageTypeIder)
+	if !ok {
+		return errNoMessageTypeID
+	}
+
+	mtid := mti.MessageTypeId()
+	ms.Item = append(ms.Item, &_MessageSet_Item{
+		TypeId:  &mtid,
+		Message: msg,
+	})
+	return nil
+}
+
+func (ms *messageSet) Reset()         { *ms = messageSet{} }
+func (ms *messageSet) String() string { return CompactTextString(ms) }
+func (*messageSet) ProtoMessage()     {}
+
+// Support for the message_set_wire_format message option.
+
+func skipVarint(buf []byte) []byte {
+	i := 0
+	for ; buf[i]&0x80 != 0; i++ {
+	}
+	return buf[i+1:]
+}
+
+// MarshalMessageSet encodes the extension map represented by m in the message set wire format.
+// It is called by generated Marshal methods on protocol buffer messages with the message_set_wire_format option.
+func MarshalMessageSet(exts interface{}) ([]byte, error) {
+	var m map[int32]Extension
+	switch exts := exts.(type) {
+	case *XXX_InternalExtensions:
+		if err := encodeExtensions(exts); err != nil {
+			return nil, err
+		}
+		m, _ = exts.extensionsRead()
+	case map[int32]Extension:
+		if err := encodeExtensionsMap(exts); err != nil {
+			return nil, err
+		}
+		m = exts
+	default:
+		return nil, errors.New("proto: not an extension map")
+	}
+
+	// Sort extension IDs to provide a deterministic encoding.
+	// See also enc_map in encode.go.
+	ids := make([]int, 0, len(m))
+	for id := range m {
+		ids = append(ids, int(id))
+	}
+	sort.Ints(ids)
+
+	ms := &messageSet{Item: make([]*_MessageSet_Item, 0, len(m))}
+	for _, id := range ids {
+		e := m[int32(id)]
+		// Remove the wire type and field number varint, as well as the length varint.
+		msg := skipVarint(skipVarint(e.enc))
+
+		ms.Item = append(ms.Item, &_MessageSet_Item{
+			TypeId:  Int32(int32(id)),
+			Message: msg,
+		})
+	}
+	return Marshal(ms)
+}
+
+// UnmarshalMessageSet decodes the extension map encoded in buf in the message set wire format.
+// It is called by generated Unmarshal methods on protocol buffer messages with the message_set_wire_format option.
+func UnmarshalMessageSet(buf []byte, exts interface{}) error {
+	var m map[int32]Extension
+	switch exts := exts.(type) {
+	case *XXX_InternalExtensions:
+		m = exts.extensionsWrite()
+	case map[int32]Extension:
+		m = exts
+	default:
+		return errors.New("proto: not an extension map")
+	}
+
+	ms := new(messageSet)
+	if err := Unmarshal(buf, ms); err != nil {
+		return err
+	}
+	for _, item := range ms.Item {
+		id := *item.TypeId
+		msg := item.Message
+
+		// Restore wire type and field number varint, plus length varint.
+		// Be careful to preserve duplicate items.
+		b := EncodeVarint(uint64(id)<<3 | WireBytes)
+		if ext, ok := m[id]; ok {
+			// Existing data; rip off the tag and length varint
+			// so we join the new data correctly.
+			// We can assume that ext.enc is set because we are unmarshaling.
+			o := ext.enc[len(b):]   // skip wire type and field number
+			_, n := DecodeVarint(o) // calculate length of length varint
+			o = o[n:]               // skip length varint
+			msg = append(o, msg...) // join old data and new data
+		}
+		b = append(b, EncodeVarint(uint64(len(msg)))...)
+		b = append(b, msg...)
+
+		m[id] = Extension{enc: b}
+	}
+	return nil
+}
+
+// MarshalMessageSetJSON encodes the extension map represented by m in JSON format.
+// It is called by generated MarshalJSON methods on protocol buffer messages with the message_set_wire_format option.
+func MarshalMessageSetJSON(exts interface{}) ([]byte, error) {
+	var m map[int32]Extension
+	switch exts := exts.(type) {
+	case *XXX_InternalExtensions:
+		m, _ = exts.extensionsRead()
+	case map[int32]Extension:
+		m = exts
+	default:
+		return nil, errors.New("proto: not an extension map")
+	}
+	var b bytes.Buffer
+	b.WriteByte('{')
+
+	// Process the map in key order for deterministic output.
+	ids := make([]int32, 0, len(m))
+	for id := range m {
+		ids = append(ids, id)
+	}
+	sort.Sort(int32Slice(ids)) // int32Slice defined in text.go
+
+	for i, id := range ids {
+		ext := m[id]
+		if i > 0 {
+			b.WriteByte(',')
+		}
+
+		msd, ok := messageSetMap[id]
+		if !ok {
+			// Unknown type; we can't render it, so skip it.
+			continue
+		}
+		fmt.Fprintf(&b, `"[%s]":`, msd.name)
+
+		x := ext.value
+		if x == nil {
+			x = reflect.New(msd.t.Elem()).Interface()
+			if err := Unmarshal(ext.enc, x.(Message)); err != nil {
+				return nil, err
+			}
+		}
+		d, err := json.Marshal(x)
+		if err != nil {
+			return nil, err
+		}
+		b.Write(d)
+	}
+	b.WriteByte('}')
+	return b.Bytes(), nil
+}
+
+// UnmarshalMessageSetJSON decodes the extension map encoded in buf in JSON format.
+// It is called by generated UnmarshalJSON methods on protocol buffer messages with the message_set_wire_format option.
+func UnmarshalMessageSetJSON(buf []byte, exts interface{}) error {
+	// Common-case fast path.
+	if len(buf) == 0 || bytes.Equal(buf, []byte("{}")) {
+		return nil
+	}
+
+	// This is fairly tricky, and it's not clear that it is needed.
+	return errors.New("TODO: UnmarshalMessageSetJSON not yet implemented")
+}
+
+// A global registry of types that can be used in a MessageSet.
+
+var messageSetMap = make(map[int32]messageSetDesc)
+
+type messageSetDesc struct {
+	t    reflect.Type // pointer to struct
+	name string
+}
+
+// RegisterMessageSetType is called from the generated code.
+func RegisterMessageSetType(m Message, fieldNum int32, name string) {
+	messageSetMap[fieldNum] = messageSetDesc{
+		t:    reflect.TypeOf(m),
+		name: name,
+	}
+}
diff --git a/vendor/github.com/golang/protobuf/proto/pointer_reflect.go b/vendor/github.com/golang/protobuf/proto/pointer_reflect.go
new file mode 100644
index 00000000..fb512e2e
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/pointer_reflect.go
@@ -0,0 +1,484 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2012 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// +build appengine js
+
+// This file contains an implementation of proto field accesses using package reflect.
+// It is slower than the code in pointer_unsafe.go but it avoids package unsafe and can
+// be used on App Engine.
+
+package proto
+
+import (
+	"math"
+	"reflect"
+)
+
+// A structPointer is a pointer to a struct.
+type structPointer struct {
+	v reflect.Value
+}
+
+// toStructPointer returns a structPointer equivalent to the given reflect value.
+// The reflect value must itself be a pointer to a struct.
+func toStructPointer(v reflect.Value) structPointer {
+	return structPointer{v}
+}
+
+// IsNil reports whether p is nil.
+func structPointer_IsNil(p structPointer) bool {
+	return p.v.IsNil()
+}
+
+// Interface returns the struct pointer as an interface value.
+func structPointer_Interface(p structPointer, _ reflect.Type) interface{} {
+	return p.v.Interface()
+}
+
+// A field identifies a field in a struct, accessible from a structPointer.
+// In this implementation, a field is identified by the sequence of field indices
+// passed to reflect's FieldByIndex.
+type field []int
+
+// toField returns a field equivalent to the given reflect field.
+func toField(f *reflect.StructField) field {
+	return f.Index
+}
+
+// invalidField is an invalid field identifier.
+var invalidField = field(nil)
+
+// IsValid reports whether the field identifier is valid.
+func (f field) IsValid() bool { return f != nil }
+
+// field returns the given field in the struct as a reflect value.
+func structPointer_field(p structPointer, f field) reflect.Value {
+	// Special case: an extension map entry with a value of type T
+	// passes a *T to the struct-handling code with a zero field,
+	// expecting that it will be treated as equivalent to *struct{ X T },
+	// which has the same memory layout. We have to handle that case
+	// specially, because reflect will panic if we call FieldByIndex on a
+	// non-struct.
+	if f == nil {
+		return p.v.Elem()
+	}
+
+	return p.v.Elem().FieldByIndex(f)
+}
+
+// ifield returns the given field in the struct as an interface value.
+func structPointer_ifield(p structPointer, f field) interface{} {
+	return structPointer_field(p, f).Addr().Interface()
+}
+
+// Bytes returns the address of a []byte field in the struct.
+func structPointer_Bytes(p structPointer, f field) *[]byte {
+	return structPointer_ifield(p, f).(*[]byte)
+}
+
+// BytesSlice returns the address of a [][]byte field in the struct.
+func structPointer_BytesSlice(p structPointer, f field) *[][]byte {
+	return structPointer_ifield(p, f).(*[][]byte)
+}
+
+// Bool returns the address of a *bool field in the struct.
+func structPointer_Bool(p structPointer, f field) **bool {
+	return structPointer_ifield(p, f).(**bool)
+}
+
+// BoolVal returns the address of a bool field in the struct.
+func structPointer_BoolVal(p structPointer, f field) *bool {
+	return structPointer_ifield(p, f).(*bool)
+}
+
+// BoolSlice returns the address of a []bool field in the struct.
+func structPointer_BoolSlice(p structPointer, f field) *[]bool {
+	return structPointer_ifield(p, f).(*[]bool)
+}
+
+// String returns the address of a *string field in the struct.
+func structPointer_String(p structPointer, f field) **string {
+	return structPointer_ifield(p, f).(**string)
+}
+
+// StringVal returns the address of a string field in the struct.
+func structPointer_StringVal(p structPointer, f field) *string {
+	return structPointer_ifield(p, f).(*string)
+}
+
+// StringSlice returns the address of a []string field in the struct.
+func structPointer_StringSlice(p structPointer, f field) *[]string {
+	return structPointer_ifield(p, f).(*[]string)
+}
+
+// Extensions returns the address of an extension map field in the struct.
+func structPointer_Extensions(p structPointer, f field) *XXX_InternalExtensions {
+	return structPointer_ifield(p, f).(*XXX_InternalExtensions)
+}
+
+// ExtMap returns the address of an extension map field in the struct.
+func structPointer_ExtMap(p structPointer, f field) *map[int32]Extension {
+	return structPointer_ifield(p, f).(*map[int32]Extension)
+}
+
+// NewAt returns the reflect.Value for a pointer to a field in the struct.
+func structPointer_NewAt(p structPointer, f field, typ reflect.Type) reflect.Value {
+	return structPointer_field(p, f).Addr()
+}
+
+// SetStructPointer writes a *struct field in the struct.
+func structPointer_SetStructPointer(p structPointer, f field, q structPointer) {
+	structPointer_field(p, f).Set(q.v)
+}
+
+// GetStructPointer reads a *struct field in the struct.
+func structPointer_GetStructPointer(p structPointer, f field) structPointer {
+	return structPointer{structPointer_field(p, f)}
+}
+
+// StructPointerSlice the address of a []*struct field in the struct.
+func structPointer_StructPointerSlice(p structPointer, f field) structPointerSlice {
+	return structPointerSlice{structPointer_field(p, f)}
+}
+
+// A structPointerSlice represents the address of a slice of pointers to structs
+// (themselves messages or groups). That is, v.Type() is *[]*struct{...}.
+type structPointerSlice struct {
+	v reflect.Value
+}
+
+func (p structPointerSlice) Len() int                  { return p.v.Len() }
+func (p structPointerSlice) Index(i int) structPointer { return structPointer{p.v.Index(i)} }
+func (p structPointerSlice) Append(q structPointer) {
+	p.v.Set(reflect.Append(p.v, q.v))
+}
+
+var (
+	int32Type   = reflect.TypeOf(int32(0))
+	uint32Type  = reflect.TypeOf(uint32(0))
+	float32Type = reflect.TypeOf(float32(0))
+	int64Type   = reflect.TypeOf(int64(0))
+	uint64Type  = reflect.TypeOf(uint64(0))
+	float64Type = reflect.TypeOf(float64(0))
+)
+
+// A word32 represents a field of type *int32, *uint32, *float32, or *enum.
+// That is, v.Type() is *int32, *uint32, *float32, or *enum and v is assignable.
+type word32 struct {
+	v reflect.Value
+}
+
+// IsNil reports whether p is nil.
+func word32_IsNil(p word32) bool {
+	return p.v.IsNil()
+}
+
+// Set sets p to point at a newly allocated word with bits set to x.
+func word32_Set(p word32, o *Buffer, x uint32) {
+	t := p.v.Type().Elem()
+	switch t {
+	case int32Type:
+		if len(o.int32s) == 0 {
+			o.int32s = make([]int32, uint32PoolSize)
+		}
+		o.int32s[0] = int32(x)
+		p.v.Set(reflect.ValueOf(&o.int32s[0]))
+		o.int32s = o.int32s[1:]
+		return
+	case uint32Type:
+		if len(o.uint32s) == 0 {
+			o.uint32s = make([]uint32, uint32PoolSize)
+		}
+		o.uint32s[0] = x
+		p.v.Set(reflect.ValueOf(&o.uint32s[0]))
+		o.uint32s = o.uint32s[1:]
+		return
+	case float32Type:
+		if len(o.float32s) == 0 {
+			o.float32s = make([]float32, uint32PoolSize)
+		}
+		o.float32s[0] = math.Float32frombits(x)
+		p.v.Set(reflect.ValueOf(&o.float32s[0]))
+		o.float32s = o.float32s[1:]
+		return
+	}
+
+	// must be enum
+	p.v.Set(reflect.New(t))
+	p.v.Elem().SetInt(int64(int32(x)))
+}
+
+// Get gets the bits pointed at by p, as a uint32.
+func word32_Get(p word32) uint32 {
+	elem := p.v.Elem()
+	switch elem.Kind() {
+	case reflect.Int32:
+		return uint32(elem.Int())
+	case reflect.Uint32:
+		return uint32(elem.Uint())
+	case reflect.Float32:
+		return math.Float32bits(float32(elem.Float()))
+	}
+	panic("unreachable")
+}
+
+// Word32 returns a reference to a *int32, *uint32, *float32, or *enum field in the struct.
+func structPointer_Word32(p structPointer, f field) word32 {
+	return word32{structPointer_field(p, f)}
+}
+
+// A word32Val represents a field of type int32, uint32, float32, or enum.
+// That is, v.Type() is int32, uint32, float32, or enum and v is assignable.
+type word32Val struct {
+	v reflect.Value
+}
+
+// Set sets *p to x.
+func word32Val_Set(p word32Val, x uint32) {
+	switch p.v.Type() {
+	case int32Type:
+		p.v.SetInt(int64(x))
+		return
+	case uint32Type:
+		p.v.SetUint(uint64(x))
+		return
+	case float32Type:
+		p.v.SetFloat(float64(math.Float32frombits(x)))
+		return
+	}
+
+	// must be enum
+	p.v.SetInt(int64(int32(x)))
+}
+
+// Get gets the bits pointed at by p, as a uint32.
+func word32Val_Get(p word32Val) uint32 {
+	elem := p.v
+	switch elem.Kind() {
+	case reflect.Int32:
+		return uint32(elem.Int())
+	case reflect.Uint32:
+		return uint32(elem.Uint())
+	case reflect.Float32:
+		return math.Float32bits(float32(elem.Float()))
+	}
+	panic("unreachable")
+}
+
+// Word32Val returns a reference to a int32, uint32, float32, or enum field in the struct.
+func structPointer_Word32Val(p structPointer, f field) word32Val {
+	return word32Val{structPointer_field(p, f)}
+}
+
+// A word32Slice is a slice of 32-bit values.
+// That is, v.Type() is []int32, []uint32, []float32, or []enum.
+type word32Slice struct {
+	v reflect.Value
+}
+
+func (p word32Slice) Append(x uint32) {
+	n, m := p.v.Len(), p.v.Cap()
+	if n < m {
+		p.v.SetLen(n + 1)
+	} else {
+		t := p.v.Type().Elem()
+		p.v.Set(reflect.Append(p.v, reflect.Zero(t)))
+	}
+	elem := p.v.Index(n)
+	switch elem.Kind() {
+	case reflect.Int32:
+		elem.SetInt(int64(int32(x)))
+	case reflect.Uint32:
+		elem.SetUint(uint64(x))
+	case reflect.Float32:
+		elem.SetFloat(float64(math.Float32frombits(x)))
+	}
+}
+
+func (p word32Slice) Len() int {
+	return p.v.Len()
+}
+
+func (p word32Slice) Index(i int) uint32 {
+	elem := p.v.Index(i)
+	switch elem.Kind() {
+	case reflect.Int32:
+		return uint32(elem.Int())
+	case reflect.Uint32:
+		return uint32(elem.Uint())
+	case reflect.Float32:
+		return math.Float32bits(float32(elem.Float()))
+	}
+	panic("unreachable")
+}
+
+// Word32Slice returns a reference to a []int32, []uint32, []float32, or []enum field in the struct.
+func structPointer_Word32Slice(p structPointer, f field) word32Slice {
+	return word32Slice{structPointer_field(p, f)}
+}
+
+// word64 is like word32 but for 64-bit values.
+type word64 struct {
+	v reflect.Value
+}
+
+func word64_Set(p word64, o *Buffer, x uint64) {
+	t := p.v.Type().Elem()
+	switch t {
+	case int64Type:
+		if len(o.int64s) == 0 {
+			o.int64s = make([]int64, uint64PoolSize)
+		}
+		o.int64s[0] = int64(x)
+		p.v.Set(reflect.ValueOf(&o.int64s[0]))
+		o.int64s = o.int64s[1:]
+		return
+	case uint64Type:
+		if len(o.uint64s) == 0 {
+			o.uint64s = make([]uint64, uint64PoolSize)
+		}
+		o.uint64s[0] = x
+		p.v.Set(reflect.ValueOf(&o.uint64s[0]))
+		o.uint64s = o.uint64s[1:]
+		return
+	case float64Type:
+		if len(o.float64s) == 0 {
+			o.float64s = make([]float64, uint64PoolSize)
+		}
+		o.float64s[0] = math.Float64frombits(x)
+		p.v.Set(reflect.ValueOf(&o.float64s[0]))
+		o.float64s = o.float64s[1:]
+		return
+	}
+	panic("unreachable")
+}
+
+func word64_IsNil(p word64) bool {
+	return p.v.IsNil()
+}
+
+func word64_Get(p word64) uint64 {
+	elem := p.v.Elem()
+	switch elem.Kind() {
+	case reflect.Int64:
+		return uint64(elem.Int())
+	case reflect.Uint64:
+		return elem.Uint()
+	case reflect.Float64:
+		return math.Float64bits(elem.Float())
+	}
+	panic("unreachable")
+}
+
+func structPointer_Word64(p structPointer, f field) word64 {
+	return word64{structPointer_field(p, f)}
+}
+
+// word64Val is like word32Val but for 64-bit values.
+type word64Val struct {
+	v reflect.Value
+}
+
+func word64Val_Set(p word64Val, o *Buffer, x uint64) {
+	switch p.v.Type() {
+	case int64Type:
+		p.v.SetInt(int64(x))
+		return
+	case uint64Type:
+		p.v.SetUint(x)
+		return
+	case float64Type:
+		p.v.SetFloat(math.Float64frombits(x))
+		return
+	}
+	panic("unreachable")
+}
+
+func word64Val_Get(p word64Val) uint64 {
+	elem := p.v
+	switch elem.Kind() {
+	case reflect.Int64:
+		return uint64(elem.Int())
+	case reflect.Uint64:
+		return elem.Uint()
+	case reflect.Float64:
+		return math.Float64bits(elem.Float())
+	}
+	panic("unreachable")
+}
+
+func structPointer_Word64Val(p structPointer, f field) word64Val {
+	return word64Val{structPointer_field(p, f)}
+}
+
+type word64Slice struct {
+	v reflect.Value
+}
+
+func (p word64Slice) Append(x uint64) {
+	n, m := p.v.Len(), p.v.Cap()
+	if n < m {
+		p.v.SetLen(n + 1)
+	} else {
+		t := p.v.Type().Elem()
+		p.v.Set(reflect.Append(p.v, reflect.Zero(t)))
+	}
+	elem := p.v.Index(n)
+	switch elem.Kind() {
+	case reflect.Int64:
+		elem.SetInt(int64(int64(x)))
+	case reflect.Uint64:
+		elem.SetUint(uint64(x))
+	case reflect.Float64:
+		elem.SetFloat(float64(math.Float64frombits(x)))
+	}
+}
+
+func (p word64Slice) Len() int {
+	return p.v.Len()
+}
+
+func (p word64Slice) Index(i int) uint64 {
+	elem := p.v.Index(i)
+	switch elem.Kind() {
+	case reflect.Int64:
+		return uint64(elem.Int())
+	case reflect.Uint64:
+		return uint64(elem.Uint())
+	case reflect.Float64:
+		return math.Float64bits(float64(elem.Float()))
+	}
+	panic("unreachable")
+}
+
+func structPointer_Word64Slice(p structPointer, f field) word64Slice {
+	return word64Slice{structPointer_field(p, f)}
+}
diff --git a/vendor/github.com/golang/protobuf/proto/pointer_unsafe.go b/vendor/github.com/golang/protobuf/proto/pointer_unsafe.go
new file mode 100644
index 00000000..6b5567d4
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/pointer_unsafe.go
@@ -0,0 +1,270 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2012 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// +build !appengine,!js
+
+// This file contains the implementation of the proto field accesses using package unsafe.
+
+package proto
+
+import (
+	"reflect"
+	"unsafe"
+)
+
+// NOTE: These type_Foo functions would more idiomatically be methods,
+// but Go does not allow methods on pointer types, and we must preserve
+// some pointer type for the garbage collector. We use these
+// funcs with clunky names as our poor approximation to methods.
+//
+// An alternative would be
+//	type structPointer struct { p unsafe.Pointer }
+// but that does not registerize as well.
+
+// A structPointer is a pointer to a struct.
+type structPointer unsafe.Pointer
+
+// toStructPointer returns a structPointer equivalent to the given reflect value.
+func toStructPointer(v reflect.Value) structPointer {
+	return structPointer(unsafe.Pointer(v.Pointer()))
+}
+
+// IsNil reports whether p is nil.
+func structPointer_IsNil(p structPointer) bool {
+	return p == nil
+}
+
+// Interface returns the struct pointer, assumed to have element type t,
+// as an interface value.
+func structPointer_Interface(p structPointer, t reflect.Type) interface{} {
+	return reflect.NewAt(t, unsafe.Pointer(p)).Interface()
+}
+
+// A field identifies a field in a struct, accessible from a structPointer.
+// In this implementation, a field is identified by its byte offset from the start of the struct.
+type field uintptr
+
+// toField returns a field equivalent to the given reflect field.
+func toField(f *reflect.StructField) field {
+	return field(f.Offset)
+}
+
+// invalidField is an invalid field identifier.
+const invalidField = ^field(0)
+
+// IsValid reports whether the field identifier is valid.
+func (f field) IsValid() bool {
+	return f != ^field(0)
+}
+
+// Bytes returns the address of a []byte field in the struct.
+func structPointer_Bytes(p structPointer, f field) *[]byte {
+	return (*[]byte)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+// BytesSlice returns the address of a [][]byte field in the struct.
+func structPointer_BytesSlice(p structPointer, f field) *[][]byte {
+	return (*[][]byte)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+// Bool returns the address of a *bool field in the struct.
+func structPointer_Bool(p structPointer, f field) **bool {
+	return (**bool)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+// BoolVal returns the address of a bool field in the struct.
+func structPointer_BoolVal(p structPointer, f field) *bool {
+	return (*bool)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+// BoolSlice returns the address of a []bool field in the struct.
+func structPointer_BoolSlice(p structPointer, f field) *[]bool {
+	return (*[]bool)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+// String returns the address of a *string field in the struct.
+func structPointer_String(p structPointer, f field) **string {
+	return (**string)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+// StringVal returns the address of a string field in the struct.
+func structPointer_StringVal(p structPointer, f field) *string {
+	return (*string)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+// StringSlice returns the address of a []string field in the struct.
+func structPointer_StringSlice(p structPointer, f field) *[]string {
+	return (*[]string)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+// ExtMap returns the address of an extension map field in the struct.
+func structPointer_Extensions(p structPointer, f field) *XXX_InternalExtensions {
+	return (*XXX_InternalExtensions)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+func structPointer_ExtMap(p structPointer, f field) *map[int32]Extension {
+	return (*map[int32]Extension)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+// NewAt returns the reflect.Value for a pointer to a field in the struct.
+func structPointer_NewAt(p structPointer, f field, typ reflect.Type) reflect.Value {
+	return reflect.NewAt(typ, unsafe.Pointer(uintptr(p)+uintptr(f)))
+}
+
+// SetStructPointer writes a *struct field in the struct.
+func structPointer_SetStructPointer(p structPointer, f field, q structPointer) {
+	*(*structPointer)(unsafe.Pointer(uintptr(p) + uintptr(f))) = q
+}
+
+// GetStructPointer reads a *struct field in the struct.
+func structPointer_GetStructPointer(p structPointer, f field) structPointer {
+	return *(*structPointer)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+// StructPointerSlice the address of a []*struct field in the struct.
+func structPointer_StructPointerSlice(p structPointer, f field) *structPointerSlice {
+	return (*structPointerSlice)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+// A structPointerSlice represents a slice of pointers to structs (themselves submessages or groups).
+type structPointerSlice []structPointer
+
+func (v *structPointerSlice) Len() int                  { return len(*v) }
+func (v *structPointerSlice) Index(i int) structPointer { return (*v)[i] }
+func (v *structPointerSlice) Append(p structPointer)    { *v = append(*v, p) }
+
+// A word32 is the address of a "pointer to 32-bit value" field.
+type word32 **uint32
+
+// IsNil reports whether *v is nil.
+func word32_IsNil(p word32) bool {
+	return *p == nil
+}
+
+// Set sets *v to point at a newly allocated word set to x.
+func word32_Set(p word32, o *Buffer, x uint32) {
+	if len(o.uint32s) == 0 {
+		o.uint32s = make([]uint32, uint32PoolSize)
+	}
+	o.uint32s[0] = x
+	*p = &o.uint32s[0]
+	o.uint32s = o.uint32s[1:]
+}
+
+// Get gets the value pointed at by *v.
+func word32_Get(p word32) uint32 {
+	return **p
+}
+
+// Word32 returns the address of a *int32, *uint32, *float32, or *enum field in the struct.
+func structPointer_Word32(p structPointer, f field) word32 {
+	return word32((**uint32)(unsafe.Pointer(uintptr(p) + uintptr(f))))
+}
+
+// A word32Val is the address of a 32-bit value field.
+type word32Val *uint32
+
+// Set sets *p to x.
+func word32Val_Set(p word32Val, x uint32) {
+	*p = x
+}
+
+// Get gets the value pointed at by p.
+func word32Val_Get(p word32Val) uint32 {
+	return *p
+}
+
+// Word32Val returns the address of a *int32, *uint32, *float32, or *enum field in the struct.
+func structPointer_Word32Val(p structPointer, f field) word32Val {
+	return word32Val((*uint32)(unsafe.Pointer(uintptr(p) + uintptr(f))))
+}
+
+// A word32Slice is a slice of 32-bit values.
+type word32Slice []uint32
+
+func (v *word32Slice) Append(x uint32)    { *v = append(*v, x) }
+func (v *word32Slice) Len() int           { return len(*v) }
+func (v *word32Slice) Index(i int) uint32 { return (*v)[i] }
+
+// Word32Slice returns the address of a []int32, []uint32, []float32, or []enum field in the struct.
+func structPointer_Word32Slice(p structPointer, f field) *word32Slice {
+	return (*word32Slice)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
+
+// word64 is like word32 but for 64-bit values.
+type word64 **uint64
+
+func word64_Set(p word64, o *Buffer, x uint64) {
+	if len(o.uint64s) == 0 {
+		o.uint64s = make([]uint64, uint64PoolSize)
+	}
+	o.uint64s[0] = x
+	*p = &o.uint64s[0]
+	o.uint64s = o.uint64s[1:]
+}
+
+func word64_IsNil(p word64) bool {
+	return *p == nil
+}
+
+func word64_Get(p word64) uint64 {
+	return **p
+}
+
+func structPointer_Word64(p structPointer, f field) word64 {
+	return word64((**uint64)(unsafe.Pointer(uintptr(p) + uintptr(f))))
+}
+
+// word64Val is like word32Val but for 64-bit values.
+type word64Val *uint64
+
+func word64Val_Set(p word64Val, o *Buffer, x uint64) {
+	*p = x
+}
+
+func word64Val_Get(p word64Val) uint64 {
+	return *p
+}
+
+func structPointer_Word64Val(p structPointer, f field) word64Val {
+	return word64Val((*uint64)(unsafe.Pointer(uintptr(p) + uintptr(f))))
+}
+
+// word64Slice is like word32Slice but for 64-bit values.
+type word64Slice []uint64
+
+func (v *word64Slice) Append(x uint64)    { *v = append(*v, x) }
+func (v *word64Slice) Len() int           { return len(*v) }
+func (v *word64Slice) Index(i int) uint64 { return (*v)[i] }
+
+func structPointer_Word64Slice(p structPointer, f field) *word64Slice {
+	return (*word64Slice)(unsafe.Pointer(uintptr(p) + uintptr(f)))
+}
diff --git a/vendor/github.com/golang/protobuf/proto/properties.go b/vendor/github.com/golang/protobuf/proto/properties.go
new file mode 100644
index 00000000..69ddda8d
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/properties.go
@@ -0,0 +1,864 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+/*
+ * Routines for encoding data into the wire format for protocol buffers.
+ */
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"reflect"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+const debug bool = false
+
+// Constants that identify the encoding of a value on the wire.
+const (
+	WireVarint     = 0
+	WireFixed64    = 1
+	WireBytes      = 2
+	WireStartGroup = 3
+	WireEndGroup   = 4
+	WireFixed32    = 5
+)
+
+const startSize = 10 // initial slice/string sizes
+
+// Encoders are defined in encode.go
+// An encoder outputs the full representation of a field, including its
+// tag and encoder type.
+type encoder func(p *Buffer, prop *Properties, base structPointer) error
+
+// A valueEncoder encodes a single integer in a particular encoding.
+type valueEncoder func(o *Buffer, x uint64) error
+
+// Sizers are defined in encode.go
+// A sizer returns the encoded size of a field, including its tag and encoder
+// type.
+type sizer func(prop *Properties, base structPointer) int
+
+// A valueSizer returns the encoded size of a single integer in a particular
+// encoding.
+type valueSizer func(x uint64) int
+
+// Decoders are defined in decode.go
+// A decoder creates a value from its wire representation.
+// Unrecognized subelements are saved in unrec.
+type decoder func(p *Buffer, prop *Properties, base structPointer) error
+
+// A valueDecoder decodes a single integer in a particular encoding.
+type valueDecoder func(o *Buffer) (x uint64, err error)
+
+// A oneofMarshaler does the marshaling for all oneof fields in a message.
+type oneofMarshaler func(Message, *Buffer) error
+
+// A oneofUnmarshaler does the unmarshaling for a oneof field in a message.
+type oneofUnmarshaler func(Message, int, int, *Buffer) (bool, error)
+
+// A oneofSizer does the sizing for all oneof fields in a message.
+type oneofSizer func(Message) int
+
+// tagMap is an optimization over map[int]int for typical protocol buffer
+// use-cases. Encoded protocol buffers are often in tag order with small tag
+// numbers.
+type tagMap struct {
+	fastTags []int
+	slowTags map[int]int
+}
+
+// tagMapFastLimit is the upper bound on the tag number that will be stored in
+// the tagMap slice rather than its map.
+const tagMapFastLimit = 1024
+
+func (p *tagMap) get(t int) (int, bool) {
+	if t > 0 && t < tagMapFastLimit {
+		if t >= len(p.fastTags) {
+			return 0, false
+		}
+		fi := p.fastTags[t]
+		return fi, fi >= 0
+	}
+	fi, ok := p.slowTags[t]
+	return fi, ok
+}
+
+func (p *tagMap) put(t int, fi int) {
+	if t > 0 && t < tagMapFastLimit {
+		for len(p.fastTags) < t+1 {
+			p.fastTags = append(p.fastTags, -1)
+		}
+		p.fastTags[t] = fi
+		return
+	}
+	if p.slowTags == nil {
+		p.slowTags = make(map[int]int)
+	}
+	p.slowTags[t] = fi
+}
+
+// StructProperties represents properties for all the fields of a struct.
+// decoderTags and decoderOrigNames should only be used by the decoder.
+type StructProperties struct {
+	Prop             []*Properties  // properties for each field
+	reqCount         int            // required count
+	decoderTags      tagMap         // map from proto tag to struct field number
+	decoderOrigNames map[string]int // map from original name to struct field number
+	order            []int          // list of struct field numbers in tag order
+	unrecField       field          // field id of the XXX_unrecognized []byte field
+	extendable       bool           // is this an extendable proto
+
+	oneofMarshaler   oneofMarshaler
+	oneofUnmarshaler oneofUnmarshaler
+	oneofSizer       oneofSizer
+	stype            reflect.Type
+
+	// OneofTypes contains information about the oneof fields in this message.
+	// It is keyed by the original name of a field.
+	OneofTypes map[string]*OneofProperties
+}
+
+// OneofProperties represents information about a specific field in a oneof.
+type OneofProperties struct {
+	Type  reflect.Type // pointer to generated struct type for this oneof field
+	Field int          // struct field number of the containing oneof in the message
+	Prop  *Properties
+}
+
+// Implement the sorting interface so we can sort the fields in tag order, as recommended by the spec.
+// See encode.go, (*Buffer).enc_struct.
+
+func (sp *StructProperties) Len() int { return len(sp.order) }
+func (sp *StructProperties) Less(i, j int) bool {
+	return sp.Prop[sp.order[i]].Tag < sp.Prop[sp.order[j]].Tag
+}
+func (sp *StructProperties) Swap(i, j int) { sp.order[i], sp.order[j] = sp.order[j], sp.order[i] }
+
+// Properties represents the protocol-specific behavior of a single struct field.
+type Properties struct {
+	Name     string // name of the field, for error messages
+	OrigName string // original name before protocol compiler (always set)
+	JSONName string // name to use for JSON; determined by protoc
+	Wire     string
+	WireType int
+	Tag      int
+	Required bool
+	Optional bool
+	Repeated bool
+	Packed   bool   // relevant for repeated primitives only
+	Enum     string // set for enum types only
+	proto3   bool   // whether this is known to be a proto3 field; set for []byte only
+	oneof    bool   // whether this is a oneof field
+
+	Default    string // default value
+	HasDefault bool   // whether an explicit default was provided
+	def_uint64 uint64
+
+	enc           encoder
+	valEnc        valueEncoder // set for bool and numeric types only
+	field         field
+	tagcode       []byte // encoding of EncodeVarint((Tag<<3)|WireType)
+	tagbuf        [8]byte
+	stype         reflect.Type      // set for struct types only
+	sprop         *StructProperties // set for struct types only
+	isMarshaler   bool
+	isUnmarshaler bool
+
+	mtype    reflect.Type // set for map types only
+	mkeyprop *Properties  // set for map types only
+	mvalprop *Properties  // set for map types only
+
+	size    sizer
+	valSize valueSizer // set for bool and numeric types only
+
+	dec    decoder
+	valDec valueDecoder // set for bool and numeric types only
+
+	// If this is a packable field, this will be the decoder for the packed version of the field.
+	packedDec decoder
+}
+
+// String formats the properties in the protobuf struct field tag style.
+func (p *Properties) String() string {
+	s := p.Wire
+	s = ","
+	s += strconv.Itoa(p.Tag)
+	if p.Required {
+		s += ",req"
+	}
+	if p.Optional {
+		s += ",opt"
+	}
+	if p.Repeated {
+		s += ",rep"
+	}
+	if p.Packed {
+		s += ",packed"
+	}
+	s += ",name=" + p.OrigName
+	if p.JSONName != p.OrigName {
+		s += ",json=" + p.JSONName
+	}
+	if p.proto3 {
+		s += ",proto3"
+	}
+	if p.oneof {
+		s += ",oneof"
+	}
+	if len(p.Enum) > 0 {
+		s += ",enum=" + p.Enum
+	}
+	if p.HasDefault {
+		s += ",def=" + p.Default
+	}
+	return s
+}
+
+// Parse populates p by parsing a string in the protobuf struct field tag style.
+func (p *Properties) Parse(s string) {
+	// "bytes,49,opt,name=foo,def=hello!"
+	fields := strings.Split(s, ",") // breaks def=, but handled below.
+	if len(fields) < 2 {
+		fmt.Fprintf(os.Stderr, "proto: tag has too few fields: %q\n", s)
+		return
+	}
+
+	p.Wire = fields[0]
+	switch p.Wire {
+	case "varint":
+		p.WireType = WireVarint
+		p.valEnc = (*Buffer).EncodeVarint
+		p.valDec = (*Buffer).DecodeVarint
+		p.valSize = sizeVarint
+	case "fixed32":
+		p.WireType = WireFixed32
+		p.valEnc = (*Buffer).EncodeFixed32
+		p.valDec = (*Buffer).DecodeFixed32
+		p.valSize = sizeFixed32
+	case "fixed64":
+		p.WireType = WireFixed64
+		p.valEnc = (*Buffer).EncodeFixed64
+		p.valDec = (*Buffer).DecodeFixed64
+		p.valSize = sizeFixed64
+	case "zigzag32":
+		p.WireType = WireVarint
+		p.valEnc = (*Buffer).EncodeZigzag32
+		p.valDec = (*Buffer).DecodeZigzag32
+		p.valSize = sizeZigzag32
+	case "zigzag64":
+		p.WireType = WireVarint
+		p.valEnc = (*Buffer).EncodeZigzag64
+		p.valDec = (*Buffer).DecodeZigzag64
+		p.valSize = sizeZigzag64
+	case "bytes", "group":
+		p.WireType = WireBytes
+		// no numeric converter for non-numeric types
+	default:
+		fmt.Fprintf(os.Stderr, "proto: tag has unknown wire type: %q\n", s)
+		return
+	}
+
+	var err error
+	p.Tag, err = strconv.Atoi(fields[1])
+	if err != nil {
+		return
+	}
+
+	for i := 2; i < len(fields); i++ {
+		f := fields[i]
+		switch {
+		case f == "req":
+			p.Required = true
+		case f == "opt":
+			p.Optional = true
+		case f == "rep":
+			p.Repeated = true
+		case f == "packed":
+			p.Packed = true
+		case strings.HasPrefix(f, "name="):
+			p.OrigName = f[5:]
+		case strings.HasPrefix(f, "json="):
+			p.JSONName = f[5:]
+		case strings.HasPrefix(f, "enum="):
+			p.Enum = f[5:]
+		case f == "proto3":
+			p.proto3 = true
+		case f == "oneof":
+			p.oneof = true
+		case strings.HasPrefix(f, "def="):
+			p.HasDefault = true
+			p.Default = f[4:] // rest of string
+			if i+1 < len(fields) {
+				// Commas aren't escaped, and def is always last.
+				p.Default += "," + strings.Join(fields[i+1:], ",")
+				break
+			}
+		}
+	}
+}
+
+func logNoSliceEnc(t1, t2 reflect.Type) {
+	fmt.Fprintf(os.Stderr, "proto: no slice oenc for %T = []%T\n", t1, t2)
+}
+
+var protoMessageType = reflect.TypeOf((*Message)(nil)).Elem()
+
+// Initialize the fields for encoding and decoding.
+func (p *Properties) setEncAndDec(typ reflect.Type, f *reflect.StructField, lockGetProp bool) {
+	p.enc = nil
+	p.dec = nil
+	p.size = nil
+
+	switch t1 := typ; t1.Kind() {
+	default:
+		fmt.Fprintf(os.Stderr, "proto: no coders for %v\n", t1)
+
+	// proto3 scalar types
+
+	case reflect.Bool:
+		p.enc = (*Buffer).enc_proto3_bool
+		p.dec = (*Buffer).dec_proto3_bool
+		p.size = size_proto3_bool
+	case reflect.Int32:
+		p.enc = (*Buffer).enc_proto3_int32
+		p.dec = (*Buffer).dec_proto3_int32
+		p.size = size_proto3_int32
+	case reflect.Uint32:
+		p.enc = (*Buffer).enc_proto3_uint32
+		p.dec = (*Buffer).dec_proto3_int32 // can reuse
+		p.size = size_proto3_uint32
+	case reflect.Int64, reflect.Uint64:
+		p.enc = (*Buffer).enc_proto3_int64
+		p.dec = (*Buffer).dec_proto3_int64
+		p.size = size_proto3_int64
+	case reflect.Float32:
+		p.enc = (*Buffer).enc_proto3_uint32 // can just treat them as bits
+		p.dec = (*Buffer).dec_proto3_int32
+		p.size = size_proto3_uint32
+	case reflect.Float64:
+		p.enc = (*Buffer).enc_proto3_int64 // can just treat them as bits
+		p.dec = (*Buffer).dec_proto3_int64
+		p.size = size_proto3_int64
+	case reflect.String:
+		p.enc = (*Buffer).enc_proto3_string
+		p.dec = (*Buffer).dec_proto3_string
+		p.size = size_proto3_string
+
+	case reflect.Ptr:
+		switch t2 := t1.Elem(); t2.Kind() {
+		default:
+			fmt.Fprintf(os.Stderr, "proto: no encoder function for %v -> %v\n", t1, t2)
+			break
+		case reflect.Bool:
+			p.enc = (*Buffer).enc_bool
+			p.dec = (*Buffer).dec_bool
+			p.size = size_bool
+		case reflect.Int32:
+			p.enc = (*Buffer).enc_int32
+			p.dec = (*Buffer).dec_int32
+			p.size = size_int32
+		case reflect.Uint32:
+			p.enc = (*Buffer).enc_uint32
+			p.dec = (*Buffer).dec_int32 // can reuse
+			p.size = size_uint32
+		case reflect.Int64, reflect.Uint64:
+			p.enc = (*Buffer).enc_int64
+			p.dec = (*Buffer).dec_int64
+			p.size = size_int64
+		case reflect.Float32:
+			p.enc = (*Buffer).enc_uint32 // can just treat them as bits
+			p.dec = (*Buffer).dec_int32
+			p.size = size_uint32
+		case reflect.Float64:
+			p.enc = (*Buffer).enc_int64 // can just treat them as bits
+			p.dec = (*Buffer).dec_int64
+			p.size = size_int64
+		case reflect.String:
+			p.enc = (*Buffer).enc_string
+			p.dec = (*Buffer).dec_string
+			p.size = size_string
+		case reflect.Struct:
+			p.stype = t1.Elem()
+			p.isMarshaler = isMarshaler(t1)
+			p.isUnmarshaler = isUnmarshaler(t1)
+			if p.Wire == "bytes" {
+				p.enc = (*Buffer).enc_struct_message
+				p.dec = (*Buffer).dec_struct_message
+				p.size = size_struct_message
+			} else {
+				p.enc = (*Buffer).enc_struct_group
+				p.dec = (*Buffer).dec_struct_group
+				p.size = size_struct_group
+			}
+		}
+
+	case reflect.Slice:
+		switch t2 := t1.Elem(); t2.Kind() {
+		default:
+			logNoSliceEnc(t1, t2)
+			break
+		case reflect.Bool:
+			if p.Packed {
+				p.enc = (*Buffer).enc_slice_packed_bool
+				p.size = size_slice_packed_bool
+			} else {
+				p.enc = (*Buffer).enc_slice_bool
+				p.size = size_slice_bool
+			}
+			p.dec = (*Buffer).dec_slice_bool
+			p.packedDec = (*Buffer).dec_slice_packed_bool
+		case reflect.Int32:
+			if p.Packed {
+				p.enc = (*Buffer).enc_slice_packed_int32
+				p.size = size_slice_packed_int32
+			} else {
+				p.enc = (*Buffer).enc_slice_int32
+				p.size = size_slice_int32
+			}
+			p.dec = (*Buffer).dec_slice_int32
+			p.packedDec = (*Buffer).dec_slice_packed_int32
+		case reflect.Uint32:
+			if p.Packed {
+				p.enc = (*Buffer).enc_slice_packed_uint32
+				p.size = size_slice_packed_uint32
+			} else {
+				p.enc = (*Buffer).enc_slice_uint32
+				p.size = size_slice_uint32
+			}
+			p.dec = (*Buffer).dec_slice_int32
+			p.packedDec = (*Buffer).dec_slice_packed_int32
+		case reflect.Int64, reflect.Uint64:
+			if p.Packed {
+				p.enc = (*Buffer).enc_slice_packed_int64
+				p.size = size_slice_packed_int64
+			} else {
+				p.enc = (*Buffer).enc_slice_int64
+				p.size = size_slice_int64
+			}
+			p.dec = (*Buffer).dec_slice_int64
+			p.packedDec = (*Buffer).dec_slice_packed_int64
+		case reflect.Uint8:
+			p.dec = (*Buffer).dec_slice_byte
+			if p.proto3 {
+				p.enc = (*Buffer).enc_proto3_slice_byte
+				p.size = size_proto3_slice_byte
+			} else {
+				p.enc = (*Buffer).enc_slice_byte
+				p.size = size_slice_byte
+			}
+		case reflect.Float32, reflect.Float64:
+			switch t2.Bits() {
+			case 32:
+				// can just treat them as bits
+				if p.Packed {
+					p.enc = (*Buffer).enc_slice_packed_uint32
+					p.size = size_slice_packed_uint32
+				} else {
+					p.enc = (*Buffer).enc_slice_uint32
+					p.size = size_slice_uint32
+				}
+				p.dec = (*Buffer).dec_slice_int32
+				p.packedDec = (*Buffer).dec_slice_packed_int32
+			case 64:
+				// can just treat them as bits
+				if p.Packed {
+					p.enc = (*Buffer).enc_slice_packed_int64
+					p.size = size_slice_packed_int64
+				} else {
+					p.enc = (*Buffer).enc_slice_int64
+					p.size = size_slice_int64
+				}
+				p.dec = (*Buffer).dec_slice_int64
+				p.packedDec = (*Buffer).dec_slice_packed_int64
+			default:
+				logNoSliceEnc(t1, t2)
+				break
+			}
+		case reflect.String:
+			p.enc = (*Buffer).enc_slice_string
+			p.dec = (*Buffer).dec_slice_string
+			p.size = size_slice_string
+		case reflect.Ptr:
+			switch t3 := t2.Elem(); t3.Kind() {
+			default:
+				fmt.Fprintf(os.Stderr, "proto: no ptr oenc for %T -> %T -> %T\n", t1, t2, t3)
+				break
+			case reflect.Struct:
+				p.stype = t2.Elem()
+				p.isMarshaler = isMarshaler(t2)
+				p.isUnmarshaler = isUnmarshaler(t2)
+				if p.Wire == "bytes" {
+					p.enc = (*Buffer).enc_slice_struct_message
+					p.dec = (*Buffer).dec_slice_struct_message
+					p.size = size_slice_struct_message
+				} else {
+					p.enc = (*Buffer).enc_slice_struct_group
+					p.dec = (*Buffer).dec_slice_struct_group
+					p.size = size_slice_struct_group
+				}
+			}
+		case reflect.Slice:
+			switch t2.Elem().Kind() {
+			default:
+				fmt.Fprintf(os.Stderr, "proto: no slice elem oenc for %T -> %T -> %T\n", t1, t2, t2.Elem())
+				break
+			case reflect.Uint8:
+				p.enc = (*Buffer).enc_slice_slice_byte
+				p.dec = (*Buffer).dec_slice_slice_byte
+				p.size = size_slice_slice_byte
+			}
+		}
+
+	case reflect.Map:
+		p.enc = (*Buffer).enc_new_map
+		p.dec = (*Buffer).dec_new_map
+		p.size = size_new_map
+
+		p.mtype = t1
+		p.mkeyprop = &Properties{}
+		p.mkeyprop.init(reflect.PtrTo(p.mtype.Key()), "Key", f.Tag.Get("protobuf_key"), nil, lockGetProp)
+		p.mvalprop = &Properties{}
+		vtype := p.mtype.Elem()
+		if vtype.Kind() != reflect.Ptr && vtype.Kind() != reflect.Slice {
+			// The value type is not a message (*T) or bytes ([]byte),
+			// so we need encoders for the pointer to this type.
+			vtype = reflect.PtrTo(vtype)
+		}
+		p.mvalprop.init(vtype, "Value", f.Tag.Get("protobuf_val"), nil, lockGetProp)
+	}
+
+	// precalculate tag code
+	wire := p.WireType
+	if p.Packed {
+		wire = WireBytes
+	}
+	x := uint32(p.Tag)<<3 | uint32(wire)
+	i := 0
+	for i = 0; x > 127; i++ {
+		p.tagbuf[i] = 0x80 | uint8(x&0x7F)
+		x >>= 7
+	}
+	p.tagbuf[i] = uint8(x)
+	p.tagcode = p.tagbuf[0 : i+1]
+
+	if p.stype != nil {
+		if lockGetProp {
+			p.sprop = GetProperties(p.stype)
+		} else {
+			p.sprop = getPropertiesLocked(p.stype)
+		}
+	}
+}
+
+var (
+	marshalerType   = reflect.TypeOf((*Marshaler)(nil)).Elem()
+	unmarshalerType = reflect.TypeOf((*Unmarshaler)(nil)).Elem()
+)
+
+// isMarshaler reports whether type t implements Marshaler.
+func isMarshaler(t reflect.Type) bool {
+	// We're checking for (likely) pointer-receiver methods
+	// so if t is not a pointer, something is very wrong.
+	// The calls above only invoke isMarshaler on pointer types.
+	if t.Kind() != reflect.Ptr {
+		panic("proto: misuse of isMarshaler")
+	}
+	return t.Implements(marshalerType)
+}
+
+// isUnmarshaler reports whether type t implements Unmarshaler.
+func isUnmarshaler(t reflect.Type) bool {
+	// We're checking for (likely) pointer-receiver methods
+	// so if t is not a pointer, something is very wrong.
+	// The calls above only invoke isUnmarshaler on pointer types.
+	if t.Kind() != reflect.Ptr {
+		panic("proto: misuse of isUnmarshaler")
+	}
+	return t.Implements(unmarshalerType)
+}
+
+// Init populates the properties from a protocol buffer struct tag.
+func (p *Properties) Init(typ reflect.Type, name, tag string, f *reflect.StructField) {
+	p.init(typ, name, tag, f, true)
+}
+
+func (p *Properties) init(typ reflect.Type, name, tag string, f *reflect.StructField, lockGetProp bool) {
+	// "bytes,49,opt,def=hello!"
+	p.Name = name
+	p.OrigName = name
+	if f != nil {
+		p.field = toField(f)
+	}
+	if tag == "" {
+		return
+	}
+	p.Parse(tag)
+	p.setEncAndDec(typ, f, lockGetProp)
+}
+
+var (
+	propertiesMu  sync.RWMutex
+	propertiesMap = make(map[reflect.Type]*StructProperties)
+)
+
+// GetProperties returns the list of properties for the type represented by t.
+// t must represent a generated struct type of a protocol message.
+func GetProperties(t reflect.Type) *StructProperties {
+	if t.Kind() != reflect.Struct {
+		panic("proto: type must have kind struct")
+	}
+
+	// Most calls to GetProperties in a long-running program will be
+	// retrieving details for types we have seen before.
+	propertiesMu.RLock()
+	sprop, ok := propertiesMap[t]
+	propertiesMu.RUnlock()
+	if ok {
+		if collectStats {
+			stats.Chit++
+		}
+		return sprop
+	}
+
+	propertiesMu.Lock()
+	sprop = getPropertiesLocked(t)
+	propertiesMu.Unlock()
+	return sprop
+}
+
+// getPropertiesLocked requires that propertiesMu is held.
+func getPropertiesLocked(t reflect.Type) *StructProperties {
+	if prop, ok := propertiesMap[t]; ok {
+		if collectStats {
+			stats.Chit++
+		}
+		return prop
+	}
+	if collectStats {
+		stats.Cmiss++
+	}
+
+	prop := new(StructProperties)
+	// in case of recursive protos, fill this in now.
+	propertiesMap[t] = prop
+
+	// build properties
+	prop.extendable = reflect.PtrTo(t).Implements(extendableProtoType) ||
+		reflect.PtrTo(t).Implements(extendableProtoV1Type)
+	prop.unrecField = invalidField
+	prop.Prop = make([]*Properties, t.NumField())
+	prop.order = make([]int, t.NumField())
+
+	for i := 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+		p := new(Properties)
+		name := f.Name
+		p.init(f.Type, name, f.Tag.Get("protobuf"), &f, false)
+
+		if f.Name == "XXX_InternalExtensions" { // special case
+			p.enc = (*Buffer).enc_exts
+			p.dec = nil // not needed
+			p.size = size_exts
+		} else if f.Name == "XXX_extensions" { // special case
+			p.enc = (*Buffer).enc_map
+			p.dec = nil // not needed
+			p.size = size_map
+		} else if f.Name == "XXX_unrecognized" { // special case
+			prop.unrecField = toField(&f)
+		}
+		oneof := f.Tag.Get("protobuf_oneof") // special case
+		if oneof != "" {
+			// Oneof fields don't use the traditional protobuf tag.
+			p.OrigName = oneof
+		}
+		prop.Prop[i] = p
+		prop.order[i] = i
+		if debug {
+			print(i, " ", f.Name, " ", t.String(), " ")
+			if p.Tag > 0 {
+				print(p.String())
+			}
+			print("\n")
+		}
+		if p.enc == nil && !strings.HasPrefix(f.Name, "XXX_") && oneof == "" {
+			fmt.Fprintln(os.Stderr, "proto: no encoder for", f.Name, f.Type.String(), "[GetProperties]")
+		}
+	}
+
+	// Re-order prop.order.
+	sort.Sort(prop)
+
+	type oneofMessage interface {
+		XXX_OneofFuncs() (func(Message, *Buffer) error, func(Message, int, int, *Buffer) (bool, error), func(Message) int, []interface{})
+	}
+	if om, ok := reflect.Zero(reflect.PtrTo(t)).Interface().(oneofMessage); ok {
+		var oots []interface{}
+		prop.oneofMarshaler, prop.oneofUnmarshaler, prop.oneofSizer, oots = om.XXX_OneofFuncs()
+		prop.stype = t
+
+		// Interpret oneof metadata.
+		prop.OneofTypes = make(map[string]*OneofProperties)
+		for _, oot := range oots {
+			oop := &OneofProperties{
+				Type: reflect.ValueOf(oot).Type(), // *T
+				Prop: new(Properties),
+			}
+			sft := oop.Type.Elem().Field(0)
+			oop.Prop.Name = sft.Name
+			oop.Prop.Parse(sft.Tag.Get("protobuf"))
+			// There will be exactly one interface field that
+			// this new value is assignable to.
+			for i := 0; i < t.NumField(); i++ {
+				f := t.Field(i)
+				if f.Type.Kind() != reflect.Interface {
+					continue
+				}
+				if !oop.Type.AssignableTo(f.Type) {
+					continue
+				}
+				oop.Field = i
+				break
+			}
+			prop.OneofTypes[oop.Prop.OrigName] = oop
+		}
+	}
+
+	// build required counts
+	// build tags
+	reqCount := 0
+	prop.decoderOrigNames = make(map[string]int)
+	for i, p := range prop.Prop {
+		if strings.HasPrefix(p.Name, "XXX_") {
+			// Internal fields should not appear in tags/origNames maps.
+			// They are handled specially when encoding and decoding.
+			continue
+		}
+		if p.Required {
+			reqCount++
+		}
+		prop.decoderTags.put(p.Tag, i)
+		prop.decoderOrigNames[p.OrigName] = i
+	}
+	prop.reqCount = reqCount
+
+	return prop
+}
+
+// Return the Properties object for the x[0]'th field of the structure.
+func propByIndex(t reflect.Type, x []int) *Properties {
+	if len(x) != 1 {
+		fmt.Fprintf(os.Stderr, "proto: field index dimension %d (not 1) for type %s\n", len(x), t)
+		return nil
+	}
+	prop := GetProperties(t)
+	return prop.Prop[x[0]]
+}
+
+// Get the address and type of a pointer to a struct from an interface.
+func getbase(pb Message) (t reflect.Type, b structPointer, err error) {
+	if pb == nil {
+		err = ErrNil
+		return
+	}
+	// get the reflect type of the pointer to the struct.
+	t = reflect.TypeOf(pb)
+	// get the address of the struct.
+	value := reflect.ValueOf(pb)
+	b = toStructPointer(value)
+	return
+}
+
+// A global registry of enum types.
+// The generated code will register the generated maps by calling RegisterEnum.
+
+var enumValueMaps = make(map[string]map[string]int32)
+
+// RegisterEnum is called from the generated code to install the enum descriptor
+// maps into the global table to aid parsing text format protocol buffers.
+func RegisterEnum(typeName string, unusedNameMap map[int32]string, valueMap map[string]int32) {
+	if _, ok := enumValueMaps[typeName]; ok {
+		panic("proto: duplicate enum registered: " + typeName)
+	}
+	enumValueMaps[typeName] = valueMap
+}
+
+// EnumValueMap returns the mapping from names to integers of the
+// enum type enumType, or a nil if not found.
+func EnumValueMap(enumType string) map[string]int32 {
+	return enumValueMaps[enumType]
+}
+
+// A registry of all linked message types.
+// The string is a fully-qualified proto name ("pkg.Message").
+var (
+	protoTypes    = make(map[string]reflect.Type)
+	revProtoTypes = make(map[reflect.Type]string)
+)
+
+// RegisterType is called from generated code and maps from the fully qualified
+// proto name to the type (pointer to struct) of the protocol buffer.
+func RegisterType(x Message, name string) {
+	if _, ok := protoTypes[name]; ok {
+		// TODO: Some day, make this a panic.
+		log.Printf("proto: duplicate proto type registered: %s", name)
+		return
+	}
+	t := reflect.TypeOf(x)
+	protoTypes[name] = t
+	revProtoTypes[t] = name
+}
+
+// MessageName returns the fully-qualified proto name for the given message type.
+func MessageName(x Message) string { return revProtoTypes[reflect.TypeOf(x)] }
+
+// MessageType returns the message type (pointer to struct) for a named message.
+func MessageType(name string) reflect.Type { return protoTypes[name] }
+
+// A registry of all linked proto files.
+var (
+	protoFiles = make(map[string][]byte) // file name => fileDescriptor
+)
+
+// RegisterFile is called from generated code and maps from the
+// full file name of a .proto file to its compressed FileDescriptorProto.
+func RegisterFile(filename string, fileDescriptor []byte) {
+	protoFiles[filename] = fileDescriptor
+}
+
+// FileDescriptor returns the compressed FileDescriptorProto for a .proto file.
+func FileDescriptor(filename string) []byte { return protoFiles[filename] }
diff --git a/vendor/github.com/golang/protobuf/proto/text.go b/vendor/github.com/golang/protobuf/proto/text.go
new file mode 100644
index 00000000..965876bf
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/text.go
@@ -0,0 +1,854 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+// Functions for writing the text protocol buffer format.
+
+import (
+	"bufio"
+	"bytes"
+	"encoding"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"math"
+	"reflect"
+	"sort"
+	"strings"
+)
+
+var (
+	newline         = []byte("\n")
+	spaces          = []byte("                                        ")
+	gtNewline       = []byte(">\n")
+	endBraceNewline = []byte("}\n")
+	backslashN      = []byte{'\\', 'n'}
+	backslashR      = []byte{'\\', 'r'}
+	backslashT      = []byte{'\\', 't'}
+	backslashDQ     = []byte{'\\', '"'}
+	backslashBS     = []byte{'\\', '\\'}
+	posInf          = []byte("inf")
+	negInf          = []byte("-inf")
+	nan             = []byte("nan")
+)
+
+type writer interface {
+	io.Writer
+	WriteByte(byte) error
+}
+
+// textWriter is an io.Writer that tracks its indentation level.
+type textWriter struct {
+	ind      int
+	complete bool // if the current position is a complete line
+	compact  bool // whether to write out as a one-liner
+	w        writer
+}
+
+func (w *textWriter) WriteString(s string) (n int, err error) {
+	if !strings.Contains(s, "\n") {
+		if !w.compact && w.complete {
+			w.writeIndent()
+		}
+		w.complete = false
+		return io.WriteString(w.w, s)
+	}
+	// WriteString is typically called without newlines, so this
+	// codepath and its copy are rare.  We copy to avoid
+	// duplicating all of Write's logic here.
+	return w.Write([]byte(s))
+}
+
+func (w *textWriter) Write(p []byte) (n int, err error) {
+	newlines := bytes.Count(p, newline)
+	if newlines == 0 {
+		if !w.compact && w.complete {
+			w.writeIndent()
+		}
+		n, err = w.w.Write(p)
+		w.complete = false
+		return n, err
+	}
+
+	frags := bytes.SplitN(p, newline, newlines+1)
+	if w.compact {
+		for i, frag := range frags {
+			if i > 0 {
+				if err := w.w.WriteByte(' '); err != nil {
+					return n, err
+				}
+				n++
+			}
+			nn, err := w.w.Write(frag)
+			n += nn
+			if err != nil {
+				return n, err
+			}
+		}
+		return n, nil
+	}
+
+	for i, frag := range frags {
+		if w.complete {
+			w.writeIndent()
+		}
+		nn, err := w.w.Write(frag)
+		n += nn
+		if err != nil {
+			return n, err
+		}
+		if i+1 < len(frags) {
+			if err := w.w.WriteByte('\n'); err != nil {
+				return n, err
+			}
+			n++
+		}
+	}
+	w.complete = len(frags[len(frags)-1]) == 0
+	return n, nil
+}
+
+func (w *textWriter) WriteByte(c byte) error {
+	if w.compact && c == '\n' {
+		c = ' '
+	}
+	if !w.compact && w.complete {
+		w.writeIndent()
+	}
+	err := w.w.WriteByte(c)
+	w.complete = c == '\n'
+	return err
+}
+
+func (w *textWriter) indent() { w.ind++ }
+
+func (w *textWriter) unindent() {
+	if w.ind == 0 {
+		log.Print("proto: textWriter unindented too far")
+		return
+	}
+	w.ind--
+}
+
+func writeName(w *textWriter, props *Properties) error {
+	if _, err := w.WriteString(props.OrigName); err != nil {
+		return err
+	}
+	if props.Wire != "group" {
+		return w.WriteByte(':')
+	}
+	return nil
+}
+
+// raw is the interface satisfied by RawMessage.
+type raw interface {
+	Bytes() []byte
+}
+
+func requiresQuotes(u string) bool {
+	// When type URL contains any characters except [0-9A-Za-z./\-]*, it must be quoted.
+	for _, ch := range u {
+		switch {
+		case ch == '.' || ch == '/' || ch == '_':
+			continue
+		case '0' <= ch && ch <= '9':
+			continue
+		case 'A' <= ch && ch <= 'Z':
+			continue
+		case 'a' <= ch && ch <= 'z':
+			continue
+		default:
+			return true
+		}
+	}
+	return false
+}
+
+// isAny reports whether sv is a google.protobuf.Any message
+func isAny(sv reflect.Value) bool {
+	type wkt interface {
+		XXX_WellKnownType() string
+	}
+	t, ok := sv.Addr().Interface().(wkt)
+	return ok && t.XXX_WellKnownType() == "Any"
+}
+
+// writeProto3Any writes an expanded google.protobuf.Any message.
+//
+// It returns (false, nil) if sv value can't be unmarshaled (e.g. because
+// required messages are not linked in).
+//
+// It returns (true, error) when sv was written in expanded format or an error
+// was encountered.
+func (tm *TextMarshaler) writeProto3Any(w *textWriter, sv reflect.Value) (bool, error) {
+	turl := sv.FieldByName("TypeUrl")
+	val := sv.FieldByName("Value")
+	if !turl.IsValid() || !val.IsValid() {
+		return true, errors.New("proto: invalid google.protobuf.Any message")
+	}
+
+	b, ok := val.Interface().([]byte)
+	if !ok {
+		return true, errors.New("proto: invalid google.protobuf.Any message")
+	}
+
+	parts := strings.Split(turl.String(), "/")
+	mt := MessageType(parts[len(parts)-1])
+	if mt == nil {
+		return false, nil
+	}
+	m := reflect.New(mt.Elem())
+	if err := Unmarshal(b, m.Interface().(Message)); err != nil {
+		return false, nil
+	}
+	w.Write([]byte("["))
+	u := turl.String()
+	if requiresQuotes(u) {
+		writeString(w, u)
+	} else {
+		w.Write([]byte(u))
+	}
+	if w.compact {
+		w.Write([]byte("]:<"))
+	} else {
+		w.Write([]byte("]: <\n"))
+		w.ind++
+	}
+	if err := tm.writeStruct(w, m.Elem()); err != nil {
+		return true, err
+	}
+	if w.compact {
+		w.Write([]byte("> "))
+	} else {
+		w.ind--
+		w.Write([]byte(">\n"))
+	}
+	return true, nil
+}
+
+func (tm *TextMarshaler) writeStruct(w *textWriter, sv reflect.Value) error {
+	if tm.ExpandAny && isAny(sv) {
+		if canExpand, err := tm.writeProto3Any(w, sv); canExpand {
+			return err
+		}
+	}
+	st := sv.Type()
+	sprops := GetProperties(st)
+	for i := 0; i < sv.NumField(); i++ {
+		fv := sv.Field(i)
+		props := sprops.Prop[i]
+		name := st.Field(i).Name
+
+		if strings.HasPrefix(name, "XXX_") {
+			// There are two XXX_ fields:
+			//   XXX_unrecognized []byte
+			//   XXX_extensions   map[int32]proto.Extension
+			// The first is handled here;
+			// the second is handled at the bottom of this function.
+			if name == "XXX_unrecognized" && !fv.IsNil() {
+				if err := writeUnknownStruct(w, fv.Interface().([]byte)); err != nil {
+					return err
+				}
+			}
+			continue
+		}
+		if fv.Kind() == reflect.Ptr && fv.IsNil() {
+			// Field not filled in. This could be an optional field or
+			// a required field that wasn't filled in. Either way, there
+			// isn't anything we can show for it.
+			continue
+		}
+		if fv.Kind() == reflect.Slice && fv.IsNil() {
+			// Repeated field that is empty, or a bytes field that is unused.
+			continue
+		}
+
+		if props.Repeated && fv.Kind() == reflect.Slice {
+			// Repeated field.
+			for j := 0; j < fv.Len(); j++ {
+				if err := writeName(w, props); err != nil {
+					return err
+				}
+				if !w.compact {
+					if err := w.WriteByte(' '); err != nil {
+						return err
+					}
+				}
+				v := fv.Index(j)
+				if v.Kind() == reflect.Ptr && v.IsNil() {
+					// A nil message in a repeated field is not valid,
+					// but we can handle that more gracefully than panicking.
+					if _, err := w.Write([]byte("<nil>\n")); err != nil {
+						return err
+					}
+					continue
+				}
+				if err := tm.writeAny(w, v, props); err != nil {
+					return err
+				}
+				if err := w.WriteByte('\n'); err != nil {
+					return err
+				}
+			}
+			continue
+		}
+		if fv.Kind() == reflect.Map {
+			// Map fields are rendered as a repeated struct with key/value fields.
+			keys := fv.MapKeys()
+			sort.Sort(mapKeys(keys))
+			for _, key := range keys {
+				val := fv.MapIndex(key)
+				if err := writeName(w, props); err != nil {
+					return err
+				}
+				if !w.compact {
+					if err := w.WriteByte(' '); err != nil {
+						return err
+					}
+				}
+				// open struct
+				if err := w.WriteByte('<'); err != nil {
+					return err
+				}
+				if !w.compact {
+					if err := w.WriteByte('\n'); err != nil {
+						return err
+					}
+				}
+				w.indent()
+				// key
+				if _, err := w.WriteString("key:"); err != nil {
+					return err
+				}
+				if !w.compact {
+					if err := w.WriteByte(' '); err != nil {
+						return err
+					}
+				}
+				if err := tm.writeAny(w, key, props.mkeyprop); err != nil {
+					return err
+				}
+				if err := w.WriteByte('\n'); err != nil {
+					return err
+				}
+				// nil values aren't legal, but we can avoid panicking because of them.
+				if val.Kind() != reflect.Ptr || !val.IsNil() {
+					// value
+					if _, err := w.WriteString("value:"); err != nil {
+						return err
+					}
+					if !w.compact {
+						if err := w.WriteByte(' '); err != nil {
+							return err
+						}
+					}
+					if err := tm.writeAny(w, val, props.mvalprop); err != nil {
+						return err
+					}
+					if err := w.WriteByte('\n'); err != nil {
+						return err
+					}
+				}
+				// close struct
+				w.unindent()
+				if err := w.WriteByte('>'); err != nil {
+					return err
+				}
+				if err := w.WriteByte('\n'); err != nil {
+					return err
+				}
+			}
+			continue
+		}
+		if props.proto3 && fv.Kind() == reflect.Slice && fv.Len() == 0 {
+			// empty bytes field
+			continue
+		}
+		if fv.Kind() != reflect.Ptr && fv.Kind() != reflect.Slice {
+			// proto3 non-repeated scalar field; skip if zero value
+			if isProto3Zero(fv) {
+				continue
+			}
+		}
+
+		if fv.Kind() == reflect.Interface {
+			// Check if it is a oneof.
+			if st.Field(i).Tag.Get("protobuf_oneof") != "" {
+				// fv is nil, or holds a pointer to generated struct.
+				// That generated struct has exactly one field,
+				// which has a protobuf struct tag.
+				if fv.IsNil() {
+					continue
+				}
+				inner := fv.Elem().Elem() // interface -> *T -> T
+				tag := inner.Type().Field(0).Tag.Get("protobuf")
+				props = new(Properties) // Overwrite the outer props var, but not its pointee.
+				props.Parse(tag)
+				// Write the value in the oneof, not the oneof itself.
+				fv = inner.Field(0)
+
+				// Special case to cope with malformed messages gracefully:
+				// If the value in the oneof is a nil pointer, don't panic
+				// in writeAny.
+				if fv.Kind() == reflect.Ptr && fv.IsNil() {
+					// Use errors.New so writeAny won't render quotes.
+					msg := errors.New("/* nil */")
+					fv = reflect.ValueOf(&msg).Elem()
+				}
+			}
+		}
+
+		if err := writeName(w, props); err != nil {
+			return err
+		}
+		if !w.compact {
+			if err := w.WriteByte(' '); err != nil {
+				return err
+			}
+		}
+		if b, ok := fv.Interface().(raw); ok {
+			if err := writeRaw(w, b.Bytes()); err != nil {
+				return err
+			}
+			continue
+		}
+
+		// Enums have a String method, so writeAny will work fine.
+		if err := tm.writeAny(w, fv, props); err != nil {
+			return err
+		}
+
+		if err := w.WriteByte('\n'); err != nil {
+			return err
+		}
+	}
+
+	// Extensions (the XXX_extensions field).
+	pv := sv.Addr()
+	if _, ok := extendable(pv.Interface()); ok {
+		if err := tm.writeExtensions(w, pv); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// writeRaw writes an uninterpreted raw message.
+func writeRaw(w *textWriter, b []byte) error {
+	if err := w.WriteByte('<'); err != nil {
+		return err
+	}
+	if !w.compact {
+		if err := w.WriteByte('\n'); err != nil {
+			return err
+		}
+	}
+	w.indent()
+	if err := writeUnknownStruct(w, b); err != nil {
+		return err
+	}
+	w.unindent()
+	if err := w.WriteByte('>'); err != nil {
+		return err
+	}
+	return nil
+}
+
+// writeAny writes an arbitrary field.
+func (tm *TextMarshaler) writeAny(w *textWriter, v reflect.Value, props *Properties) error {
+	v = reflect.Indirect(v)
+
+	// Floats have special cases.
+	if v.Kind() == reflect.Float32 || v.Kind() == reflect.Float64 {
+		x := v.Float()
+		var b []byte
+		switch {
+		case math.IsInf(x, 1):
+			b = posInf
+		case math.IsInf(x, -1):
+			b = negInf
+		case math.IsNaN(x):
+			b = nan
+		}
+		if b != nil {
+			_, err := w.Write(b)
+			return err
+		}
+		// Other values are handled below.
+	}
+
+	// We don't attempt to serialise every possible value type; only those
+	// that can occur in protocol buffers.
+	switch v.Kind() {
+	case reflect.Slice:
+		// Should only be a []byte; repeated fields are handled in writeStruct.
+		if err := writeString(w, string(v.Bytes())); err != nil {
+			return err
+		}
+	case reflect.String:
+		if err := writeString(w, v.String()); err != nil {
+			return err
+		}
+	case reflect.Struct:
+		// Required/optional group/message.
+		var bra, ket byte = '<', '>'
+		if props != nil && props.Wire == "group" {
+			bra, ket = '{', '}'
+		}
+		if err := w.WriteByte(bra); err != nil {
+			return err
+		}
+		if !w.compact {
+			if err := w.WriteByte('\n'); err != nil {
+				return err
+			}
+		}
+		w.indent()
+		if etm, ok := v.Interface().(encoding.TextMarshaler); ok {
+			text, err := etm.MarshalText()
+			if err != nil {
+				return err
+			}
+			if _, err = w.Write(text); err != nil {
+				return err
+			}
+		} else if err := tm.writeStruct(w, v); err != nil {
+			return err
+		}
+		w.unindent()
+		if err := w.WriteByte(ket); err != nil {
+			return err
+		}
+	default:
+		_, err := fmt.Fprint(w, v.Interface())
+		return err
+	}
+	return nil
+}
+
+// equivalent to C's isprint.
+func isprint(c byte) bool {
+	return c >= 0x20 && c < 0x7f
+}
+
+// writeString writes a string in the protocol buffer text format.
+// It is similar to strconv.Quote except we don't use Go escape sequences,
+// we treat the string as a byte sequence, and we use octal escapes.
+// These differences are to maintain interoperability with the other
+// languages' implementations of the text format.
+func writeString(w *textWriter, s string) error {
+	// use WriteByte here to get any needed indent
+	if err := w.WriteByte('"'); err != nil {
+		return err
+	}
+	// Loop over the bytes, not the runes.
+	for i := 0; i < len(s); i++ {
+		var err error
+		// Divergence from C++: we don't escape apostrophes.
+		// There's no need to escape them, and the C++ parser
+		// copes with a naked apostrophe.
+		switch c := s[i]; c {
+		case '\n':
+			_, err = w.w.Write(backslashN)
+		case '\r':
+			_, err = w.w.Write(backslashR)
+		case '\t':
+			_, err = w.w.Write(backslashT)
+		case '"':
+			_, err = w.w.Write(backslashDQ)
+		case '\\':
+			_, err = w.w.Write(backslashBS)
+		default:
+			if isprint(c) {
+				err = w.w.WriteByte(c)
+			} else {
+				_, err = fmt.Fprintf(w.w, "\\%03o", c)
+			}
+		}
+		if err != nil {
+			return err
+		}
+	}
+	return w.WriteByte('"')
+}
+
+func writeUnknownStruct(w *textWriter, data []byte) (err error) {
+	if !w.compact {
+		if _, err := fmt.Fprintf(w, "/* %d unknown bytes */\n", len(data)); err != nil {
+			return err
+		}
+	}
+	b := NewBuffer(data)
+	for b.index < len(b.buf) {
+		x, err := b.DecodeVarint()
+		if err != nil {
+			_, err := fmt.Fprintf(w, "/* %v */\n", err)
+			return err
+		}
+		wire, tag := x&7, x>>3
+		if wire == WireEndGroup {
+			w.unindent()
+			if _, err := w.Write(endBraceNewline); err != nil {
+				return err
+			}
+			continue
+		}
+		if _, err := fmt.Fprint(w, tag); err != nil {
+			return err
+		}
+		if wire != WireStartGroup {
+			if err := w.WriteByte(':'); err != nil {
+				return err
+			}
+		}
+		if !w.compact || wire == WireStartGroup {
+			if err := w.WriteByte(' '); err != nil {
+				return err
+			}
+		}
+		switch wire {
+		case WireBytes:
+			buf, e := b.DecodeRawBytes(false)
+			if e == nil {
+				_, err = fmt.Fprintf(w, "%q", buf)
+			} else {
+				_, err = fmt.Fprintf(w, "/* %v */", e)
+			}
+		case WireFixed32:
+			x, err = b.DecodeFixed32()
+			err = writeUnknownInt(w, x, err)
+		case WireFixed64:
+			x, err = b.DecodeFixed64()
+			err = writeUnknownInt(w, x, err)
+		case WireStartGroup:
+			err = w.WriteByte('{')
+			w.indent()
+		case WireVarint:
+			x, err = b.DecodeVarint()
+			err = writeUnknownInt(w, x, err)
+		default:
+			_, err = fmt.Fprintf(w, "/* unknown wire type %d */", wire)
+		}
+		if err != nil {
+			return err
+		}
+		if err = w.WriteByte('\n'); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func writeUnknownInt(w *textWriter, x uint64, err error) error {
+	if err == nil {
+		_, err = fmt.Fprint(w, x)
+	} else {
+		_, err = fmt.Fprintf(w, "/* %v */", err)
+	}
+	return err
+}
+
+type int32Slice []int32
+
+func (s int32Slice) Len() int           { return len(s) }
+func (s int32Slice) Less(i, j int) bool { return s[i] < s[j] }
+func (s int32Slice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+
+// writeExtensions writes all the extensions in pv.
+// pv is assumed to be a pointer to a protocol message struct that is extendable.
+func (tm *TextMarshaler) writeExtensions(w *textWriter, pv reflect.Value) error {
+	emap := extensionMaps[pv.Type().Elem()]
+	ep, _ := extendable(pv.Interface())
+
+	// Order the extensions by ID.
+	// This isn't strictly necessary, but it will give us
+	// canonical output, which will also make testing easier.
+	m, mu := ep.extensionsRead()
+	if m == nil {
+		return nil
+	}
+	mu.Lock()
+	ids := make([]int32, 0, len(m))
+	for id := range m {
+		ids = append(ids, id)
+	}
+	sort.Sort(int32Slice(ids))
+	mu.Unlock()
+
+	for _, extNum := range ids {
+		ext := m[extNum]
+		var desc *ExtensionDesc
+		if emap != nil {
+			desc = emap[extNum]
+		}
+		if desc == nil {
+			// Unknown extension.
+			if err := writeUnknownStruct(w, ext.enc); err != nil {
+				return err
+			}
+			continue
+		}
+
+		pb, err := GetExtension(ep, desc)
+		if err != nil {
+			return fmt.Errorf("failed getting extension: %v", err)
+		}
+
+		// Repeated extensions will appear as a slice.
+		if !desc.repeated() {
+			if err := tm.writeExtension(w, desc.Name, pb); err != nil {
+				return err
+			}
+		} else {
+			v := reflect.ValueOf(pb)
+			for i := 0; i < v.Len(); i++ {
+				if err := tm.writeExtension(w, desc.Name, v.Index(i).Interface()); err != nil {
+					return err
+				}
+			}
+		}
+	}
+	return nil
+}
+
+func (tm *TextMarshaler) writeExtension(w *textWriter, name string, pb interface{}) error {
+	if _, err := fmt.Fprintf(w, "[%s]:", name); err != nil {
+		return err
+	}
+	if !w.compact {
+		if err := w.WriteByte(' '); err != nil {
+			return err
+		}
+	}
+	if err := tm.writeAny(w, reflect.ValueOf(pb), nil); err != nil {
+		return err
+	}
+	if err := w.WriteByte('\n'); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (w *textWriter) writeIndent() {
+	if !w.complete {
+		return
+	}
+	remain := w.ind * 2
+	for remain > 0 {
+		n := remain
+		if n > len(spaces) {
+			n = len(spaces)
+		}
+		w.w.Write(spaces[:n])
+		remain -= n
+	}
+	w.complete = false
+}
+
+// TextMarshaler is a configurable text format marshaler.
+type TextMarshaler struct {
+	Compact   bool // use compact text format (one line).
+	ExpandAny bool // expand google.protobuf.Any messages of known types
+}
+
+// Marshal writes a given protocol buffer in text format.
+// The only errors returned are from w.
+func (tm *TextMarshaler) Marshal(w io.Writer, pb Message) error {
+	val := reflect.ValueOf(pb)
+	if pb == nil || val.IsNil() {
+		w.Write([]byte("<nil>"))
+		return nil
+	}
+	var bw *bufio.Writer
+	ww, ok := w.(writer)
+	if !ok {
+		bw = bufio.NewWriter(w)
+		ww = bw
+	}
+	aw := &textWriter{
+		w:        ww,
+		complete: true,
+		compact:  tm.Compact,
+	}
+
+	if etm, ok := pb.(encoding.TextMarshaler); ok {
+		text, err := etm.MarshalText()
+		if err != nil {
+			return err
+		}
+		if _, err = aw.Write(text); err != nil {
+			return err
+		}
+		if bw != nil {
+			return bw.Flush()
+		}
+		return nil
+	}
+	// Dereference the received pointer so we don't have outer < and >.
+	v := reflect.Indirect(val)
+	if err := tm.writeStruct(aw, v); err != nil {
+		return err
+	}
+	if bw != nil {
+		return bw.Flush()
+	}
+	return nil
+}
+
+// Text is the same as Marshal, but returns the string directly.
+func (tm *TextMarshaler) Text(pb Message) string {
+	var buf bytes.Buffer
+	tm.Marshal(&buf, pb)
+	return buf.String()
+}
+
+var (
+	defaultTextMarshaler = TextMarshaler{}
+	compactTextMarshaler = TextMarshaler{Compact: true}
+)
+
+// TODO: consider removing some of the Marshal functions below.
+
+// MarshalText writes a given protocol buffer in text format.
+// The only errors returned are from w.
+func MarshalText(w io.Writer, pb Message) error { return defaultTextMarshaler.Marshal(w, pb) }
+
+// MarshalTextString is the same as MarshalText, but returns the string directly.
+func MarshalTextString(pb Message) string { return defaultTextMarshaler.Text(pb) }
+
+// CompactText writes a given protocol buffer in compact text format (one line).
+func CompactText(w io.Writer, pb Message) error { return compactTextMarshaler.Marshal(w, pb) }
+
+// CompactTextString is the same as CompactText, but returns the string directly.
+func CompactTextString(pb Message) string { return compactTextMarshaler.Text(pb) }
diff --git a/vendor/github.com/golang/protobuf/proto/text_parser.go b/vendor/github.com/golang/protobuf/proto/text_parser.go
new file mode 100644
index 00000000..7e6f145a
--- /dev/null
+++ b/vendor/github.com/golang/protobuf/proto/text_parser.go
@@ -0,0 +1,891 @@
+// Go support for Protocol Buffers - Google's data interchange format
+//
+// Copyright 2010 The Go Authors.  All rights reserved.
+// https://github.com/golang/protobuf
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package proto
+
+// Functions for parsing the Text protocol buffer format.
+// TODO: message sets.
+
+import (
+	"encoding"
+	"errors"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+)
+
+// Error string emitted when deserializing Any and fields are already set
+const anyRepeatedlyUnpacked = "Any message unpacked multiple times, or %q already set"
+
+type ParseError struct {
+	Message string
+	Line    int // 1-based line number
+	Offset  int // 0-based byte offset from start of input
+}
+
+func (p *ParseError) Error() string {
+	if p.Line == 1 {
+		// show offset only for first line
+		return fmt.Sprintf("line 1.%d: %v", p.Offset, p.Message)
+	}
+	return fmt.Sprintf("line %d: %v", p.Line, p.Message)
+}
+
+type token struct {
+	value    string
+	err      *ParseError
+	line     int    // line number
+	offset   int    // byte number from start of input, not start of line
+	unquoted string // the unquoted version of value, if it was a quoted string
+}
+
+func (t *token) String() string {
+	if t.err == nil {
+		return fmt.Sprintf("%q (line=%d, offset=%d)", t.value, t.line, t.offset)
+	}
+	return fmt.Sprintf("parse error: %v", t.err)
+}
+
+type textParser struct {
+	s            string // remaining input
+	done         bool   // whether the parsing is finished (success or error)
+	backed       bool   // whether back() was called
+	offset, line int
+	cur          token
+}
+
+func newTextParser(s string) *textParser {
+	p := new(textParser)
+	p.s = s
+	p.line = 1
+	p.cur.line = 1
+	return p
+}
+
+func (p *textParser) errorf(format string, a ...interface{}) *ParseError {
+	pe := &ParseError{fmt.Sprintf(format, a...), p.cur.line, p.cur.offset}
+	p.cur.err = pe
+	p.done = true
+	return pe
+}
+
+// Numbers and identifiers are matched by [-+._A-Za-z0-9]
+func isIdentOrNumberChar(c byte) bool {
+	switch {
+	case 'A' <= c && c <= 'Z', 'a' <= c && c <= 'z':
+		return true
+	case '0' <= c && c <= '9':
+		return true
+	}
+	switch c {
+	case '-', '+', '.', '_':
+		return true
+	}
+	return false
+}
+
+func isWhitespace(c byte) bool {
+	switch c {
+	case ' ', '\t', '\n', '\r':
+		return true
+	}
+	return false
+}
+
+func isQuote(c byte) bool {
+	switch c {
+	case '"', '\'':
+		return true
+	}
+	return false
+}
+
+func (p *textParser) skipWhitespace() {
+	i := 0
+	for i < len(p.s) && (isWhitespace(p.s[i]) || p.s[i] == '#') {
+		if p.s[i] == '#' {
+			// comment; skip to end of line or input
+			for i < len(p.s) && p.s[i] != '\n' {
+				i++
+			}
+			if i == len(p.s) {
+				break
+			}
+		}
+		if p.s[i] == '\n' {
+			p.line++
+		}
+		i++
+	}
+	p.offset += i
+	p.s = p.s[i:len(p.s)]
+	if len(p.s) == 0 {
+		p.done = true
+	}
+}
+
+func (p *textParser) advance() {
+	// Skip whitespace
+	p.skipWhitespace()
+	if p.done {
+		return
+	}
+
+	// Start of non-whitespace
+	p.cur.err = nil
+	p.cur.offset, p.cur.line = p.offset, p.line
+	p.cur.unquoted = ""
+	switch p.s[0] {
+	case '<', '>', '{', '}', ':', '[', ']', ';', ',', '/':
+		// Single symbol
+		p.cur.value, p.s = p.s[0:1], p.s[1:len(p.s)]
+	case '"', '\'':
+		// Quoted string
+		i := 1
+		for i < len(p.s) && p.s[i] != p.s[0] && p.s[i] != '\n' {
+			if p.s[i] == '\\' && i+1 < len(p.s) {
+				// skip escaped char
+				i++
+			}
+			i++
+		}
+		if i >= len(p.s) || p.s[i] != p.s[0] {
+			p.errorf("unmatched quote")
+			return
+		}
+		unq, err := unquoteC(p.s[1:i], rune(p.s[0]))
+		if err != nil {
+			p.errorf("invalid quoted string %s: %v", p.s[0:i+1], err)
+			return
+		}
+		p.cur.value, p.s = p.s[0:i+1], p.s[i+1:len(p.s)]
+		p.cur.unquoted = unq
+	default:
+		i := 0
+		for i < len(p.s) && isIdentOrNumberChar(p.s[i]) {
+			i++
+		}
+		if i == 0 {
+			p.errorf("unexpected byte %#x", p.s[0])
+			return
+		}
+		p.cur.value, p.s = p.s[0:i], p.s[i:len(p.s)]
+	}
+	p.offset += len(p.cur.value)
+}
+
+var (
+	errBadUTF8 = errors.New("proto: bad UTF-8")
+	errBadHex  = errors.New("proto: bad hexadecimal")
+)
+
+func unquoteC(s string, quote rune) (string, error) {
+	// This is based on C++'s tokenizer.cc.
+	// Despite its name, this is *not* parsing C syntax.
+	// For instance, "\0" is an invalid quoted string.
+
+	// Avoid allocation in trivial cases.
+	simple := true
+	for _, r := range s {
+		if r == '\\' || r == quote {
+			simple = false
+			break
+		}
+	}
+	if simple {
+		return s, nil
+	}
+
+	buf := make([]byte, 0, 3*len(s)/2)
+	for len(s) > 0 {
+		r, n := utf8.DecodeRuneInString(s)
+		if r == utf8.RuneError && n == 1 {
+			return "", errBadUTF8
+		}
+		s = s[n:]
+		if r != '\\' {
+			if r < utf8.RuneSelf {
+				buf = append(buf, byte(r))
+			} else {
+				buf = append(buf, string(r)...)
+			}
+			continue
+		}
+
+		ch, tail, err := unescape(s)
+		if err != nil {
+			return "", err
+		}
+		buf = append(buf, ch...)
+		s = tail
+	}
+	return string(buf), nil
+}
+
+func unescape(s string) (ch string, tail string, err error) {
+	r, n := utf8.DecodeRuneInString(s)
+	if r == utf8.RuneError && n == 1 {
+		return "", "", errBadUTF8
+	}
+	s = s[n:]
+	switch r {
+	case 'a':
+		return "\a", s, nil
+	case 'b':
+		return "\b", s, nil
+	case 'f':
+		return "\f", s, nil
+	case 'n':
+		return "\n", s, nil
+	case 'r':
+		return "\r", s, nil
+	case 't':
+		return "\t", s, nil
+	case 'v':
+		return "\v", s, nil
+	case '?':
+		return "?", s, nil // trigraph workaround
+	case '\'', '"', '\\':
+		return string(r), s, nil
+	case '0', '1', '2', '3', '4', '5', '6', '7', 'x', 'X':
+		if len(s) < 2 {
+			return "", "", fmt.Errorf(`\%c requires 2 following digits`, r)
+		}
+		base := 8
+		ss := s[:2]
+		s = s[2:]
+		if r == 'x' || r == 'X' {
+			base = 16
+		} else {
+			ss = string(r) + ss
+		}
+		i, err := strconv.ParseUint(ss, base, 8)
+		if err != nil {
+			return "", "", err
+		}
+		return string([]byte{byte(i)}), s, nil
+	case 'u', 'U':
+		n := 4
+		if r == 'U' {
+			n = 8
+		}
+		if len(s) < n {
+			return "", "", fmt.Errorf(`\%c requires %d digits`, r, n)
+		}
+
+		bs := make([]byte, n/2)
+		for i := 0; i < n; i += 2 {
+			a, ok1 := unhex(s[i])
+			b, ok2 := unhex(s[i+1])
+			if !ok1 || !ok2 {
+				return "", "", errBadHex
+			}
+			bs[i/2] = a<<4 | b
+		}
+		s = s[n:]
+		return string(bs), s, nil
+	}
+	return "", "", fmt.Errorf(`unknown escape \%c`, r)
+}
+
+// Adapted from src/pkg/strconv/quote.go.
+func unhex(b byte) (v byte, ok bool) {
+	switch {
+	case '0' <= b && b <= '9':
+		return b - '0', true
+	case 'a' <= b && b <= 'f':
+		return b - 'a' + 10, true
+	case 'A' <= b && b <= 'F':
+		return b - 'A' + 10, true
+	}
+	return 0, false
+}
+
+// Back off the parser by one token. Can only be done between calls to next().
+// It makes the next advance() a no-op.
+func (p *textParser) back() { p.backed = true }
+
+// Advances the parser and returns the new current token.
+func (p *textParser) next() *token {
+	if p.backed || p.done {
+		p.backed = false
+		return &p.cur
+	}
+	p.advance()
+	if p.done {
+		p.cur.value = ""
+	} else if len(p.cur.value) > 0 && isQuote(p.cur.value[0]) {
+		// Look for multiple quoted strings separated by whitespace,
+		// and concatenate them.
+		cat := p.cur
+		for {
+			p.skipWhitespace()
+			if p.done || !isQuote(p.s[0]) {
+				break
+			}
+			p.advance()
+			if p.cur.err != nil {
+				return &p.cur
+			}
+			cat.value += " " + p.cur.value
+			cat.unquoted += p.cur.unquoted
+		}
+		p.done = false // parser may have seen EOF, but we want to return cat
+		p.cur = cat
+	}
+	return &p.cur
+}
+
+func (p *textParser) consumeToken(s string) error {
+	tok := p.next()
+	if tok.err != nil {
+		return tok.err
+	}
+	if tok.value != s {
+		p.back()
+		return p.errorf("expected %q, found %q", s, tok.value)
+	}
+	return nil
+}
+
+// Return a RequiredNotSetError indicating which required field was not set.
+func (p *textParser) missingRequiredFieldError(sv reflect.Value) *RequiredNotSetError {
+	st := sv.Type()
+	sprops := GetProperties(st)
+	for i := 0; i < st.NumField(); i++ {
+		if !isNil(sv.Field(i)) {
+			continue
+		}
+
+		props := sprops.Prop[i]
+		if props.Required {
+			return &RequiredNotSetError{fmt.Sprintf("%v.%v", st, props.OrigName)}
+		}
+	}
+	return &RequiredNotSetError{fmt.Sprintf("%v.<unknown field name>", st)} // should not happen
+}
+
+// Returns the index in the struct for the named field, as well as the parsed tag properties.
+func structFieldByName(sprops *StructProperties, name string) (int, *Properties, bool) {
+	i, ok := sprops.decoderOrigNames[name]
+	if ok {
+		return i, sprops.Prop[i], true
+	}
+	return -1, nil, false
+}
+
+// Consume a ':' from the input stream (if the next token is a colon),
+// returning an error if a colon is needed but not present.
+func (p *textParser) checkForColon(props *Properties, typ reflect.Type) *ParseError {
+	tok := p.next()
+	if tok.err != nil {
+		return tok.err
+	}
+	if tok.value != ":" {
+		// Colon is optional when the field is a group or message.
+		needColon := true
+		switch props.Wire {
+		case "group":
+			needColon = false
+		case "bytes":
+			// A "bytes" field is either a message, a string, or a repeated field;
+			// those three become *T, *string and []T respectively, so we can check for
+			// this field being a pointer to a non-string.
+			if typ.Kind() == reflect.Ptr {
+				// *T or *string
+				if typ.Elem().Kind() == reflect.String {
+					break
+				}
+			} else if typ.Kind() == reflect.Slice {
+				// []T or []*T
+				if typ.Elem().Kind() != reflect.Ptr {
+					break
+				}
+			} else if typ.Kind() == reflect.String {
+				// The proto3 exception is for a string field,
+				// which requires a colon.
+				break
+			}
+			needColon = false
+		}
+		if needColon {
+			return p.errorf("expected ':', found %q", tok.value)
+		}
+		p.back()
+	}
+	return nil
+}
+
+func (p *textParser) readStruct(sv reflect.Value, terminator string) error {
+	st := sv.Type()
+	sprops := GetProperties(st)
+	reqCount := sprops.reqCount
+	var reqFieldErr error
+	fieldSet := make(map[string]bool)
+	// A struct is a sequence of "name: value", terminated by one of
+	// '>' or '}', or the end of the input.  A name may also be
+	// "[extension]" or "[type/url]".
+	//
+	// The whole struct can also be an expanded Any message, like:
+	// [type/url] < ... struct contents ... >
+	for {
+		tok := p.next()
+		if tok.err != nil {
+			return tok.err
+		}
+		if tok.value == terminator {
+			break
+		}
+		if tok.value == "[" {
+			// Looks like an extension or an Any.
+			//
+			// TODO: Check whether we need to handle
+			// namespace rooted names (e.g. ".something.Foo").
+			extName, err := p.consumeExtName()
+			if err != nil {
+				return err
+			}
+
+			if s := strings.LastIndex(extName, "/"); s >= 0 {
+				// If it contains a slash, it's an Any type URL.
+				messageName := extName[s+1:]
+				mt := MessageType(messageName)
+				if mt == nil {
+					return p.errorf("unrecognized message %q in google.protobuf.Any", messageName)
+				}
+				tok = p.next()
+				if tok.err != nil {
+					return tok.err
+				}
+				// consume an optional colon
+				if tok.value == ":" {
+					tok = p.next()
+					if tok.err != nil {
+						return tok.err
+					}
+				}
+				var terminator string
+				switch tok.value {
+				case "<":
+					terminator = ">"
+				case "{":
+					terminator = "}"
+				default:
+					return p.errorf("expected '{' or '<', found %q", tok.value)
+				}
+				v := reflect.New(mt.Elem())
+				if pe := p.readStruct(v.Elem(), terminator); pe != nil {
+					return pe
+				}
+				b, err := Marshal(v.Interface().(Message))
+				if err != nil {
+					return p.errorf("failed to marshal message of type %q: %v", messageName, err)
+				}
+				if fieldSet["type_url"] {
+					return p.errorf(anyRepeatedlyUnpacked, "type_url")
+				}
+				if fieldSet["value"] {
+					return p.errorf(anyRepeatedlyUnpacked, "value")
+				}
+				sv.FieldByName("TypeUrl").SetString(extName)
+				sv.FieldByName("Value").SetBytes(b)
+				fieldSet["type_url"] = true
+				fieldSet["value"] = true
+				continue
+			}
+
+			var desc *ExtensionDesc
+			// This could be faster, but it's functional.
+			// TODO: Do something smarter than a linear scan.
+			for _, d := range RegisteredExtensions(reflect.New(st).Interface().(Message)) {
+				if d.Name == extName {
+					desc = d
+					break
+				}
+			}
+			if desc == nil {
+				return p.errorf("unrecognized extension %q", extName)
+			}
+
+			props := &Properties{}
+			props.Parse(desc.Tag)
+
+			typ := reflect.TypeOf(desc.ExtensionType)
+			if err := p.checkForColon(props, typ); err != nil {
+				return err
+			}
+
+			rep := desc.repeated()
+
+			// Read the extension structure, and set it in
+			// the value we're constructing.
+			var ext reflect.Value
+			if !rep {
+				ext = reflect.New(typ).Elem()
+			} else {
+				ext = reflect.New(typ.Elem()).Elem()
+			}
+			if err := p.readAny(ext, props); err != nil {
+				if _, ok := err.(*RequiredNotSetError); !ok {
+					return err
+				}
+				reqFieldErr = err
+			}
+			ep := sv.Addr().Interface().(Message)
+			if !rep {
+				SetExtension(ep, desc, ext.Interface())
+			} else {
+				old, err := GetExtension(ep, desc)
+				var sl reflect.Value
+				if err == nil {
+					sl = reflect.ValueOf(old) // existing slice
+				} else {
+					sl = reflect.MakeSlice(typ, 0, 1)
+				}
+				sl = reflect.Append(sl, ext)
+				SetExtension(ep, desc, sl.Interface())
+			}
+			if err := p.consumeOptionalSeparator(); err != nil {
+				return err
+			}
+			continue
+		}
+
+		// This is a normal, non-extension field.
+		name := tok.value
+		var dst reflect.Value
+		fi, props, ok := structFieldByName(sprops, name)
+		if ok {
+			dst = sv.Field(fi)
+		} else if oop, ok := sprops.OneofTypes[name]; ok {
+			// It is a oneof.
+			props = oop.Prop
+			nv := reflect.New(oop.Type.Elem())
+			dst = nv.Elem().Field(0)
+			sv.Field(oop.Field).Set(nv)
+		}
+		if !dst.IsValid() {
+			return p.errorf("unknown field name %q in %v", name, st)
+		}
+
+		if dst.Kind() == reflect.Map {
+			// Consume any colon.
+			if err := p.checkForColon(props, dst.Type()); err != nil {
+				return err
+			}
+
+			// Construct the map if it doesn't already exist.
+			if dst.IsNil() {
+				dst.Set(reflect.MakeMap(dst.Type()))
+			}
+			key := reflect.New(dst.Type().Key()).Elem()
+			val := reflect.New(dst.Type().Elem()).Elem()
+
+			// The map entry should be this sequence of tokens:
+			//	< key : KEY value : VALUE >
+			// However, implementations may omit key or value, and technically
+			// we should support them in any order.  See b/28924776 for a time
+			// this went wrong.
+
+			tok := p.next()
+			var terminator string
+			switch tok.value {
+			case "<":
+				terminator = ">"
+			case "{":
+				terminator = "}"
+			default:
+				return p.errorf("expected '{' or '<', found %q", tok.value)
+			}
+			for {
+				tok := p.next()
+				if tok.err != nil {
+					return tok.err
+				}
+				if tok.value == terminator {
+					break
+				}
+				switch tok.value {
+				case "key":
+					if err := p.consumeToken(":"); err != nil {
+						return err
+					}
+					if err := p.readAny(key, props.mkeyprop); err != nil {
+						return err
+					}
+					if err := p.consumeOptionalSeparator(); err != nil {
+						return err
+					}
+				case "value":
+					if err := p.checkForColon(props.mvalprop, dst.Type().Elem()); err != nil {
+						return err
+					}
+					if err := p.readAny(val, props.mvalprop); err != nil {
+						return err
+					}
+					if err := p.consumeOptionalSeparator(); err != nil {
+						return err
+					}
+				default:
+					p.back()
+					return p.errorf(`expected "key", "value", or %q, found %q`, terminator, tok.value)
+				}
+			}
+
+			dst.SetMapIndex(key, val)
+			continue
+		}
+
+		// Check that it's not already set if it's not a repeated field.
+		if !props.Repeated && fieldSet[name] {
+			return p.errorf("non-repeated field %q was repeated", name)
+		}
+
+		if err := p.checkForColon(props, dst.Type()); err != nil {
+			return err
+		}
+
+		// Parse into the field.
+		fieldSet[name] = true
+		if err := p.readAny(dst, props); err != nil {
+			if _, ok := err.(*RequiredNotSetError); !ok {
+				return err
+			}
+			reqFieldErr = err
+		}
+		if props.Required {
+			reqCount--
+		}
+
+		if err := p.consumeOptionalSeparator(); err != nil {
+			return err
+		}
+
+	}
+
+	if reqCount > 0 {
+		return p.missingRequiredFieldError(sv)
+	}
+	return reqFieldErr
+}
+
+// consumeExtName consumes extension name or expanded Any type URL and the
+// following ']'. It returns the name or URL consumed.
+func (p *textParser) consumeExtName() (string, error) {
+	tok := p.next()
+	if tok.err != nil {
+		return "", tok.err
+	}
+
+	// If extension name or type url is quoted, it's a single token.
+	if len(tok.value) > 2 && isQuote(tok.value[0]) && tok.value[len(tok.value)-1] == tok.value[0] {
+		name, err := unquoteC(tok.value[1:len(tok.value)-1], rune(tok.value[0]))
+		if err != nil {
+			return "", err
+		}
+		return name, p.consumeToken("]")
+	}
+
+	// Consume everything up to "]"
+	var parts []string
+	for tok.value != "]" {
+		parts = append(parts, tok.value)
+		tok = p.next()
+		if tok.err != nil {
+			return "", p.errorf("unrecognized type_url or extension name: %s", tok.err)
+		}
+	}
+	return strings.Join(parts, ""), nil
+}
+
+// consumeOptionalSeparator consumes an optional semicolon or comma.
+// It is used in readStruct to provide backward compatibility.
+func (p *textParser) consumeOptionalSeparator() error {
+	tok := p.next()
+	if tok.err != nil {
+		return tok.err
+	}
+	if tok.value != ";" && tok.value != "," {
+		p.back()
+	}
+	return nil
+}
+
+func (p *textParser) readAny(v reflect.Value, props *Properties) error {
+	tok := p.next()
+	if tok.err != nil {
+		return tok.err
+	}
+	if tok.value == "" {
+		return p.errorf("unexpected EOF")
+	}
+
+	switch fv := v; fv.Kind() {
+	case reflect.Slice:
+		at := v.Type()
+		if at.Elem().Kind() == reflect.Uint8 {
+			// Special case for []byte
+			if tok.value[0] != '"' && tok.value[0] != '\'' {
+				// Deliberately written out here, as the error after
+				// this switch statement would write "invalid []byte: ...",
+				// which is not as user-friendly.
+				return p.errorf("invalid string: %v", tok.value)
+			}
+			bytes := []byte(tok.unquoted)
+			fv.Set(reflect.ValueOf(bytes))
+			return nil
+		}
+		// Repeated field.
+		if tok.value == "[" {
+			// Repeated field with list notation, like [1,2,3].
+			for {
+				fv.Set(reflect.Append(fv, reflect.New(at.Elem()).Elem()))
+				err := p.readAny(fv.Index(fv.Len()-1), props)
+				if err != nil {
+					return err
+				}
+				tok := p.next()
+				if tok.err != nil {
+					return tok.err
+				}
+				if tok.value == "]" {
+					break
+				}
+				if tok.value != "," {
+					return p.errorf("Expected ']' or ',' found %q", tok.value)
+				}
+			}
+			return nil
+		}
+		// One value of the repeated field.
+		p.back()
+		fv.Set(reflect.Append(fv, reflect.New(at.Elem()).Elem()))
+		return p.readAny(fv.Index(fv.Len()-1), props)
+	case reflect.Bool:
+		// Either "true", "false", 1 or 0.
+		switch tok.value {
+		case "true", "1":
+			fv.SetBool(true)
+			return nil
+		case "false", "0":
+			fv.SetBool(false)
+			return nil
+		}
+	case reflect.Float32, reflect.Float64:
+		v := tok.value
+		// Ignore 'f' for compatibility with output generated by C++, but don't
+		// remove 'f' when the value is "-inf" or "inf".
+		if strings.HasSuffix(v, "f") && tok.value != "-inf" && tok.value != "inf" {
+			v = v[:len(v)-1]
+		}
+		if f, err := strconv.ParseFloat(v, fv.Type().Bits()); err == nil {
+			fv.SetFloat(f)
+			return nil
+		}
+	case reflect.Int32:
+		if x, err := strconv.ParseInt(tok.value, 0, 32); err == nil {
+			fv.SetInt(x)
+			return nil
+		}
+
+		if len(props.Enum) == 0 {
+			break
+		}
+		m, ok := enumValueMaps[props.Enum]
+		if !ok {
+			break
+		}
+		x, ok := m[tok.value]
+		if !ok {
+			break
+		}
+		fv.SetInt(int64(x))
+		return nil
+	case reflect.Int64:
+		if x, err := strconv.ParseInt(tok.value, 0, 64); err == nil {
+			fv.SetInt(x)
+			return nil
+		}
+
+	case reflect.Ptr:
+		// A basic field (indirected through pointer), or a repeated message/group
+		p.back()
+		fv.Set(reflect.New(fv.Type().Elem()))
+		return p.readAny(fv.Elem(), props)
+	case reflect.String:
+		if tok.value[0] == '"' || tok.value[0] == '\'' {
+			fv.SetString(tok.unquoted)
+			return nil
+		}
+	case reflect.Struct:
+		var terminator string
+		switch tok.value {
+		case "{":
+			terminator = "}"
+		case "<":
+			terminator = ">"
+		default:
+			return p.errorf("expected '{' or '<', found %q", tok.value)
+		}
+		// TODO: Handle nested messages which implement encoding.TextUnmarshaler.
+		return p.readStruct(fv, terminator)
+	case reflect.Uint32:
+		if x, err := strconv.ParseUint(tok.value, 0, 32); err == nil {
+			fv.SetUint(uint64(x))
+			return nil
+		}
+	case reflect.Uint64:
+		if x, err := strconv.ParseUint(tok.value, 0, 64); err == nil {
+			fv.SetUint(x)
+			return nil
+		}
+	}
+	return p.errorf("invalid %v: %v", v.Type(), tok.value)
+}
+
+// UnmarshalText reads a protocol buffer in Text format. UnmarshalText resets pb
+// before starting to unmarshal, so any existing data in pb is always removed.
+// If a required field is not set and no other error occurs,
+// UnmarshalText returns *RequiredNotSetError.
+func UnmarshalText(s string, pb Message) error {
+	if um, ok := pb.(encoding.TextUnmarshaler); ok {
+		err := um.UnmarshalText([]byte(s))
+		return err
+	}
+	pb.Reset()
+	v := reflect.ValueOf(pb)
+	if pe := newTextParser(s).readStruct(v.Elem(), ""); pe != nil {
+		return pe
+	}
+	return nil
+}
diff --git a/vendor/github.com/matttproud/golang_protobuf_extensions/LICENSE b/vendor/github.com/matttproud/golang_protobuf_extensions/LICENSE
new file mode 100644
index 00000000..8dada3ed
--- /dev/null
+++ b/vendor/github.com/matttproud/golang_protobuf_extensions/LICENSE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/vendor/github.com/matttproud/golang_protobuf_extensions/NOTICE b/vendor/github.com/matttproud/golang_protobuf_extensions/NOTICE
new file mode 100644
index 00000000..5d8cb5b7
--- /dev/null
+++ b/vendor/github.com/matttproud/golang_protobuf_extensions/NOTICE
@@ -0,0 +1 @@
+Copyright 2012 Matt T. Proud (matt.proud@gmail.com)
diff --git a/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/.gitignore b/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/.gitignore
new file mode 100644
index 00000000..e16fb946
--- /dev/null
+++ b/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/.gitignore
@@ -0,0 +1 @@
+cover.dat
diff --git a/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/Makefile b/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/Makefile
new file mode 100644
index 00000000..81be2143
--- /dev/null
+++ b/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/Makefile
@@ -0,0 +1,7 @@
+all:
+
+cover:
+	go test -cover -v -coverprofile=cover.dat ./...
+	go tool cover -func cover.dat
+
+.PHONY: cover
diff --git a/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/decode.go b/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/decode.go
new file mode 100644
index 00000000..258c0636
--- /dev/null
+++ b/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/decode.go
@@ -0,0 +1,75 @@
+// Copyright 2013 Matt T. Proud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pbutil
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+
+	"github.com/golang/protobuf/proto"
+)
+
+var errInvalidVarint = errors.New("invalid varint32 encountered")
+
+// ReadDelimited decodes a message from the provided length-delimited stream,
+// where the length is encoded as 32-bit varint prefix to the message body.
+// It returns the total number of bytes read and any applicable error.  This is
+// roughly equivalent to the companion Java API's
+// MessageLite#parseDelimitedFrom.  As per the reader contract, this function
+// calls r.Read repeatedly as required until exactly one message including its
+// prefix is read and decoded (or an error has occurred).  The function never
+// reads more bytes from the stream than required.  The function never returns
+// an error if a message has been read and decoded correctly, even if the end
+// of the stream has been reached in doing so.  In that case, any subsequent
+// calls return (0, io.EOF).
+func ReadDelimited(r io.Reader, m proto.Message) (n int, err error) {
+	// Per AbstractParser#parsePartialDelimitedFrom with
+	// CodedInputStream#readRawVarint32.
+	var headerBuf [binary.MaxVarintLen32]byte
+	var bytesRead, varIntBytes int
+	var messageLength uint64
+	for varIntBytes == 0 { // i.e. no varint has been decoded yet.
+		if bytesRead >= len(headerBuf) {
+			return bytesRead, errInvalidVarint
+		}
+		// We have to read byte by byte here to avoid reading more bytes
+		// than required. Each read byte is appended to what we have
+		// read before.
+		newBytesRead, err := r.Read(headerBuf[bytesRead : bytesRead+1])
+		if newBytesRead == 0 {
+			if err != nil {
+				return bytesRead, err
+			}
+			// A Reader should not return (0, nil), but if it does,
+			// it should be treated as no-op (according to the
+			// Reader contract). So let's go on...
+			continue
+		}
+		bytesRead += newBytesRead
+		// Now present everything read so far to the varint decoder and
+		// see if a varint can be decoded already.
+		messageLength, varIntBytes = proto.DecodeVarint(headerBuf[:bytesRead])
+	}
+
+	messageBuf := make([]byte, messageLength)
+	newBytesRead, err := io.ReadFull(r, messageBuf)
+	bytesRead += newBytesRead
+	if err != nil {
+		return bytesRead, err
+	}
+
+	return bytesRead, proto.Unmarshal(messageBuf, m)
+}
diff --git a/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/doc.go b/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/doc.go
new file mode 100644
index 00000000..c318385c
--- /dev/null
+++ b/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/doc.go
@@ -0,0 +1,16 @@
+// Copyright 2013 Matt T. Proud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package pbutil provides record length-delimited Protocol Buffer streaming.
+package pbutil
diff --git a/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/encode.go b/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/encode.go
new file mode 100644
index 00000000..8fb59ad2
--- /dev/null
+++ b/vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/encode.go
@@ -0,0 +1,46 @@
+// Copyright 2013 Matt T. Proud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pbutil
+
+import (
+	"encoding/binary"
+	"io"
+
+	"github.com/golang/protobuf/proto"
+)
+
+// WriteDelimited encodes and dumps a message to the provided writer prefixed
+// with a 32-bit varint indicating the length of the encoded message, producing
+// a length-delimited record stream, which can be used to chain together
+// encoded messages of the same type together in a file.  It returns the total
+// number of bytes written and any applicable error.  This is roughly
+// equivalent to the companion Java API's MessageLite#writeDelimitedTo.
+func WriteDelimited(w io.Writer, m proto.Message) (n int, err error) {
+	buffer, err := proto.Marshal(m)
+	if err != nil {
+		return 0, err
+	}
+
+	var buf [binary.MaxVarintLen32]byte
+	encodedLength := binary.PutUvarint(buf[:], uint64(len(buffer)))
+
+	sync, err := w.Write(buf[:encodedLength])
+	if err != nil {
+		return sync, err
+	}
+
+	n, err = w.Write(buffer)
+	return n + sync, err
+}
diff --git a/vendor/github.com/prometheus/client_golang/AUTHORS.md b/vendor/github.com/prometheus/client_golang/AUTHORS.md
new file mode 100644
index 00000000..c5275d5a
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/AUTHORS.md
@@ -0,0 +1,18 @@
+The Prometheus project was started by Matt T. Proud (emeritus) and
+Julius Volz in 2012.
+
+Maintainers of this repository:
+
+* Björn Rabenstein <beorn@soundcloud.com>
+
+The following individuals have contributed code to this repository
+(listed in alphabetical order):
+
+* Bernerd Schaefer <bj.schaefer@gmail.com>
+* Björn Rabenstein <beorn@soundcloud.com>
+* Daniel Bornkessel <daniel@soundcloud.com>
+* Jeff Younker <jeff@drinktomi.com>
+* Julius Volz <julius.volz@gmail.com>
+* Matt T. Proud <matt.proud@gmail.com>
+* Tobias Schmidt <ts@soundcloud.com>
+
diff --git a/vendor/github.com/prometheus/client_golang/LICENSE b/vendor/github.com/prometheus/client_golang/LICENSE
new file mode 100644
index 00000000..261eeb9e
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/LICENSE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/vendor/github.com/prometheus/client_golang/NOTICE b/vendor/github.com/prometheus/client_golang/NOTICE
new file mode 100644
index 00000000..dd878a30
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/NOTICE
@@ -0,0 +1,23 @@
+Prometheus instrumentation library for Go applications
+Copyright 2012-2015 The Prometheus Authors
+
+This product includes software developed at
+SoundCloud Ltd. (http://soundcloud.com/).
+
+
+The following components are included in this product:
+
+perks - a fork of https://github.com/bmizerany/perks
+https://github.com/beorn7/perks
+Copyright 2013-2015 Blake Mizerany, Björn Rabenstein
+See https://github.com/beorn7/perks/blob/master/README.md for license details.
+
+Go support for Protocol Buffers - Google's data interchange format
+http://github.com/golang/protobuf/
+Copyright 2010 The Go Authors
+See source code for license details.
+
+Support for streaming Protocol Buffer messages for the Go language (golang).
+https://github.com/matttproud/golang_protobuf_extensions
+Copyright 2013 Matt T. Proud
+Licensed under the Apache License, Version 2.0
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/.gitignore b/vendor/github.com/prometheus/client_golang/prometheus/.gitignore
new file mode 100644
index 00000000..3460f034
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/.gitignore
@@ -0,0 +1 @@
+command-line-arguments.test
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/README.md b/vendor/github.com/prometheus/client_golang/prometheus/README.md
new file mode 100644
index 00000000..44986bff
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/README.md
@@ -0,0 +1 @@
+See [![go-doc](https://godoc.org/github.com/prometheus/client_golang/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/prometheus).
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/collector.go b/vendor/github.com/prometheus/client_golang/prometheus/collector.go
new file mode 100644
index 00000000..623d3d83
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/collector.go
@@ -0,0 +1,75 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Collector is the interface implemented by anything that can be used by
+// Prometheus to collect metrics. A Collector has to be registered for
+// collection. See Registerer.Register.
+//
+// The stock metrics provided by this package (Gauge, Counter, Summary,
+// Histogram, Untyped) are also Collectors (which only ever collect one metric,
+// namely itself). An implementer of Collector may, however, collect multiple
+// metrics in a coordinated fashion and/or create metrics on the fly. Examples
+// for collectors already implemented in this library are the metric vectors
+// (i.e. collection of multiple instances of the same Metric but with different
+// label values) like GaugeVec or SummaryVec, and the ExpvarCollector.
+type Collector interface {
+	// Describe sends the super-set of all possible descriptors of metrics
+	// collected by this Collector to the provided channel and returns once
+	// the last descriptor has been sent. The sent descriptors fulfill the
+	// consistency and uniqueness requirements described in the Desc
+	// documentation. (It is valid if one and the same Collector sends
+	// duplicate descriptors. Those duplicates are simply ignored. However,
+	// two different Collectors must not send duplicate descriptors.) This
+	// method idempotently sends the same descriptors throughout the
+	// lifetime of the Collector. If a Collector encounters an error while
+	// executing this method, it must send an invalid descriptor (created
+	// with NewInvalidDesc) to signal the error to the registry.
+	Describe(chan<- *Desc)
+	// Collect is called by the Prometheus registry when collecting
+	// metrics. The implementation sends each collected metric via the
+	// provided channel and returns once the last metric has been sent. The
+	// descriptor of each sent metric is one of those returned by
+	// Describe. Returned metrics that share the same descriptor must differ
+	// in their variable label values. This method may be called
+	// concurrently and must therefore be implemented in a concurrency safe
+	// way. Blocking occurs at the expense of total performance of rendering
+	// all registered metrics. Ideally, Collector implementations support
+	// concurrent readers.
+	Collect(chan<- Metric)
+}
+
+// selfCollector implements Collector for a single Metric so that the Metric
+// collects itself. Add it as an anonymous field to a struct that implements
+// Metric, and call init with the Metric itself as an argument.
+type selfCollector struct {
+	self Metric
+}
+
+// init provides the selfCollector with a reference to the metric it is supposed
+// to collect. It is usually called within the factory function to create a
+// metric. See example.
+func (c *selfCollector) init(self Metric) {
+	c.self = self
+}
+
+// Describe implements Collector.
+func (c *selfCollector) Describe(ch chan<- *Desc) {
+	ch <- c.self.Desc()
+}
+
+// Collect implements Collector.
+func (c *selfCollector) Collect(ch chan<- Metric) {
+	ch <- c.self
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/counter.go b/vendor/github.com/prometheus/client_golang/prometheus/counter.go
new file mode 100644
index 00000000..ee37949a
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/counter.go
@@ -0,0 +1,172 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+)
+
+// Counter is a Metric that represents a single numerical value that only ever
+// goes up. That implies that it cannot be used to count items whose number can
+// also go down, e.g. the number of currently running goroutines. Those
+// "counters" are represented by Gauges.
+//
+// A Counter is typically used to count requests served, tasks completed, errors
+// occurred, etc.
+//
+// To create Counter instances, use NewCounter.
+type Counter interface {
+	Metric
+	Collector
+
+	// Set is used to set the Counter to an arbitrary value. It is only used
+	// if you have to transfer a value from an external counter into this
+	// Prometheus metric. Do not use it for regular handling of a
+	// Prometheus counter (as it can be used to break the contract of
+	// monotonically increasing values).
+	//
+	// Deprecated: Use NewConstMetric to create a counter for an external
+	// value. A Counter should never be set.
+	Set(float64)
+	// Inc increments the counter by 1.
+	Inc()
+	// Add adds the given value to the counter. It panics if the value is <
+	// 0.
+	Add(float64)
+}
+
+// CounterOpts is an alias for Opts. See there for doc comments.
+type CounterOpts Opts
+
+// NewCounter creates a new Counter based on the provided CounterOpts.
+func NewCounter(opts CounterOpts) Counter {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	)
+	result := &counter{value: value{desc: desc, valType: CounterValue, labelPairs: desc.constLabelPairs}}
+	result.init(result) // Init self-collection.
+	return result
+}
+
+type counter struct {
+	value
+}
+
+func (c *counter) Add(v float64) {
+	if v < 0 {
+		panic(errors.New("counter cannot decrease in value"))
+	}
+	c.value.Add(v)
+}
+
+// CounterVec is a Collector that bundles a set of Counters that all share the
+// same Desc, but have different values for their variable labels. This is used
+// if you want to count the same thing partitioned by various dimensions
+// (e.g. number of HTTP requests, partitioned by response code and
+// method). Create instances with NewCounterVec.
+//
+// CounterVec embeds MetricVec. See there for a full list of methods with
+// detailed documentation.
+type CounterVec struct {
+	*MetricVec
+}
+
+// NewCounterVec creates a new CounterVec based on the provided CounterOpts and
+// partitioned by the given label names. At least one label name must be
+// provided.
+func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		labelNames,
+		opts.ConstLabels,
+	)
+	return &CounterVec{
+		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			result := &counter{value: value{
+				desc:       desc,
+				valType:    CounterValue,
+				labelPairs: makeLabelPairs(desc, lvs),
+			}}
+			result.init(result) // Init self-collection.
+			return result
+		}),
+	}
+}
+
+// GetMetricWithLabelValues replaces the method of the same name in
+// MetricVec. The difference is that this method returns a Counter and not a
+// Metric so that no type conversion is required.
+func (m *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
+	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Counter), err
+	}
+	return nil, err
+}
+
+// GetMetricWith replaces the method of the same name in MetricVec. The
+// difference is that this method returns a Counter and not a Metric so that no
+// type conversion is required.
+func (m *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
+	metric, err := m.MetricVec.GetMetricWith(labels)
+	if metric != nil {
+		return metric.(Counter), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. By not returning an
+// error, WithLabelValues allows shortcuts like
+//     myVec.WithLabelValues("404", "GET").Add(42)
+func (m *CounterVec) WithLabelValues(lvs ...string) Counter {
+	return m.MetricVec.WithLabelValues(lvs...).(Counter)
+}
+
+// With works as GetMetricWith, but panics where GetMetricWithLabels would have
+// returned an error. By not returning an error, With allows shortcuts like
+//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
+func (m *CounterVec) With(labels Labels) Counter {
+	return m.MetricVec.With(labels).(Counter)
+}
+
+// CounterFunc is a Counter whose value is determined at collect time by calling a
+// provided function.
+//
+// To create CounterFunc instances, use NewCounterFunc.
+type CounterFunc interface {
+	Metric
+	Collector
+}
+
+// NewCounterFunc creates a new CounterFunc based on the provided
+// CounterOpts. The value reported is determined by calling the given function
+// from within the Write method. Take into account that metric collection may
+// happen concurrently. If that results in concurrent calls to Write, like in
+// the case where a CounterFunc is directly registered with Prometheus, the
+// provided function must be concurrency-safe. The function should also honor
+// the contract for a Counter (values only go up, not down), but compliance will
+// not be checked.
+func NewCounterFunc(opts CounterOpts, function func() float64) CounterFunc {
+	return newValueFunc(NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	), CounterValue, function)
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/desc.go b/vendor/github.com/prometheus/client_golang/prometheus/desc.go
new file mode 100644
index 00000000..0593be50
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/desc.go
@@ -0,0 +1,205 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"sort"
+	"strings"
+
+	"github.com/golang/protobuf/proto"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+var (
+	metricNameRE = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_:]*$`)
+	labelNameRE  = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
+)
+
+// reservedLabelPrefix is a prefix which is not legal in user-supplied
+// label names.
+const reservedLabelPrefix = "__"
+
+// Labels represents a collection of label name -> value mappings. This type is
+// commonly used with the With(Labels) and GetMetricWith(Labels) methods of
+// metric vector Collectors, e.g.:
+//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
+//
+// The other use-case is the specification of constant label pairs in Opts or to
+// create a Desc.
+type Labels map[string]string
+
+// Desc is the descriptor used by every Prometheus Metric. It is essentially
+// the immutable meta-data of a Metric. The normal Metric implementations
+// included in this package manage their Desc under the hood. Users only have to
+// deal with Desc if they use advanced features like the ExpvarCollector or
+// custom Collectors and Metrics.
+//
+// Descriptors registered with the same registry have to fulfill certain
+// consistency and uniqueness criteria if they share the same fully-qualified
+// name: They must have the same help string and the same label names (aka label
+// dimensions) in each, constLabels and variableLabels, but they must differ in
+// the values of the constLabels.
+//
+// Descriptors that share the same fully-qualified names and the same label
+// values of their constLabels are considered equal.
+//
+// Use NewDesc to create new Desc instances.
+type Desc struct {
+	// fqName has been built from Namespace, Subsystem, and Name.
+	fqName string
+	// help provides some helpful information about this metric.
+	help string
+	// constLabelPairs contains precalculated DTO label pairs based on
+	// the constant labels.
+	constLabelPairs []*dto.LabelPair
+	// VariableLabels contains names of labels for which the metric
+	// maintains variable values.
+	variableLabels []string
+	// id is a hash of the values of the ConstLabels and fqName. This
+	// must be unique among all registered descriptors and can therefore be
+	// used as an identifier of the descriptor.
+	id uint64
+	// dimHash is a hash of the label names (preset and variable) and the
+	// Help string. Each Desc with the same fqName must have the same
+	// dimHash.
+	dimHash uint64
+	// err is an error that occurred during construction. It is reported on
+	// registration time.
+	err error
+}
+
+// NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc
+// and will be reported on registration time. variableLabels and constLabels can
+// be nil if no such labels should be set. fqName and help must not be empty.
+//
+// variableLabels only contain the label names. Their label values are variable
+// and therefore not part of the Desc. (They are managed within the Metric.)
+//
+// For constLabels, the label values are constant. Therefore, they are fully
+// specified in the Desc. See the Opts documentation for the implications of
+// constant labels.
+func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *Desc {
+	d := &Desc{
+		fqName:         fqName,
+		help:           help,
+		variableLabels: variableLabels,
+	}
+	if help == "" {
+		d.err = errors.New("empty help string")
+		return d
+	}
+	if !metricNameRE.MatchString(fqName) {
+		d.err = fmt.Errorf("%q is not a valid metric name", fqName)
+		return d
+	}
+	// labelValues contains the label values of const labels (in order of
+	// their sorted label names) plus the fqName (at position 0).
+	labelValues := make([]string, 1, len(constLabels)+1)
+	labelValues[0] = fqName
+	labelNames := make([]string, 0, len(constLabels)+len(variableLabels))
+	labelNameSet := map[string]struct{}{}
+	// First add only the const label names and sort them...
+	for labelName := range constLabels {
+		if !checkLabelName(labelName) {
+			d.err = fmt.Errorf("%q is not a valid label name", labelName)
+			return d
+		}
+		labelNames = append(labelNames, labelName)
+		labelNameSet[labelName] = struct{}{}
+	}
+	sort.Strings(labelNames)
+	// ... so that we can now add const label values in the order of their names.
+	for _, labelName := range labelNames {
+		labelValues = append(labelValues, constLabels[labelName])
+	}
+	// Now add the variable label names, but prefix them with something that
+	// cannot be in a regular label name. That prevents matching the label
+	// dimension with a different mix between preset and variable labels.
+	for _, labelName := range variableLabels {
+		if !checkLabelName(labelName) {
+			d.err = fmt.Errorf("%q is not a valid label name", labelName)
+			return d
+		}
+		labelNames = append(labelNames, "$"+labelName)
+		labelNameSet[labelName] = struct{}{}
+	}
+	if len(labelNames) != len(labelNameSet) {
+		d.err = errors.New("duplicate label names")
+		return d
+	}
+	vh := hashNew()
+	for _, val := range labelValues {
+		vh = hashAdd(vh, val)
+		vh = hashAddByte(vh, separatorByte)
+	}
+	d.id = vh
+	// Sort labelNames so that order doesn't matter for the hash.
+	sort.Strings(labelNames)
+	// Now hash together (in this order) the help string and the sorted
+	// label names.
+	lh := hashNew()
+	lh = hashAdd(lh, help)
+	lh = hashAddByte(lh, separatorByte)
+	for _, labelName := range labelNames {
+		lh = hashAdd(lh, labelName)
+		lh = hashAddByte(lh, separatorByte)
+	}
+	d.dimHash = lh
+
+	d.constLabelPairs = make([]*dto.LabelPair, 0, len(constLabels))
+	for n, v := range constLabels {
+		d.constLabelPairs = append(d.constLabelPairs, &dto.LabelPair{
+			Name:  proto.String(n),
+			Value: proto.String(v),
+		})
+	}
+	sort.Sort(LabelPairSorter(d.constLabelPairs))
+	return d
+}
+
+// NewInvalidDesc returns an invalid descriptor, i.e. a descriptor with the
+// provided error set. If a collector returning such a descriptor is registered,
+// registration will fail with the provided error. NewInvalidDesc can be used by
+// a Collector to signal inability to describe itself.
+func NewInvalidDesc(err error) *Desc {
+	return &Desc{
+		err: err,
+	}
+}
+
+func (d *Desc) String() string {
+	lpStrings := make([]string, 0, len(d.constLabelPairs))
+	for _, lp := range d.constLabelPairs {
+		lpStrings = append(
+			lpStrings,
+			fmt.Sprintf("%s=%q", lp.GetName(), lp.GetValue()),
+		)
+	}
+	return fmt.Sprintf(
+		"Desc{fqName: %q, help: %q, constLabels: {%s}, variableLabels: %v}",
+		d.fqName,
+		d.help,
+		strings.Join(lpStrings, ","),
+		d.variableLabels,
+	)
+}
+
+func checkLabelName(l string) bool {
+	return labelNameRE.MatchString(l) &&
+		!strings.HasPrefix(l, reservedLabelPrefix)
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/doc.go b/vendor/github.com/prometheus/client_golang/prometheus/doc.go
new file mode 100644
index 00000000..b15a2d3b
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/doc.go
@@ -0,0 +1,181 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package prometheus provides metrics primitives to instrument code for
+// monitoring. It also offers a registry for metrics. Sub-packages allow to
+// expose the registered metrics via HTTP (package promhttp) or push them to a
+// Pushgateway (package push).
+//
+// All exported functions and methods are safe to be used concurrently unless
+//specified otherwise.
+//
+// A Basic Example
+//
+// As a starting point, a very basic usage example:
+//
+//    package main
+//
+//    import (
+//    	"net/http"
+//
+//    	"github.com/prometheus/client_golang/prometheus"
+//    	"github.com/prometheus/client_golang/prometheus/promhttp"
+//    )
+//
+//    var (
+//    	cpuTemp = prometheus.NewGauge(prometheus.GaugeOpts{
+//    		Name: "cpu_temperature_celsius",
+//    		Help: "Current temperature of the CPU.",
+//    	})
+//    	hdFailures = prometheus.NewCounterVec(
+//    		prometheus.CounterOpts{
+//    			Name: "hd_errors_total",
+//    			Help: "Number of hard-disk errors.",
+//    		},
+//    		[]string{"device"},
+//    	)
+//    )
+//
+//    func init() {
+//    	// Metrics have to be registered to be exposed:
+//    	prometheus.MustRegister(cpuTemp)
+//    	prometheus.MustRegister(hdFailures)
+//    }
+//
+//    func main() {
+//    	cpuTemp.Set(65.3)
+//    	hdFailures.With(prometheus.Labels{"device":"/dev/sda"}).Inc()
+//
+//    	// The Handler function provides a default handler to expose metrics
+//    	// via an HTTP server. "/metrics" is the usual endpoint for that.
+//    	http.Handle("/metrics", promhttp.Handler())
+//    	http.ListenAndServe(":8080", nil)
+//    }
+//
+//
+// This is a complete program that exports two metrics, a Gauge and a Counter,
+// the latter with a label attached to turn it into a (one-dimensional) vector.
+//
+// Metrics
+//
+// The number of exported identifiers in this package might appear a bit
+// overwhelming. Hovever, in addition to the basic plumbing shown in the example
+// above, you only need to understand the different metric types and their
+// vector versions for basic usage.
+//
+// Above, you have already touched the Counter and the Gauge. There are two more
+// advanced metric types: the Summary and Histogram. A more thorough description
+// of those four metric types can be found in the Prometheus docs:
+// https://prometheus.io/docs/concepts/metric_types/
+//
+// A fifth "type" of metric is Untyped. It behaves like a Gauge, but signals the
+// Prometheus server not to assume anything about its type.
+//
+// In addition to the fundamental metric types Gauge, Counter, Summary,
+// Histogram, and Untyped, a very important part of the Prometheus data model is
+// the partitioning of samples along dimensions called labels, which results in
+// metric vectors. The fundamental types are GaugeVec, CounterVec, SummaryVec,
+// HistogramVec, and UntypedVec.
+//
+// While only the fundamental metric types implement the Metric interface, both
+// the metrics and their vector versions implement the Collector interface. A
+// Collector manages the collection of a number of Metrics, but for convenience,
+// a Metric can also “collect itself”. Note that Gauge, Counter, Summary,
+// Histogram, and Untyped are interfaces themselves while GaugeVec, CounterVec,
+// SummaryVec, HistogramVec, and UntypedVec are not.
+//
+// To create instances of Metrics and their vector versions, you need a suitable
+// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts,
+// HistogramOpts, or UntypedOpts.
+//
+// Custom Collectors and constant Metrics
+//
+// While you could create your own implementations of Metric, most likely you
+// will only ever implement the Collector interface on your own. At a first
+// glance, a custom Collector seems handy to bundle Metrics for common
+// registration (with the prime example of the different metric vectors above,
+// which bundle all the metrics of the same name but with different labels).
+//
+// There is a more involved use case, too: If you already have metrics
+// available, created outside of the Prometheus context, you don't need the
+// interface of the various Metric types. You essentially want to mirror the
+// existing numbers into Prometheus Metrics during collection. An own
+// implementation of the Collector interface is perfect for that. You can create
+// Metric instances “on the fly” using NewConstMetric, NewConstHistogram, and
+// NewConstSummary (and their respective Must… versions). That will happen in
+// the Collect method. The Describe method has to return separate Desc
+// instances, representative of the “throw-away” metrics to be created
+// later. NewDesc comes in handy to create those Desc instances.
+//
+// The Collector example illustrates the use case. You can also look at the
+// source code of the processCollector (mirroring process metrics), the
+// goCollector (mirroring Go metrics), or the expvarCollector (mirroring expvar
+// metrics) as examples that are used in this package itself.
+//
+// If you just need to call a function to get a single float value to collect as
+// a metric, GaugeFunc, CounterFunc, or UntypedFunc might be interesting
+// shortcuts.
+//
+// Advanced Uses of the Registry
+//
+// While MustRegister is the by far most common way of registering a Collector,
+// sometimes you might want to handle the errors the registration might
+// cause. As suggested by the name, MustRegister panics if an error occurs. With
+// the Register function, the error is returned and can be handled.
+//
+// An error is returned if the registered Collector is incompatible or
+// inconsistent with already registered metrics. The registry aims for
+// consistency of the collected metrics according to the Prometheus data
+// model. Inconsistencies are ideally detected at registration time, not at
+// collect time. The former will usually be detected at start-up time of a
+// program, while the latter will only happen at scrape time, possibly not even
+// on the first scrape if the inconsistency only becomes relevant later. That is
+// the main reason why a Collector and a Metric have to describe themselves to
+// the registry.
+//
+// So far, everything we did operated on the so-called default registry, as it
+// can be found in the global DefaultRegistry variable. With NewRegistry, you
+// can create a custom registry, or you can even implement the Registerer or
+// Gatherer interfaces yourself. The methods Register and Unregister work in
+// the same way on a custom registry as the global functions Register and
+// Unregister on the default registry.
+//
+// There are a number of uses for custom registries: You can use registries
+// with special properties, see NewPedanticRegistry. You can avoid global state,
+// as it is imposed by the DefaultRegistry. You can use multiple registries at
+// the same time to expose different metrics in different ways. You can use
+// separate registries for testing purposes.
+//
+// Also note that the DefaultRegistry comes registered with a Collector for Go
+// runtime metrics (via NewGoCollector) and a Collector for process metrics (via
+// NewProcessCollector). With a custom registry, you are in control and decide
+// yourself about the Collectors to register.
+//
+// HTTP Exposition
+//
+// The Registry implements the Gatherer interface. The caller of the Gather
+// method can then expose the gathered metrics in some way. Usually, the metrics
+// are served via HTTP on the /metrics endpoint. That's happening in the example
+// above. The tools to expose metrics via HTTP are in the promhttp
+// sub-package. (The top-level functions in the prometheus package are
+// deprecated.)
+//
+// Pushing to the Pushgateway
+//
+// Function for pushing to the Pushgateway can be found in the push sub-package.
+//
+// Other Means of Exposition
+//
+// More ways of exposing metrics can easily be added. Sending metrics to
+// Graphite would be an example that will soon be implemented.
+package prometheus
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/expvar_collector.go b/vendor/github.com/prometheus/client_golang/prometheus/expvar_collector.go
new file mode 100644
index 00000000..18a99d5f
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/expvar_collector.go
@@ -0,0 +1,119 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"encoding/json"
+	"expvar"
+)
+
+type expvarCollector struct {
+	exports map[string]*Desc
+}
+
+// NewExpvarCollector returns a newly allocated expvar Collector that still has
+// to be registered with a Prometheus registry.
+//
+// An expvar Collector collects metrics from the expvar interface. It provides a
+// quick way to expose numeric values that are already exported via expvar as
+// Prometheus metrics. Note that the data models of expvar and Prometheus are
+// fundamentally different, and that the expvar Collector is inherently slower
+// than native Prometheus metrics. Thus, the expvar Collector is probably great
+// for experiments and prototying, but you should seriously consider a more
+// direct implementation of Prometheus metrics for monitoring production
+// systems.
+//
+// The exports map has the following meaning:
+//
+// The keys in the map correspond to expvar keys, i.e. for every expvar key you
+// want to export as Prometheus metric, you need an entry in the exports
+// map. The descriptor mapped to each key describes how to export the expvar
+// value. It defines the name and the help string of the Prometheus metric
+// proxying the expvar value. The type will always be Untyped.
+//
+// For descriptors without variable labels, the expvar value must be a number or
+// a bool. The number is then directly exported as the Prometheus sample
+// value. (For a bool, 'false' translates to 0 and 'true' to 1). Expvar values
+// that are not numbers or bools are silently ignored.
+//
+// If the descriptor has one variable label, the expvar value must be an expvar
+// map. The keys in the expvar map become the various values of the one
+// Prometheus label. The values in the expvar map must be numbers or bools again
+// as above.
+//
+// For descriptors with more than one variable label, the expvar must be a
+// nested expvar map, i.e. where the values of the topmost map are maps again
+// etc. until a depth is reached that corresponds to the number of labels. The
+// leaves of that structure must be numbers or bools as above to serve as the
+// sample values.
+//
+// Anything that does not fit into the scheme above is silently ignored.
+func NewExpvarCollector(exports map[string]*Desc) Collector {
+	return &expvarCollector{
+		exports: exports,
+	}
+}
+
+// Describe implements Collector.
+func (e *expvarCollector) Describe(ch chan<- *Desc) {
+	for _, desc := range e.exports {
+		ch <- desc
+	}
+}
+
+// Collect implements Collector.
+func (e *expvarCollector) Collect(ch chan<- Metric) {
+	for name, desc := range e.exports {
+		var m Metric
+		expVar := expvar.Get(name)
+		if expVar == nil {
+			continue
+		}
+		var v interface{}
+		labels := make([]string, len(desc.variableLabels))
+		if err := json.Unmarshal([]byte(expVar.String()), &v); err != nil {
+			ch <- NewInvalidMetric(desc, err)
+			continue
+		}
+		var processValue func(v interface{}, i int)
+		processValue = func(v interface{}, i int) {
+			if i >= len(labels) {
+				copiedLabels := append(make([]string, 0, len(labels)), labels...)
+				switch v := v.(type) {
+				case float64:
+					m = MustNewConstMetric(desc, UntypedValue, v, copiedLabels...)
+				case bool:
+					if v {
+						m = MustNewConstMetric(desc, UntypedValue, 1, copiedLabels...)
+					} else {
+						m = MustNewConstMetric(desc, UntypedValue, 0, copiedLabels...)
+					}
+				default:
+					return
+				}
+				ch <- m
+				return
+			}
+			vm, ok := v.(map[string]interface{})
+			if !ok {
+				return
+			}
+			for lv, val := range vm {
+				labels[i] = lv
+				processValue(val, i+1)
+			}
+		}
+		processValue(v, 0)
+	}
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/fnv.go b/vendor/github.com/prometheus/client_golang/prometheus/fnv.go
new file mode 100644
index 00000000..e3b67df8
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/fnv.go
@@ -0,0 +1,29 @@
+package prometheus
+
+// Inline and byte-free variant of hash/fnv's fnv64a.
+
+const (
+	offset64 = 14695981039346656037
+	prime64  = 1099511628211
+)
+
+// hashNew initializies a new fnv64a hash value.
+func hashNew() uint64 {
+	return offset64
+}
+
+// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
+func hashAdd(h uint64, s string) uint64 {
+	for i := 0; i < len(s); i++ {
+		h ^= uint64(s[i])
+		h *= prime64
+	}
+	return h
+}
+
+// hashAddByte adds a byte to a fnv64a hash value, returning the updated hash.
+func hashAddByte(h uint64, b byte) uint64 {
+	h ^= uint64(b)
+	h *= prime64
+	return h
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/gauge.go b/vendor/github.com/prometheus/client_golang/prometheus/gauge.go
new file mode 100644
index 00000000..8b70e514
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/gauge.go
@@ -0,0 +1,140 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Gauge is a Metric that represents a single numerical value that can
+// arbitrarily go up and down.
+//
+// A Gauge is typically used for measured values like temperatures or current
+// memory usage, but also "counts" that can go up and down, like the number of
+// running goroutines.
+//
+// To create Gauge instances, use NewGauge.
+type Gauge interface {
+	Metric
+	Collector
+
+	// Set sets the Gauge to an arbitrary value.
+	Set(float64)
+	// Inc increments the Gauge by 1.
+	Inc()
+	// Dec decrements the Gauge by 1.
+	Dec()
+	// Add adds the given value to the Gauge. (The value can be
+	// negative, resulting in a decrease of the Gauge.)
+	Add(float64)
+	// Sub subtracts the given value from the Gauge. (The value can be
+	// negative, resulting in an increase of the Gauge.)
+	Sub(float64)
+}
+
+// GaugeOpts is an alias for Opts. See there for doc comments.
+type GaugeOpts Opts
+
+// NewGauge creates a new Gauge based on the provided GaugeOpts.
+func NewGauge(opts GaugeOpts) Gauge {
+	return newValue(NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	), GaugeValue, 0)
+}
+
+// GaugeVec is a Collector that bundles a set of Gauges that all share the same
+// Desc, but have different values for their variable labels. This is used if
+// you want to count the same thing partitioned by various dimensions
+// (e.g. number of operations queued, partitioned by user and operation
+// type). Create instances with NewGaugeVec.
+type GaugeVec struct {
+	*MetricVec
+}
+
+// NewGaugeVec creates a new GaugeVec based on the provided GaugeOpts and
+// partitioned by the given label names. At least one label name must be
+// provided.
+func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		labelNames,
+		opts.ConstLabels,
+	)
+	return &GaugeVec{
+		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			return newValue(desc, GaugeValue, 0, lvs...)
+		}),
+	}
+}
+
+// GetMetricWithLabelValues replaces the method of the same name in
+// MetricVec. The difference is that this method returns a Gauge and not a
+// Metric so that no type conversion is required.
+func (m *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
+	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Gauge), err
+	}
+	return nil, err
+}
+
+// GetMetricWith replaces the method of the same name in MetricVec. The
+// difference is that this method returns a Gauge and not a Metric so that no
+// type conversion is required.
+func (m *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
+	metric, err := m.MetricVec.GetMetricWith(labels)
+	if metric != nil {
+		return metric.(Gauge), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. By not returning an
+// error, WithLabelValues allows shortcuts like
+//     myVec.WithLabelValues("404", "GET").Add(42)
+func (m *GaugeVec) WithLabelValues(lvs ...string) Gauge {
+	return m.MetricVec.WithLabelValues(lvs...).(Gauge)
+}
+
+// With works as GetMetricWith, but panics where GetMetricWithLabels would have
+// returned an error. By not returning an error, With allows shortcuts like
+//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
+func (m *GaugeVec) With(labels Labels) Gauge {
+	return m.MetricVec.With(labels).(Gauge)
+}
+
+// GaugeFunc is a Gauge whose value is determined at collect time by calling a
+// provided function.
+//
+// To create GaugeFunc instances, use NewGaugeFunc.
+type GaugeFunc interface {
+	Metric
+	Collector
+}
+
+// NewGaugeFunc creates a new GaugeFunc based on the provided GaugeOpts. The
+// value reported is determined by calling the given function from within the
+// Write method. Take into account that metric collection may happen
+// concurrently. If that results in concurrent calls to Write, like in the case
+// where a GaugeFunc is directly registered with Prometheus, the provided
+// function must be concurrency-safe.
+func NewGaugeFunc(opts GaugeOpts, function func() float64) GaugeFunc {
+	return newValueFunc(NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	), GaugeValue, function)
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/go_collector.go b/vendor/github.com/prometheus/client_golang/prometheus/go_collector.go
new file mode 100644
index 00000000..abc9d4ec
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/go_collector.go
@@ -0,0 +1,263 @@
+package prometheus
+
+import (
+	"fmt"
+	"runtime"
+	"runtime/debug"
+	"time"
+)
+
+type goCollector struct {
+	goroutines Gauge
+	gcDesc     *Desc
+
+	// metrics to describe and collect
+	metrics memStatsMetrics
+}
+
+// NewGoCollector returns a collector which exports metrics about the current
+// go process.
+func NewGoCollector() Collector {
+	return &goCollector{
+		goroutines: NewGauge(GaugeOpts{
+			Namespace: "go",
+			Name:      "goroutines",
+			Help:      "Number of goroutines that currently exist.",
+		}),
+		gcDesc: NewDesc(
+			"go_gc_duration_seconds",
+			"A summary of the GC invocation durations.",
+			nil, nil),
+		metrics: memStatsMetrics{
+			{
+				desc: NewDesc(
+					memstatNamespace("alloc_bytes"),
+					"Number of bytes allocated and still in use.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Alloc) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("alloc_bytes_total"),
+					"Total number of bytes allocated, even if freed.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.TotalAlloc) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("sys_bytes"),
+					"Number of bytes obtained by system. Sum of all system allocations.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Sys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("lookups_total"),
+					"Total number of pointer lookups.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Lookups) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mallocs_total"),
+					"Total number of mallocs.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Mallocs) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("frees_total"),
+					"Total number of frees.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Frees) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_alloc_bytes"),
+					"Number of heap bytes allocated and still in use.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapAlloc) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_sys_bytes"),
+					"Number of heap bytes obtained from system.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_idle_bytes"),
+					"Number of heap bytes waiting to be used.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapIdle) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_inuse_bytes"),
+					"Number of heap bytes that are in use.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapInuse) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_released_bytes_total"),
+					"Total number of heap bytes released to OS.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_objects"),
+					"Number of allocated objects.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapObjects) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("stack_inuse_bytes"),
+					"Number of bytes in use by the stack allocator.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.StackInuse) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("stack_sys_bytes"),
+					"Number of bytes obtained from system for stack allocator.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.StackSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mspan_inuse_bytes"),
+					"Number of bytes in use by mspan structures.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MSpanInuse) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mspan_sys_bytes"),
+					"Number of bytes used for mspan structures obtained from system.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MSpanSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mcache_inuse_bytes"),
+					"Number of bytes in use by mcache structures.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MCacheInuse) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mcache_sys_bytes"),
+					"Number of bytes used for mcache structures obtained from system.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MCacheSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("buck_hash_sys_bytes"),
+					"Number of bytes used by the profiling bucket hash table.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.BuckHashSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("gc_sys_bytes"),
+					"Number of bytes used for garbage collection system metadata.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.GCSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("other_sys_bytes"),
+					"Number of bytes used for other system allocations.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.OtherSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("next_gc_bytes"),
+					"Number of heap bytes when next garbage collection will take place.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.NextGC) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("last_gc_time_seconds"),
+					"Number of seconds since 1970 of last garbage collection.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.LastGC) / 1e9 },
+				valType: GaugeValue,
+			},
+		},
+	}
+}
+
+func memstatNamespace(s string) string {
+	return fmt.Sprintf("go_memstats_%s", s)
+}
+
+// Describe returns all descriptions of the collector.
+func (c *goCollector) Describe(ch chan<- *Desc) {
+	ch <- c.goroutines.Desc()
+	ch <- c.gcDesc
+
+	for _, i := range c.metrics {
+		ch <- i.desc
+	}
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *goCollector) Collect(ch chan<- Metric) {
+	c.goroutines.Set(float64(runtime.NumGoroutine()))
+	ch <- c.goroutines
+
+	var stats debug.GCStats
+	stats.PauseQuantiles = make([]time.Duration, 5)
+	debug.ReadGCStats(&stats)
+
+	quantiles := make(map[float64]float64)
+	for idx, pq := range stats.PauseQuantiles[1:] {
+		quantiles[float64(idx+1)/float64(len(stats.PauseQuantiles)-1)] = pq.Seconds()
+	}
+	quantiles[0.0] = stats.PauseQuantiles[0].Seconds()
+	ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), float64(stats.PauseTotal.Seconds()), quantiles)
+
+	ms := &runtime.MemStats{}
+	runtime.ReadMemStats(ms)
+	for _, i := range c.metrics {
+		ch <- MustNewConstMetric(i.desc, i.valType, i.eval(ms))
+	}
+}
+
+// memStatsMetrics provide description, value, and value type for memstat metrics.
+type memStatsMetrics []struct {
+	desc    *Desc
+	eval    func(*runtime.MemStats) float64
+	valType ValueType
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/histogram.go b/vendor/github.com/prometheus/client_golang/prometheus/histogram.go
new file mode 100644
index 00000000..9719e8fa
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/histogram.go
@@ -0,0 +1,444 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"fmt"
+	"math"
+	"sort"
+	"sync/atomic"
+
+	"github.com/golang/protobuf/proto"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// A Histogram counts individual observations from an event or sample stream in
+// configurable buckets. Similar to a summary, it also provides a sum of
+// observations and an observation count.
+//
+// On the Prometheus server, quantiles can be calculated from a Histogram using
+// the histogram_quantile function in the query language.
+//
+// Note that Histograms, in contrast to Summaries, can be aggregated with the
+// Prometheus query language (see the documentation for detailed
+// procedures). However, Histograms require the user to pre-define suitable
+// buckets, and they are in general less accurate. The Observe method of a
+// Histogram has a very low performance overhead in comparison with the Observe
+// method of a Summary.
+//
+// To create Histogram instances, use NewHistogram.
+type Histogram interface {
+	Metric
+	Collector
+
+	// Observe adds a single observation to the histogram.
+	Observe(float64)
+}
+
+// bucketLabel is used for the label that defines the upper bound of a
+// bucket of a histogram ("le" -> "less or equal").
+const bucketLabel = "le"
+
+// DefBuckets are the default Histogram buckets. The default buckets are
+// tailored to broadly measure the response time (in seconds) of a network
+// service. Most likely, however, you will be required to define buckets
+// customized to your use case.
+var (
+	DefBuckets = []float64{.005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10}
+
+	errBucketLabelNotAllowed = fmt.Errorf(
+		"%q is not allowed as label name in histograms", bucketLabel,
+	)
+)
+
+// LinearBuckets creates 'count' buckets, each 'width' wide, where the lowest
+// bucket has an upper bound of 'start'. The final +Inf bucket is not counted
+// and not included in the returned slice. The returned slice is meant to be
+// used for the Buckets field of HistogramOpts.
+//
+// The function panics if 'count' is zero or negative.
+func LinearBuckets(start, width float64, count int) []float64 {
+	if count < 1 {
+		panic("LinearBuckets needs a positive count")
+	}
+	buckets := make([]float64, count)
+	for i := range buckets {
+		buckets[i] = start
+		start += width
+	}
+	return buckets
+}
+
+// ExponentialBuckets creates 'count' buckets, where the lowest bucket has an
+// upper bound of 'start' and each following bucket's upper bound is 'factor'
+// times the previous bucket's upper bound. The final +Inf bucket is not counted
+// and not included in the returned slice. The returned slice is meant to be
+// used for the Buckets field of HistogramOpts.
+//
+// The function panics if 'count' is 0 or negative, if 'start' is 0 or negative,
+// or if 'factor' is less than or equal 1.
+func ExponentialBuckets(start, factor float64, count int) []float64 {
+	if count < 1 {
+		panic("ExponentialBuckets needs a positive count")
+	}
+	if start <= 0 {
+		panic("ExponentialBuckets needs a positive start value")
+	}
+	if factor <= 1 {
+		panic("ExponentialBuckets needs a factor greater than 1")
+	}
+	buckets := make([]float64, count)
+	for i := range buckets {
+		buckets[i] = start
+		start *= factor
+	}
+	return buckets
+}
+
+// HistogramOpts bundles the options for creating a Histogram metric. It is
+// mandatory to set Name and Help to a non-empty string. All other fields are
+// optional and can safely be left at their zero value.
+type HistogramOpts struct {
+	// Namespace, Subsystem, and Name are components of the fully-qualified
+	// name of the Histogram (created by joining these components with
+	// "_"). Only Name is mandatory, the others merely help structuring the
+	// name. Note that the fully-qualified name of the Histogram must be a
+	// valid Prometheus metric name.
+	Namespace string
+	Subsystem string
+	Name      string
+
+	// Help provides information about this Histogram. Mandatory!
+	//
+	// Metrics with the same fully-qualified name must have the same Help
+	// string.
+	Help string
+
+	// ConstLabels are used to attach fixed labels to this
+	// Histogram. Histograms with the same fully-qualified name must have the
+	// same label names in their ConstLabels.
+	//
+	// Note that in most cases, labels have a value that varies during the
+	// lifetime of a process. Those labels are usually managed with a
+	// HistogramVec. ConstLabels serve only special purposes. One is for the
+	// special case where the value of a label does not change during the
+	// lifetime of a process, e.g. if the revision of the running binary is
+	// put into a label. Another, more advanced purpose is if more than one
+	// Collector needs to collect Histograms with the same fully-qualified
+	// name. In that case, those Summaries must differ in the values of
+	// their ConstLabels. See the Collector examples.
+	//
+	// If the value of a label never changes (not even between binaries),
+	// that label most likely should not be a label at all (but part of the
+	// metric name).
+	ConstLabels Labels
+
+	// Buckets defines the buckets into which observations are counted. Each
+	// element in the slice is the upper inclusive bound of a bucket. The
+	// values must be sorted in strictly increasing order. There is no need
+	// to add a highest bucket with +Inf bound, it will be added
+	// implicitly. The default value is DefBuckets.
+	Buckets []float64
+}
+
+// NewHistogram creates a new Histogram based on the provided HistogramOpts. It
+// panics if the buckets in HistogramOpts are not in strictly increasing order.
+func NewHistogram(opts HistogramOpts) Histogram {
+	return newHistogram(
+		NewDesc(
+			BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+			opts.Help,
+			nil,
+			opts.ConstLabels,
+		),
+		opts,
+	)
+}
+
+func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogram {
+	if len(desc.variableLabels) != len(labelValues) {
+		panic(errInconsistentCardinality)
+	}
+
+	for _, n := range desc.variableLabels {
+		if n == bucketLabel {
+			panic(errBucketLabelNotAllowed)
+		}
+	}
+	for _, lp := range desc.constLabelPairs {
+		if lp.GetName() == bucketLabel {
+			panic(errBucketLabelNotAllowed)
+		}
+	}
+
+	if len(opts.Buckets) == 0 {
+		opts.Buckets = DefBuckets
+	}
+
+	h := &histogram{
+		desc:        desc,
+		upperBounds: opts.Buckets,
+		labelPairs:  makeLabelPairs(desc, labelValues),
+	}
+	for i, upperBound := range h.upperBounds {
+		if i < len(h.upperBounds)-1 {
+			if upperBound >= h.upperBounds[i+1] {
+				panic(fmt.Errorf(
+					"histogram buckets must be in increasing order: %f >= %f",
+					upperBound, h.upperBounds[i+1],
+				))
+			}
+		} else {
+			if math.IsInf(upperBound, +1) {
+				// The +Inf bucket is implicit. Remove it here.
+				h.upperBounds = h.upperBounds[:i]
+			}
+		}
+	}
+	// Finally we know the final length of h.upperBounds and can make counts.
+	h.counts = make([]uint64, len(h.upperBounds))
+
+	h.init(h) // Init self-collection.
+	return h
+}
+
+type histogram struct {
+	// sumBits contains the bits of the float64 representing the sum of all
+	// observations. sumBits and count have to go first in the struct to
+	// guarantee alignment for atomic operations.
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	sumBits uint64
+	count   uint64
+
+	selfCollector
+	// Note that there is no mutex required.
+
+	desc *Desc
+
+	upperBounds []float64
+	counts      []uint64
+
+	labelPairs []*dto.LabelPair
+}
+
+func (h *histogram) Desc() *Desc {
+	return h.desc
+}
+
+func (h *histogram) Observe(v float64) {
+	// TODO(beorn7): For small numbers of buckets (<30), a linear search is
+	// slightly faster than the binary search. If we really care, we could
+	// switch from one search strategy to the other depending on the number
+	// of buckets.
+	//
+	// Microbenchmarks (BenchmarkHistogramNoLabels):
+	// 11 buckets: 38.3 ns/op linear - binary 48.7 ns/op
+	// 100 buckets: 78.1 ns/op linear - binary 54.9 ns/op
+	// 300 buckets: 154 ns/op linear - binary 61.6 ns/op
+	i := sort.SearchFloat64s(h.upperBounds, v)
+	if i < len(h.counts) {
+		atomic.AddUint64(&h.counts[i], 1)
+	}
+	atomic.AddUint64(&h.count, 1)
+	for {
+		oldBits := atomic.LoadUint64(&h.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
+		if atomic.CompareAndSwapUint64(&h.sumBits, oldBits, newBits) {
+			break
+		}
+	}
+}
+
+func (h *histogram) Write(out *dto.Metric) error {
+	his := &dto.Histogram{}
+	buckets := make([]*dto.Bucket, len(h.upperBounds))
+
+	his.SampleSum = proto.Float64(math.Float64frombits(atomic.LoadUint64(&h.sumBits)))
+	his.SampleCount = proto.Uint64(atomic.LoadUint64(&h.count))
+	var count uint64
+	for i, upperBound := range h.upperBounds {
+		count += atomic.LoadUint64(&h.counts[i])
+		buckets[i] = &dto.Bucket{
+			CumulativeCount: proto.Uint64(count),
+			UpperBound:      proto.Float64(upperBound),
+		}
+	}
+	his.Bucket = buckets
+	out.Histogram = his
+	out.Label = h.labelPairs
+	return nil
+}
+
+// HistogramVec is a Collector that bundles a set of Histograms that all share the
+// same Desc, but have different values for their variable labels. This is used
+// if you want to count the same thing partitioned by various dimensions
+// (e.g. HTTP request latencies, partitioned by status code and method). Create
+// instances with NewHistogramVec.
+type HistogramVec struct {
+	*MetricVec
+}
+
+// NewHistogramVec creates a new HistogramVec based on the provided HistogramOpts and
+// partitioned by the given label names. At least one label name must be
+// provided.
+func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		labelNames,
+		opts.ConstLabels,
+	)
+	return &HistogramVec{
+		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			return newHistogram(desc, opts, lvs...)
+		}),
+	}
+}
+
+// GetMetricWithLabelValues replaces the method of the same name in
+// MetricVec. The difference is that this method returns a Histogram and not a
+// Metric so that no type conversion is required.
+func (m *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Histogram, error) {
+	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Histogram), err
+	}
+	return nil, err
+}
+
+// GetMetricWith replaces the method of the same name in MetricVec. The
+// difference is that this method returns a Histogram and not a Metric so that no
+// type conversion is required.
+func (m *HistogramVec) GetMetricWith(labels Labels) (Histogram, error) {
+	metric, err := m.MetricVec.GetMetricWith(labels)
+	if metric != nil {
+		return metric.(Histogram), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. By not returning an
+// error, WithLabelValues allows shortcuts like
+//     myVec.WithLabelValues("404", "GET").Observe(42.21)
+func (m *HistogramVec) WithLabelValues(lvs ...string) Histogram {
+	return m.MetricVec.WithLabelValues(lvs...).(Histogram)
+}
+
+// With works as GetMetricWith, but panics where GetMetricWithLabels would have
+// returned an error. By not returning an error, With allows shortcuts like
+//     myVec.With(Labels{"code": "404", "method": "GET"}).Observe(42.21)
+func (m *HistogramVec) With(labels Labels) Histogram {
+	return m.MetricVec.With(labels).(Histogram)
+}
+
+type constHistogram struct {
+	desc       *Desc
+	count      uint64
+	sum        float64
+	buckets    map[float64]uint64
+	labelPairs []*dto.LabelPair
+}
+
+func (h *constHistogram) Desc() *Desc {
+	return h.desc
+}
+
+func (h *constHistogram) Write(out *dto.Metric) error {
+	his := &dto.Histogram{}
+	buckets := make([]*dto.Bucket, 0, len(h.buckets))
+
+	his.SampleCount = proto.Uint64(h.count)
+	his.SampleSum = proto.Float64(h.sum)
+
+	for upperBound, count := range h.buckets {
+		buckets = append(buckets, &dto.Bucket{
+			CumulativeCount: proto.Uint64(count),
+			UpperBound:      proto.Float64(upperBound),
+		})
+	}
+
+	if len(buckets) > 0 {
+		sort.Sort(buckSort(buckets))
+	}
+	his.Bucket = buckets
+
+	out.Histogram = his
+	out.Label = h.labelPairs
+
+	return nil
+}
+
+// NewConstHistogram returns a metric representing a Prometheus histogram with
+// fixed values for the count, sum, and bucket counts. As those parameters
+// cannot be changed, the returned value does not implement the Histogram
+// interface (but only the Metric interface). Users of this package will not
+// have much use for it in regular operations. However, when implementing custom
+// Collectors, it is useful as a throw-away metric that is generated on the fly
+// to send it to Prometheus in the Collect method.
+//
+// buckets is a map of upper bounds to cumulative counts, excluding the +Inf
+// bucket.
+//
+// NewConstHistogram returns an error if the length of labelValues is not
+// consistent with the variable labels in Desc.
+func NewConstHistogram(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	buckets map[float64]uint64,
+	labelValues ...string,
+) (Metric, error) {
+	if len(desc.variableLabels) != len(labelValues) {
+		return nil, errInconsistentCardinality
+	}
+	return &constHistogram{
+		desc:       desc,
+		count:      count,
+		sum:        sum,
+		buckets:    buckets,
+		labelPairs: makeLabelPairs(desc, labelValues),
+	}, nil
+}
+
+// MustNewConstHistogram is a version of NewConstHistogram that panics where
+// NewConstMetric would have returned an error.
+func MustNewConstHistogram(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	buckets map[float64]uint64,
+	labelValues ...string,
+) Metric {
+	m, err := NewConstHistogram(desc, count, sum, buckets, labelValues...)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}
+
+type buckSort []*dto.Bucket
+
+func (s buckSort) Len() int {
+	return len(s)
+}
+
+func (s buckSort) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s buckSort) Less(i, j int) bool {
+	return s[i].GetUpperBound() < s[j].GetUpperBound()
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/http.go b/vendor/github.com/prometheus/client_golang/prometheus/http.go
new file mode 100644
index 00000000..b2b00196
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/http.go
@@ -0,0 +1,499 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"bufio"
+	"bytes"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/prometheus/common/expfmt"
+)
+
+// TODO(beorn7): Remove this whole file. It is a partial mirror of
+// promhttp/http.go (to avoid circular import chains) where everything HTTP
+// related should live. The functions here are just for avoiding
+// breakage. Everything is deprecated.
+
+const (
+	contentTypeHeader     = "Content-Type"
+	contentLengthHeader   = "Content-Length"
+	contentEncodingHeader = "Content-Encoding"
+	acceptEncodingHeader  = "Accept-Encoding"
+)
+
+var bufPool sync.Pool
+
+func getBuf() *bytes.Buffer {
+	buf := bufPool.Get()
+	if buf == nil {
+		return &bytes.Buffer{}
+	}
+	return buf.(*bytes.Buffer)
+}
+
+func giveBuf(buf *bytes.Buffer) {
+	buf.Reset()
+	bufPool.Put(buf)
+}
+
+// Handler returns an HTTP handler for the DefaultGatherer. It is
+// already instrumented with InstrumentHandler (using "prometheus" as handler
+// name).
+//
+// Deprecated: Please note the issues described in the doc comment of
+// InstrumentHandler. You might want to consider using promhttp.Handler instead
+// (which is non instrumented).
+func Handler() http.Handler {
+	return InstrumentHandler("prometheus", UninstrumentedHandler())
+}
+
+// UninstrumentedHandler returns an HTTP handler for the DefaultGatherer.
+//
+// Deprecated: Use promhttp.Handler instead. See there for further documentation.
+func UninstrumentedHandler() http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		mfs, err := DefaultGatherer.Gather()
+		if err != nil {
+			http.Error(w, "An error has occurred during metrics collection:\n\n"+err.Error(), http.StatusInternalServerError)
+			return
+		}
+
+		contentType := expfmt.Negotiate(req.Header)
+		buf := getBuf()
+		defer giveBuf(buf)
+		writer, encoding := decorateWriter(req, buf)
+		enc := expfmt.NewEncoder(writer, contentType)
+		var lastErr error
+		for _, mf := range mfs {
+			if err := enc.Encode(mf); err != nil {
+				lastErr = err
+				http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
+				return
+			}
+		}
+		if closer, ok := writer.(io.Closer); ok {
+			closer.Close()
+		}
+		if lastErr != nil && buf.Len() == 0 {
+			http.Error(w, "No metrics encoded, last error:\n\n"+err.Error(), http.StatusInternalServerError)
+			return
+		}
+		header := w.Header()
+		header.Set(contentTypeHeader, string(contentType))
+		header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
+		if encoding != "" {
+			header.Set(contentEncodingHeader, encoding)
+		}
+		w.Write(buf.Bytes())
+	})
+}
+
+// decorateWriter wraps a writer to handle gzip compression if requested.  It
+// returns the decorated writer and the appropriate "Content-Encoding" header
+// (which is empty if no compression is enabled).
+func decorateWriter(request *http.Request, writer io.Writer) (io.Writer, string) {
+	header := request.Header.Get(acceptEncodingHeader)
+	parts := strings.Split(header, ",")
+	for _, part := range parts {
+		part := strings.TrimSpace(part)
+		if part == "gzip" || strings.HasPrefix(part, "gzip;") {
+			return gzip.NewWriter(writer), "gzip"
+		}
+	}
+	return writer, ""
+}
+
+var instLabels = []string{"method", "code"}
+
+type nower interface {
+	Now() time.Time
+}
+
+type nowFunc func() time.Time
+
+func (n nowFunc) Now() time.Time {
+	return n()
+}
+
+var now nower = nowFunc(func() time.Time {
+	return time.Now()
+})
+
+func nowSeries(t ...time.Time) nower {
+	return nowFunc(func() time.Time {
+		defer func() {
+			t = t[1:]
+		}()
+
+		return t[0]
+	})
+}
+
+// InstrumentHandler wraps the given HTTP handler for instrumentation. It
+// registers four metric collectors (if not already done) and reports HTTP
+// metrics to the (newly or already) registered collectors: http_requests_total
+// (CounterVec), http_request_duration_microseconds (Summary),
+// http_request_size_bytes (Summary), http_response_size_bytes (Summary). Each
+// has a constant label named "handler" with the provided handlerName as
+// value. http_requests_total is a metric vector partitioned by HTTP method
+// (label name "method") and HTTP status code (label name "code").
+//
+// Deprecated: InstrumentHandler has several issues:
+//
+// - It uses Summaries rather than Histograms. Summaries are not useful if
+// aggregation across multiple instances is required.
+//
+// - It uses microseconds as unit, which is deprecated and should be replaced by
+// seconds.
+//
+// - The size of the request is calculated in a separate goroutine. Since this
+// calculator requires access to the request header, it creates a race with
+// any writes to the header performed during request handling.
+// httputil.ReverseProxy is a prominent example for a handler
+// performing such writes.
+//
+// Upcoming versions of this package will provide ways of instrumenting HTTP
+// handlers that are more flexible and have fewer issues. Please prefer direct
+// instrumentation in the meantime.
+func InstrumentHandler(handlerName string, handler http.Handler) http.HandlerFunc {
+	return InstrumentHandlerFunc(handlerName, handler.ServeHTTP)
+}
+
+// InstrumentHandlerFunc wraps the given function for instrumentation. It
+// otherwise works in the same way as InstrumentHandler (and shares the same
+// issues).
+//
+// Deprecated: InstrumentHandlerFunc is deprecated for the same reasons as
+// InstrumentHandler is.
+func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
+	return InstrumentHandlerFuncWithOpts(
+		SummaryOpts{
+			Subsystem:   "http",
+			ConstLabels: Labels{"handler": handlerName},
+		},
+		handlerFunc,
+	)
+}
+
+// InstrumentHandlerWithOpts works like InstrumentHandler (and shares the same
+// issues) but provides more flexibility (at the cost of a more complex call
+// syntax). As InstrumentHandler, this function registers four metric
+// collectors, but it uses the provided SummaryOpts to create them. However, the
+// fields "Name" and "Help" in the SummaryOpts are ignored. "Name" is replaced
+// by "requests_total", "request_duration_microseconds", "request_size_bytes",
+// and "response_size_bytes", respectively. "Help" is replaced by an appropriate
+// help string. The names of the variable labels of the http_requests_total
+// CounterVec are "method" (get, post, etc.), and "code" (HTTP status code).
+//
+// If InstrumentHandlerWithOpts is called as follows, it mimics exactly the
+// behavior of InstrumentHandler:
+//
+//     prometheus.InstrumentHandlerWithOpts(
+//         prometheus.SummaryOpts{
+//              Subsystem:   "http",
+//              ConstLabels: prometheus.Labels{"handler": handlerName},
+//         },
+//         handler,
+//     )
+//
+// Technical detail: "requests_total" is a CounterVec, not a SummaryVec, so it
+// cannot use SummaryOpts. Instead, a CounterOpts struct is created internally,
+// and all its fields are set to the equally named fields in the provided
+// SummaryOpts.
+//
+// Deprecated: InstrumentHandlerWithOpts is deprecated for the same reasons as
+// InstrumentHandler is.
+func InstrumentHandlerWithOpts(opts SummaryOpts, handler http.Handler) http.HandlerFunc {
+	return InstrumentHandlerFuncWithOpts(opts, handler.ServeHTTP)
+}
+
+// InstrumentHandlerFuncWithOpts works like InstrumentHandlerFunc (and shares
+// the same issues) but provides more flexibility (at the cost of a more complex
+// call syntax). See InstrumentHandlerWithOpts for details how the provided
+// SummaryOpts are used.
+//
+// Deprecated: InstrumentHandlerFuncWithOpts is deprecated for the same reasons
+// as InstrumentHandler is.
+func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
+	reqCnt := NewCounterVec(
+		CounterOpts{
+			Namespace:   opts.Namespace,
+			Subsystem:   opts.Subsystem,
+			Name:        "requests_total",
+			Help:        "Total number of HTTP requests made.",
+			ConstLabels: opts.ConstLabels,
+		},
+		instLabels,
+	)
+
+	opts.Name = "request_duration_microseconds"
+	opts.Help = "The HTTP request latencies in microseconds."
+	reqDur := NewSummary(opts)
+
+	opts.Name = "request_size_bytes"
+	opts.Help = "The HTTP request sizes in bytes."
+	reqSz := NewSummary(opts)
+
+	opts.Name = "response_size_bytes"
+	opts.Help = "The HTTP response sizes in bytes."
+	resSz := NewSummary(opts)
+
+	regReqCnt := MustRegisterOrGet(reqCnt).(*CounterVec)
+	regReqDur := MustRegisterOrGet(reqDur).(Summary)
+	regReqSz := MustRegisterOrGet(reqSz).(Summary)
+	regResSz := MustRegisterOrGet(resSz).(Summary)
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		now := time.Now()
+
+		delegate := &responseWriterDelegator{ResponseWriter: w}
+		out := computeApproximateRequestSize(r)
+
+		_, cn := w.(http.CloseNotifier)
+		_, fl := w.(http.Flusher)
+		_, hj := w.(http.Hijacker)
+		_, rf := w.(io.ReaderFrom)
+		var rw http.ResponseWriter
+		if cn && fl && hj && rf {
+			rw = &fancyResponseWriterDelegator{delegate}
+		} else {
+			rw = delegate
+		}
+		handlerFunc(rw, r)
+
+		elapsed := float64(time.Since(now)) / float64(time.Microsecond)
+
+		method := sanitizeMethod(r.Method)
+		code := sanitizeCode(delegate.status)
+		regReqCnt.WithLabelValues(method, code).Inc()
+		regReqDur.Observe(elapsed)
+		regResSz.Observe(float64(delegate.written))
+		regReqSz.Observe(float64(<-out))
+	})
+}
+
+func computeApproximateRequestSize(r *http.Request) <-chan int {
+	// Get URL length in current go routine for avoiding a race condition.
+	// HandlerFunc that runs in parallel may modify the URL.
+	s := 0
+	if r.URL != nil {
+		s += len(r.URL.String())
+	}
+
+	out := make(chan int, 1)
+
+	go func() {
+		s += len(r.Method)
+		s += len(r.Proto)
+		for name, values := range r.Header {
+			s += len(name)
+			for _, value := range values {
+				s += len(value)
+			}
+		}
+		s += len(r.Host)
+
+		// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
+
+		if r.ContentLength != -1 {
+			s += int(r.ContentLength)
+		}
+		out <- s
+		close(out)
+	}()
+
+	return out
+}
+
+type responseWriterDelegator struct {
+	http.ResponseWriter
+
+	handler, method string
+	status          int
+	written         int64
+	wroteHeader     bool
+}
+
+func (r *responseWriterDelegator) WriteHeader(code int) {
+	r.status = code
+	r.wroteHeader = true
+	r.ResponseWriter.WriteHeader(code)
+}
+
+func (r *responseWriterDelegator) Write(b []byte) (int, error) {
+	if !r.wroteHeader {
+		r.WriteHeader(http.StatusOK)
+	}
+	n, err := r.ResponseWriter.Write(b)
+	r.written += int64(n)
+	return n, err
+}
+
+type fancyResponseWriterDelegator struct {
+	*responseWriterDelegator
+}
+
+func (f *fancyResponseWriterDelegator) CloseNotify() <-chan bool {
+	return f.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+
+func (f *fancyResponseWriterDelegator) Flush() {
+	f.ResponseWriter.(http.Flusher).Flush()
+}
+
+func (f *fancyResponseWriterDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	return f.ResponseWriter.(http.Hijacker).Hijack()
+}
+
+func (f *fancyResponseWriterDelegator) ReadFrom(r io.Reader) (int64, error) {
+	if !f.wroteHeader {
+		f.WriteHeader(http.StatusOK)
+	}
+	n, err := f.ResponseWriter.(io.ReaderFrom).ReadFrom(r)
+	f.written += n
+	return n, err
+}
+
+func sanitizeMethod(m string) string {
+	switch m {
+	case "GET", "get":
+		return "get"
+	case "PUT", "put":
+		return "put"
+	case "HEAD", "head":
+		return "head"
+	case "POST", "post":
+		return "post"
+	case "DELETE", "delete":
+		return "delete"
+	case "CONNECT", "connect":
+		return "connect"
+	case "OPTIONS", "options":
+		return "options"
+	case "NOTIFY", "notify":
+		return "notify"
+	default:
+		return strings.ToLower(m)
+	}
+}
+
+func sanitizeCode(s int) string {
+	switch s {
+	case 100:
+		return "100"
+	case 101:
+		return "101"
+
+	case 200:
+		return "200"
+	case 201:
+		return "201"
+	case 202:
+		return "202"
+	case 203:
+		return "203"
+	case 204:
+		return "204"
+	case 205:
+		return "205"
+	case 206:
+		return "206"
+
+	case 300:
+		return "300"
+	case 301:
+		return "301"
+	case 302:
+		return "302"
+	case 304:
+		return "304"
+	case 305:
+		return "305"
+	case 307:
+		return "307"
+
+	case 400:
+		return "400"
+	case 401:
+		return "401"
+	case 402:
+		return "402"
+	case 403:
+		return "403"
+	case 404:
+		return "404"
+	case 405:
+		return "405"
+	case 406:
+		return "406"
+	case 407:
+		return "407"
+	case 408:
+		return "408"
+	case 409:
+		return "409"
+	case 410:
+		return "410"
+	case 411:
+		return "411"
+	case 412:
+		return "412"
+	case 413:
+		return "413"
+	case 414:
+		return "414"
+	case 415:
+		return "415"
+	case 416:
+		return "416"
+	case 417:
+		return "417"
+	case 418:
+		return "418"
+
+	case 500:
+		return "500"
+	case 501:
+		return "501"
+	case 502:
+		return "502"
+	case 503:
+		return "503"
+	case 504:
+		return "504"
+	case 505:
+		return "505"
+
+	case 428:
+		return "428"
+	case 429:
+		return "429"
+	case 431:
+		return "431"
+	case 511:
+		return "511"
+
+	default:
+		return strconv.Itoa(s)
+	}
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/metric.go b/vendor/github.com/prometheus/client_golang/prometheus/metric.go
new file mode 100644
index 00000000..d4063d98
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/metric.go
@@ -0,0 +1,166 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"strings"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+const separatorByte byte = 255
+
+// A Metric models a single sample value with its meta data being exported to
+// Prometheus. Implementations of Metric in this package are Gauge, Counter,
+// Histogram, Summary, and Untyped.
+type Metric interface {
+	// Desc returns the descriptor for the Metric. This method idempotently
+	// returns the same descriptor throughout the lifetime of the
+	// Metric. The returned descriptor is immutable by contract. A Metric
+	// unable to describe itself must return an invalid descriptor (created
+	// with NewInvalidDesc).
+	Desc() *Desc
+	// Write encodes the Metric into a "Metric" Protocol Buffer data
+	// transmission object.
+	//
+	// Metric implementations must observe concurrency safety as reads of
+	// this metric may occur at any time, and any blocking occurs at the
+	// expense of total performance of rendering all registered
+	// metrics. Ideally, Metric implementations should support concurrent
+	// readers.
+	//
+	// While populating dto.Metric, it is the responsibility of the
+	// implementation to ensure validity of the Metric protobuf (like valid
+	// UTF-8 strings or syntactically valid metric and label names). It is
+	// recommended to sort labels lexicographically. (Implementers may find
+	// LabelPairSorter useful for that.) Callers of Write should still make
+	// sure of sorting if they depend on it.
+	Write(*dto.Metric) error
+	// TODO(beorn7): The original rationale of passing in a pre-allocated
+	// dto.Metric protobuf to save allocations has disappeared. The
+	// signature of this method should be changed to "Write() (*dto.Metric,
+	// error)".
+}
+
+// Opts bundles the options for creating most Metric types. Each metric
+// implementation XXX has its own XXXOpts type, but in most cases, it is just be
+// an alias of this type (which might change when the requirement arises.)
+//
+// It is mandatory to set Name and Help to a non-empty string. All other fields
+// are optional and can safely be left at their zero value.
+type Opts struct {
+	// Namespace, Subsystem, and Name are components of the fully-qualified
+	// name of the Metric (created by joining these components with
+	// "_"). Only Name is mandatory, the others merely help structuring the
+	// name. Note that the fully-qualified name of the metric must be a
+	// valid Prometheus metric name.
+	Namespace string
+	Subsystem string
+	Name      string
+
+	// Help provides information about this metric. Mandatory!
+	//
+	// Metrics with the same fully-qualified name must have the same Help
+	// string.
+	Help string
+
+	// ConstLabels are used to attach fixed labels to this metric. Metrics
+	// with the same fully-qualified name must have the same label names in
+	// their ConstLabels.
+	//
+	// Note that in most cases, labels have a value that varies during the
+	// lifetime of a process. Those labels are usually managed with a metric
+	// vector collector (like CounterVec, GaugeVec, UntypedVec). ConstLabels
+	// serve only special purposes. One is for the special case where the
+	// value of a label does not change during the lifetime of a process,
+	// e.g. if the revision of the running binary is put into a
+	// label. Another, more advanced purpose is if more than one Collector
+	// needs to collect Metrics with the same fully-qualified name. In that
+	// case, those Metrics must differ in the values of their
+	// ConstLabels. See the Collector examples.
+	//
+	// If the value of a label never changes (not even between binaries),
+	// that label most likely should not be a label at all (but part of the
+	// metric name).
+	ConstLabels Labels
+}
+
+// BuildFQName joins the given three name components by "_". Empty name
+// components are ignored. If the name parameter itself is empty, an empty
+// string is returned, no matter what. Metric implementations included in this
+// library use this function internally to generate the fully-qualified metric
+// name from the name component in their Opts. Users of the library will only
+// need this function if they implement their own Metric or instantiate a Desc
+// (with NewDesc) directly.
+func BuildFQName(namespace, subsystem, name string) string {
+	if name == "" {
+		return ""
+	}
+	switch {
+	case namespace != "" && subsystem != "":
+		return strings.Join([]string{namespace, subsystem, name}, "_")
+	case namespace != "":
+		return strings.Join([]string{namespace, name}, "_")
+	case subsystem != "":
+		return strings.Join([]string{subsystem, name}, "_")
+	}
+	return name
+}
+
+// LabelPairSorter implements sort.Interface. It is used to sort a slice of
+// dto.LabelPair pointers. This is useful for implementing the Write method of
+// custom metrics.
+type LabelPairSorter []*dto.LabelPair
+
+func (s LabelPairSorter) Len() int {
+	return len(s)
+}
+
+func (s LabelPairSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s LabelPairSorter) Less(i, j int) bool {
+	return s[i].GetName() < s[j].GetName()
+}
+
+type hashSorter []uint64
+
+func (s hashSorter) Len() int {
+	return len(s)
+}
+
+func (s hashSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s hashSorter) Less(i, j int) bool {
+	return s[i] < s[j]
+}
+
+type invalidMetric struct {
+	desc *Desc
+	err  error
+}
+
+// NewInvalidMetric returns a metric whose Write method always returns the
+// provided error. It is useful if a Collector finds itself unable to collect
+// a metric and wishes to report an error to the registry.
+func NewInvalidMetric(desc *Desc, err error) Metric {
+	return &invalidMetric{desc, err}
+}
+
+func (m *invalidMetric) Desc() *Desc { return m.desc }
+
+func (m *invalidMetric) Write(*dto.Metric) error { return m.err }
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/process_collector.go b/vendor/github.com/prometheus/client_golang/prometheus/process_collector.go
new file mode 100644
index 00000000..e31e62e7
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/process_collector.go
@@ -0,0 +1,142 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import "github.com/prometheus/procfs"
+
+type processCollector struct {
+	pid             int
+	collectFn       func(chan<- Metric)
+	pidFn           func() (int, error)
+	cpuTotal        Counter
+	openFDs, maxFDs Gauge
+	vsize, rss      Gauge
+	startTime       Gauge
+}
+
+// NewProcessCollector returns a collector which exports the current state of
+// process metrics including cpu, memory and file descriptor usage as well as
+// the process start time for the given process id under the given namespace.
+func NewProcessCollector(pid int, namespace string) Collector {
+	return NewProcessCollectorPIDFn(
+		func() (int, error) { return pid, nil },
+		namespace,
+	)
+}
+
+// NewProcessCollectorPIDFn returns a collector which exports the current state
+// of process metrics including cpu, memory and file descriptor usage as well
+// as the process start time under the given namespace. The given pidFn is
+// called on each collect and is used to determine the process to export
+// metrics for.
+func NewProcessCollectorPIDFn(
+	pidFn func() (int, error),
+	namespace string,
+) Collector {
+	c := processCollector{
+		pidFn:     pidFn,
+		collectFn: func(chan<- Metric) {},
+
+		cpuTotal: NewCounter(CounterOpts{
+			Namespace: namespace,
+			Name:      "process_cpu_seconds_total",
+			Help:      "Total user and system CPU time spent in seconds.",
+		}),
+		openFDs: NewGauge(GaugeOpts{
+			Namespace: namespace,
+			Name:      "process_open_fds",
+			Help:      "Number of open file descriptors.",
+		}),
+		maxFDs: NewGauge(GaugeOpts{
+			Namespace: namespace,
+			Name:      "process_max_fds",
+			Help:      "Maximum number of open file descriptors.",
+		}),
+		vsize: NewGauge(GaugeOpts{
+			Namespace: namespace,
+			Name:      "process_virtual_memory_bytes",
+			Help:      "Virtual memory size in bytes.",
+		}),
+		rss: NewGauge(GaugeOpts{
+			Namespace: namespace,
+			Name:      "process_resident_memory_bytes",
+			Help:      "Resident memory size in bytes.",
+		}),
+		startTime: NewGauge(GaugeOpts{
+			Namespace: namespace,
+			Name:      "process_start_time_seconds",
+			Help:      "Start time of the process since unix epoch in seconds.",
+		}),
+	}
+
+	// Set up process metric collection if supported by the runtime.
+	if _, err := procfs.NewStat(); err == nil {
+		c.collectFn = c.processCollect
+	}
+
+	return &c
+}
+
+// Describe returns all descriptions of the collector.
+func (c *processCollector) Describe(ch chan<- *Desc) {
+	ch <- c.cpuTotal.Desc()
+	ch <- c.openFDs.Desc()
+	ch <- c.maxFDs.Desc()
+	ch <- c.vsize.Desc()
+	ch <- c.rss.Desc()
+	ch <- c.startTime.Desc()
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *processCollector) Collect(ch chan<- Metric) {
+	c.collectFn(ch)
+}
+
+// TODO(ts): Bring back error reporting by reverting 7faf9e7 as soon as the
+// client allows users to configure the error behavior.
+func (c *processCollector) processCollect(ch chan<- Metric) {
+	pid, err := c.pidFn()
+	if err != nil {
+		return
+	}
+
+	p, err := procfs.NewProc(pid)
+	if err != nil {
+		return
+	}
+
+	if stat, err := p.NewStat(); err == nil {
+		c.cpuTotal.Set(stat.CPUTime())
+		ch <- c.cpuTotal
+		c.vsize.Set(float64(stat.VirtualMemory()))
+		ch <- c.vsize
+		c.rss.Set(float64(stat.ResidentMemory()))
+		ch <- c.rss
+
+		if startTime, err := stat.StartTime(); err == nil {
+			c.startTime.Set(startTime)
+			ch <- c.startTime
+		}
+	}
+
+	if fds, err := p.FileDescriptorsLen(); err == nil {
+		c.openFDs.Set(float64(fds))
+		ch <- c.openFDs
+	}
+
+	if limits, err := p.NewLimits(); err == nil {
+		c.maxFDs.Set(float64(limits.OpenFiles))
+		ch <- c.maxFDs
+	}
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go
new file mode 100644
index 00000000..b6dd5a26
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go
@@ -0,0 +1,201 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Copyright (c) 2013, The Prometheus Authors
+// All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license that can be found
+// in the LICENSE file.
+
+// Package promhttp contains functions to create http.Handler instances to
+// expose Prometheus metrics via HTTP. In later versions of this package, it
+// will also contain tooling to instrument instances of http.Handler and
+// http.RoundTripper.
+//
+// promhttp.Handler acts on the prometheus.DefaultGatherer. With HandlerFor,
+// you can create a handler for a custom registry or anything that implements
+// the Gatherer interface. It also allows to create handlers that act
+// differently on errors or allow to log errors.
+package promhttp
+
+import (
+	"bytes"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"sync"
+
+	"github.com/prometheus/common/expfmt"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	contentTypeHeader     = "Content-Type"
+	contentLengthHeader   = "Content-Length"
+	contentEncodingHeader = "Content-Encoding"
+	acceptEncodingHeader  = "Accept-Encoding"
+)
+
+var bufPool sync.Pool
+
+func getBuf() *bytes.Buffer {
+	buf := bufPool.Get()
+	if buf == nil {
+		return &bytes.Buffer{}
+	}
+	return buf.(*bytes.Buffer)
+}
+
+func giveBuf(buf *bytes.Buffer) {
+	buf.Reset()
+	bufPool.Put(buf)
+}
+
+// Handler returns an HTTP handler for the prometheus.DefaultGatherer. The
+// Handler uses the default HandlerOpts, i.e. report the first error as an HTTP
+// error, no error logging, and compression if requested by the client.
+//
+// If you want to create a Handler for the DefaultGatherer with different
+// HandlerOpts, create it with HandlerFor with prometheus.DefaultGatherer and
+// your desired HandlerOpts.
+func Handler() http.Handler {
+	return HandlerFor(prometheus.DefaultGatherer, HandlerOpts{})
+}
+
+// HandlerFor returns an http.Handler for the provided Gatherer. The behavior
+// of the Handler is defined by the provided HandlerOpts.
+func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		mfs, err := reg.Gather()
+		if err != nil {
+			if opts.ErrorLog != nil {
+				opts.ErrorLog.Println("error gathering metrics:", err)
+			}
+			switch opts.ErrorHandling {
+			case PanicOnError:
+				panic(err)
+			case ContinueOnError:
+				if len(mfs) == 0 {
+					http.Error(w, "No metrics gathered, last error:\n\n"+err.Error(), http.StatusInternalServerError)
+					return
+				}
+			case HTTPErrorOnError:
+				http.Error(w, "An error has occurred during metrics gathering:\n\n"+err.Error(), http.StatusInternalServerError)
+				return
+			}
+		}
+
+		contentType := expfmt.Negotiate(req.Header)
+		buf := getBuf()
+		defer giveBuf(buf)
+		writer, encoding := decorateWriter(req, buf, opts.DisableCompression)
+		enc := expfmt.NewEncoder(writer, contentType)
+		var lastErr error
+		for _, mf := range mfs {
+			if err := enc.Encode(mf); err != nil {
+				lastErr = err
+				if opts.ErrorLog != nil {
+					opts.ErrorLog.Println("error encoding metric family:", err)
+				}
+				switch opts.ErrorHandling {
+				case PanicOnError:
+					panic(err)
+				case ContinueOnError:
+					// Handled later.
+				case HTTPErrorOnError:
+					http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
+					return
+				}
+			}
+		}
+		if closer, ok := writer.(io.Closer); ok {
+			closer.Close()
+		}
+		if lastErr != nil && buf.Len() == 0 {
+			http.Error(w, "No metrics encoded, last error:\n\n"+err.Error(), http.StatusInternalServerError)
+			return
+		}
+		header := w.Header()
+		header.Set(contentTypeHeader, string(contentType))
+		header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
+		if encoding != "" {
+			header.Set(contentEncodingHeader, encoding)
+		}
+		w.Write(buf.Bytes())
+		// TODO(beorn7): Consider streaming serving of metrics.
+	})
+}
+
+// HandlerErrorHandling defines how a Handler serving metrics will handle
+// errors.
+type HandlerErrorHandling int
+
+// These constants cause handlers serving metrics to behave as described if
+// errors are encountered.
+const (
+	// Serve an HTTP status code 500 upon the first error
+	// encountered. Report the error message in the body.
+	HTTPErrorOnError HandlerErrorHandling = iota
+	// Ignore errors and try to serve as many metrics as possible.  However,
+	// if no metrics can be served, serve an HTTP status code 500 and the
+	// last error message in the body. Only use this in deliberate "best
+	// effort" metrics collection scenarios. It is recommended to at least
+	// log errors (by providing an ErrorLog in HandlerOpts) to not mask
+	// errors completely.
+	ContinueOnError
+	// Panic upon the first error encountered (useful for "crash only" apps).
+	PanicOnError
+)
+
+// Logger is the minimal interface HandlerOpts needs for logging. Note that
+// log.Logger from the standard library implements this interface, and it is
+// easy to implement by custom loggers, if they don't do so already anyway.
+type Logger interface {
+	Println(v ...interface{})
+}
+
+// HandlerOpts specifies options how to serve metrics via an http.Handler. The
+// zero value of HandlerOpts is a reasonable default.
+type HandlerOpts struct {
+	// ErrorLog specifies an optional logger for errors collecting and
+	// serving metrics. If nil, errors are not logged at all.
+	ErrorLog Logger
+	// ErrorHandling defines how errors are handled. Note that errors are
+	// logged regardless of the configured ErrorHandling provided ErrorLog
+	// is not nil.
+	ErrorHandling HandlerErrorHandling
+	// If DisableCompression is true, the handler will never compress the
+	// response, even if requested by the client.
+	DisableCompression bool
+}
+
+// decorateWriter wraps a writer to handle gzip compression if requested.  It
+// returns the decorated writer and the appropriate "Content-Encoding" header
+// (which is empty if no compression is enabled).
+func decorateWriter(request *http.Request, writer io.Writer, compressionDisabled bool) (io.Writer, string) {
+	if compressionDisabled {
+		return writer, ""
+	}
+	header := request.Header.Get(acceptEncodingHeader)
+	parts := strings.Split(header, ",")
+	for _, part := range parts {
+		part := strings.TrimSpace(part)
+		if part == "gzip" || strings.HasPrefix(part, "gzip;") {
+			return gzip.NewWriter(writer), "gzip"
+		}
+	}
+	return writer, ""
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/registry.go b/vendor/github.com/prometheus/client_golang/prometheus/registry.go
new file mode 100644
index 00000000..405d6ddf
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/registry.go
@@ -0,0 +1,806 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"os"
+	"sort"
+	"sync"
+
+	"github.com/golang/protobuf/proto"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+const (
+	// Capacity for the channel to collect metrics and descriptors.
+	capMetricChan = 1000
+	capDescChan   = 10
+)
+
+// DefaultRegisterer and DefaultGatherer are the implementations of the
+// Registerer and Gatherer interface a number of convenience functions in this
+// package act on. Initially, both variables point to the same Registry, which
+// has a process collector (see NewProcessCollector) and a Go collector (see
+// NewGoCollector) already registered. This approach to keep default instances
+// as global state mirrors the approach of other packages in the Go standard
+// library. Note that there are caveats. Change the variables with caution and
+// only if you understand the consequences. Users who want to avoid global state
+// altogether should not use the convenience function and act on custom
+// instances instead.
+var (
+	defaultRegistry              = NewRegistry()
+	DefaultRegisterer Registerer = defaultRegistry
+	DefaultGatherer   Gatherer   = defaultRegistry
+)
+
+func init() {
+	MustRegister(NewProcessCollector(os.Getpid(), ""))
+	MustRegister(NewGoCollector())
+}
+
+// NewRegistry creates a new vanilla Registry without any Collectors
+// pre-registered.
+func NewRegistry() *Registry {
+	return &Registry{
+		collectorsByID:  map[uint64]Collector{},
+		descIDs:         map[uint64]struct{}{},
+		dimHashesByName: map[string]uint64{},
+	}
+}
+
+// NewPedanticRegistry returns a registry that checks during collection if each
+// collected Metric is consistent with its reported Desc, and if the Desc has
+// actually been registered with the registry.
+//
+// Usually, a Registry will be happy as long as the union of all collected
+// Metrics is consistent and valid even if some metrics are not consistent with
+// their own Desc or a Desc provided by their registered Collector. Well-behaved
+// Collectors and Metrics will only provide consistent Descs. This Registry is
+// useful to test the implementation of Collectors and Metrics.
+func NewPedanticRegistry() *Registry {
+	r := NewRegistry()
+	r.pedanticChecksEnabled = true
+	return r
+}
+
+// Registerer is the interface for the part of a registry in charge of
+// registering and unregistering. Users of custom registries should use
+// Registerer as type for registration purposes (rather then the Registry type
+// directly). In that way, they are free to use custom Registerer implementation
+// (e.g. for testing purposes).
+type Registerer interface {
+	// Register registers a new Collector to be included in metrics
+	// collection. It returns an error if the descriptors provided by the
+	// Collector are invalid or if they — in combination with descriptors of
+	// already registered Collectors — do not fulfill the consistency and
+	// uniqueness criteria described in the documentation of metric.Desc.
+	//
+	// If the provided Collector is equal to a Collector already registered
+	// (which includes the case of re-registering the same Collector), the
+	// returned error is an instance of AlreadyRegisteredError, which
+	// contains the previously registered Collector.
+	//
+	// It is in general not safe to register the same Collector multiple
+	// times concurrently.
+	Register(Collector) error
+	// MustRegister works like Register but registers any number of
+	// Collectors and panics upon the first registration that causes an
+	// error.
+	MustRegister(...Collector)
+	// Unregister unregisters the Collector that equals the Collector passed
+	// in as an argument.  (Two Collectors are considered equal if their
+	// Describe method yields the same set of descriptors.) The function
+	// returns whether a Collector was unregistered.
+	//
+	// Note that even after unregistering, it will not be possible to
+	// register a new Collector that is inconsistent with the unregistered
+	// Collector, e.g. a Collector collecting metrics with the same name but
+	// a different help string. The rationale here is that the same registry
+	// instance must only collect consistent metrics throughout its
+	// lifetime.
+	Unregister(Collector) bool
+}
+
+// Gatherer is the interface for the part of a registry in charge of gathering
+// the collected metrics into a number of MetricFamilies. The Gatherer interface
+// comes with the same general implication as described for the Registerer
+// interface.
+type Gatherer interface {
+	// Gather calls the Collect method of the registered Collectors and then
+	// gathers the collected metrics into a lexicographically sorted slice
+	// of MetricFamily protobufs. Even if an error occurs, Gather attempts
+	// to gather as many metrics as possible. Hence, if a non-nil error is
+	// returned, the returned MetricFamily slice could be nil (in case of a
+	// fatal error that prevented any meaningful metric collection) or
+	// contain a number of MetricFamily protobufs, some of which might be
+	// incomplete, and some might be missing altogether. The returned error
+	// (which might be a MultiError) explains the details. In scenarios
+	// where complete collection is critical, the returned MetricFamily
+	// protobufs should be disregarded if the returned error is non-nil.
+	Gather() ([]*dto.MetricFamily, error)
+}
+
+// Register registers the provided Collector with the DefaultRegisterer.
+//
+// Register is a shortcut for DefaultRegisterer.Register(c). See there for more
+// details.
+func Register(c Collector) error {
+	return DefaultRegisterer.Register(c)
+}
+
+// MustRegister registers the provided Collectors with the DefaultRegisterer and
+// panics if any error occurs.
+//
+// MustRegister is a shortcut for DefaultRegisterer.MustRegister(cs...). See
+// there for more details.
+func MustRegister(cs ...Collector) {
+	DefaultRegisterer.MustRegister(cs...)
+}
+
+// RegisterOrGet registers the provided Collector with the DefaultRegisterer and
+// returns the Collector, unless an equal Collector was registered before, in
+// which case that Collector is returned.
+//
+// Deprecated: RegisterOrGet is merely a convenience function for the
+// implementation as described in the documentation for
+// AlreadyRegisteredError. As the use case is relatively rare, this function
+// will be removed in a future version of this package to clean up the
+// namespace.
+func RegisterOrGet(c Collector) (Collector, error) {
+	if err := Register(c); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			return are.ExistingCollector, nil
+		}
+		return nil, err
+	}
+	return c, nil
+}
+
+// MustRegisterOrGet behaves like RegisterOrGet but panics instead of returning
+// an error.
+//
+// Deprecated: This is deprecated for the same reason RegisterOrGet is. See
+// there for details.
+func MustRegisterOrGet(c Collector) Collector {
+	c, err := RegisterOrGet(c)
+	if err != nil {
+		panic(err)
+	}
+	return c
+}
+
+// Unregister removes the registration of the provided Collector from the
+// DefaultRegisterer.
+//
+// Unregister is a shortcut for DefaultRegisterer.Unregister(c). See there for
+// more details.
+func Unregister(c Collector) bool {
+	return DefaultRegisterer.Unregister(c)
+}
+
+// GathererFunc turns a function into a Gatherer.
+type GathererFunc func() ([]*dto.MetricFamily, error)
+
+// Gather implements Gatherer.
+func (gf GathererFunc) Gather() ([]*dto.MetricFamily, error) {
+	return gf()
+}
+
+// SetMetricFamilyInjectionHook replaces the DefaultGatherer with one that
+// gathers from the previous DefaultGatherers but then merges the MetricFamily
+// protobufs returned from the provided hook function with the MetricFamily
+// protobufs returned from the original DefaultGatherer.
+//
+// Deprecated: This function manipulates the DefaultGatherer variable. Consider
+// the implications, i.e. don't do this concurrently with any uses of the
+// DefaultGatherer. In the rare cases where you need to inject MetricFamily
+// protobufs directly, it is recommended to use a custom Registry and combine it
+// with a custom Gatherer using the Gatherers type (see
+// there). SetMetricFamilyInjectionHook only exists for compatibility reasons
+// with previous versions of this package.
+func SetMetricFamilyInjectionHook(hook func() []*dto.MetricFamily) {
+	DefaultGatherer = Gatherers{
+		DefaultGatherer,
+		GathererFunc(func() ([]*dto.MetricFamily, error) { return hook(), nil }),
+	}
+}
+
+// AlreadyRegisteredError is returned by the Register method if the Collector to
+// be registered has already been registered before, or a different Collector
+// that collects the same metrics has been registered before. Registration fails
+// in that case, but you can detect from the kind of error what has
+// happened. The error contains fields for the existing Collector and the
+// (rejected) new Collector that equals the existing one. This can be used to
+// find out if an equal Collector has been registered before and switch over to
+// using the old one, as demonstrated in the example.
+type AlreadyRegisteredError struct {
+	ExistingCollector, NewCollector Collector
+}
+
+func (err AlreadyRegisteredError) Error() string {
+	return "duplicate metrics collector registration attempted"
+}
+
+// MultiError is a slice of errors implementing the error interface. It is used
+// by a Gatherer to report multiple errors during MetricFamily gathering.
+type MultiError []error
+
+func (errs MultiError) Error() string {
+	if len(errs) == 0 {
+		return ""
+	}
+	buf := &bytes.Buffer{}
+	fmt.Fprintf(buf, "%d error(s) occurred:", len(errs))
+	for _, err := range errs {
+		fmt.Fprintf(buf, "\n* %s", err)
+	}
+	return buf.String()
+}
+
+// MaybeUnwrap returns nil if len(errs) is 0. It returns the first and only
+// contained error as error if len(errs is 1). In all other cases, it returns
+// the MultiError directly. This is helpful for returning a MultiError in a way
+// that only uses the MultiError if needed.
+func (errs MultiError) MaybeUnwrap() error {
+	switch len(errs) {
+	case 0:
+		return nil
+	case 1:
+		return errs[0]
+	default:
+		return errs
+	}
+}
+
+// Registry registers Prometheus collectors, collects their metrics, and gathers
+// them into MetricFamilies for exposition. It implements both Registerer and
+// Gatherer. The zero value is not usable. Create instances with NewRegistry or
+// NewPedanticRegistry.
+type Registry struct {
+	mtx                   sync.RWMutex
+	collectorsByID        map[uint64]Collector // ID is a hash of the descIDs.
+	descIDs               map[uint64]struct{}
+	dimHashesByName       map[string]uint64
+	pedanticChecksEnabled bool
+}
+
+// Register implements Registerer.
+func (r *Registry) Register(c Collector) error {
+	var (
+		descChan           = make(chan *Desc, capDescChan)
+		newDescIDs         = map[uint64]struct{}{}
+		newDimHashesByName = map[string]uint64{}
+		collectorID        uint64 // Just a sum of all desc IDs.
+		duplicateDescErr   error
+	)
+	go func() {
+		c.Describe(descChan)
+		close(descChan)
+	}()
+	r.mtx.Lock()
+	defer r.mtx.Unlock()
+	// Coduct various tests...
+	for desc := range descChan {
+
+		// Is the descriptor valid at all?
+		if desc.err != nil {
+			return fmt.Errorf("descriptor %s is invalid: %s", desc, desc.err)
+		}
+
+		// Is the descID unique?
+		// (In other words: Is the fqName + constLabel combination unique?)
+		if _, exists := r.descIDs[desc.id]; exists {
+			duplicateDescErr = fmt.Errorf("descriptor %s already exists with the same fully-qualified name and const label values", desc)
+		}
+		// If it is not a duplicate desc in this collector, add it to
+		// the collectorID.  (We allow duplicate descs within the same
+		// collector, but their existence must be a no-op.)
+		if _, exists := newDescIDs[desc.id]; !exists {
+			newDescIDs[desc.id] = struct{}{}
+			collectorID += desc.id
+		}
+
+		// Are all the label names and the help string consistent with
+		// previous descriptors of the same name?
+		// First check existing descriptors...
+		if dimHash, exists := r.dimHashesByName[desc.fqName]; exists {
+			if dimHash != desc.dimHash {
+				return fmt.Errorf("a previously registered descriptor with the same fully-qualified name as %s has different label names or a different help string", desc)
+			}
+		} else {
+			// ...then check the new descriptors already seen.
+			if dimHash, exists := newDimHashesByName[desc.fqName]; exists {
+				if dimHash != desc.dimHash {
+					return fmt.Errorf("descriptors reported by collector have inconsistent label names or help strings for the same fully-qualified name, offender is %s", desc)
+				}
+			} else {
+				newDimHashesByName[desc.fqName] = desc.dimHash
+			}
+		}
+	}
+	// Did anything happen at all?
+	if len(newDescIDs) == 0 {
+		return errors.New("collector has no descriptors")
+	}
+	if existing, exists := r.collectorsByID[collectorID]; exists {
+		return AlreadyRegisteredError{
+			ExistingCollector: existing,
+			NewCollector:      c,
+		}
+	}
+	// If the collectorID is new, but at least one of the descs existed
+	// before, we are in trouble.
+	if duplicateDescErr != nil {
+		return duplicateDescErr
+	}
+
+	// Only after all tests have passed, actually register.
+	r.collectorsByID[collectorID] = c
+	for hash := range newDescIDs {
+		r.descIDs[hash] = struct{}{}
+	}
+	for name, dimHash := range newDimHashesByName {
+		r.dimHashesByName[name] = dimHash
+	}
+	return nil
+}
+
+// Unregister implements Registerer.
+func (r *Registry) Unregister(c Collector) bool {
+	var (
+		descChan    = make(chan *Desc, capDescChan)
+		descIDs     = map[uint64]struct{}{}
+		collectorID uint64 // Just a sum of the desc IDs.
+	)
+	go func() {
+		c.Describe(descChan)
+		close(descChan)
+	}()
+	for desc := range descChan {
+		if _, exists := descIDs[desc.id]; !exists {
+			collectorID += desc.id
+			descIDs[desc.id] = struct{}{}
+		}
+	}
+
+	r.mtx.RLock()
+	if _, exists := r.collectorsByID[collectorID]; !exists {
+		r.mtx.RUnlock()
+		return false
+	}
+	r.mtx.RUnlock()
+
+	r.mtx.Lock()
+	defer r.mtx.Unlock()
+
+	delete(r.collectorsByID, collectorID)
+	for id := range descIDs {
+		delete(r.descIDs, id)
+	}
+	// dimHashesByName is left untouched as those must be consistent
+	// throughout the lifetime of a program.
+	return true
+}
+
+// MustRegister implements Registerer.
+func (r *Registry) MustRegister(cs ...Collector) {
+	for _, c := range cs {
+		if err := r.Register(c); err != nil {
+			panic(err)
+		}
+	}
+}
+
+// Gather implements Gatherer.
+func (r *Registry) Gather() ([]*dto.MetricFamily, error) {
+	var (
+		metricChan        = make(chan Metric, capMetricChan)
+		metricHashes      = map[uint64]struct{}{}
+		dimHashes         = map[string]uint64{}
+		wg                sync.WaitGroup
+		errs              MultiError          // The collected errors to return in the end.
+		registeredDescIDs map[uint64]struct{} // Only used for pedantic checks
+	)
+
+	r.mtx.RLock()
+	metricFamiliesByName := make(map[string]*dto.MetricFamily, len(r.dimHashesByName))
+
+	// Scatter.
+	// (Collectors could be complex and slow, so we call them all at once.)
+	wg.Add(len(r.collectorsByID))
+	go func() {
+		wg.Wait()
+		close(metricChan)
+	}()
+	for _, collector := range r.collectorsByID {
+		go func(collector Collector) {
+			defer wg.Done()
+			collector.Collect(metricChan)
+		}(collector)
+	}
+
+	// In case pedantic checks are enabled, we have to copy the map before
+	// giving up the RLock.
+	if r.pedanticChecksEnabled {
+		registeredDescIDs = make(map[uint64]struct{}, len(r.descIDs))
+		for id := range r.descIDs {
+			registeredDescIDs[id] = struct{}{}
+		}
+	}
+
+	r.mtx.RUnlock()
+
+	// Drain metricChan in case of premature return.
+	defer func() {
+		for range metricChan {
+		}
+	}()
+
+	// Gather.
+	for metric := range metricChan {
+		// This could be done concurrently, too, but it required locking
+		// of metricFamiliesByName (and of metricHashes if checks are
+		// enabled). Most likely not worth it.
+		desc := metric.Desc()
+		dtoMetric := &dto.Metric{}
+		if err := metric.Write(dtoMetric); err != nil {
+			errs = append(errs, fmt.Errorf(
+				"error collecting metric %v: %s", desc, err,
+			))
+			continue
+		}
+		metricFamily, ok := metricFamiliesByName[desc.fqName]
+		if ok {
+			if metricFamily.GetHelp() != desc.help {
+				errs = append(errs, fmt.Errorf(
+					"collected metric %s %s has help %q but should have %q",
+					desc.fqName, dtoMetric, desc.help, metricFamily.GetHelp(),
+				))
+				continue
+			}
+			// TODO(beorn7): Simplify switch once Desc has type.
+			switch metricFamily.GetType() {
+			case dto.MetricType_COUNTER:
+				if dtoMetric.Counter == nil {
+					errs = append(errs, fmt.Errorf(
+						"collected metric %s %s should be a Counter",
+						desc.fqName, dtoMetric,
+					))
+					continue
+				}
+			case dto.MetricType_GAUGE:
+				if dtoMetric.Gauge == nil {
+					errs = append(errs, fmt.Errorf(
+						"collected metric %s %s should be a Gauge",
+						desc.fqName, dtoMetric,
+					))
+					continue
+				}
+			case dto.MetricType_SUMMARY:
+				if dtoMetric.Summary == nil {
+					errs = append(errs, fmt.Errorf(
+						"collected metric %s %s should be a Summary",
+						desc.fqName, dtoMetric,
+					))
+					continue
+				}
+			case dto.MetricType_UNTYPED:
+				if dtoMetric.Untyped == nil {
+					errs = append(errs, fmt.Errorf(
+						"collected metric %s %s should be Untyped",
+						desc.fqName, dtoMetric,
+					))
+					continue
+				}
+			case dto.MetricType_HISTOGRAM:
+				if dtoMetric.Histogram == nil {
+					errs = append(errs, fmt.Errorf(
+						"collected metric %s %s should be a Histogram",
+						desc.fqName, dtoMetric,
+					))
+					continue
+				}
+			default:
+				panic("encountered MetricFamily with invalid type")
+			}
+		} else {
+			metricFamily = &dto.MetricFamily{}
+			metricFamily.Name = proto.String(desc.fqName)
+			metricFamily.Help = proto.String(desc.help)
+			// TODO(beorn7): Simplify switch once Desc has type.
+			switch {
+			case dtoMetric.Gauge != nil:
+				metricFamily.Type = dto.MetricType_GAUGE.Enum()
+			case dtoMetric.Counter != nil:
+				metricFamily.Type = dto.MetricType_COUNTER.Enum()
+			case dtoMetric.Summary != nil:
+				metricFamily.Type = dto.MetricType_SUMMARY.Enum()
+			case dtoMetric.Untyped != nil:
+				metricFamily.Type = dto.MetricType_UNTYPED.Enum()
+			case dtoMetric.Histogram != nil:
+				metricFamily.Type = dto.MetricType_HISTOGRAM.Enum()
+			default:
+				errs = append(errs, fmt.Errorf(
+					"empty metric collected: %s", dtoMetric,
+				))
+				continue
+			}
+			metricFamiliesByName[desc.fqName] = metricFamily
+		}
+		if err := checkMetricConsistency(metricFamily, dtoMetric, metricHashes, dimHashes); err != nil {
+			errs = append(errs, err)
+			continue
+		}
+		if r.pedanticChecksEnabled {
+			// Is the desc registered at all?
+			if _, exist := registeredDescIDs[desc.id]; !exist {
+				errs = append(errs, fmt.Errorf(
+					"collected metric %s %s with unregistered descriptor %s",
+					metricFamily.GetName(), dtoMetric, desc,
+				))
+				continue
+			}
+			if err := checkDescConsistency(metricFamily, dtoMetric, desc); err != nil {
+				errs = append(errs, err)
+				continue
+			}
+		}
+		metricFamily.Metric = append(metricFamily.Metric, dtoMetric)
+	}
+	return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
+}
+
+// Gatherers is a slice of Gatherer instances that implements the Gatherer
+// interface itself. Its Gather method calls Gather on all Gatherers in the
+// slice in order and returns the merged results. Errors returned from the
+// Gather calles are all returned in a flattened MultiError. Duplicate and
+// inconsistent Metrics are skipped (first occurrence in slice order wins) and
+// reported in the returned error.
+//
+// Gatherers can be used to merge the Gather results from multiple
+// Registries. It also provides a way to directly inject existing MetricFamily
+// protobufs into the gathering by creating a custom Gatherer with a Gather
+// method that simply returns the existing MetricFamily protobufs. Note that no
+// registration is involved (in contrast to Collector registration), so
+// obviously registration-time checks cannot happen. Any inconsistencies between
+// the gathered MetricFamilies are reported as errors by the Gather method, and
+// inconsistent Metrics are dropped. Invalid parts of the MetricFamilies
+// (e.g. syntactically invalid metric or label names) will go undetected.
+type Gatherers []Gatherer
+
+// Gather implements Gatherer.
+func (gs Gatherers) Gather() ([]*dto.MetricFamily, error) {
+	var (
+		metricFamiliesByName = map[string]*dto.MetricFamily{}
+		metricHashes         = map[uint64]struct{}{}
+		dimHashes            = map[string]uint64{}
+		errs                 MultiError // The collected errors to return in the end.
+	)
+
+	for i, g := range gs {
+		mfs, err := g.Gather()
+		if err != nil {
+			if multiErr, ok := err.(MultiError); ok {
+				for _, err := range multiErr {
+					errs = append(errs, fmt.Errorf("[from Gatherer #%d] %s", i+1, err))
+				}
+			} else {
+				errs = append(errs, fmt.Errorf("[from Gatherer #%d] %s", i+1, err))
+			}
+		}
+		for _, mf := range mfs {
+			existingMF, exists := metricFamiliesByName[mf.GetName()]
+			if exists {
+				if existingMF.GetHelp() != mf.GetHelp() {
+					errs = append(errs, fmt.Errorf(
+						"gathered metric family %s has help %q but should have %q",
+						mf.GetName(), mf.GetHelp(), existingMF.GetHelp(),
+					))
+					continue
+				}
+				if existingMF.GetType() != mf.GetType() {
+					errs = append(errs, fmt.Errorf(
+						"gathered metric family %s has type %s but should have %s",
+						mf.GetName(), mf.GetType(), existingMF.GetType(),
+					))
+					continue
+				}
+			} else {
+				existingMF = &dto.MetricFamily{}
+				existingMF.Name = mf.Name
+				existingMF.Help = mf.Help
+				existingMF.Type = mf.Type
+				metricFamiliesByName[mf.GetName()] = existingMF
+			}
+			for _, m := range mf.Metric {
+				if err := checkMetricConsistency(existingMF, m, metricHashes, dimHashes); err != nil {
+					errs = append(errs, err)
+					continue
+				}
+				existingMF.Metric = append(existingMF.Metric, m)
+			}
+		}
+	}
+	return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap()
+}
+
+// metricSorter is a sortable slice of *dto.Metric.
+type metricSorter []*dto.Metric
+
+func (s metricSorter) Len() int {
+	return len(s)
+}
+
+func (s metricSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s metricSorter) Less(i, j int) bool {
+	if len(s[i].Label) != len(s[j].Label) {
+		// This should not happen. The metrics are
+		// inconsistent. However, we have to deal with the fact, as
+		// people might use custom collectors or metric family injection
+		// to create inconsistent metrics. So let's simply compare the
+		// number of labels in this case. That will still yield
+		// reproducible sorting.
+		return len(s[i].Label) < len(s[j].Label)
+	}
+	for n, lp := range s[i].Label {
+		vi := lp.GetValue()
+		vj := s[j].Label[n].GetValue()
+		if vi != vj {
+			return vi < vj
+		}
+	}
+
+	// We should never arrive here. Multiple metrics with the same
+	// label set in the same scrape will lead to undefined ingestion
+	// behavior. However, as above, we have to provide stable sorting
+	// here, even for inconsistent metrics. So sort equal metrics
+	// by their timestamp, with missing timestamps (implying "now")
+	// coming last.
+	if s[i].TimestampMs == nil {
+		return false
+	}
+	if s[j].TimestampMs == nil {
+		return true
+	}
+	return s[i].GetTimestampMs() < s[j].GetTimestampMs()
+}
+
+// normalizeMetricFamilies returns a MetricFamily slice with empty
+// MetricFamilies pruned and the remaining MetricFamilies sorted by name within
+// the slice, with the contained Metrics sorted within each MetricFamily.
+func normalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily {
+	for _, mf := range metricFamiliesByName {
+		sort.Sort(metricSorter(mf.Metric))
+	}
+	names := make([]string, 0, len(metricFamiliesByName))
+	for name, mf := range metricFamiliesByName {
+		if len(mf.Metric) > 0 {
+			names = append(names, name)
+		}
+	}
+	sort.Strings(names)
+	result := make([]*dto.MetricFamily, 0, len(names))
+	for _, name := range names {
+		result = append(result, metricFamiliesByName[name])
+	}
+	return result
+}
+
+// checkMetricConsistency checks if the provided Metric is consistent with the
+// provided MetricFamily. It also hashed the Metric labels and the MetricFamily
+// name. If the resulting hash is alread in the provided metricHashes, an error
+// is returned. If not, it is added to metricHashes. The provided dimHashes maps
+// MetricFamily names to their dimHash (hashed sorted label names). If dimHashes
+// doesn't yet contain a hash for the provided MetricFamily, it is
+// added. Otherwise, an error is returned if the existing dimHashes in not equal
+// the calculated dimHash.
+func checkMetricConsistency(
+	metricFamily *dto.MetricFamily,
+	dtoMetric *dto.Metric,
+	metricHashes map[uint64]struct{},
+	dimHashes map[string]uint64,
+) error {
+	// Type consistency with metric family.
+	if metricFamily.GetType() == dto.MetricType_GAUGE && dtoMetric.Gauge == nil ||
+		metricFamily.GetType() == dto.MetricType_COUNTER && dtoMetric.Counter == nil ||
+		metricFamily.GetType() == dto.MetricType_SUMMARY && dtoMetric.Summary == nil ||
+		metricFamily.GetType() == dto.MetricType_HISTOGRAM && dtoMetric.Histogram == nil ||
+		metricFamily.GetType() == dto.MetricType_UNTYPED && dtoMetric.Untyped == nil {
+		return fmt.Errorf(
+			"collected metric %s %s is not a %s",
+			metricFamily.GetName(), dtoMetric, metricFamily.GetType(),
+		)
+	}
+
+	// Is the metric unique (i.e. no other metric with the same name and the same label values)?
+	h := hashNew()
+	h = hashAdd(h, metricFamily.GetName())
+	h = hashAddByte(h, separatorByte)
+	dh := hashNew()
+	// Make sure label pairs are sorted. We depend on it for the consistency
+	// check.
+	sort.Sort(LabelPairSorter(dtoMetric.Label))
+	for _, lp := range dtoMetric.Label {
+		h = hashAdd(h, lp.GetValue())
+		h = hashAddByte(h, separatorByte)
+		dh = hashAdd(dh, lp.GetName())
+		dh = hashAddByte(dh, separatorByte)
+	}
+	if _, exists := metricHashes[h]; exists {
+		return fmt.Errorf(
+			"collected metric %s %s was collected before with the same name and label values",
+			metricFamily.GetName(), dtoMetric,
+		)
+	}
+	if dimHash, ok := dimHashes[metricFamily.GetName()]; ok {
+		if dimHash != dh {
+			return fmt.Errorf(
+				"collected metric %s %s has label dimensions inconsistent with previously collected metrics in the same metric family",
+				metricFamily.GetName(), dtoMetric,
+			)
+		}
+	} else {
+		dimHashes[metricFamily.GetName()] = dh
+	}
+	metricHashes[h] = struct{}{}
+	return nil
+}
+
+func checkDescConsistency(
+	metricFamily *dto.MetricFamily,
+	dtoMetric *dto.Metric,
+	desc *Desc,
+) error {
+	// Desc help consistency with metric family help.
+	if metricFamily.GetHelp() != desc.help {
+		return fmt.Errorf(
+			"collected metric %s %s has help %q but should have %q",
+			metricFamily.GetName(), dtoMetric, metricFamily.GetHelp(), desc.help,
+		)
+	}
+
+	// Is the desc consistent with the content of the metric?
+	lpsFromDesc := make([]*dto.LabelPair, 0, len(dtoMetric.Label))
+	lpsFromDesc = append(lpsFromDesc, desc.constLabelPairs...)
+	for _, l := range desc.variableLabels {
+		lpsFromDesc = append(lpsFromDesc, &dto.LabelPair{
+			Name: proto.String(l),
+		})
+	}
+	if len(lpsFromDesc) != len(dtoMetric.Label) {
+		return fmt.Errorf(
+			"labels in collected metric %s %s are inconsistent with descriptor %s",
+			metricFamily.GetName(), dtoMetric, desc,
+		)
+	}
+	sort.Sort(LabelPairSorter(lpsFromDesc))
+	for i, lpFromDesc := range lpsFromDesc {
+		lpFromMetric := dtoMetric.Label[i]
+		if lpFromDesc.GetName() != lpFromMetric.GetName() ||
+			lpFromDesc.Value != nil && lpFromDesc.GetValue() != lpFromMetric.GetValue() {
+			return fmt.Errorf(
+				"labels in collected metric %s %s are inconsistent with descriptor %s",
+				metricFamily.GetName(), dtoMetric, desc,
+			)
+		}
+	}
+	return nil
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/summary.go b/vendor/github.com/prometheus/client_golang/prometheus/summary.go
new file mode 100644
index 00000000..bce05bf9
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/summary.go
@@ -0,0 +1,534 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"fmt"
+	"math"
+	"sort"
+	"sync"
+	"time"
+
+	"github.com/beorn7/perks/quantile"
+	"github.com/golang/protobuf/proto"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// quantileLabel is used for the label that defines the quantile in a
+// summary.
+const quantileLabel = "quantile"
+
+// A Summary captures individual observations from an event or sample stream and
+// summarizes them in a manner similar to traditional summary statistics: 1. sum
+// of observations, 2. observation count, 3. rank estimations.
+//
+// A typical use-case is the observation of request latencies. By default, a
+// Summary provides the median, the 90th and the 99th percentile of the latency
+// as rank estimations.
+//
+// Note that the rank estimations cannot be aggregated in a meaningful way with
+// the Prometheus query language (i.e. you cannot average or add them). If you
+// need aggregatable quantiles (e.g. you want the 99th percentile latency of all
+// queries served across all instances of a service), consider the Histogram
+// metric type. See the Prometheus documentation for more details.
+//
+// To create Summary instances, use NewSummary.
+type Summary interface {
+	Metric
+	Collector
+
+	// Observe adds a single observation to the summary.
+	Observe(float64)
+}
+
+// DefObjectives are the default Summary quantile values.
+var (
+	DefObjectives = map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001}
+
+	errQuantileLabelNotAllowed = fmt.Errorf(
+		"%q is not allowed as label name in summaries", quantileLabel,
+	)
+)
+
+// Default values for SummaryOpts.
+const (
+	// DefMaxAge is the default duration for which observations stay
+	// relevant.
+	DefMaxAge time.Duration = 10 * time.Minute
+	// DefAgeBuckets is the default number of buckets used to calculate the
+	// age of observations.
+	DefAgeBuckets = 5
+	// DefBufCap is the standard buffer size for collecting Summary observations.
+	DefBufCap = 500
+)
+
+// SummaryOpts bundles the options for creating a Summary metric. It is
+// mandatory to set Name and Help to a non-empty string. All other fields are
+// optional and can safely be left at their zero value.
+type SummaryOpts struct {
+	// Namespace, Subsystem, and Name are components of the fully-qualified
+	// name of the Summary (created by joining these components with
+	// "_"). Only Name is mandatory, the others merely help structuring the
+	// name. Note that the fully-qualified name of the Summary must be a
+	// valid Prometheus metric name.
+	Namespace string
+	Subsystem string
+	Name      string
+
+	// Help provides information about this Summary. Mandatory!
+	//
+	// Metrics with the same fully-qualified name must have the same Help
+	// string.
+	Help string
+
+	// ConstLabels are used to attach fixed labels to this
+	// Summary. Summaries with the same fully-qualified name must have the
+	// same label names in their ConstLabels.
+	//
+	// Note that in most cases, labels have a value that varies during the
+	// lifetime of a process. Those labels are usually managed with a
+	// SummaryVec. ConstLabels serve only special purposes. One is for the
+	// special case where the value of a label does not change during the
+	// lifetime of a process, e.g. if the revision of the running binary is
+	// put into a label. Another, more advanced purpose is if more than one
+	// Collector needs to collect Summaries with the same fully-qualified
+	// name. In that case, those Summaries must differ in the values of
+	// their ConstLabels. See the Collector examples.
+	//
+	// If the value of a label never changes (not even between binaries),
+	// that label most likely should not be a label at all (but part of the
+	// metric name).
+	ConstLabels Labels
+
+	// Objectives defines the quantile rank estimates with their respective
+	// absolute error. If Objectives[q] = e, then the value reported
+	// for q will be the φ-quantile value for some φ between q-e and q+e.
+	// The default value is DefObjectives.
+	Objectives map[float64]float64
+
+	// MaxAge defines the duration for which an observation stays relevant
+	// for the summary. Must be positive. The default value is DefMaxAge.
+	MaxAge time.Duration
+
+	// AgeBuckets is the number of buckets used to exclude observations that
+	// are older than MaxAge from the summary. A higher number has a
+	// resource penalty, so only increase it if the higher resolution is
+	// really required. For very high observation rates, you might want to
+	// reduce the number of age buckets. With only one age bucket, you will
+	// effectively see a complete reset of the summary each time MaxAge has
+	// passed. The default value is DefAgeBuckets.
+	AgeBuckets uint32
+
+	// BufCap defines the default sample stream buffer size.  The default
+	// value of DefBufCap should suffice for most uses. If there is a need
+	// to increase the value, a multiple of 500 is recommended (because that
+	// is the internal buffer size of the underlying package
+	// "github.com/bmizerany/perks/quantile").
+	BufCap uint32
+}
+
+// Great fuck-up with the sliding-window decay algorithm... The Merge method of
+// perk/quantile is actually not working as advertised - and it might be
+// unfixable, as the underlying algorithm is apparently not capable of merging
+// summaries in the first place. To avoid using Merge, we are currently adding
+// observations to _each_ age bucket, i.e. the effort to add a sample is
+// essentially multiplied by the number of age buckets. When rotating age
+// buckets, we empty the previous head stream. On scrape time, we simply take
+// the quantiles from the head stream (no merging required). Result: More effort
+// on observation time, less effort on scrape time, which is exactly the
+// opposite of what we try to accomplish, but at least the results are correct.
+//
+// The quite elegant previous contraption to merge the age buckets efficiently
+// on scrape time (see code up commit 6b9530d72ea715f0ba612c0120e6e09fbf1d49d0)
+// can't be used anymore.
+
+// NewSummary creates a new Summary based on the provided SummaryOpts.
+func NewSummary(opts SummaryOpts) Summary {
+	return newSummary(
+		NewDesc(
+			BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+			opts.Help,
+			nil,
+			opts.ConstLabels,
+		),
+		opts,
+	)
+}
+
+func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
+	if len(desc.variableLabels) != len(labelValues) {
+		panic(errInconsistentCardinality)
+	}
+
+	for _, n := range desc.variableLabels {
+		if n == quantileLabel {
+			panic(errQuantileLabelNotAllowed)
+		}
+	}
+	for _, lp := range desc.constLabelPairs {
+		if lp.GetName() == quantileLabel {
+			panic(errQuantileLabelNotAllowed)
+		}
+	}
+
+	if len(opts.Objectives) == 0 {
+		opts.Objectives = DefObjectives
+	}
+
+	if opts.MaxAge < 0 {
+		panic(fmt.Errorf("illegal max age MaxAge=%v", opts.MaxAge))
+	}
+	if opts.MaxAge == 0 {
+		opts.MaxAge = DefMaxAge
+	}
+
+	if opts.AgeBuckets == 0 {
+		opts.AgeBuckets = DefAgeBuckets
+	}
+
+	if opts.BufCap == 0 {
+		opts.BufCap = DefBufCap
+	}
+
+	s := &summary{
+		desc: desc,
+
+		objectives:       opts.Objectives,
+		sortedObjectives: make([]float64, 0, len(opts.Objectives)),
+
+		labelPairs: makeLabelPairs(desc, labelValues),
+
+		hotBuf:         make([]float64, 0, opts.BufCap),
+		coldBuf:        make([]float64, 0, opts.BufCap),
+		streamDuration: opts.MaxAge / time.Duration(opts.AgeBuckets),
+	}
+	s.headStreamExpTime = time.Now().Add(s.streamDuration)
+	s.hotBufExpTime = s.headStreamExpTime
+
+	for i := uint32(0); i < opts.AgeBuckets; i++ {
+		s.streams = append(s.streams, s.newStream())
+	}
+	s.headStream = s.streams[0]
+
+	for qu := range s.objectives {
+		s.sortedObjectives = append(s.sortedObjectives, qu)
+	}
+	sort.Float64s(s.sortedObjectives)
+
+	s.init(s) // Init self-collection.
+	return s
+}
+
+type summary struct {
+	selfCollector
+
+	bufMtx sync.Mutex // Protects hotBuf and hotBufExpTime.
+	mtx    sync.Mutex // Protects every other moving part.
+	// Lock bufMtx before mtx if both are needed.
+
+	desc *Desc
+
+	objectives       map[float64]float64
+	sortedObjectives []float64
+
+	labelPairs []*dto.LabelPair
+
+	sum float64
+	cnt uint64
+
+	hotBuf, coldBuf []float64
+
+	streams                          []*quantile.Stream
+	streamDuration                   time.Duration
+	headStream                       *quantile.Stream
+	headStreamIdx                    int
+	headStreamExpTime, hotBufExpTime time.Time
+}
+
+func (s *summary) Desc() *Desc {
+	return s.desc
+}
+
+func (s *summary) Observe(v float64) {
+	s.bufMtx.Lock()
+	defer s.bufMtx.Unlock()
+
+	now := time.Now()
+	if now.After(s.hotBufExpTime) {
+		s.asyncFlush(now)
+	}
+	s.hotBuf = append(s.hotBuf, v)
+	if len(s.hotBuf) == cap(s.hotBuf) {
+		s.asyncFlush(now)
+	}
+}
+
+func (s *summary) Write(out *dto.Metric) error {
+	sum := &dto.Summary{}
+	qs := make([]*dto.Quantile, 0, len(s.objectives))
+
+	s.bufMtx.Lock()
+	s.mtx.Lock()
+	// Swap bufs even if hotBuf is empty to set new hotBufExpTime.
+	s.swapBufs(time.Now())
+	s.bufMtx.Unlock()
+
+	s.flushColdBuf()
+	sum.SampleCount = proto.Uint64(s.cnt)
+	sum.SampleSum = proto.Float64(s.sum)
+
+	for _, rank := range s.sortedObjectives {
+		var q float64
+		if s.headStream.Count() == 0 {
+			q = math.NaN()
+		} else {
+			q = s.headStream.Query(rank)
+		}
+		qs = append(qs, &dto.Quantile{
+			Quantile: proto.Float64(rank),
+			Value:    proto.Float64(q),
+		})
+	}
+
+	s.mtx.Unlock()
+
+	if len(qs) > 0 {
+		sort.Sort(quantSort(qs))
+	}
+	sum.Quantile = qs
+
+	out.Summary = sum
+	out.Label = s.labelPairs
+	return nil
+}
+
+func (s *summary) newStream() *quantile.Stream {
+	return quantile.NewTargeted(s.objectives)
+}
+
+// asyncFlush needs bufMtx locked.
+func (s *summary) asyncFlush(now time.Time) {
+	s.mtx.Lock()
+	s.swapBufs(now)
+
+	// Unblock the original goroutine that was responsible for the mutation
+	// that triggered the compaction.  But hold onto the global non-buffer
+	// state mutex until the operation finishes.
+	go func() {
+		s.flushColdBuf()
+		s.mtx.Unlock()
+	}()
+}
+
+// rotateStreams needs mtx AND bufMtx locked.
+func (s *summary) maybeRotateStreams() {
+	for !s.hotBufExpTime.Equal(s.headStreamExpTime) {
+		s.headStream.Reset()
+		s.headStreamIdx++
+		if s.headStreamIdx >= len(s.streams) {
+			s.headStreamIdx = 0
+		}
+		s.headStream = s.streams[s.headStreamIdx]
+		s.headStreamExpTime = s.headStreamExpTime.Add(s.streamDuration)
+	}
+}
+
+// flushColdBuf needs mtx locked.
+func (s *summary) flushColdBuf() {
+	for _, v := range s.coldBuf {
+		for _, stream := range s.streams {
+			stream.Insert(v)
+		}
+		s.cnt++
+		s.sum += v
+	}
+	s.coldBuf = s.coldBuf[0:0]
+	s.maybeRotateStreams()
+}
+
+// swapBufs needs mtx AND bufMtx locked, coldBuf must be empty.
+func (s *summary) swapBufs(now time.Time) {
+	if len(s.coldBuf) != 0 {
+		panic("coldBuf is not empty")
+	}
+	s.hotBuf, s.coldBuf = s.coldBuf, s.hotBuf
+	// hotBuf is now empty and gets new expiration set.
+	for now.After(s.hotBufExpTime) {
+		s.hotBufExpTime = s.hotBufExpTime.Add(s.streamDuration)
+	}
+}
+
+type quantSort []*dto.Quantile
+
+func (s quantSort) Len() int {
+	return len(s)
+}
+
+func (s quantSort) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s quantSort) Less(i, j int) bool {
+	return s[i].GetQuantile() < s[j].GetQuantile()
+}
+
+// SummaryVec is a Collector that bundles a set of Summaries that all share the
+// same Desc, but have different values for their variable labels. This is used
+// if you want to count the same thing partitioned by various dimensions
+// (e.g. HTTP request latencies, partitioned by status code and method). Create
+// instances with NewSummaryVec.
+type SummaryVec struct {
+	*MetricVec
+}
+
+// NewSummaryVec creates a new SummaryVec based on the provided SummaryOpts and
+// partitioned by the given label names. At least one label name must be
+// provided.
+func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		labelNames,
+		opts.ConstLabels,
+	)
+	return &SummaryVec{
+		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			return newSummary(desc, opts, lvs...)
+		}),
+	}
+}
+
+// GetMetricWithLabelValues replaces the method of the same name in
+// MetricVec. The difference is that this method returns a Summary and not a
+// Metric so that no type conversion is required.
+func (m *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Summary, error) {
+	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Summary), err
+	}
+	return nil, err
+}
+
+// GetMetricWith replaces the method of the same name in MetricVec. The
+// difference is that this method returns a Summary and not a Metric so that no
+// type conversion is required.
+func (m *SummaryVec) GetMetricWith(labels Labels) (Summary, error) {
+	metric, err := m.MetricVec.GetMetricWith(labels)
+	if metric != nil {
+		return metric.(Summary), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. By not returning an
+// error, WithLabelValues allows shortcuts like
+//     myVec.WithLabelValues("404", "GET").Observe(42.21)
+func (m *SummaryVec) WithLabelValues(lvs ...string) Summary {
+	return m.MetricVec.WithLabelValues(lvs...).(Summary)
+}
+
+// With works as GetMetricWith, but panics where GetMetricWithLabels would have
+// returned an error. By not returning an error, With allows shortcuts like
+//     myVec.With(Labels{"code": "404", "method": "GET"}).Observe(42.21)
+func (m *SummaryVec) With(labels Labels) Summary {
+	return m.MetricVec.With(labels).(Summary)
+}
+
+type constSummary struct {
+	desc       *Desc
+	count      uint64
+	sum        float64
+	quantiles  map[float64]float64
+	labelPairs []*dto.LabelPair
+}
+
+func (s *constSummary) Desc() *Desc {
+	return s.desc
+}
+
+func (s *constSummary) Write(out *dto.Metric) error {
+	sum := &dto.Summary{}
+	qs := make([]*dto.Quantile, 0, len(s.quantiles))
+
+	sum.SampleCount = proto.Uint64(s.count)
+	sum.SampleSum = proto.Float64(s.sum)
+
+	for rank, q := range s.quantiles {
+		qs = append(qs, &dto.Quantile{
+			Quantile: proto.Float64(rank),
+			Value:    proto.Float64(q),
+		})
+	}
+
+	if len(qs) > 0 {
+		sort.Sort(quantSort(qs))
+	}
+	sum.Quantile = qs
+
+	out.Summary = sum
+	out.Label = s.labelPairs
+
+	return nil
+}
+
+// NewConstSummary returns a metric representing a Prometheus summary with fixed
+// values for the count, sum, and quantiles. As those parameters cannot be
+// changed, the returned value does not implement the Summary interface (but
+// only the Metric interface). Users of this package will not have much use for
+// it in regular operations. However, when implementing custom Collectors, it is
+// useful as a throw-away metric that is generated on the fly to send it to
+// Prometheus in the Collect method.
+//
+// quantiles maps ranks to quantile values. For example, a median latency of
+// 0.23s and a 99th percentile latency of 0.56s would be expressed as:
+//     map[float64]float64{0.5: 0.23, 0.99: 0.56}
+//
+// NewConstSummary returns an error if the length of labelValues is not
+// consistent with the variable labels in Desc.
+func NewConstSummary(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	quantiles map[float64]float64,
+	labelValues ...string,
+) (Metric, error) {
+	if len(desc.variableLabels) != len(labelValues) {
+		return nil, errInconsistentCardinality
+	}
+	return &constSummary{
+		desc:       desc,
+		count:      count,
+		sum:        sum,
+		quantiles:  quantiles,
+		labelPairs: makeLabelPairs(desc, labelValues),
+	}, nil
+}
+
+// MustNewConstSummary is a version of NewConstSummary that panics where
+// NewConstMetric would have returned an error.
+func MustNewConstSummary(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	quantiles map[float64]float64,
+	labelValues ...string,
+) Metric {
+	m, err := NewConstSummary(desc, count, sum, quantiles, labelValues...)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/untyped.go b/vendor/github.com/prometheus/client_golang/prometheus/untyped.go
new file mode 100644
index 00000000..5faf7e6e
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/untyped.go
@@ -0,0 +1,138 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Untyped is a Metric that represents a single numerical value that can
+// arbitrarily go up and down.
+//
+// An Untyped metric works the same as a Gauge. The only difference is that to
+// no type information is implied.
+//
+// To create Untyped instances, use NewUntyped.
+type Untyped interface {
+	Metric
+	Collector
+
+	// Set sets the Untyped metric to an arbitrary value.
+	Set(float64)
+	// Inc increments the Untyped metric by 1.
+	Inc()
+	// Dec decrements the Untyped metric by 1.
+	Dec()
+	// Add adds the given value to the Untyped metric. (The value can be
+	// negative, resulting in a decrease.)
+	Add(float64)
+	// Sub subtracts the given value from the Untyped metric. (The value can
+	// be negative, resulting in an increase.)
+	Sub(float64)
+}
+
+// UntypedOpts is an alias for Opts. See there for doc comments.
+type UntypedOpts Opts
+
+// NewUntyped creates a new Untyped metric from the provided UntypedOpts.
+func NewUntyped(opts UntypedOpts) Untyped {
+	return newValue(NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	), UntypedValue, 0)
+}
+
+// UntypedVec is a Collector that bundles a set of Untyped metrics that all
+// share the same Desc, but have different values for their variable
+// labels. This is used if you want to count the same thing partitioned by
+// various dimensions. Create instances with NewUntypedVec.
+type UntypedVec struct {
+	*MetricVec
+}
+
+// NewUntypedVec creates a new UntypedVec based on the provided UntypedOpts and
+// partitioned by the given label names. At least one label name must be
+// provided.
+func NewUntypedVec(opts UntypedOpts, labelNames []string) *UntypedVec {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		labelNames,
+		opts.ConstLabels,
+	)
+	return &UntypedVec{
+		MetricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			return newValue(desc, UntypedValue, 0, lvs...)
+		}),
+	}
+}
+
+// GetMetricWithLabelValues replaces the method of the same name in
+// MetricVec. The difference is that this method returns an Untyped and not a
+// Metric so that no type conversion is required.
+func (m *UntypedVec) GetMetricWithLabelValues(lvs ...string) (Untyped, error) {
+	metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Untyped), err
+	}
+	return nil, err
+}
+
+// GetMetricWith replaces the method of the same name in MetricVec. The
+// difference is that this method returns an Untyped and not a Metric so that no
+// type conversion is required.
+func (m *UntypedVec) GetMetricWith(labels Labels) (Untyped, error) {
+	metric, err := m.MetricVec.GetMetricWith(labels)
+	if metric != nil {
+		return metric.(Untyped), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. By not returning an
+// error, WithLabelValues allows shortcuts like
+//     myVec.WithLabelValues("404", "GET").Add(42)
+func (m *UntypedVec) WithLabelValues(lvs ...string) Untyped {
+	return m.MetricVec.WithLabelValues(lvs...).(Untyped)
+}
+
+// With works as GetMetricWith, but panics where GetMetricWithLabels would have
+// returned an error. By not returning an error, With allows shortcuts like
+//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
+func (m *UntypedVec) With(labels Labels) Untyped {
+	return m.MetricVec.With(labels).(Untyped)
+}
+
+// UntypedFunc is an Untyped whose value is determined at collect time by
+// calling a provided function.
+//
+// To create UntypedFunc instances, use NewUntypedFunc.
+type UntypedFunc interface {
+	Metric
+	Collector
+}
+
+// NewUntypedFunc creates a new UntypedFunc based on the provided
+// UntypedOpts. The value reported is determined by calling the given function
+// from within the Write method. Take into account that metric collection may
+// happen concurrently. If that results in concurrent calls to Write, like in
+// the case where an UntypedFunc is directly registered with Prometheus, the
+// provided function must be concurrency-safe.
+func NewUntypedFunc(opts UntypedOpts, function func() float64) UntypedFunc {
+	return newValueFunc(NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	), UntypedValue, function)
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/value.go b/vendor/github.com/prometheus/client_golang/prometheus/value.go
new file mode 100644
index 00000000..a944c377
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/value.go
@@ -0,0 +1,234 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"math"
+	"sort"
+	"sync/atomic"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/golang/protobuf/proto"
+)
+
+// ValueType is an enumeration of metric types that represent a simple value.
+type ValueType int
+
+// Possible values for the ValueType enum.
+const (
+	_ ValueType = iota
+	CounterValue
+	GaugeValue
+	UntypedValue
+)
+
+var errInconsistentCardinality = errors.New("inconsistent label cardinality")
+
+// value is a generic metric for simple values. It implements Metric, Collector,
+// Counter, Gauge, and Untyped. Its effective type is determined by
+// ValueType. This is a low-level building block used by the library to back the
+// implementations of Counter, Gauge, and Untyped.
+type value struct {
+	// valBits containst the bits of the represented float64 value. It has
+	// to go first in the struct to guarantee alignment for atomic
+	// operations.  http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	valBits uint64
+
+	selfCollector
+
+	desc       *Desc
+	valType    ValueType
+	labelPairs []*dto.LabelPair
+}
+
+// newValue returns a newly allocated value with the given Desc, ValueType,
+// sample value and label values. It panics if the number of label
+// values is different from the number of variable labels in Desc.
+func newValue(desc *Desc, valueType ValueType, val float64, labelValues ...string) *value {
+	if len(labelValues) != len(desc.variableLabels) {
+		panic(errInconsistentCardinality)
+	}
+	result := &value{
+		desc:       desc,
+		valType:    valueType,
+		valBits:    math.Float64bits(val),
+		labelPairs: makeLabelPairs(desc, labelValues),
+	}
+	result.init(result)
+	return result
+}
+
+func (v *value) Desc() *Desc {
+	return v.desc
+}
+
+func (v *value) Set(val float64) {
+	atomic.StoreUint64(&v.valBits, math.Float64bits(val))
+}
+
+func (v *value) Inc() {
+	v.Add(1)
+}
+
+func (v *value) Dec() {
+	v.Add(-1)
+}
+
+func (v *value) Add(val float64) {
+	for {
+		oldBits := atomic.LoadUint64(&v.valBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + val)
+		if atomic.CompareAndSwapUint64(&v.valBits, oldBits, newBits) {
+			return
+		}
+	}
+}
+
+func (v *value) Sub(val float64) {
+	v.Add(val * -1)
+}
+
+func (v *value) Write(out *dto.Metric) error {
+	val := math.Float64frombits(atomic.LoadUint64(&v.valBits))
+	return populateMetric(v.valType, val, v.labelPairs, out)
+}
+
+// valueFunc is a generic metric for simple values retrieved on collect time
+// from a function. It implements Metric and Collector. Its effective type is
+// determined by ValueType. This is a low-level building block used by the
+// library to back the implementations of CounterFunc, GaugeFunc, and
+// UntypedFunc.
+type valueFunc struct {
+	selfCollector
+
+	desc       *Desc
+	valType    ValueType
+	function   func() float64
+	labelPairs []*dto.LabelPair
+}
+
+// newValueFunc returns a newly allocated valueFunc with the given Desc and
+// ValueType. The value reported is determined by calling the given function
+// from within the Write method. Take into account that metric collection may
+// happen concurrently. If that results in concurrent calls to Write, like in
+// the case where a valueFunc is directly registered with Prometheus, the
+// provided function must be concurrency-safe.
+func newValueFunc(desc *Desc, valueType ValueType, function func() float64) *valueFunc {
+	result := &valueFunc{
+		desc:       desc,
+		valType:    valueType,
+		function:   function,
+		labelPairs: makeLabelPairs(desc, nil),
+	}
+	result.init(result)
+	return result
+}
+
+func (v *valueFunc) Desc() *Desc {
+	return v.desc
+}
+
+func (v *valueFunc) Write(out *dto.Metric) error {
+	return populateMetric(v.valType, v.function(), v.labelPairs, out)
+}
+
+// NewConstMetric returns a metric with one fixed value that cannot be
+// changed. Users of this package will not have much use for it in regular
+// operations. However, when implementing custom Collectors, it is useful as a
+// throw-away metric that is generated on the fly to send it to Prometheus in
+// the Collect method. NewConstMetric returns an error if the length of
+// labelValues is not consistent with the variable labels in Desc.
+func NewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) (Metric, error) {
+	if len(desc.variableLabels) != len(labelValues) {
+		return nil, errInconsistentCardinality
+	}
+	return &constMetric{
+		desc:       desc,
+		valType:    valueType,
+		val:        value,
+		labelPairs: makeLabelPairs(desc, labelValues),
+	}, nil
+}
+
+// MustNewConstMetric is a version of NewConstMetric that panics where
+// NewConstMetric would have returned an error.
+func MustNewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) Metric {
+	m, err := NewConstMetric(desc, valueType, value, labelValues...)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}
+
+type constMetric struct {
+	desc       *Desc
+	valType    ValueType
+	val        float64
+	labelPairs []*dto.LabelPair
+}
+
+func (m *constMetric) Desc() *Desc {
+	return m.desc
+}
+
+func (m *constMetric) Write(out *dto.Metric) error {
+	return populateMetric(m.valType, m.val, m.labelPairs, out)
+}
+
+func populateMetric(
+	t ValueType,
+	v float64,
+	labelPairs []*dto.LabelPair,
+	m *dto.Metric,
+) error {
+	m.Label = labelPairs
+	switch t {
+	case CounterValue:
+		m.Counter = &dto.Counter{Value: proto.Float64(v)}
+	case GaugeValue:
+		m.Gauge = &dto.Gauge{Value: proto.Float64(v)}
+	case UntypedValue:
+		m.Untyped = &dto.Untyped{Value: proto.Float64(v)}
+	default:
+		return fmt.Errorf("encountered unknown type %v", t)
+	}
+	return nil
+}
+
+func makeLabelPairs(desc *Desc, labelValues []string) []*dto.LabelPair {
+	totalLen := len(desc.variableLabels) + len(desc.constLabelPairs)
+	if totalLen == 0 {
+		// Super fast path.
+		return nil
+	}
+	if len(desc.variableLabels) == 0 {
+		// Moderately fast path.
+		return desc.constLabelPairs
+	}
+	labelPairs := make([]*dto.LabelPair, 0, totalLen)
+	for i, n := range desc.variableLabels {
+		labelPairs = append(labelPairs, &dto.LabelPair{
+			Name:  proto.String(n),
+			Value: proto.String(labelValues[i]),
+		})
+	}
+	for _, lp := range desc.constLabelPairs {
+		labelPairs = append(labelPairs, lp)
+	}
+	sort.Sort(LabelPairSorter(labelPairs))
+	return labelPairs
+}
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/vec.go b/vendor/github.com/prometheus/client_golang/prometheus/vec.go
new file mode 100644
index 00000000..7f3eef9a
--- /dev/null
+++ b/vendor/github.com/prometheus/client_golang/prometheus/vec.go
@@ -0,0 +1,404 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/prometheus/common/model"
+)
+
+// MetricVec is a Collector to bundle metrics of the same name that
+// differ in their label values. MetricVec is usually not used directly but as a
+// building block for implementations of vectors of a given metric
+// type. GaugeVec, CounterVec, SummaryVec, and UntypedVec are examples already
+// provided in this package.
+type MetricVec struct {
+	mtx      sync.RWMutex // Protects the children.
+	children map[uint64][]metricWithLabelValues
+	desc     *Desc
+
+	newMetric   func(labelValues ...string) Metric
+	hashAdd     func(h uint64, s string) uint64 // replace hash function for testing collision handling
+	hashAddByte func(h uint64, b byte) uint64
+}
+
+// newMetricVec returns an initialized MetricVec. The concrete value is
+// returned for embedding into another struct.
+func newMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *MetricVec {
+	return &MetricVec{
+		children:    map[uint64][]metricWithLabelValues{},
+		desc:        desc,
+		newMetric:   newMetric,
+		hashAdd:     hashAdd,
+		hashAddByte: hashAddByte,
+	}
+}
+
+// metricWithLabelValues provides the metric and its label values for
+// disambiguation on hash collision.
+type metricWithLabelValues struct {
+	values []string
+	metric Metric
+}
+
+// Describe implements Collector. The length of the returned slice
+// is always one.
+func (m *MetricVec) Describe(ch chan<- *Desc) {
+	ch <- m.desc
+}
+
+// Collect implements Collector.
+func (m *MetricVec) Collect(ch chan<- Metric) {
+	m.mtx.RLock()
+	defer m.mtx.RUnlock()
+
+	for _, metrics := range m.children {
+		for _, metric := range metrics {
+			ch <- metric.metric
+		}
+	}
+}
+
+// GetMetricWithLabelValues returns the Metric for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new Metric is created.
+//
+// It is possible to call this method without using the returned Metric to only
+// create the new Metric but leave it at its start value (e.g. a Summary or
+// Histogram without any observations). See also the SummaryVec example.
+//
+// Keeping the Metric for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Metric from the MetricVec. In that case, the
+// Metric will still exist, but it will not be exported anymore, even if a
+// Metric with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of VariableLabels in Desc.
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) {
+	h, err := m.hashLabelValues(lvs)
+	if err != nil {
+		return nil, err
+	}
+
+	return m.getOrCreateMetricWithLabelValues(h, lvs), nil
+}
+
+// GetMetricWith returns the Metric for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new Metric is created. Implications of
+// creating a Metric without using it and keeping the Metric for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc.
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (m *MetricVec) GetMetricWith(labels Labels) (Metric, error) {
+	h, err := m.hashLabels(labels)
+	if err != nil {
+		return nil, err
+	}
+
+	return m.getOrCreateMetricWithLabels(h, labels), nil
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics if an error
+// occurs. The method allows neat syntax like:
+//     httpReqs.WithLabelValues("404", "POST").Inc()
+func (m *MetricVec) WithLabelValues(lvs ...string) Metric {
+	metric, err := m.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return metric
+}
+
+// With works as GetMetricWith, but panics if an error occurs. The method allows
+// neat syntax like:
+//     httpReqs.With(Labels{"status":"404", "method":"POST"}).Inc()
+func (m *MetricVec) With(labels Labels) Metric {
+	metric, err := m.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return metric
+}
+
+// DeleteLabelValues removes the metric where the variable labels are the same
+// as those passed in as labels (same order as the VariableLabels in Desc). It
+// returns true if a metric was deleted.
+//
+// It is not an error if the number of label values is not the same as the
+// number of VariableLabels in Desc.  However, such inconsistent label count can
+// never match an actual Metric, so the method will always return false in that
+// case.
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider Delete(Labels) as an
+// alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the CounterVec example.
+func (m *MetricVec) DeleteLabelValues(lvs ...string) bool {
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	h, err := m.hashLabelValues(lvs)
+	if err != nil {
+		return false
+	}
+	return m.deleteByHashWithLabelValues(h, lvs)
+}
+
+// Delete deletes the metric where the variable labels are the same as those
+// passed in as labels. It returns true if a metric was deleted.
+//
+// It is not an error if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in the Desc of the MetricVec. However, such
+// inconsistent Labels can never match an actual Metric, so the method will
+// always return false in that case.
+//
+// This method is used for the same purpose as DeleteLabelValues(...string). See
+// there for pros and cons of the two methods.
+func (m *MetricVec) Delete(labels Labels) bool {
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	h, err := m.hashLabels(labels)
+	if err != nil {
+		return false
+	}
+
+	return m.deleteByHashWithLabels(h, labels)
+}
+
+// deleteByHashWithLabelValues removes the metric from the hash bucket h. If
+// there are multiple matches in the bucket, use lvs to select a metric and
+// remove only that metric.
+func (m *MetricVec) deleteByHashWithLabelValues(h uint64, lvs []string) bool {
+	metrics, ok := m.children[h]
+	if !ok {
+		return false
+	}
+
+	i := m.findMetricWithLabelValues(metrics, lvs)
+	if i >= len(metrics) {
+		return false
+	}
+
+	if len(metrics) > 1 {
+		m.children[h] = append(metrics[:i], metrics[i+1:]...)
+	} else {
+		delete(m.children, h)
+	}
+	return true
+}
+
+// deleteByHashWithLabels removes the metric from the hash bucket h. If there
+// are multiple matches in the bucket, use lvs to select a metric and remove
+// only that metric.
+func (m *MetricVec) deleteByHashWithLabels(h uint64, labels Labels) bool {
+	metrics, ok := m.children[h]
+	if !ok {
+		return false
+	}
+	i := m.findMetricWithLabels(metrics, labels)
+	if i >= len(metrics) {
+		return false
+	}
+
+	if len(metrics) > 1 {
+		m.children[h] = append(metrics[:i], metrics[i+1:]...)
+	} else {
+		delete(m.children, h)
+	}
+	return true
+}
+
+// Reset deletes all metrics in this vector.
+func (m *MetricVec) Reset() {
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+
+	for h := range m.children {
+		delete(m.children, h)
+	}
+}
+
+func (m *MetricVec) hashLabelValues(vals []string) (uint64, error) {
+	if len(vals) != len(m.desc.variableLabels) {
+		return 0, errInconsistentCardinality
+	}
+	h := hashNew()
+	for _, val := range vals {
+		h = m.hashAdd(h, val)
+		h = m.hashAddByte(h, model.SeparatorByte)
+	}
+	return h, nil
+}
+
+func (m *MetricVec) hashLabels(labels Labels) (uint64, error) {
+	if len(labels) != len(m.desc.variableLabels) {
+		return 0, errInconsistentCardinality
+	}
+	h := hashNew()
+	for _, label := range m.desc.variableLabels {
+		val, ok := labels[label]
+		if !ok {
+			return 0, fmt.Errorf("label name %q missing in label map", label)
+		}
+		h = m.hashAdd(h, val)
+		h = m.hashAddByte(h, model.SeparatorByte)
+	}
+	return h, nil
+}
+
+// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
+// or creates it and returns the new one.
+//
+// This function holds the mutex.
+func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string) Metric {
+	m.mtx.RLock()
+	metric, ok := m.getMetricWithLabelValues(hash, lvs)
+	m.mtx.RUnlock()
+	if ok {
+		return metric
+	}
+
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	metric, ok = m.getMetricWithLabelValues(hash, lvs)
+	if !ok {
+		// Copy to avoid allocation in case wo don't go down this code path.
+		copiedLVs := make([]string, len(lvs))
+		copy(copiedLVs, lvs)
+		metric = m.newMetric(copiedLVs...)
+		m.children[hash] = append(m.children[hash], metricWithLabelValues{values: copiedLVs, metric: metric})
+	}
+	return metric
+}
+
+// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
+// or creates it and returns the new one.
+//
+// This function holds the mutex.
+func (m *MetricVec) getOrCreateMetricWithLabels(hash uint64, labels Labels) Metric {
+	m.mtx.RLock()
+	metric, ok := m.getMetricWithLabels(hash, labels)
+	m.mtx.RUnlock()
+	if ok {
+		return metric
+	}
+
+	m.mtx.Lock()
+	defer m.mtx.Unlock()
+	metric, ok = m.getMetricWithLabels(hash, labels)
+	if !ok {
+		lvs := m.extractLabelValues(labels)
+		metric = m.newMetric(lvs...)
+		m.children[hash] = append(m.children[hash], metricWithLabelValues{values: lvs, metric: metric})
+	}
+	return metric
+}
+
+// getMetricWithLabelValues gets a metric while handling possible collisions in
+// the hash space. Must be called while holding read mutex.
+func (m *MetricVec) getMetricWithLabelValues(h uint64, lvs []string) (Metric, bool) {
+	metrics, ok := m.children[h]
+	if ok {
+		if i := m.findMetricWithLabelValues(metrics, lvs); i < len(metrics) {
+			return metrics[i].metric, true
+		}
+	}
+	return nil, false
+}
+
+// getMetricWithLabels gets a metric while handling possible collisions in
+// the hash space. Must be called while holding read mutex.
+func (m *MetricVec) getMetricWithLabels(h uint64, labels Labels) (Metric, bool) {
+	metrics, ok := m.children[h]
+	if ok {
+		if i := m.findMetricWithLabels(metrics, labels); i < len(metrics) {
+			return metrics[i].metric, true
+		}
+	}
+	return nil, false
+}
+
+// findMetricWithLabelValues returns the index of the matching metric or
+// len(metrics) if not found.
+func (m *MetricVec) findMetricWithLabelValues(metrics []metricWithLabelValues, lvs []string) int {
+	for i, metric := range metrics {
+		if m.matchLabelValues(metric.values, lvs) {
+			return i
+		}
+	}
+	return len(metrics)
+}
+
+// findMetricWithLabels returns the index of the matching metric or len(metrics)
+// if not found.
+func (m *MetricVec) findMetricWithLabels(metrics []metricWithLabelValues, labels Labels) int {
+	for i, metric := range metrics {
+		if m.matchLabels(metric.values, labels) {
+			return i
+		}
+	}
+	return len(metrics)
+}
+
+func (m *MetricVec) matchLabelValues(values []string, lvs []string) bool {
+	if len(values) != len(lvs) {
+		return false
+	}
+	for i, v := range values {
+		if v != lvs[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func (m *MetricVec) matchLabels(values []string, labels Labels) bool {
+	if len(labels) != len(values) {
+		return false
+	}
+	for i, k := range m.desc.variableLabels {
+		if values[i] != labels[k] {
+			return false
+		}
+	}
+	return true
+}
+
+func (m *MetricVec) extractLabelValues(labels Labels) []string {
+	labelValues := make([]string, len(labels))
+	for i, k := range m.desc.variableLabels {
+		labelValues[i] = labels[k]
+	}
+	return labelValues
+}
diff --git a/vendor/github.com/prometheus/client_model/AUTHORS.md b/vendor/github.com/prometheus/client_model/AUTHORS.md
new file mode 100644
index 00000000..e8b3efa6
--- /dev/null
+++ b/vendor/github.com/prometheus/client_model/AUTHORS.md
@@ -0,0 +1,13 @@
+The Prometheus project was started by Matt T. Proud (emeritus) and
+Julius Volz in 2012.
+
+Maintainers of this repository:
+
+* Björn Rabenstein <beorn@soundcloud.com>
+
+The following individuals have contributed code to this repository
+(listed in alphabetical order):
+
+* Björn Rabenstein <beorn@soundcloud.com>
+* Matt T. Proud <matt.proud@gmail.com>
+* Tobias Schmidt <ts@soundcloud.com>
diff --git a/vendor/github.com/prometheus/client_model/LICENSE b/vendor/github.com/prometheus/client_model/LICENSE
new file mode 100644
index 00000000..261eeb9e
--- /dev/null
+++ b/vendor/github.com/prometheus/client_model/LICENSE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/vendor/github.com/prometheus/client_model/NOTICE b/vendor/github.com/prometheus/client_model/NOTICE
new file mode 100644
index 00000000..20110e41
--- /dev/null
+++ b/vendor/github.com/prometheus/client_model/NOTICE
@@ -0,0 +1,5 @@
+Data model artifacts for Prometheus.
+Copyright 2012-2015 The Prometheus Authors
+
+This product includes software developed at
+SoundCloud Ltd. (http://soundcloud.com/).
diff --git a/vendor/github.com/prometheus/client_model/go/metrics.pb.go b/vendor/github.com/prometheus/client_model/go/metrics.pb.go
new file mode 100644
index 00000000..b065f868
--- /dev/null
+++ b/vendor/github.com/prometheus/client_model/go/metrics.pb.go
@@ -0,0 +1,364 @@
+// Code generated by protoc-gen-go.
+// source: metrics.proto
+// DO NOT EDIT!
+
+/*
+Package io_prometheus_client is a generated protocol buffer package.
+
+It is generated from these files:
+	metrics.proto
+
+It has these top-level messages:
+	LabelPair
+	Gauge
+	Counter
+	Quantile
+	Summary
+	Untyped
+	Histogram
+	Bucket
+	Metric
+	MetricFamily
+*/
+package io_prometheus_client
+
+import proto "github.com/golang/protobuf/proto"
+import math "math"
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = math.Inf
+
+type MetricType int32
+
+const (
+	MetricType_COUNTER   MetricType = 0
+	MetricType_GAUGE     MetricType = 1
+	MetricType_SUMMARY   MetricType = 2
+	MetricType_UNTYPED   MetricType = 3
+	MetricType_HISTOGRAM MetricType = 4
+)
+
+var MetricType_name = map[int32]string{
+	0: "COUNTER",
+	1: "GAUGE",
+	2: "SUMMARY",
+	3: "UNTYPED",
+	4: "HISTOGRAM",
+}
+var MetricType_value = map[string]int32{
+	"COUNTER":   0,
+	"GAUGE":     1,
+	"SUMMARY":   2,
+	"UNTYPED":   3,
+	"HISTOGRAM": 4,
+}
+
+func (x MetricType) Enum() *MetricType {
+	p := new(MetricType)
+	*p = x
+	return p
+}
+func (x MetricType) String() string {
+	return proto.EnumName(MetricType_name, int32(x))
+}
+func (x *MetricType) UnmarshalJSON(data []byte) error {
+	value, err := proto.UnmarshalJSONEnum(MetricType_value, data, "MetricType")
+	if err != nil {
+		return err
+	}
+	*x = MetricType(value)
+	return nil
+}
+
+type LabelPair struct {
+	Name             *string `protobuf:"bytes,1,opt,name=name" json:"name,omitempty"`
+	Value            *string `protobuf:"bytes,2,opt,name=value" json:"value,omitempty"`
+	XXX_unrecognized []byte  `json:"-"`
+}
+
+func (m *LabelPair) Reset()         { *m = LabelPair{} }
+func (m *LabelPair) String() string { return proto.CompactTextString(m) }
+func (*LabelPair) ProtoMessage()    {}
+
+func (m *LabelPair) GetName() string {
+	if m != nil && m.Name != nil {
+		return *m.Name
+	}
+	return ""
+}
+
+func (m *LabelPair) GetValue() string {
+	if m != nil && m.Value != nil {
+		return *m.Value
+	}
+	return ""
+}
+
+type Gauge struct {
+	Value            *float64 `protobuf:"fixed64,1,opt,name=value" json:"value,omitempty"`
+	XXX_unrecognized []byte   `json:"-"`
+}
+
+func (m *Gauge) Reset()         { *m = Gauge{} }
+func (m *Gauge) String() string { return proto.CompactTextString(m) }
+func (*Gauge) ProtoMessage()    {}
+
+func (m *Gauge) GetValue() float64 {
+	if m != nil && m.Value != nil {
+		return *m.Value
+	}
+	return 0
+}
+
+type Counter struct {
+	Value            *float64 `protobuf:"fixed64,1,opt,name=value" json:"value,omitempty"`
+	XXX_unrecognized []byte   `json:"-"`
+}
+
+func (m *Counter) Reset()         { *m = Counter{} }
+func (m *Counter) String() string { return proto.CompactTextString(m) }
+func (*Counter) ProtoMessage()    {}
+
+func (m *Counter) GetValue() float64 {
+	if m != nil && m.Value != nil {
+		return *m.Value
+	}
+	return 0
+}
+
+type Quantile struct {
+	Quantile         *float64 `protobuf:"fixed64,1,opt,name=quantile" json:"quantile,omitempty"`
+	Value            *float64 `protobuf:"fixed64,2,opt,name=value" json:"value,omitempty"`
+	XXX_unrecognized []byte   `json:"-"`
+}
+
+func (m *Quantile) Reset()         { *m = Quantile{} }
+func (m *Quantile) String() string { return proto.CompactTextString(m) }
+func (*Quantile) ProtoMessage()    {}
+
+func (m *Quantile) GetQuantile() float64 {
+	if m != nil && m.Quantile != nil {
+		return *m.Quantile
+	}
+	return 0
+}
+
+func (m *Quantile) GetValue() float64 {
+	if m != nil && m.Value != nil {
+		return *m.Value
+	}
+	return 0
+}
+
+type Summary struct {
+	SampleCount      *uint64     `protobuf:"varint,1,opt,name=sample_count" json:"sample_count,omitempty"`
+	SampleSum        *float64    `protobuf:"fixed64,2,opt,name=sample_sum" json:"sample_sum,omitempty"`
+	Quantile         []*Quantile `protobuf:"bytes,3,rep,name=quantile" json:"quantile,omitempty"`
+	XXX_unrecognized []byte      `json:"-"`
+}
+
+func (m *Summary) Reset()         { *m = Summary{} }
+func (m *Summary) String() string { return proto.CompactTextString(m) }
+func (*Summary) ProtoMessage()    {}
+
+func (m *Summary) GetSampleCount() uint64 {
+	if m != nil && m.SampleCount != nil {
+		return *m.SampleCount
+	}
+	return 0
+}
+
+func (m *Summary) GetSampleSum() float64 {
+	if m != nil && m.SampleSum != nil {
+		return *m.SampleSum
+	}
+	return 0
+}
+
+func (m *Summary) GetQuantile() []*Quantile {
+	if m != nil {
+		return m.Quantile
+	}
+	return nil
+}
+
+type Untyped struct {
+	Value            *float64 `protobuf:"fixed64,1,opt,name=value" json:"value,omitempty"`
+	XXX_unrecognized []byte   `json:"-"`
+}
+
+func (m *Untyped) Reset()         { *m = Untyped{} }
+func (m *Untyped) String() string { return proto.CompactTextString(m) }
+func (*Untyped) ProtoMessage()    {}
+
+func (m *Untyped) GetValue() float64 {
+	if m != nil && m.Value != nil {
+		return *m.Value
+	}
+	return 0
+}
+
+type Histogram struct {
+	SampleCount      *uint64   `protobuf:"varint,1,opt,name=sample_count" json:"sample_count,omitempty"`
+	SampleSum        *float64  `protobuf:"fixed64,2,opt,name=sample_sum" json:"sample_sum,omitempty"`
+	Bucket           []*Bucket `protobuf:"bytes,3,rep,name=bucket" json:"bucket,omitempty"`
+	XXX_unrecognized []byte    `json:"-"`
+}
+
+func (m *Histogram) Reset()         { *m = Histogram{} }
+func (m *Histogram) String() string { return proto.CompactTextString(m) }
+func (*Histogram) ProtoMessage()    {}
+
+func (m *Histogram) GetSampleCount() uint64 {
+	if m != nil && m.SampleCount != nil {
+		return *m.SampleCount
+	}
+	return 0
+}
+
+func (m *Histogram) GetSampleSum() float64 {
+	if m != nil && m.SampleSum != nil {
+		return *m.SampleSum
+	}
+	return 0
+}
+
+func (m *Histogram) GetBucket() []*Bucket {
+	if m != nil {
+		return m.Bucket
+	}
+	return nil
+}
+
+type Bucket struct {
+	CumulativeCount  *uint64  `protobuf:"varint,1,opt,name=cumulative_count" json:"cumulative_count,omitempty"`
+	UpperBound       *float64 `protobuf:"fixed64,2,opt,name=upper_bound" json:"upper_bound,omitempty"`
+	XXX_unrecognized []byte   `json:"-"`
+}
+
+func (m *Bucket) Reset()         { *m = Bucket{} }
+func (m *Bucket) String() string { return proto.CompactTextString(m) }
+func (*Bucket) ProtoMessage()    {}
+
+func (m *Bucket) GetCumulativeCount() uint64 {
+	if m != nil && m.CumulativeCount != nil {
+		return *m.CumulativeCount
+	}
+	return 0
+}
+
+func (m *Bucket) GetUpperBound() float64 {
+	if m != nil && m.UpperBound != nil {
+		return *m.UpperBound
+	}
+	return 0
+}
+
+type Metric struct {
+	Label            []*LabelPair `protobuf:"bytes,1,rep,name=label" json:"label,omitempty"`
+	Gauge            *Gauge       `protobuf:"bytes,2,opt,name=gauge" json:"gauge,omitempty"`
+	Counter          *Counter     `protobuf:"bytes,3,opt,name=counter" json:"counter,omitempty"`
+	Summary          *Summary     `protobuf:"bytes,4,opt,name=summary" json:"summary,omitempty"`
+	Untyped          *Untyped     `protobuf:"bytes,5,opt,name=untyped" json:"untyped,omitempty"`
+	Histogram        *Histogram   `protobuf:"bytes,7,opt,name=histogram" json:"histogram,omitempty"`
+	TimestampMs      *int64       `protobuf:"varint,6,opt,name=timestamp_ms" json:"timestamp_ms,omitempty"`
+	XXX_unrecognized []byte       `json:"-"`
+}
+
+func (m *Metric) Reset()         { *m = Metric{} }
+func (m *Metric) String() string { return proto.CompactTextString(m) }
+func (*Metric) ProtoMessage()    {}
+
+func (m *Metric) GetLabel() []*LabelPair {
+	if m != nil {
+		return m.Label
+	}
+	return nil
+}
+
+func (m *Metric) GetGauge() *Gauge {
+	if m != nil {
+		return m.Gauge
+	}
+	return nil
+}
+
+func (m *Metric) GetCounter() *Counter {
+	if m != nil {
+		return m.Counter
+	}
+	return nil
+}
+
+func (m *Metric) GetSummary() *Summary {
+	if m != nil {
+		return m.Summary
+	}
+	return nil
+}
+
+func (m *Metric) GetUntyped() *Untyped {
+	if m != nil {
+		return m.Untyped
+	}
+	return nil
+}
+
+func (m *Metric) GetHistogram() *Histogram {
+	if m != nil {
+		return m.Histogram
+	}
+	return nil
+}
+
+func (m *Metric) GetTimestampMs() int64 {
+	if m != nil && m.TimestampMs != nil {
+		return *m.TimestampMs
+	}
+	return 0
+}
+
+type MetricFamily struct {
+	Name             *string     `protobuf:"bytes,1,opt,name=name" json:"name,omitempty"`
+	Help             *string     `protobuf:"bytes,2,opt,name=help" json:"help,omitempty"`
+	Type             *MetricType `protobuf:"varint,3,opt,name=type,enum=io.prometheus.client.MetricType" json:"type,omitempty"`
+	Metric           []*Metric   `protobuf:"bytes,4,rep,name=metric" json:"metric,omitempty"`
+	XXX_unrecognized []byte      `json:"-"`
+}
+
+func (m *MetricFamily) Reset()         { *m = MetricFamily{} }
+func (m *MetricFamily) String() string { return proto.CompactTextString(m) }
+func (*MetricFamily) ProtoMessage()    {}
+
+func (m *MetricFamily) GetName() string {
+	if m != nil && m.Name != nil {
+		return *m.Name
+	}
+	return ""
+}
+
+func (m *MetricFamily) GetHelp() string {
+	if m != nil && m.Help != nil {
+		return *m.Help
+	}
+	return ""
+}
+
+func (m *MetricFamily) GetType() MetricType {
+	if m != nil && m.Type != nil {
+		return *m.Type
+	}
+	return MetricType_COUNTER
+}
+
+func (m *MetricFamily) GetMetric() []*Metric {
+	if m != nil {
+		return m.Metric
+	}
+	return nil
+}
+
+func init() {
+	proto.RegisterEnum("io.prometheus.client.MetricType", MetricType_name, MetricType_value)
+}
diff --git a/vendor/github.com/prometheus/common/AUTHORS.md b/vendor/github.com/prometheus/common/AUTHORS.md
new file mode 100644
index 00000000..c63f4d39
--- /dev/null
+++ b/vendor/github.com/prometheus/common/AUTHORS.md
@@ -0,0 +1,11 @@
+Maintainers of this repository:
+
+* Fabian Reinartz <fabian@soundcloud.com>
+
+The following individuals have contributed code to this repository
+(listed in alphabetical order):
+
+* Björn Rabenstein <beorn@soundcloud.com>
+* Fabian Reinartz <fabian@soundcloud.com>
+* Julius Volz <julius.volz@gmail.com>
+* Miguel Molina <hi@mvader.me>
diff --git a/vendor/github.com/prometheus/common/LICENSE b/vendor/github.com/prometheus/common/LICENSE
new file mode 100644
index 00000000..261eeb9e
--- /dev/null
+++ b/vendor/github.com/prometheus/common/LICENSE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/vendor/github.com/prometheus/common/NOTICE b/vendor/github.com/prometheus/common/NOTICE
new file mode 100644
index 00000000..636a2c1a
--- /dev/null
+++ b/vendor/github.com/prometheus/common/NOTICE
@@ -0,0 +1,5 @@
+Common libraries shared by Prometheus Go components.
+Copyright 2015 The Prometheus Authors
+
+This product includes software developed at
+SoundCloud Ltd. (http://soundcloud.com/).
diff --git a/vendor/github.com/prometheus/common/expfmt/decode.go b/vendor/github.com/prometheus/common/expfmt/decode.go
new file mode 100644
index 00000000..487fdc6c
--- /dev/null
+++ b/vendor/github.com/prometheus/common/expfmt/decode.go
@@ -0,0 +1,412 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expfmt
+
+import (
+	"fmt"
+	"io"
+	"math"
+	"mime"
+	"net/http"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/matttproud/golang_protobuf_extensions/pbutil"
+	"github.com/prometheus/common/model"
+)
+
+// Decoder types decode an input stream into metric families.
+type Decoder interface {
+	Decode(*dto.MetricFamily) error
+}
+
+type DecodeOptions struct {
+	// Timestamp is added to each value from the stream that has no explicit timestamp set.
+	Timestamp model.Time
+}
+
+// ResponseFormat extracts the correct format from a HTTP response header.
+// If no matching format can be found FormatUnknown is returned.
+func ResponseFormat(h http.Header) Format {
+	ct := h.Get(hdrContentType)
+
+	mediatype, params, err := mime.ParseMediaType(ct)
+	if err != nil {
+		return FmtUnknown
+	}
+
+	const textType = "text/plain"
+
+	switch mediatype {
+	case ProtoType:
+		if p, ok := params["proto"]; ok && p != ProtoProtocol {
+			return FmtUnknown
+		}
+		if e, ok := params["encoding"]; ok && e != "delimited" {
+			return FmtUnknown
+		}
+		return FmtProtoDelim
+
+	case textType:
+		if v, ok := params["version"]; ok && v != TextVersion {
+			return FmtUnknown
+		}
+		return FmtText
+	}
+
+	return FmtUnknown
+}
+
+// NewDecoder returns a new decoder based on the given input format.
+// If the input format does not imply otherwise, a text format decoder is returned.
+func NewDecoder(r io.Reader, format Format) Decoder {
+	switch format {
+	case FmtProtoDelim:
+		return &protoDecoder{r: r}
+	}
+	return &textDecoder{r: r}
+}
+
+// protoDecoder implements the Decoder interface for protocol buffers.
+type protoDecoder struct {
+	r io.Reader
+}
+
+// Decode implements the Decoder interface.
+func (d *protoDecoder) Decode(v *dto.MetricFamily) error {
+	_, err := pbutil.ReadDelimited(d.r, v)
+	if err != nil {
+		return err
+	}
+	if !model.IsValidMetricName(model.LabelValue(v.GetName())) {
+		return fmt.Errorf("invalid metric name %q", v.GetName())
+	}
+	for _, m := range v.GetMetric() {
+		if m == nil {
+			continue
+		}
+		for _, l := range m.GetLabel() {
+			if l == nil {
+				continue
+			}
+			if !model.LabelValue(l.GetValue()).IsValid() {
+				return fmt.Errorf("invalid label value %q", l.GetValue())
+			}
+			if !model.LabelName(l.GetName()).IsValid() {
+				return fmt.Errorf("invalid label name %q", l.GetName())
+			}
+		}
+	}
+	return nil
+}
+
+// textDecoder implements the Decoder interface for the text protocol.
+type textDecoder struct {
+	r    io.Reader
+	p    TextParser
+	fams []*dto.MetricFamily
+}
+
+// Decode implements the Decoder interface.
+func (d *textDecoder) Decode(v *dto.MetricFamily) error {
+	// TODO(fabxc): Wrap this as a line reader to make streaming safer.
+	if len(d.fams) == 0 {
+		// No cached metric families, read everything and parse metrics.
+		fams, err := d.p.TextToMetricFamilies(d.r)
+		if err != nil {
+			return err
+		}
+		if len(fams) == 0 {
+			return io.EOF
+		}
+		d.fams = make([]*dto.MetricFamily, 0, len(fams))
+		for _, f := range fams {
+			d.fams = append(d.fams, f)
+		}
+	}
+
+	*v = *d.fams[0]
+	d.fams = d.fams[1:]
+
+	return nil
+}
+
+type SampleDecoder struct {
+	Dec  Decoder
+	Opts *DecodeOptions
+
+	f dto.MetricFamily
+}
+
+func (sd *SampleDecoder) Decode(s *model.Vector) error {
+	if err := sd.Dec.Decode(&sd.f); err != nil {
+		return err
+	}
+	*s = extractSamples(&sd.f, sd.Opts)
+	return nil
+}
+
+// Extract samples builds a slice of samples from the provided metric families.
+func ExtractSamples(o *DecodeOptions, fams ...*dto.MetricFamily) model.Vector {
+	var all model.Vector
+	for _, f := range fams {
+		all = append(all, extractSamples(f, o)...)
+	}
+	return all
+}
+
+func extractSamples(f *dto.MetricFamily, o *DecodeOptions) model.Vector {
+	switch f.GetType() {
+	case dto.MetricType_COUNTER:
+		return extractCounter(o, f)
+	case dto.MetricType_GAUGE:
+		return extractGauge(o, f)
+	case dto.MetricType_SUMMARY:
+		return extractSummary(o, f)
+	case dto.MetricType_UNTYPED:
+		return extractUntyped(o, f)
+	case dto.MetricType_HISTOGRAM:
+		return extractHistogram(o, f)
+	}
+	panic("expfmt.extractSamples: unknown metric family type")
+}
+
+func extractCounter(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
+	samples := make(model.Vector, 0, len(f.Metric))
+
+	for _, m := range f.Metric {
+		if m.Counter == nil {
+			continue
+		}
+
+		lset := make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName())
+
+		smpl := &model.Sample{
+			Metric: model.Metric(lset),
+			Value:  model.SampleValue(m.Counter.GetValue()),
+		}
+
+		if m.TimestampMs != nil {
+			smpl.Timestamp = model.TimeFromUnixNano(*m.TimestampMs * 1000000)
+		} else {
+			smpl.Timestamp = o.Timestamp
+		}
+
+		samples = append(samples, smpl)
+	}
+
+	return samples
+}
+
+func extractGauge(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
+	samples := make(model.Vector, 0, len(f.Metric))
+
+	for _, m := range f.Metric {
+		if m.Gauge == nil {
+			continue
+		}
+
+		lset := make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName())
+
+		smpl := &model.Sample{
+			Metric: model.Metric(lset),
+			Value:  model.SampleValue(m.Gauge.GetValue()),
+		}
+
+		if m.TimestampMs != nil {
+			smpl.Timestamp = model.TimeFromUnixNano(*m.TimestampMs * 1000000)
+		} else {
+			smpl.Timestamp = o.Timestamp
+		}
+
+		samples = append(samples, smpl)
+	}
+
+	return samples
+}
+
+func extractUntyped(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
+	samples := make(model.Vector, 0, len(f.Metric))
+
+	for _, m := range f.Metric {
+		if m.Untyped == nil {
+			continue
+		}
+
+		lset := make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName())
+
+		smpl := &model.Sample{
+			Metric: model.Metric(lset),
+			Value:  model.SampleValue(m.Untyped.GetValue()),
+		}
+
+		if m.TimestampMs != nil {
+			smpl.Timestamp = model.TimeFromUnixNano(*m.TimestampMs * 1000000)
+		} else {
+			smpl.Timestamp = o.Timestamp
+		}
+
+		samples = append(samples, smpl)
+	}
+
+	return samples
+}
+
+func extractSummary(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
+	samples := make(model.Vector, 0, len(f.Metric))
+
+	for _, m := range f.Metric {
+		if m.Summary == nil {
+			continue
+		}
+
+		timestamp := o.Timestamp
+		if m.TimestampMs != nil {
+			timestamp = model.TimeFromUnixNano(*m.TimestampMs * 1000000)
+		}
+
+		for _, q := range m.Summary.Quantile {
+			lset := make(model.LabelSet, len(m.Label)+2)
+			for _, p := range m.Label {
+				lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+			}
+			// BUG(matt): Update other names to "quantile".
+			lset[model.LabelName(model.QuantileLabel)] = model.LabelValue(fmt.Sprint(q.GetQuantile()))
+			lset[model.MetricNameLabel] = model.LabelValue(f.GetName())
+
+			samples = append(samples, &model.Sample{
+				Metric:    model.Metric(lset),
+				Value:     model.SampleValue(q.GetValue()),
+				Timestamp: timestamp,
+			})
+		}
+
+		lset := make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_sum")
+
+		samples = append(samples, &model.Sample{
+			Metric:    model.Metric(lset),
+			Value:     model.SampleValue(m.Summary.GetSampleSum()),
+			Timestamp: timestamp,
+		})
+
+		lset = make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_count")
+
+		samples = append(samples, &model.Sample{
+			Metric:    model.Metric(lset),
+			Value:     model.SampleValue(m.Summary.GetSampleCount()),
+			Timestamp: timestamp,
+		})
+	}
+
+	return samples
+}
+
+func extractHistogram(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
+	samples := make(model.Vector, 0, len(f.Metric))
+
+	for _, m := range f.Metric {
+		if m.Histogram == nil {
+			continue
+		}
+
+		timestamp := o.Timestamp
+		if m.TimestampMs != nil {
+			timestamp = model.TimeFromUnixNano(*m.TimestampMs * 1000000)
+		}
+
+		infSeen := false
+
+		for _, q := range m.Histogram.Bucket {
+			lset := make(model.LabelSet, len(m.Label)+2)
+			for _, p := range m.Label {
+				lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+			}
+			lset[model.LabelName(model.BucketLabel)] = model.LabelValue(fmt.Sprint(q.GetUpperBound()))
+			lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_bucket")
+
+			if math.IsInf(q.GetUpperBound(), +1) {
+				infSeen = true
+			}
+
+			samples = append(samples, &model.Sample{
+				Metric:    model.Metric(lset),
+				Value:     model.SampleValue(q.GetCumulativeCount()),
+				Timestamp: timestamp,
+			})
+		}
+
+		lset := make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_sum")
+
+		samples = append(samples, &model.Sample{
+			Metric:    model.Metric(lset),
+			Value:     model.SampleValue(m.Histogram.GetSampleSum()),
+			Timestamp: timestamp,
+		})
+
+		lset = make(model.LabelSet, len(m.Label)+1)
+		for _, p := range m.Label {
+			lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+		}
+		lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_count")
+
+		count := &model.Sample{
+			Metric:    model.Metric(lset),
+			Value:     model.SampleValue(m.Histogram.GetSampleCount()),
+			Timestamp: timestamp,
+		}
+		samples = append(samples, count)
+
+		if !infSeen {
+			// Append an infinity bucket sample.
+			lset := make(model.LabelSet, len(m.Label)+2)
+			for _, p := range m.Label {
+				lset[model.LabelName(p.GetName())] = model.LabelValue(p.GetValue())
+			}
+			lset[model.LabelName(model.BucketLabel)] = model.LabelValue("+Inf")
+			lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_bucket")
+
+			samples = append(samples, &model.Sample{
+				Metric:    model.Metric(lset),
+				Value:     count.Value,
+				Timestamp: timestamp,
+			})
+		}
+	}
+
+	return samples
+}
diff --git a/vendor/github.com/prometheus/common/expfmt/encode.go b/vendor/github.com/prometheus/common/expfmt/encode.go
new file mode 100644
index 00000000..11839ed6
--- /dev/null
+++ b/vendor/github.com/prometheus/common/expfmt/encode.go
@@ -0,0 +1,88 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expfmt
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/matttproud/golang_protobuf_extensions/pbutil"
+	"github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// Encoder types encode metric families into an underlying wire protocol.
+type Encoder interface {
+	Encode(*dto.MetricFamily) error
+}
+
+type encoder func(*dto.MetricFamily) error
+
+func (e encoder) Encode(v *dto.MetricFamily) error {
+	return e(v)
+}
+
+// Negotiate returns the Content-Type based on the given Accept header.
+// If no appropriate accepted type is found, FmtText is returned.
+func Negotiate(h http.Header) Format {
+	for _, ac := range goautoneg.ParseAccept(h.Get(hdrAccept)) {
+		// Check for protocol buffer
+		if ac.Type+"/"+ac.SubType == ProtoType && ac.Params["proto"] == ProtoProtocol {
+			switch ac.Params["encoding"] {
+			case "delimited":
+				return FmtProtoDelim
+			case "text":
+				return FmtProtoText
+			case "compact-text":
+				return FmtProtoCompact
+			}
+		}
+		// Check for text format.
+		ver := ac.Params["version"]
+		if ac.Type == "text" && ac.SubType == "plain" && (ver == TextVersion || ver == "") {
+			return FmtText
+		}
+	}
+	return FmtText
+}
+
+// NewEncoder returns a new encoder based on content type negotiation.
+func NewEncoder(w io.Writer, format Format) Encoder {
+	switch format {
+	case FmtProtoDelim:
+		return encoder(func(v *dto.MetricFamily) error {
+			_, err := pbutil.WriteDelimited(w, v)
+			return err
+		})
+	case FmtProtoCompact:
+		return encoder(func(v *dto.MetricFamily) error {
+			_, err := fmt.Fprintln(w, v.String())
+			return err
+		})
+	case FmtProtoText:
+		return encoder(func(v *dto.MetricFamily) error {
+			_, err := fmt.Fprintln(w, proto.MarshalTextString(v))
+			return err
+		})
+	case FmtText:
+		return encoder(func(v *dto.MetricFamily) error {
+			_, err := MetricFamilyToText(w, v)
+			return err
+		})
+	}
+	panic("expfmt.NewEncoder: unknown format")
+}
diff --git a/vendor/github.com/prometheus/common/expfmt/expfmt.go b/vendor/github.com/prometheus/common/expfmt/expfmt.go
new file mode 100644
index 00000000..366fbde9
--- /dev/null
+++ b/vendor/github.com/prometheus/common/expfmt/expfmt.go
@@ -0,0 +1,40 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// A package for reading and writing Prometheus metrics.
+package expfmt
+
+type Format string
+
+const (
+	TextVersion = "0.0.4"
+
+	ProtoType     = `application/vnd.google.protobuf`
+	ProtoProtocol = `io.prometheus.client.MetricFamily`
+	ProtoFmt      = ProtoType + "; proto=" + ProtoProtocol + ";"
+
+	// The Content-Type values for the different wire protocols.
+	FmtUnknown      Format = `<unknown>`
+	FmtText         Format = `text/plain; version=` + TextVersion
+	FmtProtoDelim   Format = ProtoFmt + ` encoding=delimited`
+	FmtProtoText    Format = ProtoFmt + ` encoding=text`
+	FmtProtoCompact Format = ProtoFmt + ` encoding=compact-text`
+
+	// fmtJSON2 is hidden as it is deprecated.
+	fmtJSON2 Format = `application/json; version=0.0.2`
+)
+
+const (
+	hdrContentType = "Content-Type"
+	hdrAccept      = "Accept"
+)
diff --git a/vendor/github.com/prometheus/common/expfmt/fuzz.go b/vendor/github.com/prometheus/common/expfmt/fuzz.go
new file mode 100644
index 00000000..dc2eedee
--- /dev/null
+++ b/vendor/github.com/prometheus/common/expfmt/fuzz.go
@@ -0,0 +1,36 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Build only when actually fuzzing
+// +build gofuzz
+
+package expfmt
+
+import "bytes"
+
+// Fuzz text metric parser with with github.com/dvyukov/go-fuzz:
+//
+//     go-fuzz-build github.com/prometheus/common/expfmt
+//     go-fuzz -bin expfmt-fuzz.zip -workdir fuzz
+//
+// Further input samples should go in the folder fuzz/corpus.
+func Fuzz(in []byte) int {
+	parser := TextParser{}
+	_, err := parser.TextToMetricFamilies(bytes.NewReader(in))
+
+	if err != nil {
+		return 0
+	}
+
+	return 1
+}
diff --git a/vendor/github.com/prometheus/common/expfmt/text_create.go b/vendor/github.com/prometheus/common/expfmt/text_create.go
new file mode 100644
index 00000000..1e060879
--- /dev/null
+++ b/vendor/github.com/prometheus/common/expfmt/text_create.go
@@ -0,0 +1,300 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expfmt
+
+import (
+	"fmt"
+	"io"
+	"math"
+	"strings"
+
+	dto "github.com/prometheus/client_model/go"
+	"github.com/prometheus/common/model"
+)
+
+// MetricFamilyToText converts a MetricFamily proto message into text format and
+// writes the resulting lines to 'out'. It returns the number of bytes written
+// and any error encountered.  This function does not perform checks on the
+// content of the metric and label names, i.e. invalid metric or label names
+// will result in invalid text format output.
+// This method fulfills the type 'prometheus.encoder'.
+func MetricFamilyToText(out io.Writer, in *dto.MetricFamily) (int, error) {
+	var written int
+
+	// Fail-fast checks.
+	if len(in.Metric) == 0 {
+		return written, fmt.Errorf("MetricFamily has no metrics: %s", in)
+	}
+	name := in.GetName()
+	if name == "" {
+		return written, fmt.Errorf("MetricFamily has no name: %s", in)
+	}
+
+	// Comments, first HELP, then TYPE.
+	if in.Help != nil {
+		n, err := fmt.Fprintf(
+			out, "# HELP %s %s\n",
+			name, escapeString(*in.Help, false),
+		)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	metricType := in.GetType()
+	n, err := fmt.Fprintf(
+		out, "# TYPE %s %s\n",
+		name, strings.ToLower(metricType.String()),
+	)
+	written += n
+	if err != nil {
+		return written, err
+	}
+
+	// Finally the samples, one line for each.
+	for _, metric := range in.Metric {
+		switch metricType {
+		case dto.MetricType_COUNTER:
+			if metric.Counter == nil {
+				return written, fmt.Errorf(
+					"expected counter in metric %s %s", name, metric,
+				)
+			}
+			n, err = writeSample(
+				name, metric, "", "",
+				metric.Counter.GetValue(),
+				out,
+			)
+		case dto.MetricType_GAUGE:
+			if metric.Gauge == nil {
+				return written, fmt.Errorf(
+					"expected gauge in metric %s %s", name, metric,
+				)
+			}
+			n, err = writeSample(
+				name, metric, "", "",
+				metric.Gauge.GetValue(),
+				out,
+			)
+		case dto.MetricType_UNTYPED:
+			if metric.Untyped == nil {
+				return written, fmt.Errorf(
+					"expected untyped in metric %s %s", name, metric,
+				)
+			}
+			n, err = writeSample(
+				name, metric, "", "",
+				metric.Untyped.GetValue(),
+				out,
+			)
+		case dto.MetricType_SUMMARY:
+			if metric.Summary == nil {
+				return written, fmt.Errorf(
+					"expected summary in metric %s %s", name, metric,
+				)
+			}
+			for _, q := range metric.Summary.Quantile {
+				n, err = writeSample(
+					name, metric,
+					model.QuantileLabel, fmt.Sprint(q.GetQuantile()),
+					q.GetValue(),
+					out,
+				)
+				written += n
+				if err != nil {
+					return written, err
+				}
+			}
+			n, err = writeSample(
+				name+"_sum", metric, "", "",
+				metric.Summary.GetSampleSum(),
+				out,
+			)
+			if err != nil {
+				return written, err
+			}
+			written += n
+			n, err = writeSample(
+				name+"_count", metric, "", "",
+				float64(metric.Summary.GetSampleCount()),
+				out,
+			)
+		case dto.MetricType_HISTOGRAM:
+			if metric.Histogram == nil {
+				return written, fmt.Errorf(
+					"expected histogram in metric %s %s", name, metric,
+				)
+			}
+			infSeen := false
+			for _, q := range metric.Histogram.Bucket {
+				n, err = writeSample(
+					name+"_bucket", metric,
+					model.BucketLabel, fmt.Sprint(q.GetUpperBound()),
+					float64(q.GetCumulativeCount()),
+					out,
+				)
+				written += n
+				if err != nil {
+					return written, err
+				}
+				if math.IsInf(q.GetUpperBound(), +1) {
+					infSeen = true
+				}
+			}
+			if !infSeen {
+				n, err = writeSample(
+					name+"_bucket", metric,
+					model.BucketLabel, "+Inf",
+					float64(metric.Histogram.GetSampleCount()),
+					out,
+				)
+				if err != nil {
+					return written, err
+				}
+				written += n
+			}
+			n, err = writeSample(
+				name+"_sum", metric, "", "",
+				metric.Histogram.GetSampleSum(),
+				out,
+			)
+			if err != nil {
+				return written, err
+			}
+			written += n
+			n, err = writeSample(
+				name+"_count", metric, "", "",
+				float64(metric.Histogram.GetSampleCount()),
+				out,
+			)
+		default:
+			return written, fmt.Errorf(
+				"unexpected type in metric %s %s", name, metric,
+			)
+		}
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	return written, nil
+}
+
+// writeSample writes a single sample in text format to out, given the metric
+// name, the metric proto message itself, optionally an additional label name
+// and value (use empty strings if not required), and the value. The function
+// returns the number of bytes written and any error encountered.
+func writeSample(
+	name string,
+	metric *dto.Metric,
+	additionalLabelName, additionalLabelValue string,
+	value float64,
+	out io.Writer,
+) (int, error) {
+	var written int
+	n, err := fmt.Fprint(out, name)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	n, err = labelPairsToText(
+		metric.Label,
+		additionalLabelName, additionalLabelValue,
+		out,
+	)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	n, err = fmt.Fprintf(out, " %v", value)
+	written += n
+	if err != nil {
+		return written, err
+	}
+	if metric.TimestampMs != nil {
+		n, err = fmt.Fprintf(out, " %v", *metric.TimestampMs)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	n, err = out.Write([]byte{'\n'})
+	written += n
+	if err != nil {
+		return written, err
+	}
+	return written, nil
+}
+
+// labelPairsToText converts a slice of LabelPair proto messages plus the
+// explicitly given additional label pair into text formatted as required by the
+// text format and writes it to 'out'. An empty slice in combination with an
+// empty string 'additionalLabelName' results in nothing being
+// written. Otherwise, the label pairs are written, escaped as required by the
+// text format, and enclosed in '{...}'. The function returns the number of
+// bytes written and any error encountered.
+func labelPairsToText(
+	in []*dto.LabelPair,
+	additionalLabelName, additionalLabelValue string,
+	out io.Writer,
+) (int, error) {
+	if len(in) == 0 && additionalLabelName == "" {
+		return 0, nil
+	}
+	var written int
+	separator := '{'
+	for _, lp := range in {
+		n, err := fmt.Fprintf(
+			out, `%c%s="%s"`,
+			separator, lp.GetName(), escapeString(lp.GetValue(), true),
+		)
+		written += n
+		if err != nil {
+			return written, err
+		}
+		separator = ','
+	}
+	if additionalLabelName != "" {
+		n, err := fmt.Fprintf(
+			out, `%c%s="%s"`,
+			separator, additionalLabelName,
+			escapeString(additionalLabelValue, true),
+		)
+		written += n
+		if err != nil {
+			return written, err
+		}
+	}
+	n, err := out.Write([]byte{'}'})
+	written += n
+	if err != nil {
+		return written, err
+	}
+	return written, nil
+}
+
+var (
+	escape                = strings.NewReplacer("\\", `\\`, "\n", `\n`)
+	escapeWithDoubleQuote = strings.NewReplacer("\\", `\\`, "\n", `\n`, "\"", `\"`)
+)
+
+// escapeString replaces '\' by '\\', new line character by '\n', and - if
+// includeDoubleQuote is true - '"' by '\"'.
+func escapeString(v string, includeDoubleQuote bool) string {
+	if includeDoubleQuote {
+		return escapeWithDoubleQuote.Replace(v)
+	}
+
+	return escape.Replace(v)
+}
diff --git a/vendor/github.com/prometheus/common/expfmt/text_parse.go b/vendor/github.com/prometheus/common/expfmt/text_parse.go
new file mode 100644
index 00000000..bd170b16
--- /dev/null
+++ b/vendor/github.com/prometheus/common/expfmt/text_parse.go
@@ -0,0 +1,753 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expfmt
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"math"
+	"strconv"
+	"strings"
+
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/prometheus/common/model"
+)
+
+// A stateFn is a function that represents a state in a state machine. By
+// executing it, the state is progressed to the next state. The stateFn returns
+// another stateFn, which represents the new state. The end state is represented
+// by nil.
+type stateFn func() stateFn
+
+// ParseError signals errors while parsing the simple and flat text-based
+// exchange format.
+type ParseError struct {
+	Line int
+	Msg  string
+}
+
+// Error implements the error interface.
+func (e ParseError) Error() string {
+	return fmt.Sprintf("text format parsing error in line %d: %s", e.Line, e.Msg)
+}
+
+// TextParser is used to parse the simple and flat text-based exchange format. Its
+// nil value is ready to use.
+type TextParser struct {
+	metricFamiliesByName map[string]*dto.MetricFamily
+	buf                  *bufio.Reader // Where the parsed input is read through.
+	err                  error         // Most recent error.
+	lineCount            int           // Tracks the line count for error messages.
+	currentByte          byte          // The most recent byte read.
+	currentToken         bytes.Buffer  // Re-used each time a token has to be gathered from multiple bytes.
+	currentMF            *dto.MetricFamily
+	currentMetric        *dto.Metric
+	currentLabelPair     *dto.LabelPair
+
+	// The remaining member variables are only used for summaries/histograms.
+	currentLabels map[string]string // All labels including '__name__' but excluding 'quantile'/'le'
+	// Summary specific.
+	summaries       map[uint64]*dto.Metric // Key is created with LabelsToSignature.
+	currentQuantile float64
+	// Histogram specific.
+	histograms    map[uint64]*dto.Metric // Key is created with LabelsToSignature.
+	currentBucket float64
+	// These tell us if the currently processed line ends on '_count' or
+	// '_sum' respectively and belong to a summary/histogram, representing the sample
+	// count and sum of that summary/histogram.
+	currentIsSummaryCount, currentIsSummarySum     bool
+	currentIsHistogramCount, currentIsHistogramSum bool
+}
+
+// TextToMetricFamilies reads 'in' as the simple and flat text-based exchange
+// format and creates MetricFamily proto messages. It returns the MetricFamily
+// proto messages in a map where the metric names are the keys, along with any
+// error encountered.
+//
+// If the input contains duplicate metrics (i.e. lines with the same metric name
+// and exactly the same label set), the resulting MetricFamily will contain
+// duplicate Metric proto messages. Similar is true for duplicate label
+// names. Checks for duplicates have to be performed separately, if required.
+// Also note that neither the metrics within each MetricFamily are sorted nor
+// the label pairs within each Metric. Sorting is not required for the most
+// frequent use of this method, which is sample ingestion in the Prometheus
+// server. However, for presentation purposes, you might want to sort the
+// metrics, and in some cases, you must sort the labels, e.g. for consumption by
+// the metric family injection hook of the Prometheus registry.
+//
+// Summaries and histograms are rather special beasts. You would probably not
+// use them in the simple text format anyway. This method can deal with
+// summaries and histograms if they are presented in exactly the way the
+// text.Create function creates them.
+//
+// This method must not be called concurrently. If you want to parse different
+// input concurrently, instantiate a separate Parser for each goroutine.
+func (p *TextParser) TextToMetricFamilies(in io.Reader) (map[string]*dto.MetricFamily, error) {
+	p.reset(in)
+	for nextState := p.startOfLine; nextState != nil; nextState = nextState() {
+		// Magic happens here...
+	}
+	// Get rid of empty metric families.
+	for k, mf := range p.metricFamiliesByName {
+		if len(mf.GetMetric()) == 0 {
+			delete(p.metricFamiliesByName, k)
+		}
+	}
+	// If p.err is io.EOF now, we have run into a premature end of the input
+	// stream. Turn this error into something nicer and more
+	// meaningful. (io.EOF is often used as a signal for the legitimate end
+	// of an input stream.)
+	if p.err == io.EOF {
+		p.parseError("unexpected end of input stream")
+	}
+	return p.metricFamiliesByName, p.err
+}
+
+func (p *TextParser) reset(in io.Reader) {
+	p.metricFamiliesByName = map[string]*dto.MetricFamily{}
+	if p.buf == nil {
+		p.buf = bufio.NewReader(in)
+	} else {
+		p.buf.Reset(in)
+	}
+	p.err = nil
+	p.lineCount = 0
+	if p.summaries == nil || len(p.summaries) > 0 {
+		p.summaries = map[uint64]*dto.Metric{}
+	}
+	if p.histograms == nil || len(p.histograms) > 0 {
+		p.histograms = map[uint64]*dto.Metric{}
+	}
+	p.currentQuantile = math.NaN()
+	p.currentBucket = math.NaN()
+}
+
+// startOfLine represents the state where the next byte read from p.buf is the
+// start of a line (or whitespace leading up to it).
+func (p *TextParser) startOfLine() stateFn {
+	p.lineCount++
+	if p.skipBlankTab(); p.err != nil {
+		// End of input reached. This is the only case where
+		// that is not an error but a signal that we are done.
+		p.err = nil
+		return nil
+	}
+	switch p.currentByte {
+	case '#':
+		return p.startComment
+	case '\n':
+		return p.startOfLine // Empty line, start the next one.
+	}
+	return p.readingMetricName
+}
+
+// startComment represents the state where the next byte read from p.buf is the
+// start of a comment (or whitespace leading up to it).
+func (p *TextParser) startComment() stateFn {
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte == '\n' {
+		return p.startOfLine
+	}
+	if p.readTokenUntilWhitespace(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	// If we have hit the end of line already, there is nothing left
+	// to do. This is not considered a syntax error.
+	if p.currentByte == '\n' {
+		return p.startOfLine
+	}
+	keyword := p.currentToken.String()
+	if keyword != "HELP" && keyword != "TYPE" {
+		// Generic comment, ignore by fast forwarding to end of line.
+		for p.currentByte != '\n' {
+			if p.currentByte, p.err = p.buf.ReadByte(); p.err != nil {
+				return nil // Unexpected end of input.
+			}
+		}
+		return p.startOfLine
+	}
+	// There is something. Next has to be a metric name.
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.readTokenAsMetricName(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte == '\n' {
+		// At the end of the line already.
+		// Again, this is not considered a syntax error.
+		return p.startOfLine
+	}
+	if !isBlankOrTab(p.currentByte) {
+		p.parseError("invalid metric name in comment")
+		return nil
+	}
+	p.setOrCreateCurrentMF()
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte == '\n' {
+		// At the end of the line already.
+		// Again, this is not considered a syntax error.
+		return p.startOfLine
+	}
+	switch keyword {
+	case "HELP":
+		return p.readingHelp
+	case "TYPE":
+		return p.readingType
+	}
+	panic(fmt.Sprintf("code error: unexpected keyword %q", keyword))
+}
+
+// readingMetricName represents the state where the last byte read (now in
+// p.currentByte) is the first byte of a metric name.
+func (p *TextParser) readingMetricName() stateFn {
+	if p.readTokenAsMetricName(); p.err != nil {
+		return nil
+	}
+	if p.currentToken.Len() == 0 {
+		p.parseError("invalid metric name")
+		return nil
+	}
+	p.setOrCreateCurrentMF()
+	// Now is the time to fix the type if it hasn't happened yet.
+	if p.currentMF.Type == nil {
+		p.currentMF.Type = dto.MetricType_UNTYPED.Enum()
+	}
+	p.currentMetric = &dto.Metric{}
+	// Do not append the newly created currentMetric to
+	// currentMF.Metric right now. First wait if this is a summary,
+	// and the metric exists already, which we can only know after
+	// having read all the labels.
+	if p.skipBlankTabIfCurrentBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	return p.readingLabels
+}
+
+// readingLabels represents the state where the last byte read (now in
+// p.currentByte) is either the first byte of the label set (i.e. a '{'), or the
+// first byte of the value (otherwise).
+func (p *TextParser) readingLabels() stateFn {
+	// Summaries/histograms are special. We have to reset the
+	// currentLabels map, currentQuantile and currentBucket before starting to
+	// read labels.
+	if p.currentMF.GetType() == dto.MetricType_SUMMARY || p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
+		p.currentLabels = map[string]string{}
+		p.currentLabels[string(model.MetricNameLabel)] = p.currentMF.GetName()
+		p.currentQuantile = math.NaN()
+		p.currentBucket = math.NaN()
+	}
+	if p.currentByte != '{' {
+		return p.readingValue
+	}
+	return p.startLabelName
+}
+
+// startLabelName represents the state where the next byte read from p.buf is
+// the start of a label name (or whitespace leading up to it).
+func (p *TextParser) startLabelName() stateFn {
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte == '}' {
+		if p.skipBlankTab(); p.err != nil {
+			return nil // Unexpected end of input.
+		}
+		return p.readingValue
+	}
+	if p.readTokenAsLabelName(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentToken.Len() == 0 {
+		p.parseError(fmt.Sprintf("invalid label name for metric %q", p.currentMF.GetName()))
+		return nil
+	}
+	p.currentLabelPair = &dto.LabelPair{Name: proto.String(p.currentToken.String())}
+	if p.currentLabelPair.GetName() == string(model.MetricNameLabel) {
+		p.parseError(fmt.Sprintf("label name %q is reserved", model.MetricNameLabel))
+		return nil
+	}
+	// Special summary/histogram treatment. Don't add 'quantile' and 'le'
+	// labels to 'real' labels.
+	if !(p.currentMF.GetType() == dto.MetricType_SUMMARY && p.currentLabelPair.GetName() == model.QuantileLabel) &&
+		!(p.currentMF.GetType() == dto.MetricType_HISTOGRAM && p.currentLabelPair.GetName() == model.BucketLabel) {
+		p.currentMetric.Label = append(p.currentMetric.Label, p.currentLabelPair)
+	}
+	if p.skipBlankTabIfCurrentBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte != '=' {
+		p.parseError(fmt.Sprintf("expected '=' after label name, found %q", p.currentByte))
+		return nil
+	}
+	return p.startLabelValue
+}
+
+// startLabelValue represents the state where the next byte read from p.buf is
+// the start of a (quoted) label value (or whitespace leading up to it).
+func (p *TextParser) startLabelValue() stateFn {
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentByte != '"' {
+		p.parseError(fmt.Sprintf("expected '\"' at start of label value, found %q", p.currentByte))
+		return nil
+	}
+	if p.readTokenAsLabelValue(); p.err != nil {
+		return nil
+	}
+	p.currentLabelPair.Value = proto.String(p.currentToken.String())
+	// Special treatment of summaries:
+	// - Quantile labels are special, will result in dto.Quantile later.
+	// - Other labels have to be added to currentLabels for signature calculation.
+	if p.currentMF.GetType() == dto.MetricType_SUMMARY {
+		if p.currentLabelPair.GetName() == model.QuantileLabel {
+			if p.currentQuantile, p.err = strconv.ParseFloat(p.currentLabelPair.GetValue(), 64); p.err != nil {
+				// Create a more helpful error message.
+				p.parseError(fmt.Sprintf("expected float as value for 'quantile' label, got %q", p.currentLabelPair.GetValue()))
+				return nil
+			}
+		} else {
+			p.currentLabels[p.currentLabelPair.GetName()] = p.currentLabelPair.GetValue()
+		}
+	}
+	// Similar special treatment of histograms.
+	if p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
+		if p.currentLabelPair.GetName() == model.BucketLabel {
+			if p.currentBucket, p.err = strconv.ParseFloat(p.currentLabelPair.GetValue(), 64); p.err != nil {
+				// Create a more helpful error message.
+				p.parseError(fmt.Sprintf("expected float as value for 'le' label, got %q", p.currentLabelPair.GetValue()))
+				return nil
+			}
+		} else {
+			p.currentLabels[p.currentLabelPair.GetName()] = p.currentLabelPair.GetValue()
+		}
+	}
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	switch p.currentByte {
+	case ',':
+		return p.startLabelName
+
+	case '}':
+		if p.skipBlankTab(); p.err != nil {
+			return nil // Unexpected end of input.
+		}
+		return p.readingValue
+	default:
+		p.parseError(fmt.Sprintf("unexpected end of label value %q", p.currentLabelPair.Value))
+		return nil
+	}
+}
+
+// readingValue represents the state where the last byte read (now in
+// p.currentByte) is the first byte of the sample value (i.e. a float).
+func (p *TextParser) readingValue() stateFn {
+	// When we are here, we have read all the labels, so for the
+	// special case of a summary/histogram, we can finally find out
+	// if the metric already exists.
+	if p.currentMF.GetType() == dto.MetricType_SUMMARY {
+		signature := model.LabelsToSignature(p.currentLabels)
+		if summary := p.summaries[signature]; summary != nil {
+			p.currentMetric = summary
+		} else {
+			p.summaries[signature] = p.currentMetric
+			p.currentMF.Metric = append(p.currentMF.Metric, p.currentMetric)
+		}
+	} else if p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
+		signature := model.LabelsToSignature(p.currentLabels)
+		if histogram := p.histograms[signature]; histogram != nil {
+			p.currentMetric = histogram
+		} else {
+			p.histograms[signature] = p.currentMetric
+			p.currentMF.Metric = append(p.currentMF.Metric, p.currentMetric)
+		}
+	} else {
+		p.currentMF.Metric = append(p.currentMF.Metric, p.currentMetric)
+	}
+	if p.readTokenUntilWhitespace(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	value, err := strconv.ParseFloat(p.currentToken.String(), 64)
+	if err != nil {
+		// Create a more helpful error message.
+		p.parseError(fmt.Sprintf("expected float as value, got %q", p.currentToken.String()))
+		return nil
+	}
+	switch p.currentMF.GetType() {
+	case dto.MetricType_COUNTER:
+		p.currentMetric.Counter = &dto.Counter{Value: proto.Float64(value)}
+	case dto.MetricType_GAUGE:
+		p.currentMetric.Gauge = &dto.Gauge{Value: proto.Float64(value)}
+	case dto.MetricType_UNTYPED:
+		p.currentMetric.Untyped = &dto.Untyped{Value: proto.Float64(value)}
+	case dto.MetricType_SUMMARY:
+		// *sigh*
+		if p.currentMetric.Summary == nil {
+			p.currentMetric.Summary = &dto.Summary{}
+		}
+		switch {
+		case p.currentIsSummaryCount:
+			p.currentMetric.Summary.SampleCount = proto.Uint64(uint64(value))
+		case p.currentIsSummarySum:
+			p.currentMetric.Summary.SampleSum = proto.Float64(value)
+		case !math.IsNaN(p.currentQuantile):
+			p.currentMetric.Summary.Quantile = append(
+				p.currentMetric.Summary.Quantile,
+				&dto.Quantile{
+					Quantile: proto.Float64(p.currentQuantile),
+					Value:    proto.Float64(value),
+				},
+			)
+		}
+	case dto.MetricType_HISTOGRAM:
+		// *sigh*
+		if p.currentMetric.Histogram == nil {
+			p.currentMetric.Histogram = &dto.Histogram{}
+		}
+		switch {
+		case p.currentIsHistogramCount:
+			p.currentMetric.Histogram.SampleCount = proto.Uint64(uint64(value))
+		case p.currentIsHistogramSum:
+			p.currentMetric.Histogram.SampleSum = proto.Float64(value)
+		case !math.IsNaN(p.currentBucket):
+			p.currentMetric.Histogram.Bucket = append(
+				p.currentMetric.Histogram.Bucket,
+				&dto.Bucket{
+					UpperBound:      proto.Float64(p.currentBucket),
+					CumulativeCount: proto.Uint64(uint64(value)),
+				},
+			)
+		}
+	default:
+		p.err = fmt.Errorf("unexpected type for metric name %q", p.currentMF.GetName())
+	}
+	if p.currentByte == '\n' {
+		return p.startOfLine
+	}
+	return p.startTimestamp
+}
+
+// startTimestamp represents the state where the next byte read from p.buf is
+// the start of the timestamp (or whitespace leading up to it).
+func (p *TextParser) startTimestamp() stateFn {
+	if p.skipBlankTab(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.readTokenUntilWhitespace(); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	timestamp, err := strconv.ParseInt(p.currentToken.String(), 10, 64)
+	if err != nil {
+		// Create a more helpful error message.
+		p.parseError(fmt.Sprintf("expected integer as timestamp, got %q", p.currentToken.String()))
+		return nil
+	}
+	p.currentMetric.TimestampMs = proto.Int64(timestamp)
+	if p.readTokenUntilNewline(false); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	if p.currentToken.Len() > 0 {
+		p.parseError(fmt.Sprintf("spurious string after timestamp: %q", p.currentToken.String()))
+		return nil
+	}
+	return p.startOfLine
+}
+
+// readingHelp represents the state where the last byte read (now in
+// p.currentByte) is the first byte of the docstring after 'HELP'.
+func (p *TextParser) readingHelp() stateFn {
+	if p.currentMF.Help != nil {
+		p.parseError(fmt.Sprintf("second HELP line for metric name %q", p.currentMF.GetName()))
+		return nil
+	}
+	// Rest of line is the docstring.
+	if p.readTokenUntilNewline(true); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	p.currentMF.Help = proto.String(p.currentToken.String())
+	return p.startOfLine
+}
+
+// readingType represents the state where the last byte read (now in
+// p.currentByte) is the first byte of the type hint after 'HELP'.
+func (p *TextParser) readingType() stateFn {
+	if p.currentMF.Type != nil {
+		p.parseError(fmt.Sprintf("second TYPE line for metric name %q, or TYPE reported after samples", p.currentMF.GetName()))
+		return nil
+	}
+	// Rest of line is the type.
+	if p.readTokenUntilNewline(false); p.err != nil {
+		return nil // Unexpected end of input.
+	}
+	metricType, ok := dto.MetricType_value[strings.ToUpper(p.currentToken.String())]
+	if !ok {
+		p.parseError(fmt.Sprintf("unknown metric type %q", p.currentToken.String()))
+		return nil
+	}
+	p.currentMF.Type = dto.MetricType(metricType).Enum()
+	return p.startOfLine
+}
+
+// parseError sets p.err to a ParseError at the current line with the given
+// message.
+func (p *TextParser) parseError(msg string) {
+	p.err = ParseError{
+		Line: p.lineCount,
+		Msg:  msg,
+	}
+}
+
+// skipBlankTab reads (and discards) bytes from p.buf until it encounters a byte
+// that is neither ' ' nor '\t'. That byte is left in p.currentByte.
+func (p *TextParser) skipBlankTab() {
+	for {
+		if p.currentByte, p.err = p.buf.ReadByte(); p.err != nil || !isBlankOrTab(p.currentByte) {
+			return
+		}
+	}
+}
+
+// skipBlankTabIfCurrentBlankTab works exactly as skipBlankTab but doesn't do
+// anything if p.currentByte is neither ' ' nor '\t'.
+func (p *TextParser) skipBlankTabIfCurrentBlankTab() {
+	if isBlankOrTab(p.currentByte) {
+		p.skipBlankTab()
+	}
+}
+
+// readTokenUntilWhitespace copies bytes from p.buf into p.currentToken.  The
+// first byte considered is the byte already read (now in p.currentByte).  The
+// first whitespace byte encountered is still copied into p.currentByte, but not
+// into p.currentToken.
+func (p *TextParser) readTokenUntilWhitespace() {
+	p.currentToken.Reset()
+	for p.err == nil && !isBlankOrTab(p.currentByte) && p.currentByte != '\n' {
+		p.currentToken.WriteByte(p.currentByte)
+		p.currentByte, p.err = p.buf.ReadByte()
+	}
+}
+
+// readTokenUntilNewline copies bytes from p.buf into p.currentToken.  The first
+// byte considered is the byte already read (now in p.currentByte).  The first
+// newline byte encountered is still copied into p.currentByte, but not into
+// p.currentToken. If recognizeEscapeSequence is true, two escape sequences are
+// recognized: '\\' tranlates into '\', and '\n' into a line-feed character. All
+// other escape sequences are invalid and cause an error.
+func (p *TextParser) readTokenUntilNewline(recognizeEscapeSequence bool) {
+	p.currentToken.Reset()
+	escaped := false
+	for p.err == nil {
+		if recognizeEscapeSequence && escaped {
+			switch p.currentByte {
+			case '\\':
+				p.currentToken.WriteByte(p.currentByte)
+			case 'n':
+				p.currentToken.WriteByte('\n')
+			default:
+				p.parseError(fmt.Sprintf("invalid escape sequence '\\%c'", p.currentByte))
+				return
+			}
+			escaped = false
+		} else {
+			switch p.currentByte {
+			case '\n':
+				return
+			case '\\':
+				escaped = true
+			default:
+				p.currentToken.WriteByte(p.currentByte)
+			}
+		}
+		p.currentByte, p.err = p.buf.ReadByte()
+	}
+}
+
+// readTokenAsMetricName copies a metric name from p.buf into p.currentToken.
+// The first byte considered is the byte already read (now in p.currentByte).
+// The first byte not part of a metric name is still copied into p.currentByte,
+// but not into p.currentToken.
+func (p *TextParser) readTokenAsMetricName() {
+	p.currentToken.Reset()
+	if !isValidMetricNameStart(p.currentByte) {
+		return
+	}
+	for {
+		p.currentToken.WriteByte(p.currentByte)
+		p.currentByte, p.err = p.buf.ReadByte()
+		if p.err != nil || !isValidMetricNameContinuation(p.currentByte) {
+			return
+		}
+	}
+}
+
+// readTokenAsLabelName copies a label name from p.buf into p.currentToken.
+// The first byte considered is the byte already read (now in p.currentByte).
+// The first byte not part of a label name is still copied into p.currentByte,
+// but not into p.currentToken.
+func (p *TextParser) readTokenAsLabelName() {
+	p.currentToken.Reset()
+	if !isValidLabelNameStart(p.currentByte) {
+		return
+	}
+	for {
+		p.currentToken.WriteByte(p.currentByte)
+		p.currentByte, p.err = p.buf.ReadByte()
+		if p.err != nil || !isValidLabelNameContinuation(p.currentByte) {
+			return
+		}
+	}
+}
+
+// readTokenAsLabelValue copies a label value from p.buf into p.currentToken.
+// In contrast to the other 'readTokenAs...' functions, which start with the
+// last read byte in p.currentByte, this method ignores p.currentByte and starts
+// with reading a new byte from p.buf. The first byte not part of a label value
+// is still copied into p.currentByte, but not into p.currentToken.
+func (p *TextParser) readTokenAsLabelValue() {
+	p.currentToken.Reset()
+	escaped := false
+	for {
+		if p.currentByte, p.err = p.buf.ReadByte(); p.err != nil {
+			return
+		}
+		if escaped {
+			switch p.currentByte {
+			case '"', '\\':
+				p.currentToken.WriteByte(p.currentByte)
+			case 'n':
+				p.currentToken.WriteByte('\n')
+			default:
+				p.parseError(fmt.Sprintf("invalid escape sequence '\\%c'", p.currentByte))
+				return
+			}
+			escaped = false
+			continue
+		}
+		switch p.currentByte {
+		case '"':
+			return
+		case '\n':
+			p.parseError(fmt.Sprintf("label value %q contains unescaped new-line", p.currentToken.String()))
+			return
+		case '\\':
+			escaped = true
+		default:
+			p.currentToken.WriteByte(p.currentByte)
+		}
+	}
+}
+
+func (p *TextParser) setOrCreateCurrentMF() {
+	p.currentIsSummaryCount = false
+	p.currentIsSummarySum = false
+	p.currentIsHistogramCount = false
+	p.currentIsHistogramSum = false
+	name := p.currentToken.String()
+	if p.currentMF = p.metricFamiliesByName[name]; p.currentMF != nil {
+		return
+	}
+	// Try out if this is a _sum or _count for a summary/histogram.
+	summaryName := summaryMetricName(name)
+	if p.currentMF = p.metricFamiliesByName[summaryName]; p.currentMF != nil {
+		if p.currentMF.GetType() == dto.MetricType_SUMMARY {
+			if isCount(name) {
+				p.currentIsSummaryCount = true
+			}
+			if isSum(name) {
+				p.currentIsSummarySum = true
+			}
+			return
+		}
+	}
+	histogramName := histogramMetricName(name)
+	if p.currentMF = p.metricFamiliesByName[histogramName]; p.currentMF != nil {
+		if p.currentMF.GetType() == dto.MetricType_HISTOGRAM {
+			if isCount(name) {
+				p.currentIsHistogramCount = true
+			}
+			if isSum(name) {
+				p.currentIsHistogramSum = true
+			}
+			return
+		}
+	}
+	p.currentMF = &dto.MetricFamily{Name: proto.String(name)}
+	p.metricFamiliesByName[name] = p.currentMF
+}
+
+func isValidLabelNameStart(b byte) bool {
+	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_'
+}
+
+func isValidLabelNameContinuation(b byte) bool {
+	return isValidLabelNameStart(b) || (b >= '0' && b <= '9')
+}
+
+func isValidMetricNameStart(b byte) bool {
+	return isValidLabelNameStart(b) || b == ':'
+}
+
+func isValidMetricNameContinuation(b byte) bool {
+	return isValidLabelNameContinuation(b) || b == ':'
+}
+
+func isBlankOrTab(b byte) bool {
+	return b == ' ' || b == '\t'
+}
+
+func isCount(name string) bool {
+	return len(name) > 6 && name[len(name)-6:] == "_count"
+}
+
+func isSum(name string) bool {
+	return len(name) > 4 && name[len(name)-4:] == "_sum"
+}
+
+func isBucket(name string) bool {
+	return len(name) > 7 && name[len(name)-7:] == "_bucket"
+}
+
+func summaryMetricName(name string) string {
+	switch {
+	case isCount(name):
+		return name[:len(name)-6]
+	case isSum(name):
+		return name[:len(name)-4]
+	default:
+		return name
+	}
+}
+
+func histogramMetricName(name string) string {
+	switch {
+	case isCount(name):
+		return name[:len(name)-6]
+	case isSum(name):
+		return name[:len(name)-4]
+	case isBucket(name):
+		return name[:len(name)-7]
+	default:
+		return name
+	}
+}
diff --git a/vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/README.txt b/vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/README.txt
new file mode 100644
index 00000000..7723656d
--- /dev/null
+++ b/vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/README.txt
@@ -0,0 +1,67 @@
+PACKAGE
+
+package goautoneg
+import "bitbucket.org/ww/goautoneg"
+
+HTTP Content-Type Autonegotiation.
+
+The functions in this package implement the behaviour specified in
+http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
+
+Copyright (c) 2011, Open Knowledge Foundation Ltd.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    Neither the name of the Open Knowledge Foundation Ltd. nor the
+    names of its contributors may be used to endorse or promote
+    products derived from this software without specific prior written
+    permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+FUNCTIONS
+
+func Negotiate(header string, alternatives []string) (content_type string)
+Negotiate the most appropriate content_type given the accept header
+and a list of alternatives.
+
+func ParseAccept(header string) (accept []Accept)
+Parse an Accept Header string returning a sorted list
+of clauses
+
+
+TYPES
+
+type Accept struct {
+    Type, SubType string
+    Q             float32
+    Params        map[string]string
+}
+Structure to represent a clause in an HTTP Accept Header
+
+
+SUBDIRECTORIES
+
+	.hg
diff --git a/vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/autoneg.go b/vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/autoneg.go
new file mode 100644
index 00000000..648b38cb
--- /dev/null
+++ b/vendor/github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg/autoneg.go
@@ -0,0 +1,162 @@
+/*
+HTTP Content-Type Autonegotiation.
+
+The functions in this package implement the behaviour specified in
+http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
+
+Copyright (c) 2011, Open Knowledge Foundation Ltd.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    Neither the name of the Open Knowledge Foundation Ltd. nor the
+    names of its contributors may be used to endorse or promote
+    products derived from this software without specific prior written
+    permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+*/
+package goautoneg
+
+import (
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// Structure to represent a clause in an HTTP Accept Header
+type Accept struct {
+	Type, SubType string
+	Q             float64
+	Params        map[string]string
+}
+
+// For internal use, so that we can use the sort interface
+type accept_slice []Accept
+
+func (accept accept_slice) Len() int {
+	slice := []Accept(accept)
+	return len(slice)
+}
+
+func (accept accept_slice) Less(i, j int) bool {
+	slice := []Accept(accept)
+	ai, aj := slice[i], slice[j]
+	if ai.Q > aj.Q {
+		return true
+	}
+	if ai.Type != "*" && aj.Type == "*" {
+		return true
+	}
+	if ai.SubType != "*" && aj.SubType == "*" {
+		return true
+	}
+	return false
+}
+
+func (accept accept_slice) Swap(i, j int) {
+	slice := []Accept(accept)
+	slice[i], slice[j] = slice[j], slice[i]
+}
+
+// Parse an Accept Header string returning a sorted list
+// of clauses
+func ParseAccept(header string) (accept []Accept) {
+	parts := strings.Split(header, ",")
+	accept = make([]Accept, 0, len(parts))
+	for _, part := range parts {
+		part := strings.Trim(part, " ")
+
+		a := Accept{}
+		a.Params = make(map[string]string)
+		a.Q = 1.0
+
+		mrp := strings.Split(part, ";")
+
+		media_range := mrp[0]
+		sp := strings.Split(media_range, "/")
+		a.Type = strings.Trim(sp[0], " ")
+
+		switch {
+		case len(sp) == 1 && a.Type == "*":
+			a.SubType = "*"
+		case len(sp) == 2:
+			a.SubType = strings.Trim(sp[1], " ")
+		default:
+			continue
+		}
+
+		if len(mrp) == 1 {
+			accept = append(accept, a)
+			continue
+		}
+
+		for _, param := range mrp[1:] {
+			sp := strings.SplitN(param, "=", 2)
+			if len(sp) != 2 {
+				continue
+			}
+			token := strings.Trim(sp[0], " ")
+			if token == "q" {
+				a.Q, _ = strconv.ParseFloat(sp[1], 32)
+			} else {
+				a.Params[token] = strings.Trim(sp[1], " ")
+			}
+		}
+
+		accept = append(accept, a)
+	}
+
+	slice := accept_slice(accept)
+	sort.Sort(slice)
+
+	return
+}
+
+// Negotiate the most appropriate content_type given the accept header
+// and a list of alternatives.
+func Negotiate(header string, alternatives []string) (content_type string) {
+	asp := make([][]string, 0, len(alternatives))
+	for _, ctype := range alternatives {
+		asp = append(asp, strings.SplitN(ctype, "/", 2))
+	}
+	for _, clause := range ParseAccept(header) {
+		for i, ctsp := range asp {
+			if clause.Type == ctsp[0] && clause.SubType == ctsp[1] {
+				content_type = alternatives[i]
+				return
+			}
+			if clause.Type == ctsp[0] && clause.SubType == "*" {
+				content_type = alternatives[i]
+				return
+			}
+			if clause.Type == "*" && clause.SubType == "*" {
+				content_type = alternatives[i]
+				return
+			}
+		}
+	}
+	return
+}
diff --git a/vendor/github.com/prometheus/common/model/alert.go b/vendor/github.com/prometheus/common/model/alert.go
new file mode 100644
index 00000000..35e739c7
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/alert.go
@@ -0,0 +1,136 @@
+// Copyright 2013 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+import (
+	"fmt"
+	"time"
+)
+
+type AlertStatus string
+
+const (
+	AlertFiring   AlertStatus = "firing"
+	AlertResolved AlertStatus = "resolved"
+)
+
+// Alert is a generic representation of an alert in the Prometheus eco-system.
+type Alert struct {
+	// Label value pairs for purpose of aggregation, matching, and disposition
+	// dispatching. This must minimally include an "alertname" label.
+	Labels LabelSet `json:"labels"`
+
+	// Extra key/value information which does not define alert identity.
+	Annotations LabelSet `json:"annotations"`
+
+	// The known time range for this alert. Both ends are optional.
+	StartsAt     time.Time `json:"startsAt,omitempty"`
+	EndsAt       time.Time `json:"endsAt,omitempty"`
+	GeneratorURL string    `json:"generatorURL"`
+}
+
+// Name returns the name of the alert. It is equivalent to the "alertname" label.
+func (a *Alert) Name() string {
+	return string(a.Labels[AlertNameLabel])
+}
+
+// Fingerprint returns a unique hash for the alert. It is equivalent to
+// the fingerprint of the alert's label set.
+func (a *Alert) Fingerprint() Fingerprint {
+	return a.Labels.Fingerprint()
+}
+
+func (a *Alert) String() string {
+	s := fmt.Sprintf("%s[%s]", a.Name(), a.Fingerprint().String()[:7])
+	if a.Resolved() {
+		return s + "[resolved]"
+	}
+	return s + "[active]"
+}
+
+// Resolved returns true iff the activity interval ended in the past.
+func (a *Alert) Resolved() bool {
+	return a.ResolvedAt(time.Now())
+}
+
+// ResolvedAt returns true off the activity interval ended before
+// the given timestamp.
+func (a *Alert) ResolvedAt(ts time.Time) bool {
+	if a.EndsAt.IsZero() {
+		return false
+	}
+	return !a.EndsAt.After(ts)
+}
+
+// Status returns the status of the alert.
+func (a *Alert) Status() AlertStatus {
+	if a.Resolved() {
+		return AlertResolved
+	}
+	return AlertFiring
+}
+
+// Validate checks whether the alert data is inconsistent.
+func (a *Alert) Validate() error {
+	if a.StartsAt.IsZero() {
+		return fmt.Errorf("start time missing")
+	}
+	if !a.EndsAt.IsZero() && a.EndsAt.Before(a.StartsAt) {
+		return fmt.Errorf("start time must be before end time")
+	}
+	if err := a.Labels.Validate(); err != nil {
+		return fmt.Errorf("invalid label set: %s", err)
+	}
+	if len(a.Labels) == 0 {
+		return fmt.Errorf("at least one label pair required")
+	}
+	if err := a.Annotations.Validate(); err != nil {
+		return fmt.Errorf("invalid annotations: %s", err)
+	}
+	return nil
+}
+
+// Alert is a list of alerts that can be sorted in chronological order.
+type Alerts []*Alert
+
+func (as Alerts) Len() int      { return len(as) }
+func (as Alerts) Swap(i, j int) { as[i], as[j] = as[j], as[i] }
+
+func (as Alerts) Less(i, j int) bool {
+	if as[i].StartsAt.Before(as[j].StartsAt) {
+		return true
+	}
+	if as[i].EndsAt.Before(as[j].EndsAt) {
+		return true
+	}
+	return as[i].Fingerprint() < as[j].Fingerprint()
+}
+
+// HasFiring returns true iff one of the alerts is not resolved.
+func (as Alerts) HasFiring() bool {
+	for _, a := range as {
+		if !a.Resolved() {
+			return true
+		}
+	}
+	return false
+}
+
+// Status returns StatusFiring iff at least one of the alerts is firing.
+func (as Alerts) Status() AlertStatus {
+	if as.HasFiring() {
+		return AlertFiring
+	}
+	return AlertResolved
+}
diff --git a/vendor/github.com/prometheus/common/model/fingerprinting.go b/vendor/github.com/prometheus/common/model/fingerprinting.go
new file mode 100644
index 00000000..fc4de410
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/fingerprinting.go
@@ -0,0 +1,105 @@
+// Copyright 2013 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// Fingerprint provides a hash-capable representation of a Metric.
+// For our purposes, FNV-1A 64-bit is used.
+type Fingerprint uint64
+
+// FingerprintFromString transforms a string representation into a Fingerprint.
+func FingerprintFromString(s string) (Fingerprint, error) {
+	num, err := strconv.ParseUint(s, 16, 64)
+	return Fingerprint(num), err
+}
+
+// ParseFingerprint parses the input string into a fingerprint.
+func ParseFingerprint(s string) (Fingerprint, error) {
+	num, err := strconv.ParseUint(s, 16, 64)
+	if err != nil {
+		return 0, err
+	}
+	return Fingerprint(num), nil
+}
+
+func (f Fingerprint) String() string {
+	return fmt.Sprintf("%016x", uint64(f))
+}
+
+// Fingerprints represents a collection of Fingerprint subject to a given
+// natural sorting scheme. It implements sort.Interface.
+type Fingerprints []Fingerprint
+
+// Len implements sort.Interface.
+func (f Fingerprints) Len() int {
+	return len(f)
+}
+
+// Less implements sort.Interface.
+func (f Fingerprints) Less(i, j int) bool {
+	return f[i] < f[j]
+}
+
+// Swap implements sort.Interface.
+func (f Fingerprints) Swap(i, j int) {
+	f[i], f[j] = f[j], f[i]
+}
+
+// FingerprintSet is a set of Fingerprints.
+type FingerprintSet map[Fingerprint]struct{}
+
+// Equal returns true if both sets contain the same elements (and not more).
+func (s FingerprintSet) Equal(o FingerprintSet) bool {
+	if len(s) != len(o) {
+		return false
+	}
+
+	for k := range s {
+		if _, ok := o[k]; !ok {
+			return false
+		}
+	}
+
+	return true
+}
+
+// Intersection returns the elements contained in both sets.
+func (s FingerprintSet) Intersection(o FingerprintSet) FingerprintSet {
+	myLength, otherLength := len(s), len(o)
+	if myLength == 0 || otherLength == 0 {
+		return FingerprintSet{}
+	}
+
+	subSet := s
+	superSet := o
+
+	if otherLength < myLength {
+		subSet = o
+		superSet = s
+	}
+
+	out := FingerprintSet{}
+
+	for k := range subSet {
+		if _, ok := superSet[k]; ok {
+			out[k] = struct{}{}
+		}
+	}
+
+	return out
+}
diff --git a/vendor/github.com/prometheus/common/model/fnv.go b/vendor/github.com/prometheus/common/model/fnv.go
new file mode 100644
index 00000000..038fc1c9
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/fnv.go
@@ -0,0 +1,42 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+// Inline and byte-free variant of hash/fnv's fnv64a.
+
+const (
+	offset64 = 14695981039346656037
+	prime64  = 1099511628211
+)
+
+// hashNew initializies a new fnv64a hash value.
+func hashNew() uint64 {
+	return offset64
+}
+
+// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
+func hashAdd(h uint64, s string) uint64 {
+	for i := 0; i < len(s); i++ {
+		h ^= uint64(s[i])
+		h *= prime64
+	}
+	return h
+}
+
+// hashAddByte adds a byte to a fnv64a hash value, returning the updated hash.
+func hashAddByte(h uint64, b byte) uint64 {
+	h ^= uint64(b)
+	h *= prime64
+	return h
+}
diff --git a/vendor/github.com/prometheus/common/model/labels.go b/vendor/github.com/prometheus/common/model/labels.go
new file mode 100644
index 00000000..3b72e7ff
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/labels.go
@@ -0,0 +1,206 @@
+// Copyright 2013 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+import (
+	"encoding/json"
+	"fmt"
+	"regexp"
+	"strings"
+	"unicode/utf8"
+)
+
+const (
+	// AlertNameLabel is the name of the label containing the an alert's name.
+	AlertNameLabel = "alertname"
+
+	// ExportedLabelPrefix is the prefix to prepend to the label names present in
+	// exported metrics if a label of the same name is added by the server.
+	ExportedLabelPrefix = "exported_"
+
+	// MetricNameLabel is the label name indicating the metric name of a
+	// timeseries.
+	MetricNameLabel = "__name__"
+
+	// SchemeLabel is the name of the label that holds the scheme on which to
+	// scrape a target.
+	SchemeLabel = "__scheme__"
+
+	// AddressLabel is the name of the label that holds the address of
+	// a scrape target.
+	AddressLabel = "__address__"
+
+	// MetricsPathLabel is the name of the label that holds the path on which to
+	// scrape a target.
+	MetricsPathLabel = "__metrics_path__"
+
+	// ReservedLabelPrefix is a prefix which is not legal in user-supplied
+	// label names.
+	ReservedLabelPrefix = "__"
+
+	// MetaLabelPrefix is a prefix for labels that provide meta information.
+	// Labels with this prefix are used for intermediate label processing and
+	// will not be attached to time series.
+	MetaLabelPrefix = "__meta_"
+
+	// TmpLabelPrefix is a prefix for temporary labels as part of relabelling.
+	// Labels with this prefix are used for intermediate label processing and
+	// will not be attached to time series. This is reserved for use in
+	// Prometheus configuration files by users.
+	TmpLabelPrefix = "__tmp_"
+
+	// ParamLabelPrefix is a prefix for labels that provide URL parameters
+	// used to scrape a target.
+	ParamLabelPrefix = "__param_"
+
+	// JobLabel is the label name indicating the job from which a timeseries
+	// was scraped.
+	JobLabel = "job"
+
+	// InstanceLabel is the label name used for the instance label.
+	InstanceLabel = "instance"
+
+	// BucketLabel is used for the label that defines the upper bound of a
+	// bucket of a histogram ("le" -> "less or equal").
+	BucketLabel = "le"
+
+	// QuantileLabel is used for the label that defines the quantile in a
+	// summary.
+	QuantileLabel = "quantile"
+)
+
+// LabelNameRE is a regular expression matching valid label names.
+var LabelNameRE = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
+
+// A LabelName is a key for a LabelSet or Metric.  It has a value associated
+// therewith.
+type LabelName string
+
+// IsValid is true iff the label name matches the pattern of LabelNameRE.
+func (ln LabelName) IsValid() bool {
+	if len(ln) == 0 {
+		return false
+	}
+	for i, b := range ln {
+		if !((b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || (b >= '0' && b <= '9' && i > 0)) {
+			return false
+		}
+	}
+	return true
+}
+
+// UnmarshalYAML implements the yaml.Unmarshaler interface.
+func (ln *LabelName) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var s string
+	if err := unmarshal(&s); err != nil {
+		return err
+	}
+	if !LabelNameRE.MatchString(s) {
+		return fmt.Errorf("%q is not a valid label name", s)
+	}
+	*ln = LabelName(s)
+	return nil
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (ln *LabelName) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+	if !LabelNameRE.MatchString(s) {
+		return fmt.Errorf("%q is not a valid label name", s)
+	}
+	*ln = LabelName(s)
+	return nil
+}
+
+// LabelNames is a sortable LabelName slice. In implements sort.Interface.
+type LabelNames []LabelName
+
+func (l LabelNames) Len() int {
+	return len(l)
+}
+
+func (l LabelNames) Less(i, j int) bool {
+	return l[i] < l[j]
+}
+
+func (l LabelNames) Swap(i, j int) {
+	l[i], l[j] = l[j], l[i]
+}
+
+func (l LabelNames) String() string {
+	labelStrings := make([]string, 0, len(l))
+	for _, label := range l {
+		labelStrings = append(labelStrings, string(label))
+	}
+	return strings.Join(labelStrings, ", ")
+}
+
+// A LabelValue is an associated value for a LabelName.
+type LabelValue string
+
+// IsValid returns true iff the string is a valid UTF8.
+func (lv LabelValue) IsValid() bool {
+	return utf8.ValidString(string(lv))
+}
+
+// LabelValues is a sortable LabelValue slice. It implements sort.Interface.
+type LabelValues []LabelValue
+
+func (l LabelValues) Len() int {
+	return len(l)
+}
+
+func (l LabelValues) Less(i, j int) bool {
+	return string(l[i]) < string(l[j])
+}
+
+func (l LabelValues) Swap(i, j int) {
+	l[i], l[j] = l[j], l[i]
+}
+
+// LabelPair pairs a name with a value.
+type LabelPair struct {
+	Name  LabelName
+	Value LabelValue
+}
+
+// LabelPairs is a sortable slice of LabelPair pointers. It implements
+// sort.Interface.
+type LabelPairs []*LabelPair
+
+func (l LabelPairs) Len() int {
+	return len(l)
+}
+
+func (l LabelPairs) Less(i, j int) bool {
+	switch {
+	case l[i].Name > l[j].Name:
+		return false
+	case l[i].Name < l[j].Name:
+		return true
+	case l[i].Value > l[j].Value:
+		return false
+	case l[i].Value < l[j].Value:
+		return true
+	default:
+		return false
+	}
+}
+
+func (l LabelPairs) Swap(i, j int) {
+	l[i], l[j] = l[j], l[i]
+}
diff --git a/vendor/github.com/prometheus/common/model/labelset.go b/vendor/github.com/prometheus/common/model/labelset.go
new file mode 100644
index 00000000..5f931cdb
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/labelset.go
@@ -0,0 +1,169 @@
+// Copyright 2013 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+import (
+	"encoding/json"
+	"fmt"
+	"sort"
+	"strings"
+)
+
+// A LabelSet is a collection of LabelName and LabelValue pairs.  The LabelSet
+// may be fully-qualified down to the point where it may resolve to a single
+// Metric in the data store or not.  All operations that occur within the realm
+// of a LabelSet can emit a vector of Metric entities to which the LabelSet may
+// match.
+type LabelSet map[LabelName]LabelValue
+
+// Validate checks whether all names and values in the label set
+// are valid.
+func (ls LabelSet) Validate() error {
+	for ln, lv := range ls {
+		if !ln.IsValid() {
+			return fmt.Errorf("invalid name %q", ln)
+		}
+		if !lv.IsValid() {
+			return fmt.Errorf("invalid value %q", lv)
+		}
+	}
+	return nil
+}
+
+// Equal returns true iff both label sets have exactly the same key/value pairs.
+func (ls LabelSet) Equal(o LabelSet) bool {
+	if len(ls) != len(o) {
+		return false
+	}
+	for ln, lv := range ls {
+		olv, ok := o[ln]
+		if !ok {
+			return false
+		}
+		if olv != lv {
+			return false
+		}
+	}
+	return true
+}
+
+// Before compares the metrics, using the following criteria:
+//
+// If m has fewer labels than o, it is before o. If it has more, it is not.
+//
+// If the number of labels is the same, the superset of all label names is
+// sorted alphanumerically. The first differing label pair found in that order
+// determines the outcome: If the label does not exist at all in m, then m is
+// before o, and vice versa. Otherwise the label value is compared
+// alphanumerically.
+//
+// If m and o are equal, the method returns false.
+func (ls LabelSet) Before(o LabelSet) bool {
+	if len(ls) < len(o) {
+		return true
+	}
+	if len(ls) > len(o) {
+		return false
+	}
+
+	lns := make(LabelNames, 0, len(ls)+len(o))
+	for ln := range ls {
+		lns = append(lns, ln)
+	}
+	for ln := range o {
+		lns = append(lns, ln)
+	}
+	// It's probably not worth it to de-dup lns.
+	sort.Sort(lns)
+	for _, ln := range lns {
+		mlv, ok := ls[ln]
+		if !ok {
+			return true
+		}
+		olv, ok := o[ln]
+		if !ok {
+			return false
+		}
+		if mlv < olv {
+			return true
+		}
+		if mlv > olv {
+			return false
+		}
+	}
+	return false
+}
+
+// Clone returns a copy of the label set.
+func (ls LabelSet) Clone() LabelSet {
+	lsn := make(LabelSet, len(ls))
+	for ln, lv := range ls {
+		lsn[ln] = lv
+	}
+	return lsn
+}
+
+// Merge is a helper function to non-destructively merge two label sets.
+func (l LabelSet) Merge(other LabelSet) LabelSet {
+	result := make(LabelSet, len(l))
+
+	for k, v := range l {
+		result[k] = v
+	}
+
+	for k, v := range other {
+		result[k] = v
+	}
+
+	return result
+}
+
+func (l LabelSet) String() string {
+	lstrs := make([]string, 0, len(l))
+	for l, v := range l {
+		lstrs = append(lstrs, fmt.Sprintf("%s=%q", l, v))
+	}
+
+	sort.Strings(lstrs)
+	return fmt.Sprintf("{%s}", strings.Join(lstrs, ", "))
+}
+
+// Fingerprint returns the LabelSet's fingerprint.
+func (ls LabelSet) Fingerprint() Fingerprint {
+	return labelSetToFingerprint(ls)
+}
+
+// FastFingerprint returns the LabelSet's Fingerprint calculated by a faster hashing
+// algorithm, which is, however, more susceptible to hash collisions.
+func (ls LabelSet) FastFingerprint() Fingerprint {
+	return labelSetToFastFingerprint(ls)
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (l *LabelSet) UnmarshalJSON(b []byte) error {
+	var m map[LabelName]LabelValue
+	if err := json.Unmarshal(b, &m); err != nil {
+		return err
+	}
+	// encoding/json only unmarshals maps of the form map[string]T. It treats
+	// LabelName as a string and does not call its UnmarshalJSON method.
+	// Thus, we have to replicate the behavior here.
+	for ln := range m {
+		if !LabelNameRE.MatchString(string(ln)) {
+			return fmt.Errorf("%q is not a valid label name", ln)
+		}
+	}
+	*l = LabelSet(m)
+	return nil
+}
diff --git a/vendor/github.com/prometheus/common/model/metric.go b/vendor/github.com/prometheus/common/model/metric.go
new file mode 100644
index 00000000..a5da59a5
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/metric.go
@@ -0,0 +1,98 @@
+// Copyright 2013 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+import (
+	"fmt"
+	"regexp"
+	"sort"
+	"strings"
+)
+
+var (
+	separator    = []byte{0}
+	MetricNameRE = regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_:]*$`)
+)
+
+// A Metric is similar to a LabelSet, but the key difference is that a Metric is
+// a singleton and refers to one and only one stream of samples.
+type Metric LabelSet
+
+// Equal compares the metrics.
+func (m Metric) Equal(o Metric) bool {
+	return LabelSet(m).Equal(LabelSet(o))
+}
+
+// Before compares the metrics' underlying label sets.
+func (m Metric) Before(o Metric) bool {
+	return LabelSet(m).Before(LabelSet(o))
+}
+
+// Clone returns a copy of the Metric.
+func (m Metric) Clone() Metric {
+	clone := Metric{}
+	for k, v := range m {
+		clone[k] = v
+	}
+	return clone
+}
+
+func (m Metric) String() string {
+	metricName, hasName := m[MetricNameLabel]
+	numLabels := len(m) - 1
+	if !hasName {
+		numLabels = len(m)
+	}
+	labelStrings := make([]string, 0, numLabels)
+	for label, value := range m {
+		if label != MetricNameLabel {
+			labelStrings = append(labelStrings, fmt.Sprintf("%s=%q", label, value))
+		}
+	}
+
+	switch numLabels {
+	case 0:
+		if hasName {
+			return string(metricName)
+		}
+		return "{}"
+	default:
+		sort.Strings(labelStrings)
+		return fmt.Sprintf("%s{%s}", metricName, strings.Join(labelStrings, ", "))
+	}
+}
+
+// Fingerprint returns a Metric's Fingerprint.
+func (m Metric) Fingerprint() Fingerprint {
+	return LabelSet(m).Fingerprint()
+}
+
+// FastFingerprint returns a Metric's Fingerprint calculated by a faster hashing
+// algorithm, which is, however, more susceptible to hash collisions.
+func (m Metric) FastFingerprint() Fingerprint {
+	return LabelSet(m).FastFingerprint()
+}
+
+// IsValidMetricName returns true iff name matches the pattern of MetricNameRE.
+func IsValidMetricName(n LabelValue) bool {
+	if len(n) == 0 {
+		return false
+	}
+	for i, b := range n {
+		if !((b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || b == ':' || (b >= '0' && b <= '9' && i > 0)) {
+			return false
+		}
+	}
+	return true
+}
diff --git a/vendor/github.com/prometheus/common/model/model.go b/vendor/github.com/prometheus/common/model/model.go
new file mode 100644
index 00000000..a7b96917
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/model.go
@@ -0,0 +1,16 @@
+// Copyright 2013 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package model contains common data structures that are shared across
+// Prometheus components and libraries.
+package model
diff --git a/vendor/github.com/prometheus/common/model/signature.go b/vendor/github.com/prometheus/common/model/signature.go
new file mode 100644
index 00000000..8762b13c
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/signature.go
@@ -0,0 +1,144 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+import (
+	"sort"
+)
+
+// SeparatorByte is a byte that cannot occur in valid UTF-8 sequences and is
+// used to separate label names, label values, and other strings from each other
+// when calculating their combined hash value (aka signature aka fingerprint).
+const SeparatorByte byte = 255
+
+var (
+	// cache the signature of an empty label set.
+	emptyLabelSignature = hashNew()
+)
+
+// LabelsToSignature returns a quasi-unique signature (i.e., fingerprint) for a
+// given label set. (Collisions are possible but unlikely if the number of label
+// sets the function is applied to is small.)
+func LabelsToSignature(labels map[string]string) uint64 {
+	if len(labels) == 0 {
+		return emptyLabelSignature
+	}
+
+	labelNames := make([]string, 0, len(labels))
+	for labelName := range labels {
+		labelNames = append(labelNames, labelName)
+	}
+	sort.Strings(labelNames)
+
+	sum := hashNew()
+	for _, labelName := range labelNames {
+		sum = hashAdd(sum, labelName)
+		sum = hashAddByte(sum, SeparatorByte)
+		sum = hashAdd(sum, labels[labelName])
+		sum = hashAddByte(sum, SeparatorByte)
+	}
+	return sum
+}
+
+// labelSetToFingerprint works exactly as LabelsToSignature but takes a LabelSet as
+// parameter (rather than a label map) and returns a Fingerprint.
+func labelSetToFingerprint(ls LabelSet) Fingerprint {
+	if len(ls) == 0 {
+		return Fingerprint(emptyLabelSignature)
+	}
+
+	labelNames := make(LabelNames, 0, len(ls))
+	for labelName := range ls {
+		labelNames = append(labelNames, labelName)
+	}
+	sort.Sort(labelNames)
+
+	sum := hashNew()
+	for _, labelName := range labelNames {
+		sum = hashAdd(sum, string(labelName))
+		sum = hashAddByte(sum, SeparatorByte)
+		sum = hashAdd(sum, string(ls[labelName]))
+		sum = hashAddByte(sum, SeparatorByte)
+	}
+	return Fingerprint(sum)
+}
+
+// labelSetToFastFingerprint works similar to labelSetToFingerprint but uses a
+// faster and less allocation-heavy hash function, which is more susceptible to
+// create hash collisions. Therefore, collision detection should be applied.
+func labelSetToFastFingerprint(ls LabelSet) Fingerprint {
+	if len(ls) == 0 {
+		return Fingerprint(emptyLabelSignature)
+	}
+
+	var result uint64
+	for labelName, labelValue := range ls {
+		sum := hashNew()
+		sum = hashAdd(sum, string(labelName))
+		sum = hashAddByte(sum, SeparatorByte)
+		sum = hashAdd(sum, string(labelValue))
+		result ^= sum
+	}
+	return Fingerprint(result)
+}
+
+// SignatureForLabels works like LabelsToSignature but takes a Metric as
+// parameter (rather than a label map) and only includes the labels with the
+// specified LabelNames into the signature calculation. The labels passed in
+// will be sorted by this function.
+func SignatureForLabels(m Metric, labels ...LabelName) uint64 {
+	if len(labels) == 0 {
+		return emptyLabelSignature
+	}
+
+	sort.Sort(LabelNames(labels))
+
+	sum := hashNew()
+	for _, label := range labels {
+		sum = hashAdd(sum, string(label))
+		sum = hashAddByte(sum, SeparatorByte)
+		sum = hashAdd(sum, string(m[label]))
+		sum = hashAddByte(sum, SeparatorByte)
+	}
+	return sum
+}
+
+// SignatureWithoutLabels works like LabelsToSignature but takes a Metric as
+// parameter (rather than a label map) and excludes the labels with any of the
+// specified LabelNames from the signature calculation.
+func SignatureWithoutLabels(m Metric, labels map[LabelName]struct{}) uint64 {
+	if len(m) == 0 {
+		return emptyLabelSignature
+	}
+
+	labelNames := make(LabelNames, 0, len(m))
+	for labelName := range m {
+		if _, exclude := labels[labelName]; !exclude {
+			labelNames = append(labelNames, labelName)
+		}
+	}
+	if len(labelNames) == 0 {
+		return emptyLabelSignature
+	}
+	sort.Sort(labelNames)
+
+	sum := hashNew()
+	for _, labelName := range labelNames {
+		sum = hashAdd(sum, string(labelName))
+		sum = hashAddByte(sum, SeparatorByte)
+		sum = hashAdd(sum, string(m[labelName]))
+		sum = hashAddByte(sum, SeparatorByte)
+	}
+	return sum
+}
diff --git a/vendor/github.com/prometheus/common/model/silence.go b/vendor/github.com/prometheus/common/model/silence.go
new file mode 100644
index 00000000..7538e299
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/silence.go
@@ -0,0 +1,106 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+import (
+	"encoding/json"
+	"fmt"
+	"regexp"
+	"time"
+)
+
+// Matcher describes a matches the value of a given label.
+type Matcher struct {
+	Name    LabelName `json:"name"`
+	Value   string    `json:"value"`
+	IsRegex bool      `json:"isRegex"`
+}
+
+func (m *Matcher) UnmarshalJSON(b []byte) error {
+	type plain Matcher
+	if err := json.Unmarshal(b, (*plain)(m)); err != nil {
+		return err
+	}
+
+	if len(m.Name) == 0 {
+		return fmt.Errorf("label name in matcher must not be empty")
+	}
+	if m.IsRegex {
+		if _, err := regexp.Compile(m.Value); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Validate returns true iff all fields of the matcher have valid values.
+func (m *Matcher) Validate() error {
+	if !m.Name.IsValid() {
+		return fmt.Errorf("invalid name %q", m.Name)
+	}
+	if m.IsRegex {
+		if _, err := regexp.Compile(m.Value); err != nil {
+			return fmt.Errorf("invalid regular expression %q", m.Value)
+		}
+	} else if !LabelValue(m.Value).IsValid() || len(m.Value) == 0 {
+		return fmt.Errorf("invalid value %q", m.Value)
+	}
+	return nil
+}
+
+// Silence defines the representation of a silence definiton
+// in the Prometheus eco-system.
+type Silence struct {
+	ID uint64 `json:"id,omitempty"`
+
+	Matchers []*Matcher `json:"matchers"`
+
+	StartsAt time.Time `json:"startsAt"`
+	EndsAt   time.Time `json:"endsAt"`
+
+	CreatedAt time.Time `json:"createdAt,omitempty"`
+	CreatedBy string    `json:"createdBy"`
+	Comment   string    `json:"comment,omitempty"`
+}
+
+// Validate returns true iff all fields of the silence have valid values.
+func (s *Silence) Validate() error {
+	if len(s.Matchers) == 0 {
+		return fmt.Errorf("at least one matcher required")
+	}
+	for _, m := range s.Matchers {
+		if err := m.Validate(); err != nil {
+			return fmt.Errorf("invalid matcher: %s", err)
+		}
+	}
+	if s.StartsAt.IsZero() {
+		return fmt.Errorf("start time missing")
+	}
+	if s.EndsAt.IsZero() {
+		return fmt.Errorf("end time missing")
+	}
+	if s.EndsAt.Before(s.StartsAt) {
+		return fmt.Errorf("start time must be before end time")
+	}
+	if s.CreatedBy == "" {
+		return fmt.Errorf("creator information missing")
+	}
+	if s.Comment == "" {
+		return fmt.Errorf("comment missing")
+	}
+	if s.CreatedAt.IsZero() {
+		return fmt.Errorf("creation timestamp missing")
+	}
+	return nil
+}
diff --git a/vendor/github.com/prometheus/common/model/time.go b/vendor/github.com/prometheus/common/model/time.go
new file mode 100644
index 00000000..548968ae
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/time.go
@@ -0,0 +1,249 @@
+// Copyright 2013 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+import (
+	"fmt"
+	"math"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const (
+	// MinimumTick is the minimum supported time resolution. This has to be
+	// at least time.Second in order for the code below to work.
+	minimumTick = time.Millisecond
+	// second is the Time duration equivalent to one second.
+	second = int64(time.Second / minimumTick)
+	// The number of nanoseconds per minimum tick.
+	nanosPerTick = int64(minimumTick / time.Nanosecond)
+
+	// Earliest is the earliest Time representable. Handy for
+	// initializing a high watermark.
+	Earliest = Time(math.MinInt64)
+	// Latest is the latest Time representable. Handy for initializing
+	// a low watermark.
+	Latest = Time(math.MaxInt64)
+)
+
+// Time is the number of milliseconds since the epoch
+// (1970-01-01 00:00 UTC) excluding leap seconds.
+type Time int64
+
+// Interval describes and interval between two timestamps.
+type Interval struct {
+	Start, End Time
+}
+
+// Now returns the current time as a Time.
+func Now() Time {
+	return TimeFromUnixNano(time.Now().UnixNano())
+}
+
+// TimeFromUnix returns the Time equivalent to the Unix Time t
+// provided in seconds.
+func TimeFromUnix(t int64) Time {
+	return Time(t * second)
+}
+
+// TimeFromUnixNano returns the Time equivalent to the Unix Time
+// t provided in nanoseconds.
+func TimeFromUnixNano(t int64) Time {
+	return Time(t / nanosPerTick)
+}
+
+// Equal reports whether two Times represent the same instant.
+func (t Time) Equal(o Time) bool {
+	return t == o
+}
+
+// Before reports whether the Time t is before o.
+func (t Time) Before(o Time) bool {
+	return t < o
+}
+
+// After reports whether the Time t is after o.
+func (t Time) After(o Time) bool {
+	return t > o
+}
+
+// Add returns the Time t + d.
+func (t Time) Add(d time.Duration) Time {
+	return t + Time(d/minimumTick)
+}
+
+// Sub returns the Duration t - o.
+func (t Time) Sub(o Time) time.Duration {
+	return time.Duration(t-o) * minimumTick
+}
+
+// Time returns the time.Time representation of t.
+func (t Time) Time() time.Time {
+	return time.Unix(int64(t)/second, (int64(t)%second)*nanosPerTick)
+}
+
+// Unix returns t as a Unix time, the number of seconds elapsed
+// since January 1, 1970 UTC.
+func (t Time) Unix() int64 {
+	return int64(t) / second
+}
+
+// UnixNano returns t as a Unix time, the number of nanoseconds elapsed
+// since January 1, 1970 UTC.
+func (t Time) UnixNano() int64 {
+	return int64(t) * nanosPerTick
+}
+
+// The number of digits after the dot.
+var dotPrecision = int(math.Log10(float64(second)))
+
+// String returns a string representation of the Time.
+func (t Time) String() string {
+	return strconv.FormatFloat(float64(t)/float64(second), 'f', -1, 64)
+}
+
+// MarshalJSON implements the json.Marshaler interface.
+func (t Time) MarshalJSON() ([]byte, error) {
+	return []byte(t.String()), nil
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (t *Time) UnmarshalJSON(b []byte) error {
+	p := strings.Split(string(b), ".")
+	switch len(p) {
+	case 1:
+		v, err := strconv.ParseInt(string(p[0]), 10, 64)
+		if err != nil {
+			return err
+		}
+		*t = Time(v * second)
+
+	case 2:
+		v, err := strconv.ParseInt(string(p[0]), 10, 64)
+		if err != nil {
+			return err
+		}
+		v *= second
+
+		prec := dotPrecision - len(p[1])
+		if prec < 0 {
+			p[1] = p[1][:dotPrecision]
+		} else if prec > 0 {
+			p[1] = p[1] + strings.Repeat("0", prec)
+		}
+
+		va, err := strconv.ParseInt(p[1], 10, 32)
+		if err != nil {
+			return err
+		}
+
+		*t = Time(v + va)
+
+	default:
+		return fmt.Errorf("invalid time %q", string(b))
+	}
+	return nil
+}
+
+// Duration wraps time.Duration. It is used to parse the custom duration format
+// from YAML.
+// This type should not propagate beyond the scope of input/output processing.
+type Duration time.Duration
+
+var durationRE = regexp.MustCompile("^([0-9]+)(y|w|d|h|m|s|ms)$")
+
+// StringToDuration parses a string into a time.Duration, assuming that a year
+// always has 365d, a week always has 7d, and a day always has 24h.
+func ParseDuration(durationStr string) (Duration, error) {
+	matches := durationRE.FindStringSubmatch(durationStr)
+	if len(matches) != 3 {
+		return 0, fmt.Errorf("not a valid duration string: %q", durationStr)
+	}
+	var (
+		n, _ = strconv.Atoi(matches[1])
+		dur  = time.Duration(n) * time.Millisecond
+	)
+	switch unit := matches[2]; unit {
+	case "y":
+		dur *= 1000 * 60 * 60 * 24 * 365
+	case "w":
+		dur *= 1000 * 60 * 60 * 24 * 7
+	case "d":
+		dur *= 1000 * 60 * 60 * 24
+	case "h":
+		dur *= 1000 * 60 * 60
+	case "m":
+		dur *= 1000 * 60
+	case "s":
+		dur *= 1000
+	case "ms":
+		// Value already correct
+	default:
+		return 0, fmt.Errorf("invalid time unit in duration string: %q", unit)
+	}
+	return Duration(dur), nil
+}
+
+func (d Duration) String() string {
+	var (
+		ms   = int64(time.Duration(d) / time.Millisecond)
+		unit = "ms"
+	)
+	factors := map[string]int64{
+		"y":  1000 * 60 * 60 * 24 * 365,
+		"w":  1000 * 60 * 60 * 24 * 7,
+		"d":  1000 * 60 * 60 * 24,
+		"h":  1000 * 60 * 60,
+		"m":  1000 * 60,
+		"s":  1000,
+		"ms": 1,
+	}
+
+	switch int64(0) {
+	case ms % factors["y"]:
+		unit = "y"
+	case ms % factors["w"]:
+		unit = "w"
+	case ms % factors["d"]:
+		unit = "d"
+	case ms % factors["h"]:
+		unit = "h"
+	case ms % factors["m"]:
+		unit = "m"
+	case ms % factors["s"]:
+		unit = "s"
+	}
+	return fmt.Sprintf("%v%v", ms/factors[unit], unit)
+}
+
+// MarshalYAML implements the yaml.Marshaler interface.
+func (d Duration) MarshalYAML() (interface{}, error) {
+	return d.String(), nil
+}
+
+// UnmarshalYAML implements the yaml.Unmarshaler interface.
+func (d *Duration) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var s string
+	if err := unmarshal(&s); err != nil {
+		return err
+	}
+	dur, err := ParseDuration(s)
+	if err != nil {
+		return err
+	}
+	*d = dur
+	return nil
+}
diff --git a/vendor/github.com/prometheus/common/model/value.go b/vendor/github.com/prometheus/common/model/value.go
new file mode 100644
index 00000000..dbf5d10e
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/value.go
@@ -0,0 +1,403 @@
+// Copyright 2013 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package model
+
+import (
+	"encoding/json"
+	"fmt"
+	"math"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// A SampleValue is a representation of a value for a given sample at a given
+// time.
+type SampleValue float64
+
+// MarshalJSON implements json.Marshaler.
+func (v SampleValue) MarshalJSON() ([]byte, error) {
+	return json.Marshal(v.String())
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (v *SampleValue) UnmarshalJSON(b []byte) error {
+	if len(b) < 2 || b[0] != '"' || b[len(b)-1] != '"' {
+		return fmt.Errorf("sample value must be a quoted string")
+	}
+	f, err := strconv.ParseFloat(string(b[1:len(b)-1]), 64)
+	if err != nil {
+		return err
+	}
+	*v = SampleValue(f)
+	return nil
+}
+
+// Equal returns true if the value of v and o is equal or if both are NaN. Note
+// that v==o is false if both are NaN. If you want the conventional float
+// behavior, use == to compare two SampleValues.
+func (v SampleValue) Equal(o SampleValue) bool {
+	if v == o {
+		return true
+	}
+	return math.IsNaN(float64(v)) && math.IsNaN(float64(o))
+}
+
+func (v SampleValue) String() string {
+	return strconv.FormatFloat(float64(v), 'f', -1, 64)
+}
+
+// SamplePair pairs a SampleValue with a Timestamp.
+type SamplePair struct {
+	Timestamp Time
+	Value     SampleValue
+}
+
+// MarshalJSON implements json.Marshaler.
+func (s SamplePair) MarshalJSON() ([]byte, error) {
+	t, err := json.Marshal(s.Timestamp)
+	if err != nil {
+		return nil, err
+	}
+	v, err := json.Marshal(s.Value)
+	if err != nil {
+		return nil, err
+	}
+	return []byte(fmt.Sprintf("[%s,%s]", t, v)), nil
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (s *SamplePair) UnmarshalJSON(b []byte) error {
+	v := [...]json.Unmarshaler{&s.Timestamp, &s.Value}
+	return json.Unmarshal(b, &v)
+}
+
+// Equal returns true if this SamplePair and o have equal Values and equal
+// Timestamps. The sematics of Value equality is defined by SampleValue.Equal.
+func (s *SamplePair) Equal(o *SamplePair) bool {
+	return s == o || (s.Value.Equal(o.Value) && s.Timestamp.Equal(o.Timestamp))
+}
+
+func (s SamplePair) String() string {
+	return fmt.Sprintf("%s @[%s]", s.Value, s.Timestamp)
+}
+
+// Sample is a sample pair associated with a metric.
+type Sample struct {
+	Metric    Metric      `json:"metric"`
+	Value     SampleValue `json:"value"`
+	Timestamp Time        `json:"timestamp"`
+}
+
+// Equal compares first the metrics, then the timestamp, then the value. The
+// sematics of value equality is defined by SampleValue.Equal.
+func (s *Sample) Equal(o *Sample) bool {
+	if s == o {
+		return true
+	}
+
+	if !s.Metric.Equal(o.Metric) {
+		return false
+	}
+	if !s.Timestamp.Equal(o.Timestamp) {
+		return false
+	}
+	if s.Value.Equal(o.Value) {
+		return false
+	}
+
+	return true
+}
+
+func (s Sample) String() string {
+	return fmt.Sprintf("%s => %s", s.Metric, SamplePair{
+		Timestamp: s.Timestamp,
+		Value:     s.Value,
+	})
+}
+
+// MarshalJSON implements json.Marshaler.
+func (s Sample) MarshalJSON() ([]byte, error) {
+	v := struct {
+		Metric Metric     `json:"metric"`
+		Value  SamplePair `json:"value"`
+	}{
+		Metric: s.Metric,
+		Value: SamplePair{
+			Timestamp: s.Timestamp,
+			Value:     s.Value,
+		},
+	}
+
+	return json.Marshal(&v)
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (s *Sample) UnmarshalJSON(b []byte) error {
+	v := struct {
+		Metric Metric     `json:"metric"`
+		Value  SamplePair `json:"value"`
+	}{
+		Metric: s.Metric,
+		Value: SamplePair{
+			Timestamp: s.Timestamp,
+			Value:     s.Value,
+		},
+	}
+
+	if err := json.Unmarshal(b, &v); err != nil {
+		return err
+	}
+
+	s.Metric = v.Metric
+	s.Timestamp = v.Value.Timestamp
+	s.Value = v.Value.Value
+
+	return nil
+}
+
+// Samples is a sortable Sample slice. It implements sort.Interface.
+type Samples []*Sample
+
+func (s Samples) Len() int {
+	return len(s)
+}
+
+// Less compares first the metrics, then the timestamp.
+func (s Samples) Less(i, j int) bool {
+	switch {
+	case s[i].Metric.Before(s[j].Metric):
+		return true
+	case s[j].Metric.Before(s[i].Metric):
+		return false
+	case s[i].Timestamp.Before(s[j].Timestamp):
+		return true
+	default:
+		return false
+	}
+}
+
+func (s Samples) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+// Equal compares two sets of samples and returns true if they are equal.
+func (s Samples) Equal(o Samples) bool {
+	if len(s) != len(o) {
+		return false
+	}
+
+	for i, sample := range s {
+		if !sample.Equal(o[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// SampleStream is a stream of Values belonging to an attached COWMetric.
+type SampleStream struct {
+	Metric Metric       `json:"metric"`
+	Values []SamplePair `json:"values"`
+}
+
+func (ss SampleStream) String() string {
+	vals := make([]string, len(ss.Values))
+	for i, v := range ss.Values {
+		vals[i] = v.String()
+	}
+	return fmt.Sprintf("%s =>\n%s", ss.Metric, strings.Join(vals, "\n"))
+}
+
+// Value is a generic interface for values resulting from a query evaluation.
+type Value interface {
+	Type() ValueType
+	String() string
+}
+
+func (Matrix) Type() ValueType  { return ValMatrix }
+func (Vector) Type() ValueType  { return ValVector }
+func (*Scalar) Type() ValueType { return ValScalar }
+func (*String) Type() ValueType { return ValString }
+
+type ValueType int
+
+const (
+	ValNone ValueType = iota
+	ValScalar
+	ValVector
+	ValMatrix
+	ValString
+)
+
+// MarshalJSON implements json.Marshaler.
+func (et ValueType) MarshalJSON() ([]byte, error) {
+	return json.Marshal(et.String())
+}
+
+func (et *ValueType) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+	switch s {
+	case "<ValNone>":
+		*et = ValNone
+	case "scalar":
+		*et = ValScalar
+	case "vector":
+		*et = ValVector
+	case "matrix":
+		*et = ValMatrix
+	case "string":
+		*et = ValString
+	default:
+		return fmt.Errorf("unknown value type %q", s)
+	}
+	return nil
+}
+
+func (e ValueType) String() string {
+	switch e {
+	case ValNone:
+		return "<ValNone>"
+	case ValScalar:
+		return "scalar"
+	case ValVector:
+		return "vector"
+	case ValMatrix:
+		return "matrix"
+	case ValString:
+		return "string"
+	}
+	panic("ValueType.String: unhandled value type")
+}
+
+// Scalar is a scalar value evaluated at the set timestamp.
+type Scalar struct {
+	Value     SampleValue `json:"value"`
+	Timestamp Time        `json:"timestamp"`
+}
+
+func (s Scalar) String() string {
+	return fmt.Sprintf("scalar: %v @[%v]", s.Value, s.Timestamp)
+}
+
+// MarshalJSON implements json.Marshaler.
+func (s Scalar) MarshalJSON() ([]byte, error) {
+	v := strconv.FormatFloat(float64(s.Value), 'f', -1, 64)
+	return json.Marshal([...]interface{}{s.Timestamp, string(v)})
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (s *Scalar) UnmarshalJSON(b []byte) error {
+	var f string
+	v := [...]interface{}{&s.Timestamp, &f}
+
+	if err := json.Unmarshal(b, &v); err != nil {
+		return err
+	}
+
+	value, err := strconv.ParseFloat(f, 64)
+	if err != nil {
+		return fmt.Errorf("error parsing sample value: %s", err)
+	}
+	s.Value = SampleValue(value)
+	return nil
+}
+
+// String is a string value evaluated at the set timestamp.
+type String struct {
+	Value     string `json:"value"`
+	Timestamp Time   `json:"timestamp"`
+}
+
+func (s *String) String() string {
+	return s.Value
+}
+
+// MarshalJSON implements json.Marshaler.
+func (s String) MarshalJSON() ([]byte, error) {
+	return json.Marshal([]interface{}{s.Timestamp, s.Value})
+}
+
+// UnmarshalJSON implements json.Unmarshaler.
+func (s *String) UnmarshalJSON(b []byte) error {
+	v := [...]interface{}{&s.Timestamp, &s.Value}
+	return json.Unmarshal(b, &v)
+}
+
+// Vector is basically only an alias for Samples, but the
+// contract is that in a Vector, all Samples have the same timestamp.
+type Vector []*Sample
+
+func (vec Vector) String() string {
+	entries := make([]string, len(vec))
+	for i, s := range vec {
+		entries[i] = s.String()
+	}
+	return strings.Join(entries, "\n")
+}
+
+func (vec Vector) Len() int      { return len(vec) }
+func (vec Vector) Swap(i, j int) { vec[i], vec[j] = vec[j], vec[i] }
+
+// Less compares first the metrics, then the timestamp.
+func (vec Vector) Less(i, j int) bool {
+	switch {
+	case vec[i].Metric.Before(vec[j].Metric):
+		return true
+	case vec[j].Metric.Before(vec[i].Metric):
+		return false
+	case vec[i].Timestamp.Before(vec[j].Timestamp):
+		return true
+	default:
+		return false
+	}
+}
+
+// Equal compares two sets of samples and returns true if they are equal.
+func (vec Vector) Equal(o Vector) bool {
+	if len(vec) != len(o) {
+		return false
+	}
+
+	for i, sample := range vec {
+		if !sample.Equal(o[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// Matrix is a list of time series.
+type Matrix []*SampleStream
+
+func (m Matrix) Len() int           { return len(m) }
+func (m Matrix) Less(i, j int) bool { return m[i].Metric.Before(m[j].Metric) }
+func (m Matrix) Swap(i, j int)      { m[i], m[j] = m[j], m[i] }
+
+func (mat Matrix) String() string {
+	matCp := make(Matrix, len(mat))
+	copy(matCp, mat)
+	sort.Sort(matCp)
+
+	strs := make([]string, len(matCp))
+
+	for i, ss := range matCp {
+		strs[i] = ss.String()
+	}
+
+	return strings.Join(strs, "\n")
+}
diff --git a/vendor/github.com/prometheus/procfs/.travis.yml b/vendor/github.com/prometheus/procfs/.travis.yml
new file mode 100644
index 00000000..2b4554da
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/.travis.yml
@@ -0,0 +1,5 @@
+sudo: false
+language: go
+go:
+    - 1.5
+    - 1.6
diff --git a/vendor/github.com/prometheus/procfs/AUTHORS.md b/vendor/github.com/prometheus/procfs/AUTHORS.md
new file mode 100644
index 00000000..0c802dd8
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/AUTHORS.md
@@ -0,0 +1,20 @@
+The Prometheus project was started by Matt T. Proud (emeritus) and
+Julius Volz in 2012.
+
+Maintainers of this repository:
+
+* Tobias Schmidt <ts@soundcloud.com>
+
+The following individuals have contributed code to this repository
+(listed in alphabetical order):
+
+* Armen Baghumian <abaghumian@noggin.com.au>
+* Bjoern Rabenstein <beorn@soundcloud.com>
+* David Cournapeau <cournape@gmail.com>
+* Ji-Hoon, Seol <jihoon.seol@gmail.com>
+* Jonas Große Sundrup <cherti@letopolis.de>
+* Julius Volz <julius.volz@gmail.com>
+* Matthias Rampke <mr@soundcloud.com>
+* Nicky Gerritsen <nicky@streamone.nl>
+* Rémi Audebert <contact@halfr.net>
+* Tobias Schmidt <tobidt@gmail.com>
diff --git a/vendor/github.com/prometheus/procfs/CONTRIBUTING.md b/vendor/github.com/prometheus/procfs/CONTRIBUTING.md
new file mode 100644
index 00000000..5705f0fb
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/CONTRIBUTING.md
@@ -0,0 +1,18 @@
+# Contributing
+
+Prometheus uses GitHub to manage reviews of pull requests.
+
+* If you have a trivial fix or improvement, go ahead and create a pull
+  request, addressing (with `@...`) one or more of the maintainers
+  (see [AUTHORS.md](AUTHORS.md)) in the description of the pull request.
+
+* If you plan to do something more involved, first discuss your ideas
+  on our [mailing list](https://groups.google.com/forum/?fromgroups#!forum/prometheus-developers).
+  This will avoid unnecessary work and surely give you and us a good deal
+  of inspiration.
+
+* Relevant coding style guidelines are the [Go Code Review
+  Comments](https://code.google.com/p/go-wiki/wiki/CodeReviewComments)
+  and the _Formatting and style_ section of Peter Bourgon's [Go: Best
+  Practices for Production
+  Environments](http://peter.bourgon.org/go-in-production/#formatting-and-style).
diff --git a/vendor/github.com/prometheus/procfs/LICENSE b/vendor/github.com/prometheus/procfs/LICENSE
new file mode 100644
index 00000000..261eeb9e
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/LICENSE
@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/vendor/github.com/prometheus/procfs/Makefile b/vendor/github.com/prometheus/procfs/Makefile
new file mode 100644
index 00000000..c264a49d
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/Makefile
@@ -0,0 +1,6 @@
+ci:
+	! gofmt -l *.go | read nothing
+	go vet
+	go test -v ./...
+	go get github.com/golang/lint/golint
+	golint *.go
diff --git a/vendor/github.com/prometheus/procfs/NOTICE b/vendor/github.com/prometheus/procfs/NOTICE
new file mode 100644
index 00000000..53c5e9aa
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/NOTICE
@@ -0,0 +1,7 @@
+procfs provides functions to retrieve system, kernel and process
+metrics from the pseudo-filesystem proc.
+
+Copyright 2014-2015 The Prometheus Authors
+
+This product includes software developed at
+SoundCloud Ltd. (http://soundcloud.com/).
diff --git a/vendor/github.com/prometheus/procfs/README.md b/vendor/github.com/prometheus/procfs/README.md
new file mode 100644
index 00000000..6e7ee6b8
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/README.md
@@ -0,0 +1,10 @@
+# procfs
+
+This procfs package provides functions to retrieve system, kernel and process
+metrics from the pseudo-filesystem proc.
+
+*WARNING*: This package is a work in progress. Its API may still break in
+backwards-incompatible ways without warnings. Use it at your own risk.
+
+[![GoDoc](https://godoc.org/github.com/prometheus/procfs?status.png)](https://godoc.org/github.com/prometheus/procfs)
+[![Build Status](https://travis-ci.org/prometheus/procfs.svg?branch=master)](https://travis-ci.org/prometheus/procfs)
diff --git a/vendor/github.com/prometheus/procfs/doc.go b/vendor/github.com/prometheus/procfs/doc.go
new file mode 100644
index 00000000..e2acd6d4
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/doc.go
@@ -0,0 +1,45 @@
+// Copyright 2014 Prometheus Team
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package procfs provides functions to retrieve system, kernel and process
+// metrics from the pseudo-filesystem proc.
+//
+// Example:
+//
+//    package main
+//
+//    import (
+//    	"fmt"
+//    	"log"
+//
+//    	"github.com/prometheus/procfs"
+//    )
+//
+//    func main() {
+//    	p, err := procfs.Self()
+//    	if err != nil {
+//    		log.Fatalf("could not get process: %s", err)
+//    	}
+//
+//    	stat, err := p.NewStat()
+//    	if err != nil {
+//    		log.Fatalf("could not get process stat: %s", err)
+//    	}
+//
+//    	fmt.Printf("command:  %s\n", stat.Comm)
+//    	fmt.Printf("cpu time: %fs\n", stat.CPUTime())
+//    	fmt.Printf("vsize:    %dB\n", stat.VirtualMemory())
+//    	fmt.Printf("rss:      %dB\n", stat.ResidentMemory())
+//    }
+//
+package procfs
diff --git a/vendor/github.com/prometheus/procfs/fs.go b/vendor/github.com/prometheus/procfs/fs.go
new file mode 100644
index 00000000..49aaab05
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/fs.go
@@ -0,0 +1,33 @@
+package procfs
+
+import (
+	"fmt"
+	"os"
+	"path"
+)
+
+// FS represents the pseudo-filesystem proc, which provides an interface to
+// kernel data structures.
+type FS string
+
+// DefaultMountPoint is the common mount point of the proc filesystem.
+const DefaultMountPoint = "/proc"
+
+// NewFS returns a new FS mounted under the given mountPoint. It will error
+// if the mount point can't be read.
+func NewFS(mountPoint string) (FS, error) {
+	info, err := os.Stat(mountPoint)
+	if err != nil {
+		return "", fmt.Errorf("could not read %s: %s", mountPoint, err)
+	}
+	if !info.IsDir() {
+		return "", fmt.Errorf("mount point %s is not a directory", mountPoint)
+	}
+
+	return FS(mountPoint), nil
+}
+
+// Path returns the path of the given subsystem relative to the procfs root.
+func (fs FS) Path(p ...string) string {
+	return path.Join(append([]string{string(fs)}, p...)...)
+}
diff --git a/vendor/github.com/prometheus/procfs/ipvs.go b/vendor/github.com/prometheus/procfs/ipvs.go
new file mode 100644
index 00000000..e7012f73
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/ipvs.go
@@ -0,0 +1,224 @@
+package procfs
+
+import (
+	"bufio"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// IPVSStats holds IPVS statistics, as exposed by the kernel in `/proc/net/ip_vs_stats`.
+type IPVSStats struct {
+	// Total count of connections.
+	Connections uint64
+	// Total incoming packages processed.
+	IncomingPackets uint64
+	// Total outgoing packages processed.
+	OutgoingPackets uint64
+	// Total incoming traffic.
+	IncomingBytes uint64
+	// Total outgoing traffic.
+	OutgoingBytes uint64
+}
+
+// IPVSBackendStatus holds current metrics of one virtual / real address pair.
+type IPVSBackendStatus struct {
+	// The local (virtual) IP address.
+	LocalAddress net.IP
+	// The local (virtual) port.
+	LocalPort uint16
+	// The transport protocol (TCP, UDP).
+	Proto string
+	// The remote (real) IP address.
+	RemoteAddress net.IP
+	// The remote (real) port.
+	RemotePort uint16
+	// The current number of active connections for this virtual/real address pair.
+	ActiveConn uint64
+	// The current number of inactive connections for this virtual/real address pair.
+	InactConn uint64
+	// The current weight of this virtual/real address pair.
+	Weight uint64
+}
+
+// NewIPVSStats reads the IPVS statistics.
+func NewIPVSStats() (IPVSStats, error) {
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+
+	return fs.NewIPVSStats()
+}
+
+// NewIPVSStats reads the IPVS statistics from the specified `proc` filesystem.
+func (fs FS) NewIPVSStats() (IPVSStats, error) {
+	file, err := os.Open(fs.Path("net/ip_vs_stats"))
+	if err != nil {
+		return IPVSStats{}, err
+	}
+	defer file.Close()
+
+	return parseIPVSStats(file)
+}
+
+// parseIPVSStats performs the actual parsing of `ip_vs_stats`.
+func parseIPVSStats(file io.Reader) (IPVSStats, error) {
+	var (
+		statContent []byte
+		statLines   []string
+		statFields  []string
+		stats       IPVSStats
+	)
+
+	statContent, err := ioutil.ReadAll(file)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+
+	statLines = strings.SplitN(string(statContent), "\n", 4)
+	if len(statLines) != 4 {
+		return IPVSStats{}, errors.New("ip_vs_stats corrupt: too short")
+	}
+
+	statFields = strings.Fields(statLines[2])
+	if len(statFields) != 5 {
+		return IPVSStats{}, errors.New("ip_vs_stats corrupt: unexpected number of fields")
+	}
+
+	stats.Connections, err = strconv.ParseUint(statFields[0], 16, 64)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+	stats.IncomingPackets, err = strconv.ParseUint(statFields[1], 16, 64)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+	stats.OutgoingPackets, err = strconv.ParseUint(statFields[2], 16, 64)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+	stats.IncomingBytes, err = strconv.ParseUint(statFields[3], 16, 64)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+	stats.OutgoingBytes, err = strconv.ParseUint(statFields[4], 16, 64)
+	if err != nil {
+		return IPVSStats{}, err
+	}
+
+	return stats, nil
+}
+
+// NewIPVSBackendStatus reads and returns the status of all (virtual,real) server pairs.
+func NewIPVSBackendStatus() ([]IPVSBackendStatus, error) {
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return []IPVSBackendStatus{}, err
+	}
+
+	return fs.NewIPVSBackendStatus()
+}
+
+// NewIPVSBackendStatus reads and returns the status of all (virtual,real) server pairs from the specified `proc` filesystem.
+func (fs FS) NewIPVSBackendStatus() ([]IPVSBackendStatus, error) {
+	file, err := os.Open(fs.Path("net/ip_vs"))
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	return parseIPVSBackendStatus(file)
+}
+
+func parseIPVSBackendStatus(file io.Reader) ([]IPVSBackendStatus, error) {
+	var (
+		status       []IPVSBackendStatus
+		scanner      = bufio.NewScanner(file)
+		proto        string
+		localAddress net.IP
+		localPort    uint16
+		err          error
+	)
+
+	for scanner.Scan() {
+		fields := strings.Fields(string(scanner.Text()))
+		if len(fields) == 0 {
+			continue
+		}
+		switch {
+		case fields[0] == "IP" || fields[0] == "Prot" || fields[1] == "RemoteAddress:Port":
+			continue
+		case fields[0] == "TCP" || fields[0] == "UDP":
+			if len(fields) < 2 {
+				continue
+			}
+			proto = fields[0]
+			localAddress, localPort, err = parseIPPort(fields[1])
+			if err != nil {
+				return nil, err
+			}
+		case fields[0] == "->":
+			if len(fields) < 6 {
+				continue
+			}
+			remoteAddress, remotePort, err := parseIPPort(fields[1])
+			if err != nil {
+				return nil, err
+			}
+			weight, err := strconv.ParseUint(fields[3], 10, 64)
+			if err != nil {
+				return nil, err
+			}
+			activeConn, err := strconv.ParseUint(fields[4], 10, 64)
+			if err != nil {
+				return nil, err
+			}
+			inactConn, err := strconv.ParseUint(fields[5], 10, 64)
+			if err != nil {
+				return nil, err
+			}
+			status = append(status, IPVSBackendStatus{
+				LocalAddress:  localAddress,
+				LocalPort:     localPort,
+				RemoteAddress: remoteAddress,
+				RemotePort:    remotePort,
+				Proto:         proto,
+				Weight:        weight,
+				ActiveConn:    activeConn,
+				InactConn:     inactConn,
+			})
+		}
+	}
+	return status, nil
+}
+
+func parseIPPort(s string) (net.IP, uint16, error) {
+	tmp := strings.SplitN(s, ":", 2)
+
+	if len(tmp) != 2 {
+		return nil, 0, fmt.Errorf("invalid IP:Port: %s", s)
+	}
+
+	if len(tmp[0]) != 8 && len(tmp[0]) != 32 {
+		return nil, 0, fmt.Errorf("invalid IP: %s", tmp[0])
+	}
+
+	ip, err := hex.DecodeString(tmp[0])
+	if err != nil {
+		return nil, 0, err
+	}
+
+	port, err := strconv.ParseUint(tmp[1], 16, 16)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	return ip, uint16(port), nil
+}
diff --git a/vendor/github.com/prometheus/procfs/mdstat.go b/vendor/github.com/prometheus/procfs/mdstat.go
new file mode 100644
index 00000000..d7a248c0
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/mdstat.go
@@ -0,0 +1,138 @@
+package procfs
+
+import (
+	"fmt"
+	"io/ioutil"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+var (
+	statuslineRE = regexp.MustCompile(`(\d+) blocks .*\[(\d+)/(\d+)\] \[[U_]+\]`)
+	buildlineRE  = regexp.MustCompile(`\((\d+)/\d+\)`)
+)
+
+// MDStat holds info parsed from /proc/mdstat.
+type MDStat struct {
+	// Name of the device.
+	Name string
+	// activity-state of the device.
+	ActivityState string
+	// Number of active disks.
+	DisksActive int64
+	// Total number of disks the device consists of.
+	DisksTotal int64
+	// Number of blocks the device holds.
+	BlocksTotal int64
+	// Number of blocks on the device that are in sync.
+	BlocksSynced int64
+}
+
+// ParseMDStat parses an mdstat-file and returns a struct with the relevant infos.
+func (fs FS) ParseMDStat() (mdstates []MDStat, err error) {
+	mdStatusFilePath := fs.Path("mdstat")
+	content, err := ioutil.ReadFile(mdStatusFilePath)
+	if err != nil {
+		return []MDStat{}, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
+	}
+
+	mdStates := []MDStat{}
+	lines := strings.Split(string(content), "\n")
+	for i, l := range lines {
+		if l == "" {
+			continue
+		}
+		if l[0] == ' ' {
+			continue
+		}
+		if strings.HasPrefix(l, "Personalities") || strings.HasPrefix(l, "unused") {
+			continue
+		}
+
+		mainLine := strings.Split(l, " ")
+		if len(mainLine) < 3 {
+			return mdStates, fmt.Errorf("error parsing mdline: %s", l)
+		}
+		mdName := mainLine[0]
+		activityState := mainLine[2]
+
+		if len(lines) <= i+3 {
+			return mdStates, fmt.Errorf(
+				"error parsing %s: too few lines for md device %s",
+				mdStatusFilePath,
+				mdName,
+			)
+		}
+
+		active, total, size, err := evalStatusline(lines[i+1])
+		if err != nil {
+			return mdStates, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
+		}
+
+		// j is the line number of the syncing-line.
+		j := i + 2
+		if strings.Contains(lines[i+2], "bitmap") { // skip bitmap line
+			j = i + 3
+		}
+
+		// If device is syncing at the moment, get the number of currently
+		// synced bytes, otherwise that number equals the size of the device.
+		syncedBlocks := size
+		if strings.Contains(lines[j], "recovery") || strings.Contains(lines[j], "resync") {
+			syncedBlocks, err = evalBuildline(lines[j])
+			if err != nil {
+				return mdStates, fmt.Errorf("error parsing %s: %s", mdStatusFilePath, err)
+			}
+		}
+
+		mdStates = append(mdStates, MDStat{
+			Name:          mdName,
+			ActivityState: activityState,
+			DisksActive:   active,
+			DisksTotal:    total,
+			BlocksTotal:   size,
+			BlocksSynced:  syncedBlocks,
+		})
+	}
+
+	return mdStates, nil
+}
+
+func evalStatusline(statusline string) (active, total, size int64, err error) {
+	matches := statuslineRE.FindStringSubmatch(statusline)
+	if len(matches) != 4 {
+		return 0, 0, 0, fmt.Errorf("unexpected statusline: %s", statusline)
+	}
+
+	size, err = strconv.ParseInt(matches[1], 10, 64)
+	if err != nil {
+		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
+	}
+
+	total, err = strconv.ParseInt(matches[2], 10, 64)
+	if err != nil {
+		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
+	}
+
+	active, err = strconv.ParseInt(matches[3], 10, 64)
+	if err != nil {
+		return 0, 0, 0, fmt.Errorf("unexpected statusline %s: %s", statusline, err)
+	}
+
+	return active, total, size, nil
+}
+
+func evalBuildline(buildline string) (syncedBlocks int64, err error) {
+	matches := buildlineRE.FindStringSubmatch(buildline)
+	if len(matches) != 2 {
+		return 0, fmt.Errorf("unexpected buildline: %s", buildline)
+	}
+
+	syncedBlocks, err = strconv.ParseInt(matches[1], 10, 64)
+	if err != nil {
+		return 0, fmt.Errorf("%s in buildline: %s", err, buildline)
+	}
+
+	return syncedBlocks, nil
+}
diff --git a/vendor/github.com/prometheus/procfs/proc.go b/vendor/github.com/prometheus/procfs/proc.go
new file mode 100644
index 00000000..0d0a6a90
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/proc.go
@@ -0,0 +1,212 @@
+package procfs
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// Proc provides information about a running process.
+type Proc struct {
+	// The process ID.
+	PID int
+
+	fs FS
+}
+
+// Procs represents a list of Proc structs.
+type Procs []Proc
+
+func (p Procs) Len() int           { return len(p) }
+func (p Procs) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
+func (p Procs) Less(i, j int) bool { return p[i].PID < p[j].PID }
+
+// Self returns a process for the current process read via /proc/self.
+func Self() (Proc, error) {
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return Proc{}, err
+	}
+	return fs.Self()
+}
+
+// NewProc returns a process for the given pid under /proc.
+func NewProc(pid int) (Proc, error) {
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return Proc{}, err
+	}
+	return fs.NewProc(pid)
+}
+
+// AllProcs returns a list of all currently available processes under /proc.
+func AllProcs() (Procs, error) {
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return Procs{}, err
+	}
+	return fs.AllProcs()
+}
+
+// Self returns a process for the current process.
+func (fs FS) Self() (Proc, error) {
+	p, err := os.Readlink(fs.Path("self"))
+	if err != nil {
+		return Proc{}, err
+	}
+	pid, err := strconv.Atoi(strings.Replace(p, string(fs), "", -1))
+	if err != nil {
+		return Proc{}, err
+	}
+	return fs.NewProc(pid)
+}
+
+// NewProc returns a process for the given pid.
+func (fs FS) NewProc(pid int) (Proc, error) {
+	if _, err := os.Stat(fs.Path(strconv.Itoa(pid))); err != nil {
+		return Proc{}, err
+	}
+	return Proc{PID: pid, fs: fs}, nil
+}
+
+// AllProcs returns a list of all currently available processes.
+func (fs FS) AllProcs() (Procs, error) {
+	d, err := os.Open(fs.Path())
+	if err != nil {
+		return Procs{}, err
+	}
+	defer d.Close()
+
+	names, err := d.Readdirnames(-1)
+	if err != nil {
+		return Procs{}, fmt.Errorf("could not read %s: %s", d.Name(), err)
+	}
+
+	p := Procs{}
+	for _, n := range names {
+		pid, err := strconv.ParseInt(n, 10, 64)
+		if err != nil {
+			continue
+		}
+		p = append(p, Proc{PID: int(pid), fs: fs})
+	}
+
+	return p, nil
+}
+
+// CmdLine returns the command line of a process.
+func (p Proc) CmdLine() ([]string, error) {
+	f, err := os.Open(p.path("cmdline"))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(data) < 1 {
+		return []string{}, nil
+	}
+
+	return strings.Split(string(data[:len(data)-1]), string(byte(0))), nil
+}
+
+// Comm returns the command name of a process.
+func (p Proc) Comm() (string, error) {
+	f, err := os.Open(p.path("comm"))
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		return "", err
+	}
+
+	return strings.TrimSpace(string(data)), nil
+}
+
+// Executable returns the absolute path of the executable command of a process.
+func (p Proc) Executable() (string, error) {
+	exe, err := os.Readlink(p.path("exe"))
+	if os.IsNotExist(err) {
+		return "", nil
+	}
+
+	return exe, err
+}
+
+// FileDescriptors returns the currently open file descriptors of a process.
+func (p Proc) FileDescriptors() ([]uintptr, error) {
+	names, err := p.fileDescriptors()
+	if err != nil {
+		return nil, err
+	}
+
+	fds := make([]uintptr, len(names))
+	for i, n := range names {
+		fd, err := strconv.ParseInt(n, 10, 32)
+		if err != nil {
+			return nil, fmt.Errorf("could not parse fd %s: %s", n, err)
+		}
+		fds[i] = uintptr(fd)
+	}
+
+	return fds, nil
+}
+
+// FileDescriptorTargets returns the targets of all file descriptors of a process.
+// If a file descriptor is not a symlink to a file (like a socket), that value will be the empty string.
+func (p Proc) FileDescriptorTargets() ([]string, error) {
+	names, err := p.fileDescriptors()
+	if err != nil {
+		return nil, err
+	}
+
+	targets := make([]string, len(names))
+
+	for i, name := range names {
+		target, err := os.Readlink(p.path("fd", name))
+		if err == nil {
+			targets[i] = target
+		}
+	}
+
+	return targets, nil
+}
+
+// FileDescriptorsLen returns the number of currently open file descriptors of
+// a process.
+func (p Proc) FileDescriptorsLen() (int, error) {
+	fds, err := p.fileDescriptors()
+	if err != nil {
+		return 0, err
+	}
+
+	return len(fds), nil
+}
+
+func (p Proc) fileDescriptors() ([]string, error) {
+	d, err := os.Open(p.path("fd"))
+	if err != nil {
+		return nil, err
+	}
+	defer d.Close()
+
+	names, err := d.Readdirnames(-1)
+	if err != nil {
+		return nil, fmt.Errorf("could not read %s: %s", d.Name(), err)
+	}
+
+	return names, nil
+}
+
+func (p Proc) path(pa ...string) string {
+	return p.fs.Path(append([]string{strconv.Itoa(p.PID)}, pa...)...)
+}
diff --git a/vendor/github.com/prometheus/procfs/proc_io.go b/vendor/github.com/prometheus/procfs/proc_io.go
new file mode 100644
index 00000000..b4e31d7b
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/proc_io.go
@@ -0,0 +1,55 @@
+package procfs
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+)
+
+// ProcIO models the content of /proc/<pid>/io.
+type ProcIO struct {
+	// Chars read.
+	RChar uint64
+	// Chars written.
+	WChar uint64
+	// Read syscalls.
+	SyscR uint64
+	// Write syscalls.
+	SyscW uint64
+	// Bytes read.
+	ReadBytes uint64
+	// Bytes written.
+	WriteBytes uint64
+	// Bytes written, but taking into account truncation. See
+	// Documentation/filesystems/proc.txt in the kernel sources for
+	// detailed explanation.
+	CancelledWriteBytes int64
+}
+
+// NewIO creates a new ProcIO instance from a given Proc instance.
+func (p Proc) NewIO() (ProcIO, error) {
+	pio := ProcIO{}
+
+	f, err := os.Open(p.path("io"))
+	if err != nil {
+		return pio, err
+	}
+	defer f.Close()
+
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		return pio, err
+	}
+
+	ioFormat := "rchar: %d\nwchar: %d\nsyscr: %d\nsyscw: %d\n" +
+		"read_bytes: %d\nwrite_bytes: %d\n" +
+		"cancelled_write_bytes: %d\n"
+
+	_, err = fmt.Sscanf(string(data), ioFormat, &pio.RChar, &pio.WChar, &pio.SyscR,
+		&pio.SyscW, &pio.ReadBytes, &pio.WriteBytes, &pio.CancelledWriteBytes)
+	if err != nil {
+		return pio, err
+	}
+
+	return pio, nil
+}
diff --git a/vendor/github.com/prometheus/procfs/proc_limits.go b/vendor/github.com/prometheus/procfs/proc_limits.go
new file mode 100644
index 00000000..2df997ce
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/proc_limits.go
@@ -0,0 +1,137 @@
+package procfs
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"regexp"
+	"strconv"
+)
+
+// ProcLimits represents the soft limits for each of the process's resource
+// limits. For more information see getrlimit(2):
+// http://man7.org/linux/man-pages/man2/getrlimit.2.html.
+type ProcLimits struct {
+	// CPU time limit in seconds.
+	CPUTime int
+	// Maximum size of files that the process may create.
+	FileSize int
+	// Maximum size of the process's data segment (initialized data,
+	// uninitialized data, and heap).
+	DataSize int
+	// Maximum size of the process stack in bytes.
+	StackSize int
+	// Maximum size of a core file.
+	CoreFileSize int
+	// Limit of the process's resident set in pages.
+	ResidentSet int
+	// Maximum number of processes that can be created for the real user ID of
+	// the calling process.
+	Processes int
+	// Value one greater than the maximum file descriptor number that can be
+	// opened by this process.
+	OpenFiles int
+	// Maximum number of bytes of memory that may be locked into RAM.
+	LockedMemory int
+	// Maximum size of the process's virtual memory address space in bytes.
+	AddressSpace int
+	// Limit on the combined number of flock(2) locks and fcntl(2) leases that
+	// this process may establish.
+	FileLocks int
+	// Limit of signals that may be queued for the real user ID of the calling
+	// process.
+	PendingSignals int
+	// Limit on the number of bytes that can be allocated for POSIX message
+	// queues for the real user ID of the calling process.
+	MsqqueueSize int
+	// Limit of the nice priority set using setpriority(2) or nice(2).
+	NicePriority int
+	// Limit of the real-time priority set using sched_setscheduler(2) or
+	// sched_setparam(2).
+	RealtimePriority int
+	// Limit (in microseconds) on the amount of CPU time that a process
+	// scheduled under a real-time scheduling policy may consume without making
+	// a blocking system call.
+	RealtimeTimeout int
+}
+
+const (
+	limitsFields    = 3
+	limitsUnlimited = "unlimited"
+)
+
+var (
+	limitsDelimiter = regexp.MustCompile("  +")
+)
+
+// NewLimits returns the current soft limits of the process.
+func (p Proc) NewLimits() (ProcLimits, error) {
+	f, err := os.Open(p.path("limits"))
+	if err != nil {
+		return ProcLimits{}, err
+	}
+	defer f.Close()
+
+	var (
+		l = ProcLimits{}
+		s = bufio.NewScanner(f)
+	)
+	for s.Scan() {
+		fields := limitsDelimiter.Split(s.Text(), limitsFields)
+		if len(fields) != limitsFields {
+			return ProcLimits{}, fmt.Errorf(
+				"couldn't parse %s line %s", f.Name(), s.Text())
+		}
+
+		switch fields[0] {
+		case "Max cpu time":
+			l.CPUTime, err = parseInt(fields[1])
+		case "Max file size":
+			l.FileSize, err = parseInt(fields[1])
+		case "Max data size":
+			l.DataSize, err = parseInt(fields[1])
+		case "Max stack size":
+			l.StackSize, err = parseInt(fields[1])
+		case "Max core file size":
+			l.CoreFileSize, err = parseInt(fields[1])
+		case "Max resident set":
+			l.ResidentSet, err = parseInt(fields[1])
+		case "Max processes":
+			l.Processes, err = parseInt(fields[1])
+		case "Max open files":
+			l.OpenFiles, err = parseInt(fields[1])
+		case "Max locked memory":
+			l.LockedMemory, err = parseInt(fields[1])
+		case "Max address space":
+			l.AddressSpace, err = parseInt(fields[1])
+		case "Max file locks":
+			l.FileLocks, err = parseInt(fields[1])
+		case "Max pending signals":
+			l.PendingSignals, err = parseInt(fields[1])
+		case "Max msgqueue size":
+			l.MsqqueueSize, err = parseInt(fields[1])
+		case "Max nice priority":
+			l.NicePriority, err = parseInt(fields[1])
+		case "Max realtime priority":
+			l.RealtimePriority, err = parseInt(fields[1])
+		case "Max realtime timeout":
+			l.RealtimeTimeout, err = parseInt(fields[1])
+		}
+		if err != nil {
+			return ProcLimits{}, err
+		}
+	}
+
+	return l, s.Err()
+}
+
+func parseInt(s string) (int, error) {
+	if s == limitsUnlimited {
+		return -1, nil
+	}
+	i, err := strconv.ParseInt(s, 10, 32)
+	if err != nil {
+		return 0, fmt.Errorf("couldn't parse value %s: %s", s, err)
+	}
+	return int(i), nil
+}
diff --git a/vendor/github.com/prometheus/procfs/proc_stat.go b/vendor/github.com/prometheus/procfs/proc_stat.go
new file mode 100644
index 00000000..724e271b
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/proc_stat.go
@@ -0,0 +1,175 @@
+package procfs
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+)
+
+// Originally, this USER_HZ value was dynamically retrieved via a sysconf call
+// which required cgo. However, that caused a lot of problems regarding
+// cross-compilation. Alternatives such as running a binary to determine the
+// value, or trying to derive it in some other way were all problematic.  After
+// much research it was determined that USER_HZ is actually hardcoded to 100 on
+// all Go-supported platforms as of the time of this writing. This is why we
+// decided to hardcode it here as well. It is not impossible that there could
+// be systems with exceptions, but they should be very exotic edge cases, and
+// in that case, the worst outcome will be two misreported metrics.
+//
+// See also the following discussions:
+//
+// - https://github.com/prometheus/node_exporter/issues/52
+// - https://github.com/prometheus/procfs/pull/2
+// - http://stackoverflow.com/questions/17410841/how-does-user-hz-solve-the-jiffy-scaling-issue
+const userHZ = 100
+
+// ProcStat provides status information about the process,
+// read from /proc/[pid]/stat.
+type ProcStat struct {
+	// The process ID.
+	PID int
+	// The filename of the executable.
+	Comm string
+	// The process state.
+	State string
+	// The PID of the parent of this process.
+	PPID int
+	// The process group ID of the process.
+	PGRP int
+	// The session ID of the process.
+	Session int
+	// The controlling terminal of the process.
+	TTY int
+	// The ID of the foreground process group of the controlling terminal of
+	// the process.
+	TPGID int
+	// The kernel flags word of the process.
+	Flags uint
+	// The number of minor faults the process has made which have not required
+	// loading a memory page from disk.
+	MinFlt uint
+	// The number of minor faults that the process's waited-for children have
+	// made.
+	CMinFlt uint
+	// The number of major faults the process has made which have required
+	// loading a memory page from disk.
+	MajFlt uint
+	// The number of major faults that the process's waited-for children have
+	// made.
+	CMajFlt uint
+	// Amount of time that this process has been scheduled in user mode,
+	// measured in clock ticks.
+	UTime uint
+	// Amount of time that this process has been scheduled in kernel mode,
+	// measured in clock ticks.
+	STime uint
+	// Amount of time that this process's waited-for children have been
+	// scheduled in user mode, measured in clock ticks.
+	CUTime uint
+	// Amount of time that this process's waited-for children have been
+	// scheduled in kernel mode, measured in clock ticks.
+	CSTime uint
+	// For processes running a real-time scheduling policy, this is the negated
+	// scheduling priority, minus one.
+	Priority int
+	// The nice value, a value in the range 19 (low priority) to -20 (high
+	// priority).
+	Nice int
+	// Number of threads in this process.
+	NumThreads int
+	// The time the process started after system boot, the value is expressed
+	// in clock ticks.
+	Starttime uint64
+	// Virtual memory size in bytes.
+	VSize int
+	// Resident set size in pages.
+	RSS int
+
+	fs FS
+}
+
+// NewStat returns the current status information of the process.
+func (p Proc) NewStat() (ProcStat, error) {
+	f, err := os.Open(p.path("stat"))
+	if err != nil {
+		return ProcStat{}, err
+	}
+	defer f.Close()
+
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		return ProcStat{}, err
+	}
+
+	var (
+		ignore int
+
+		s = ProcStat{PID: p.PID, fs: p.fs}
+		l = bytes.Index(data, []byte("("))
+		r = bytes.LastIndex(data, []byte(")"))
+	)
+
+	if l < 0 || r < 0 {
+		return ProcStat{}, fmt.Errorf(
+			"unexpected format, couldn't extract comm: %s",
+			data,
+		)
+	}
+
+	s.Comm = string(data[l+1 : r])
+	_, err = fmt.Fscan(
+		bytes.NewBuffer(data[r+2:]),
+		&s.State,
+		&s.PPID,
+		&s.PGRP,
+		&s.Session,
+		&s.TTY,
+		&s.TPGID,
+		&s.Flags,
+		&s.MinFlt,
+		&s.CMinFlt,
+		&s.MajFlt,
+		&s.CMajFlt,
+		&s.UTime,
+		&s.STime,
+		&s.CUTime,
+		&s.CSTime,
+		&s.Priority,
+		&s.Nice,
+		&s.NumThreads,
+		&ignore,
+		&s.Starttime,
+		&s.VSize,
+		&s.RSS,
+	)
+	if err != nil {
+		return ProcStat{}, err
+	}
+
+	return s, nil
+}
+
+// VirtualMemory returns the virtual memory size in bytes.
+func (s ProcStat) VirtualMemory() int {
+	return s.VSize
+}
+
+// ResidentMemory returns the resident memory size in bytes.
+func (s ProcStat) ResidentMemory() int {
+	return s.RSS * os.Getpagesize()
+}
+
+// StartTime returns the unix timestamp of the process in seconds.
+func (s ProcStat) StartTime() (float64, error) {
+	stat, err := s.fs.NewStat()
+	if err != nil {
+		return 0, err
+	}
+	return float64(stat.BootTime) + (float64(s.Starttime) / userHZ), nil
+}
+
+// CPUTime returns the total CPU user and system time in seconds.
+func (s ProcStat) CPUTime() float64 {
+	return float64(s.UTime+s.STime) / userHZ
+}
diff --git a/vendor/github.com/prometheus/procfs/stat.go b/vendor/github.com/prometheus/procfs/stat.go
new file mode 100644
index 00000000..1ca217e8
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/stat.go
@@ -0,0 +1,56 @@
+package procfs
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+// Stat represents kernel/system statistics.
+type Stat struct {
+	// Boot time in seconds since the Epoch.
+	BootTime int64
+}
+
+// NewStat returns kernel/system statistics read from /proc/stat.
+func NewStat() (Stat, error) {
+	fs, err := NewFS(DefaultMountPoint)
+	if err != nil {
+		return Stat{}, err
+	}
+
+	return fs.NewStat()
+}
+
+// NewStat returns an information about current kernel/system statistics.
+func (fs FS) NewStat() (Stat, error) {
+	f, err := os.Open(fs.Path("stat"))
+	if err != nil {
+		return Stat{}, err
+	}
+	defer f.Close()
+
+	s := bufio.NewScanner(f)
+	for s.Scan() {
+		line := s.Text()
+		if !strings.HasPrefix(line, "btime") {
+			continue
+		}
+		fields := strings.Fields(line)
+		if len(fields) != 2 {
+			return Stat{}, fmt.Errorf("couldn't parse %s line %s", f.Name(), line)
+		}
+		i, err := strconv.ParseInt(fields[1], 10, 32)
+		if err != nil {
+			return Stat{}, fmt.Errorf("couldn't parse %s: %s", fields[1], err)
+		}
+		return Stat{BootTime: i}, nil
+	}
+	if err := s.Err(); err != nil {
+		return Stat{}, fmt.Errorf("couldn't parse %s: %s", f.Name(), err)
+	}
+
+	return Stat{}, fmt.Errorf("couldn't parse %s, missing btime", f.Name())
+}
diff --git a/vendor/golang.org/x/crypto/ssh/terminal/terminal.go b/vendor/golang.org/x/crypto/ssh/terminal/terminal.go
deleted file mode 100644
index 741eeb13..00000000
--- a/vendor/golang.org/x/crypto/ssh/terminal/terminal.go
+++ /dev/null
@@ -1,892 +0,0 @@
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package terminal
-
-import (
-	"bytes"
-	"io"
-	"sync"
-	"unicode/utf8"
-)
-
-// EscapeCodes contains escape sequences that can be written to the terminal in
-// order to achieve different styles of text.
-type EscapeCodes struct {
-	// Foreground colors
-	Black, Red, Green, Yellow, Blue, Magenta, Cyan, White []byte
-
-	// Reset all attributes
-	Reset []byte
-}
-
-var vt100EscapeCodes = EscapeCodes{
-	Black:   []byte{keyEscape, '[', '3', '0', 'm'},
-	Red:     []byte{keyEscape, '[', '3', '1', 'm'},
-	Green:   []byte{keyEscape, '[', '3', '2', 'm'},
-	Yellow:  []byte{keyEscape, '[', '3', '3', 'm'},
-	Blue:    []byte{keyEscape, '[', '3', '4', 'm'},
-	Magenta: []byte{keyEscape, '[', '3', '5', 'm'},
-	Cyan:    []byte{keyEscape, '[', '3', '6', 'm'},
-	White:   []byte{keyEscape, '[', '3', '7', 'm'},
-
-	Reset: []byte{keyEscape, '[', '0', 'm'},
-}
-
-// Terminal contains the state for running a VT100 terminal that is capable of
-// reading lines of input.
-type Terminal struct {
-	// AutoCompleteCallback, if non-null, is called for each keypress with
-	// the full input line and the current position of the cursor (in
-	// bytes, as an index into |line|). If it returns ok=false, the key
-	// press is processed normally. Otherwise it returns a replacement line
-	// and the new cursor position.
-	AutoCompleteCallback func(line string, pos int, key rune) (newLine string, newPos int, ok bool)
-
-	// Escape contains a pointer to the escape codes for this terminal.
-	// It's always a valid pointer, although the escape codes themselves
-	// may be empty if the terminal doesn't support them.
-	Escape *EscapeCodes
-
-	// lock protects the terminal and the state in this object from
-	// concurrent processing of a key press and a Write() call.
-	lock sync.Mutex
-
-	c      io.ReadWriter
-	prompt []rune
-
-	// line is the current line being entered.
-	line []rune
-	// pos is the logical position of the cursor in line
-	pos int
-	// echo is true if local echo is enabled
-	echo bool
-	// pasteActive is true iff there is a bracketed paste operation in
-	// progress.
-	pasteActive bool
-
-	// cursorX contains the current X value of the cursor where the left
-	// edge is 0. cursorY contains the row number where the first row of
-	// the current line is 0.
-	cursorX, cursorY int
-	// maxLine is the greatest value of cursorY so far.
-	maxLine int
-
-	termWidth, termHeight int
-
-	// outBuf contains the terminal data to be sent.
-	outBuf []byte
-	// remainder contains the remainder of any partial key sequences after
-	// a read. It aliases into inBuf.
-	remainder []byte
-	inBuf     [256]byte
-
-	// history contains previously entered commands so that they can be
-	// accessed with the up and down keys.
-	history stRingBuffer
-	// historyIndex stores the currently accessed history entry, where zero
-	// means the immediately previous entry.
-	historyIndex int
-	// When navigating up and down the history it's possible to return to
-	// the incomplete, initial line. That value is stored in
-	// historyPending.
-	historyPending string
-}
-
-// NewTerminal runs a VT100 terminal on the given ReadWriter. If the ReadWriter is
-// a local terminal, that terminal must first have been put into raw mode.
-// prompt is a string that is written at the start of each input line (i.e.
-// "> ").
-func NewTerminal(c io.ReadWriter, prompt string) *Terminal {
-	return &Terminal{
-		Escape:       &vt100EscapeCodes,
-		c:            c,
-		prompt:       []rune(prompt),
-		termWidth:    80,
-		termHeight:   24,
-		echo:         true,
-		historyIndex: -1,
-	}
-}
-
-const (
-	keyCtrlD     = 4
-	keyCtrlU     = 21
-	keyEnter     = '\r'
-	keyEscape    = 27
-	keyBackspace = 127
-	keyUnknown   = 0xd800 /* UTF-16 surrogate area */ + iota
-	keyUp
-	keyDown
-	keyLeft
-	keyRight
-	keyAltLeft
-	keyAltRight
-	keyHome
-	keyEnd
-	keyDeleteWord
-	keyDeleteLine
-	keyClearScreen
-	keyPasteStart
-	keyPasteEnd
-)
-
-var pasteStart = []byte{keyEscape, '[', '2', '0', '0', '~'}
-var pasteEnd = []byte{keyEscape, '[', '2', '0', '1', '~'}
-
-// bytesToKey tries to parse a key sequence from b. If successful, it returns
-// the key and the remainder of the input. Otherwise it returns utf8.RuneError.
-func bytesToKey(b []byte, pasteActive bool) (rune, []byte) {
-	if len(b) == 0 {
-		return utf8.RuneError, nil
-	}
-
-	if !pasteActive {
-		switch b[0] {
-		case 1: // ^A
-			return keyHome, b[1:]
-		case 5: // ^E
-			return keyEnd, b[1:]
-		case 8: // ^H
-			return keyBackspace, b[1:]
-		case 11: // ^K
-			return keyDeleteLine, b[1:]
-		case 12: // ^L
-			return keyClearScreen, b[1:]
-		case 23: // ^W
-			return keyDeleteWord, b[1:]
-		}
-	}
-
-	if b[0] != keyEscape {
-		if !utf8.FullRune(b) {
-			return utf8.RuneError, b
-		}
-		r, l := utf8.DecodeRune(b)
-		return r, b[l:]
-	}
-
-	if !pasteActive && len(b) >= 3 && b[0] == keyEscape && b[1] == '[' {
-		switch b[2] {
-		case 'A':
-			return keyUp, b[3:]
-		case 'B':
-			return keyDown, b[3:]
-		case 'C':
-			return keyRight, b[3:]
-		case 'D':
-			return keyLeft, b[3:]
-		case 'H':
-			return keyHome, b[3:]
-		case 'F':
-			return keyEnd, b[3:]
-		}
-	}
-
-	if !pasteActive && len(b) >= 6 && b[0] == keyEscape && b[1] == '[' && b[2] == '1' && b[3] == ';' && b[4] == '3' {
-		switch b[5] {
-		case 'C':
-			return keyAltRight, b[6:]
-		case 'D':
-			return keyAltLeft, b[6:]
-		}
-	}
-
-	if !pasteActive && len(b) >= 6 && bytes.Equal(b[:6], pasteStart) {
-		return keyPasteStart, b[6:]
-	}
-
-	if pasteActive && len(b) >= 6 && bytes.Equal(b[:6], pasteEnd) {
-		return keyPasteEnd, b[6:]
-	}
-
-	// If we get here then we have a key that we don't recognise, or a
-	// partial sequence. It's not clear how one should find the end of a
-	// sequence without knowing them all, but it seems that [a-zA-Z~] only
-	// appears at the end of a sequence.
-	for i, c := range b[0:] {
-		if c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' || c == '~' {
-			return keyUnknown, b[i+1:]
-		}
-	}
-
-	return utf8.RuneError, b
-}
-
-// queue appends data to the end of t.outBuf
-func (t *Terminal) queue(data []rune) {
-	t.outBuf = append(t.outBuf, []byte(string(data))...)
-}
-
-var eraseUnderCursor = []rune{' ', keyEscape, '[', 'D'}
-var space = []rune{' '}
-
-func isPrintable(key rune) bool {
-	isInSurrogateArea := key >= 0xd800 && key <= 0xdbff
-	return key >= 32 && !isInSurrogateArea
-}
-
-// moveCursorToPos appends data to t.outBuf which will move the cursor to the
-// given, logical position in the text.
-func (t *Terminal) moveCursorToPos(pos int) {
-	if !t.echo {
-		return
-	}
-
-	x := visualLength(t.prompt) + pos
-	y := x / t.termWidth
-	x = x % t.termWidth
-
-	up := 0
-	if y < t.cursorY {
-		up = t.cursorY - y
-	}
-
-	down := 0
-	if y > t.cursorY {
-		down = y - t.cursorY
-	}
-
-	left := 0
-	if x < t.cursorX {
-		left = t.cursorX - x
-	}
-
-	right := 0
-	if x > t.cursorX {
-		right = x - t.cursorX
-	}
-
-	t.cursorX = x
-	t.cursorY = y
-	t.move(up, down, left, right)
-}
-
-func (t *Terminal) move(up, down, left, right int) {
-	movement := make([]rune, 3*(up+down+left+right))
-	m := movement
-	for i := 0; i < up; i++ {
-		m[0] = keyEscape
-		m[1] = '['
-		m[2] = 'A'
-		m = m[3:]
-	}
-	for i := 0; i < down; i++ {
-		m[0] = keyEscape
-		m[1] = '['
-		m[2] = 'B'
-		m = m[3:]
-	}
-	for i := 0; i < left; i++ {
-		m[0] = keyEscape
-		m[1] = '['
-		m[2] = 'D'
-		m = m[3:]
-	}
-	for i := 0; i < right; i++ {
-		m[0] = keyEscape
-		m[1] = '['
-		m[2] = 'C'
-		m = m[3:]
-	}
-
-	t.queue(movement)
-}
-
-func (t *Terminal) clearLineToRight() {
-	op := []rune{keyEscape, '[', 'K'}
-	t.queue(op)
-}
-
-const maxLineLength = 4096
-
-func (t *Terminal) setLine(newLine []rune, newPos int) {
-	if t.echo {
-		t.moveCursorToPos(0)
-		t.writeLine(newLine)
-		for i := len(newLine); i < len(t.line); i++ {
-			t.writeLine(space)
-		}
-		t.moveCursorToPos(newPos)
-	}
-	t.line = newLine
-	t.pos = newPos
-}
-
-func (t *Terminal) advanceCursor(places int) {
-	t.cursorX += places
-	t.cursorY += t.cursorX / t.termWidth
-	if t.cursorY > t.maxLine {
-		t.maxLine = t.cursorY
-	}
-	t.cursorX = t.cursorX % t.termWidth
-
-	if places > 0 && t.cursorX == 0 {
-		// Normally terminals will advance the current position
-		// when writing a character. But that doesn't happen
-		// for the last character in a line. However, when
-		// writing a character (except a new line) that causes
-		// a line wrap, the position will be advanced two
-		// places.
-		//
-		// So, if we are stopping at the end of a line, we
-		// need to write a newline so that our cursor can be
-		// advanced to the next line.
-		t.outBuf = append(t.outBuf, '\n')
-	}
-}
-
-func (t *Terminal) eraseNPreviousChars(n int) {
-	if n == 0 {
-		return
-	}
-
-	if t.pos < n {
-		n = t.pos
-	}
-	t.pos -= n
-	t.moveCursorToPos(t.pos)
-
-	copy(t.line[t.pos:], t.line[n+t.pos:])
-	t.line = t.line[:len(t.line)-n]
-	if t.echo {
-		t.writeLine(t.line[t.pos:])
-		for i := 0; i < n; i++ {
-			t.queue(space)
-		}
-		t.advanceCursor(n)
-		t.moveCursorToPos(t.pos)
-	}
-}
-
-// countToLeftWord returns then number of characters from the cursor to the
-// start of the previous word.
-func (t *Terminal) countToLeftWord() int {
-	if t.pos == 0 {
-		return 0
-	}
-
-	pos := t.pos - 1
-	for pos > 0 {
-		if t.line[pos] != ' ' {
-			break
-		}
-		pos--
-	}
-	for pos > 0 {
-		if t.line[pos] == ' ' {
-			pos++
-			break
-		}
-		pos--
-	}
-
-	return t.pos - pos
-}
-
-// countToRightWord returns then number of characters from the cursor to the
-// start of the next word.
-func (t *Terminal) countToRightWord() int {
-	pos := t.pos
-	for pos < len(t.line) {
-		if t.line[pos] == ' ' {
-			break
-		}
-		pos++
-	}
-	for pos < len(t.line) {
-		if t.line[pos] != ' ' {
-			break
-		}
-		pos++
-	}
-	return pos - t.pos
-}
-
-// visualLength returns the number of visible glyphs in s.
-func visualLength(runes []rune) int {
-	inEscapeSeq := false
-	length := 0
-
-	for _, r := range runes {
-		switch {
-		case inEscapeSeq:
-			if (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') {
-				inEscapeSeq = false
-			}
-		case r == '\x1b':
-			inEscapeSeq = true
-		default:
-			length++
-		}
-	}
-
-	return length
-}
-
-// handleKey processes the given key and, optionally, returns a line of text
-// that the user has entered.
-func (t *Terminal) handleKey(key rune) (line string, ok bool) {
-	if t.pasteActive && key != keyEnter {
-		t.addKeyToLine(key)
-		return
-	}
-
-	switch key {
-	case keyBackspace:
-		if t.pos == 0 {
-			return
-		}
-		t.eraseNPreviousChars(1)
-	case keyAltLeft:
-		// move left by a word.
-		t.pos -= t.countToLeftWord()
-		t.moveCursorToPos(t.pos)
-	case keyAltRight:
-		// move right by a word.
-		t.pos += t.countToRightWord()
-		t.moveCursorToPos(t.pos)
-	case keyLeft:
-		if t.pos == 0 {
-			return
-		}
-		t.pos--
-		t.moveCursorToPos(t.pos)
-	case keyRight:
-		if t.pos == len(t.line) {
-			return
-		}
-		t.pos++
-		t.moveCursorToPos(t.pos)
-	case keyHome:
-		if t.pos == 0 {
-			return
-		}
-		t.pos = 0
-		t.moveCursorToPos(t.pos)
-	case keyEnd:
-		if t.pos == len(t.line) {
-			return
-		}
-		t.pos = len(t.line)
-		t.moveCursorToPos(t.pos)
-	case keyUp:
-		entry, ok := t.history.NthPreviousEntry(t.historyIndex + 1)
-		if !ok {
-			return "", false
-		}
-		if t.historyIndex == -1 {
-			t.historyPending = string(t.line)
-		}
-		t.historyIndex++
-		runes := []rune(entry)
-		t.setLine(runes, len(runes))
-	case keyDown:
-		switch t.historyIndex {
-		case -1:
-			return
-		case 0:
-			runes := []rune(t.historyPending)
-			t.setLine(runes, len(runes))
-			t.historyIndex--
-		default:
-			entry, ok := t.history.NthPreviousEntry(t.historyIndex - 1)
-			if ok {
-				t.historyIndex--
-				runes := []rune(entry)
-				t.setLine(runes, len(runes))
-			}
-		}
-	case keyEnter:
-		t.moveCursorToPos(len(t.line))
-		t.queue([]rune("\r\n"))
-		line = string(t.line)
-		ok = true
-		t.line = t.line[:0]
-		t.pos = 0
-		t.cursorX = 0
-		t.cursorY = 0
-		t.maxLine = 0
-	case keyDeleteWord:
-		// Delete zero or more spaces and then one or more characters.
-		t.eraseNPreviousChars(t.countToLeftWord())
-	case keyDeleteLine:
-		// Delete everything from the current cursor position to the
-		// end of line.
-		for i := t.pos; i < len(t.line); i++ {
-			t.queue(space)
-			t.advanceCursor(1)
-		}
-		t.line = t.line[:t.pos]
-		t.moveCursorToPos(t.pos)
-	case keyCtrlD:
-		// Erase the character under the current position.
-		// The EOF case when the line is empty is handled in
-		// readLine().
-		if t.pos < len(t.line) {
-			t.pos++
-			t.eraseNPreviousChars(1)
-		}
-	case keyCtrlU:
-		t.eraseNPreviousChars(t.pos)
-	case keyClearScreen:
-		// Erases the screen and moves the cursor to the home position.
-		t.queue([]rune("\x1b[2J\x1b[H"))
-		t.queue(t.prompt)
-		t.cursorX, t.cursorY = 0, 0
-		t.advanceCursor(visualLength(t.prompt))
-		t.setLine(t.line, t.pos)
-	default:
-		if t.AutoCompleteCallback != nil {
-			prefix := string(t.line[:t.pos])
-			suffix := string(t.line[t.pos:])
-
-			t.lock.Unlock()
-			newLine, newPos, completeOk := t.AutoCompleteCallback(prefix+suffix, len(prefix), key)
-			t.lock.Lock()
-
-			if completeOk {
-				t.setLine([]rune(newLine), utf8.RuneCount([]byte(newLine)[:newPos]))
-				return
-			}
-		}
-		if !isPrintable(key) {
-			return
-		}
-		if len(t.line) == maxLineLength {
-			return
-		}
-		t.addKeyToLine(key)
-	}
-	return
-}
-
-// addKeyToLine inserts the given key at the current position in the current
-// line.
-func (t *Terminal) addKeyToLine(key rune) {
-	if len(t.line) == cap(t.line) {
-		newLine := make([]rune, len(t.line), 2*(1+len(t.line)))
-		copy(newLine, t.line)
-		t.line = newLine
-	}
-	t.line = t.line[:len(t.line)+1]
-	copy(t.line[t.pos+1:], t.line[t.pos:])
-	t.line[t.pos] = key
-	if t.echo {
-		t.writeLine(t.line[t.pos:])
-	}
-	t.pos++
-	t.moveCursorToPos(t.pos)
-}
-
-func (t *Terminal) writeLine(line []rune) {
-	for len(line) != 0 {
-		remainingOnLine := t.termWidth - t.cursorX
-		todo := len(line)
-		if todo > remainingOnLine {
-			todo = remainingOnLine
-		}
-		t.queue(line[:todo])
-		t.advanceCursor(visualLength(line[:todo]))
-		line = line[todo:]
-	}
-}
-
-func (t *Terminal) Write(buf []byte) (n int, err error) {
-	t.lock.Lock()
-	defer t.lock.Unlock()
-
-	if t.cursorX == 0 && t.cursorY == 0 {
-		// This is the easy case: there's nothing on the screen that we
-		// have to move out of the way.
-		return t.c.Write(buf)
-	}
-
-	// We have a prompt and possibly user input on the screen. We
-	// have to clear it first.
-	t.move(0 /* up */, 0 /* down */, t.cursorX /* left */, 0 /* right */)
-	t.cursorX = 0
-	t.clearLineToRight()
-
-	for t.cursorY > 0 {
-		t.move(1 /* up */, 0, 0, 0)
-		t.cursorY--
-		t.clearLineToRight()
-	}
-
-	if _, err = t.c.Write(t.outBuf); err != nil {
-		return
-	}
-	t.outBuf = t.outBuf[:0]
-
-	if n, err = t.c.Write(buf); err != nil {
-		return
-	}
-
-	t.writeLine(t.prompt)
-	if t.echo {
-		t.writeLine(t.line)
-	}
-
-	t.moveCursorToPos(t.pos)
-
-	if _, err = t.c.Write(t.outBuf); err != nil {
-		return
-	}
-	t.outBuf = t.outBuf[:0]
-	return
-}
-
-// ReadPassword temporarily changes the prompt and reads a password, without
-// echo, from the terminal.
-func (t *Terminal) ReadPassword(prompt string) (line string, err error) {
-	t.lock.Lock()
-	defer t.lock.Unlock()
-
-	oldPrompt := t.prompt
-	t.prompt = []rune(prompt)
-	t.echo = false
-
-	line, err = t.readLine()
-
-	t.prompt = oldPrompt
-	t.echo = true
-
-	return
-}
-
-// ReadLine returns a line of input from the terminal.
-func (t *Terminal) ReadLine() (line string, err error) {
-	t.lock.Lock()
-	defer t.lock.Unlock()
-
-	return t.readLine()
-}
-
-func (t *Terminal) readLine() (line string, err error) {
-	// t.lock must be held at this point
-
-	if t.cursorX == 0 && t.cursorY == 0 {
-		t.writeLine(t.prompt)
-		t.c.Write(t.outBuf)
-		t.outBuf = t.outBuf[:0]
-	}
-
-	lineIsPasted := t.pasteActive
-
-	for {
-		rest := t.remainder
-		lineOk := false
-		for !lineOk {
-			var key rune
-			key, rest = bytesToKey(rest, t.pasteActive)
-			if key == utf8.RuneError {
-				break
-			}
-			if !t.pasteActive {
-				if key == keyCtrlD {
-					if len(t.line) == 0 {
-						return "", io.EOF
-					}
-				}
-				if key == keyPasteStart {
-					t.pasteActive = true
-					if len(t.line) == 0 {
-						lineIsPasted = true
-					}
-					continue
-				}
-			} else if key == keyPasteEnd {
-				t.pasteActive = false
-				continue
-			}
-			if !t.pasteActive {
-				lineIsPasted = false
-			}
-			line, lineOk = t.handleKey(key)
-		}
-		if len(rest) > 0 {
-			n := copy(t.inBuf[:], rest)
-			t.remainder = t.inBuf[:n]
-		} else {
-			t.remainder = nil
-		}
-		t.c.Write(t.outBuf)
-		t.outBuf = t.outBuf[:0]
-		if lineOk {
-			if t.echo {
-				t.historyIndex = -1
-				t.history.Add(line)
-			}
-			if lineIsPasted {
-				err = ErrPasteIndicator
-			}
-			return
-		}
-
-		// t.remainder is a slice at the beginning of t.inBuf
-		// containing a partial key sequence
-		readBuf := t.inBuf[len(t.remainder):]
-		var n int
-
-		t.lock.Unlock()
-		n, err = t.c.Read(readBuf)
-		t.lock.Lock()
-
-		if err != nil {
-			return
-		}
-
-		t.remainder = t.inBuf[:n+len(t.remainder)]
-	}
-
-	panic("unreachable") // for Go 1.0.
-}
-
-// SetPrompt sets the prompt to be used when reading subsequent lines.
-func (t *Terminal) SetPrompt(prompt string) {
-	t.lock.Lock()
-	defer t.lock.Unlock()
-
-	t.prompt = []rune(prompt)
-}
-
-func (t *Terminal) clearAndRepaintLinePlusNPrevious(numPrevLines int) {
-	// Move cursor to column zero at the start of the line.
-	t.move(t.cursorY, 0, t.cursorX, 0)
-	t.cursorX, t.cursorY = 0, 0
-	t.clearLineToRight()
-	for t.cursorY < numPrevLines {
-		// Move down a line
-		t.move(0, 1, 0, 0)
-		t.cursorY++
-		t.clearLineToRight()
-	}
-	// Move back to beginning.
-	t.move(t.cursorY, 0, 0, 0)
-	t.cursorX, t.cursorY = 0, 0
-
-	t.queue(t.prompt)
-	t.advanceCursor(visualLength(t.prompt))
-	t.writeLine(t.line)
-	t.moveCursorToPos(t.pos)
-}
-
-func (t *Terminal) SetSize(width, height int) error {
-	t.lock.Lock()
-	defer t.lock.Unlock()
-
-	if width == 0 {
-		width = 1
-	}
-
-	oldWidth := t.termWidth
-	t.termWidth, t.termHeight = width, height
-
-	switch {
-	case width == oldWidth:
-		// If the width didn't change then nothing else needs to be
-		// done.
-		return nil
-	case len(t.line) == 0 && t.cursorX == 0 && t.cursorY == 0:
-		// If there is nothing on current line and no prompt printed,
-		// just do nothing
-		return nil
-	case width < oldWidth:
-		// Some terminals (e.g. xterm) will truncate lines that were
-		// too long when shinking. Others, (e.g. gnome-terminal) will
-		// attempt to wrap them. For the former, repainting t.maxLine
-		// works great, but that behaviour goes badly wrong in the case
-		// of the latter because they have doubled every full line.
-
-		// We assume that we are working on a terminal that wraps lines
-		// and adjust the cursor position based on every previous line
-		// wrapping and turning into two. This causes the prompt on
-		// xterms to move upwards, which isn't great, but it avoids a
-		// huge mess with gnome-terminal.
-		if t.cursorX >= t.termWidth {
-			t.cursorX = t.termWidth - 1
-		}
-		t.cursorY *= 2
-		t.clearAndRepaintLinePlusNPrevious(t.maxLine * 2)
-	case width > oldWidth:
-		// If the terminal expands then our position calculations will
-		// be wrong in the future because we think the cursor is
-		// |t.pos| chars into the string, but there will be a gap at
-		// the end of any wrapped line.
-		//
-		// But the position will actually be correct until we move, so
-		// we can move back to the beginning and repaint everything.
-		t.clearAndRepaintLinePlusNPrevious(t.maxLine)
-	}
-
-	_, err := t.c.Write(t.outBuf)
-	t.outBuf = t.outBuf[:0]
-	return err
-}
-
-type pasteIndicatorError struct{}
-
-func (pasteIndicatorError) Error() string {
-	return "terminal: ErrPasteIndicator not correctly handled"
-}
-
-// ErrPasteIndicator may be returned from ReadLine as the error, in addition
-// to valid line data. It indicates that bracketed paste mode is enabled and
-// that the returned line consists only of pasted data. Programs may wish to
-// interpret pasted data more literally than typed data.
-var ErrPasteIndicator = pasteIndicatorError{}
-
-// SetBracketedPasteMode requests that the terminal bracket paste operations
-// with markers. Not all terminals support this but, if it is supported, then
-// enabling this mode will stop any autocomplete callback from running due to
-// pastes. Additionally, any lines that are completely pasted will be returned
-// from ReadLine with the error set to ErrPasteIndicator.
-func (t *Terminal) SetBracketedPasteMode(on bool) {
-	if on {
-		io.WriteString(t.c, "\x1b[?2004h")
-	} else {
-		io.WriteString(t.c, "\x1b[?2004l")
-	}
-}
-
-// stRingBuffer is a ring buffer of strings.
-type stRingBuffer struct {
-	// entries contains max elements.
-	entries []string
-	max     int
-	// head contains the index of the element most recently added to the ring.
-	head int
-	// size contains the number of elements in the ring.
-	size int
-}
-
-func (s *stRingBuffer) Add(a string) {
-	if s.entries == nil {
-		const defaultNumEntries = 100
-		s.entries = make([]string, defaultNumEntries)
-		s.max = defaultNumEntries
-	}
-
-	s.head = (s.head + 1) % s.max
-	s.entries[s.head] = a
-	if s.size < s.max {
-		s.size++
-	}
-}
-
-// NthPreviousEntry returns the value passed to the nth previous call to Add.
-// If n is zero then the immediately prior value is returned, if one, then the
-// next most recent, and so on. If such an element doesn't exist then ok is
-// false.
-func (s *stRingBuffer) NthPreviousEntry(n int) (value string, ok bool) {
-	if n >= s.size {
-		return "", false
-	}
-	index := s.head - n
-	if index < 0 {
-		index += s.max
-	}
-	return s.entries[index], true
-}
diff --git a/vendor/golang.org/x/crypto/ssh/terminal/util.go b/vendor/golang.org/x/crypto/ssh/terminal/util.go
deleted file mode 100644
index 0763c9a9..00000000
--- a/vendor/golang.org/x/crypto/ssh/terminal/util.go
+++ /dev/null
@@ -1,128 +0,0 @@
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build darwin dragonfly freebsd linux,!appengine netbsd openbsd
-
-// Package terminal provides support functions for dealing with terminals, as
-// commonly found on UNIX systems.
-//
-// Putting a terminal into raw mode is the most common requirement:
-//
-// 	oldState, err := terminal.MakeRaw(0)
-// 	if err != nil {
-// 	        panic(err)
-// 	}
-// 	defer terminal.Restore(0, oldState)
-package terminal
-
-import (
-	"io"
-	"syscall"
-	"unsafe"
-)
-
-// State contains the state of a terminal.
-type State struct {
-	termios syscall.Termios
-}
-
-// IsTerminal returns true if the given file descriptor is a terminal.
-func IsTerminal(fd int) bool {
-	var termios syscall.Termios
-	_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), ioctlReadTermios, uintptr(unsafe.Pointer(&termios)), 0, 0, 0)
-	return err == 0
-}
-
-// MakeRaw put the terminal connected to the given file descriptor into raw
-// mode and returns the previous state of the terminal so that it can be
-// restored.
-func MakeRaw(fd int) (*State, error) {
-	var oldState State
-	if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), ioctlReadTermios, uintptr(unsafe.Pointer(&oldState.termios)), 0, 0, 0); err != 0 {
-		return nil, err
-	}
-
-	newState := oldState.termios
-	newState.Iflag &^= syscall.ISTRIP | syscall.INLCR | syscall.ICRNL | syscall.IGNCR | syscall.IXON | syscall.IXOFF
-	newState.Lflag &^= syscall.ECHO | syscall.ICANON | syscall.ISIG
-	if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), ioctlWriteTermios, uintptr(unsafe.Pointer(&newState)), 0, 0, 0); err != 0 {
-		return nil, err
-	}
-
-	return &oldState, nil
-}
-
-// GetState returns the current state of a terminal which may be useful to
-// restore the terminal after a signal.
-func GetState(fd int) (*State, error) {
-	var oldState State
-	if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), ioctlReadTermios, uintptr(unsafe.Pointer(&oldState.termios)), 0, 0, 0); err != 0 {
-		return nil, err
-	}
-
-	return &oldState, nil
-}
-
-// Restore restores the terminal connected to the given file descriptor to a
-// previous state.
-func Restore(fd int, state *State) error {
-	_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), ioctlWriteTermios, uintptr(unsafe.Pointer(&state.termios)), 0, 0, 0)
-	return err
-}
-
-// GetSize returns the dimensions of the given terminal.
-func GetSize(fd int) (width, height int, err error) {
-	var dimensions [4]uint16
-
-	if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), uintptr(syscall.TIOCGWINSZ), uintptr(unsafe.Pointer(&dimensions)), 0, 0, 0); err != 0 {
-		return -1, -1, err
-	}
-	return int(dimensions[1]), int(dimensions[0]), nil
-}
-
-// ReadPassword reads a line of input from a terminal without local echo.  This
-// is commonly used for inputting passwords and other sensitive data. The slice
-// returned does not include the \n.
-func ReadPassword(fd int) ([]byte, error) {
-	var oldState syscall.Termios
-	if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), ioctlReadTermios, uintptr(unsafe.Pointer(&oldState)), 0, 0, 0); err != 0 {
-		return nil, err
-	}
-
-	newState := oldState
-	newState.Lflag &^= syscall.ECHO
-	newState.Lflag |= syscall.ICANON | syscall.ISIG
-	newState.Iflag |= syscall.ICRNL
-	if _, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), ioctlWriteTermios, uintptr(unsafe.Pointer(&newState)), 0, 0, 0); err != 0 {
-		return nil, err
-	}
-
-	defer func() {
-		syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), ioctlWriteTermios, uintptr(unsafe.Pointer(&oldState)), 0, 0, 0)
-	}()
-
-	var buf [16]byte
-	var ret []byte
-	for {
-		n, err := syscall.Read(fd, buf[:])
-		if err != nil {
-			return nil, err
-		}
-		if n == 0 {
-			if len(ret) == 0 {
-				return nil, io.EOF
-			}
-			break
-		}
-		if buf[n-1] == '\n' {
-			n--
-		}
-		ret = append(ret, buf[:n]...)
-		if n < len(buf) {
-			break
-		}
-	}
-
-	return ret, nil
-}
diff --git a/vendor/golang.org/x/crypto/ssh/terminal/util_bsd.go b/vendor/golang.org/x/crypto/ssh/terminal/util_bsd.go
deleted file mode 100644
index 9c1ffd14..00000000
--- a/vendor/golang.org/x/crypto/ssh/terminal/util_bsd.go
+++ /dev/null
@@ -1,12 +0,0 @@
-// Copyright 2013 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build darwin dragonfly freebsd netbsd openbsd
-
-package terminal
-
-import "syscall"
-
-const ioctlReadTermios = syscall.TIOCGETA
-const ioctlWriteTermios = syscall.TIOCSETA
diff --git a/vendor/golang.org/x/crypto/ssh/terminal/util_linux.go b/vendor/golang.org/x/crypto/ssh/terminal/util_linux.go
deleted file mode 100644
index 5883b22d..00000000
--- a/vendor/golang.org/x/crypto/ssh/terminal/util_linux.go
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright 2013 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package terminal
-
-// These constants are declared here, rather than importing
-// them from the syscall package as some syscall packages, even
-// on linux, for example gccgo, do not declare them.
-const ioctlReadTermios = 0x5401  // syscall.TCGETS
-const ioctlWriteTermios = 0x5402 // syscall.TCSETS
diff --git a/vendor/golang.org/x/crypto/ssh/terminal/util_windows.go b/vendor/golang.org/x/crypto/ssh/terminal/util_windows.go
deleted file mode 100644
index 2dd6c3d9..00000000
--- a/vendor/golang.org/x/crypto/ssh/terminal/util_windows.go
+++ /dev/null
@@ -1,174 +0,0 @@
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build windows
-
-// Package terminal provides support functions for dealing with terminals, as
-// commonly found on UNIX systems.
-//
-// Putting a terminal into raw mode is the most common requirement:
-//
-// 	oldState, err := terminal.MakeRaw(0)
-// 	if err != nil {
-// 	        panic(err)
-// 	}
-// 	defer terminal.Restore(0, oldState)
-package terminal
-
-import (
-	"io"
-	"syscall"
-	"unsafe"
-)
-
-const (
-	enableLineInput       = 2
-	enableEchoInput       = 4
-	enableProcessedInput  = 1
-	enableWindowInput     = 8
-	enableMouseInput      = 16
-	enableInsertMode      = 32
-	enableQuickEditMode   = 64
-	enableExtendedFlags   = 128
-	enableAutoPosition    = 256
-	enableProcessedOutput = 1
-	enableWrapAtEolOutput = 2
-)
-
-var kernel32 = syscall.NewLazyDLL("kernel32.dll")
-
-var (
-	procGetConsoleMode             = kernel32.NewProc("GetConsoleMode")
-	procSetConsoleMode             = kernel32.NewProc("SetConsoleMode")
-	procGetConsoleScreenBufferInfo = kernel32.NewProc("GetConsoleScreenBufferInfo")
-)
-
-type (
-	short int16
-	word  uint16
-
-	coord struct {
-		x short
-		y short
-	}
-	smallRect struct {
-		left   short
-		top    short
-		right  short
-		bottom short
-	}
-	consoleScreenBufferInfo struct {
-		size              coord
-		cursorPosition    coord
-		attributes        word
-		window            smallRect
-		maximumWindowSize coord
-	}
-)
-
-type State struct {
-	mode uint32
-}
-
-// IsTerminal returns true if the given file descriptor is a terminal.
-func IsTerminal(fd int) bool {
-	var st uint32
-	r, _, e := syscall.Syscall(procGetConsoleMode.Addr(), 2, uintptr(fd), uintptr(unsafe.Pointer(&st)), 0)
-	return r != 0 && e == 0
-}
-
-// MakeRaw put the terminal connected to the given file descriptor into raw
-// mode and returns the previous state of the terminal so that it can be
-// restored.
-func MakeRaw(fd int) (*State, error) {
-	var st uint32
-	_, _, e := syscall.Syscall(procGetConsoleMode.Addr(), 2, uintptr(fd), uintptr(unsafe.Pointer(&st)), 0)
-	if e != 0 {
-		return nil, error(e)
-	}
-	st &^= (enableEchoInput | enableProcessedInput | enableLineInput | enableProcessedOutput)
-	_, _, e = syscall.Syscall(procSetConsoleMode.Addr(), 2, uintptr(fd), uintptr(st), 0)
-	if e != 0 {
-		return nil, error(e)
-	}
-	return &State{st}, nil
-}
-
-// GetState returns the current state of a terminal which may be useful to
-// restore the terminal after a signal.
-func GetState(fd int) (*State, error) {
-	var st uint32
-	_, _, e := syscall.Syscall(procGetConsoleMode.Addr(), 2, uintptr(fd), uintptr(unsafe.Pointer(&st)), 0)
-	if e != 0 {
-		return nil, error(e)
-	}
-	return &State{st}, nil
-}
-
-// Restore restores the terminal connected to the given file descriptor to a
-// previous state.
-func Restore(fd int, state *State) error {
-	_, _, err := syscall.Syscall(procSetConsoleMode.Addr(), 2, uintptr(fd), uintptr(state.mode), 0)
-	return err
-}
-
-// GetSize returns the dimensions of the given terminal.
-func GetSize(fd int) (width, height int, err error) {
-	var info consoleScreenBufferInfo
-	_, _, e := syscall.Syscall(procGetConsoleScreenBufferInfo.Addr(), 2, uintptr(fd), uintptr(unsafe.Pointer(&info)), 0)
-	if e != 0 {
-		return 0, 0, error(e)
-	}
-	return int(info.size.x), int(info.size.y), nil
-}
-
-// ReadPassword reads a line of input from a terminal without local echo.  This
-// is commonly used for inputting passwords and other sensitive data. The slice
-// returned does not include the \n.
-func ReadPassword(fd int) ([]byte, error) {
-	var st uint32
-	_, _, e := syscall.Syscall(procGetConsoleMode.Addr(), 2, uintptr(fd), uintptr(unsafe.Pointer(&st)), 0)
-	if e != 0 {
-		return nil, error(e)
-	}
-	old := st
-
-	st &^= (enableEchoInput)
-	st |= (enableProcessedInput | enableLineInput | enableProcessedOutput)
-	_, _, e = syscall.Syscall(procSetConsoleMode.Addr(), 2, uintptr(fd), uintptr(st), 0)
-	if e != 0 {
-		return nil, error(e)
-	}
-
-	defer func() {
-		syscall.Syscall(procSetConsoleMode.Addr(), 2, uintptr(fd), uintptr(old), 0)
-	}()
-
-	var buf [16]byte
-	var ret []byte
-	for {
-		n, err := syscall.Read(syscall.Handle(fd), buf[:])
-		if err != nil {
-			return nil, err
-		}
-		if n == 0 {
-			if len(ret) == 0 {
-				return nil, io.EOF
-			}
-			break
-		}
-		if buf[n-1] == '\n' {
-			n--
-		}
-		if n > 0 && buf[n-1] == '\r' {
-			n--
-		}
-		ret = append(ret, buf[:n]...)
-		if n < len(buf) {
-			break
-		}
-	}
-
-	return ret, nil
-}
diff --git a/vendor/golang.org/x/net/AUTHORS b/vendor/golang.org/x/net/AUTHORS
new file mode 100644
index 00000000..15167cd7
--- /dev/null
+++ b/vendor/golang.org/x/net/AUTHORS
@@ -0,0 +1,3 @@
+# This source code refers to The Go Authors for copyright purposes.
+# The master list of authors is in the main Go distribution,
+# visible at http://tip.golang.org/AUTHORS.
diff --git a/vendor/golang.org/x/net/CONTRIBUTORS b/vendor/golang.org/x/net/CONTRIBUTORS
new file mode 100644
index 00000000..1c4577e9
--- /dev/null
+++ b/vendor/golang.org/x/net/CONTRIBUTORS
@@ -0,0 +1,3 @@
+# This source code was written by the Go contributors.
+# The master list of contributors is in the main Go distribution,
+# visible at http://tip.golang.org/CONTRIBUTORS.
diff --git a/vendor/golang.org/x/net/http2/client_conn_pool.go b/vendor/golang.org/x/net/http2/client_conn_pool.go
new file mode 100644
index 00000000..b1394125
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/client_conn_pool.go
@@ -0,0 +1,256 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Transport code's client connection pooling.
+
+package http2
+
+import (
+	"crypto/tls"
+	"net/http"
+	"sync"
+)
+
+// ClientConnPool manages a pool of HTTP/2 client connections.
+type ClientConnPool interface {
+	GetClientConn(req *http.Request, addr string) (*ClientConn, error)
+	MarkDead(*ClientConn)
+}
+
+// clientConnPoolIdleCloser is the interface implemented by ClientConnPool
+// implementations which can close their idle connections.
+type clientConnPoolIdleCloser interface {
+	ClientConnPool
+	closeIdleConnections()
+}
+
+var (
+	_ clientConnPoolIdleCloser = (*clientConnPool)(nil)
+	_ clientConnPoolIdleCloser = noDialClientConnPool{}
+)
+
+// TODO: use singleflight for dialing and addConnCalls?
+type clientConnPool struct {
+	t *Transport
+
+	mu sync.Mutex // TODO: maybe switch to RWMutex
+	// TODO: add support for sharing conns based on cert names
+	// (e.g. share conn for googleapis.com and appspot.com)
+	conns        map[string][]*ClientConn // key is host:port
+	dialing      map[string]*dialCall     // currently in-flight dials
+	keys         map[*ClientConn][]string
+	addConnCalls map[string]*addConnCall // in-flight addConnIfNeede calls
+}
+
+func (p *clientConnPool) GetClientConn(req *http.Request, addr string) (*ClientConn, error) {
+	return p.getClientConn(req, addr, dialOnMiss)
+}
+
+const (
+	dialOnMiss   = true
+	noDialOnMiss = false
+)
+
+func (p *clientConnPool) getClientConn(req *http.Request, addr string, dialOnMiss bool) (*ClientConn, error) {
+	if isConnectionCloseRequest(req) && dialOnMiss {
+		// It gets its own connection.
+		const singleUse = true
+		cc, err := p.t.dialClientConn(addr, singleUse)
+		if err != nil {
+			return nil, err
+		}
+		return cc, nil
+	}
+	p.mu.Lock()
+	for _, cc := range p.conns[addr] {
+		if cc.CanTakeNewRequest() {
+			p.mu.Unlock()
+			return cc, nil
+		}
+	}
+	if !dialOnMiss {
+		p.mu.Unlock()
+		return nil, ErrNoCachedConn
+	}
+	call := p.getStartDialLocked(addr)
+	p.mu.Unlock()
+	<-call.done
+	return call.res, call.err
+}
+
+// dialCall is an in-flight Transport dial call to a host.
+type dialCall struct {
+	p    *clientConnPool
+	done chan struct{} // closed when done
+	res  *ClientConn   // valid after done is closed
+	err  error         // valid after done is closed
+}
+
+// requires p.mu is held.
+func (p *clientConnPool) getStartDialLocked(addr string) *dialCall {
+	if call, ok := p.dialing[addr]; ok {
+		// A dial is already in-flight. Don't start another.
+		return call
+	}
+	call := &dialCall{p: p, done: make(chan struct{})}
+	if p.dialing == nil {
+		p.dialing = make(map[string]*dialCall)
+	}
+	p.dialing[addr] = call
+	go call.dial(addr)
+	return call
+}
+
+// run in its own goroutine.
+func (c *dialCall) dial(addr string) {
+	const singleUse = false // shared conn
+	c.res, c.err = c.p.t.dialClientConn(addr, singleUse)
+	close(c.done)
+
+	c.p.mu.Lock()
+	delete(c.p.dialing, addr)
+	if c.err == nil {
+		c.p.addConnLocked(addr, c.res)
+	}
+	c.p.mu.Unlock()
+}
+
+// addConnIfNeeded makes a NewClientConn out of c if a connection for key doesn't
+// already exist. It coalesces concurrent calls with the same key.
+// This is used by the http1 Transport code when it creates a new connection. Because
+// the http1 Transport doesn't de-dup TCP dials to outbound hosts (because it doesn't know
+// the protocol), it can get into a situation where it has multiple TLS connections.
+// This code decides which ones live or die.
+// The return value used is whether c was used.
+// c is never closed.
+func (p *clientConnPool) addConnIfNeeded(key string, t *Transport, c *tls.Conn) (used bool, err error) {
+	p.mu.Lock()
+	for _, cc := range p.conns[key] {
+		if cc.CanTakeNewRequest() {
+			p.mu.Unlock()
+			return false, nil
+		}
+	}
+	call, dup := p.addConnCalls[key]
+	if !dup {
+		if p.addConnCalls == nil {
+			p.addConnCalls = make(map[string]*addConnCall)
+		}
+		call = &addConnCall{
+			p:    p,
+			done: make(chan struct{}),
+		}
+		p.addConnCalls[key] = call
+		go call.run(t, key, c)
+	}
+	p.mu.Unlock()
+
+	<-call.done
+	if call.err != nil {
+		return false, call.err
+	}
+	return !dup, nil
+}
+
+type addConnCall struct {
+	p    *clientConnPool
+	done chan struct{} // closed when done
+	err  error
+}
+
+func (c *addConnCall) run(t *Transport, key string, tc *tls.Conn) {
+	cc, err := t.NewClientConn(tc)
+
+	p := c.p
+	p.mu.Lock()
+	if err != nil {
+		c.err = err
+	} else {
+		p.addConnLocked(key, cc)
+	}
+	delete(p.addConnCalls, key)
+	p.mu.Unlock()
+	close(c.done)
+}
+
+func (p *clientConnPool) addConn(key string, cc *ClientConn) {
+	p.mu.Lock()
+	p.addConnLocked(key, cc)
+	p.mu.Unlock()
+}
+
+// p.mu must be held
+func (p *clientConnPool) addConnLocked(key string, cc *ClientConn) {
+	for _, v := range p.conns[key] {
+		if v == cc {
+			return
+		}
+	}
+	if p.conns == nil {
+		p.conns = make(map[string][]*ClientConn)
+	}
+	if p.keys == nil {
+		p.keys = make(map[*ClientConn][]string)
+	}
+	p.conns[key] = append(p.conns[key], cc)
+	p.keys[cc] = append(p.keys[cc], key)
+}
+
+func (p *clientConnPool) MarkDead(cc *ClientConn) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	for _, key := range p.keys[cc] {
+		vv, ok := p.conns[key]
+		if !ok {
+			continue
+		}
+		newList := filterOutClientConn(vv, cc)
+		if len(newList) > 0 {
+			p.conns[key] = newList
+		} else {
+			delete(p.conns, key)
+		}
+	}
+	delete(p.keys, cc)
+}
+
+func (p *clientConnPool) closeIdleConnections() {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	// TODO: don't close a cc if it was just added to the pool
+	// milliseconds ago and has never been used. There's currently
+	// a small race window with the HTTP/1 Transport's integration
+	// where it can add an idle conn just before using it, and
+	// somebody else can concurrently call CloseIdleConns and
+	// break some caller's RoundTrip.
+	for _, vv := range p.conns {
+		for _, cc := range vv {
+			cc.closeIfIdle()
+		}
+	}
+}
+
+func filterOutClientConn(in []*ClientConn, exclude *ClientConn) []*ClientConn {
+	out := in[:0]
+	for _, v := range in {
+		if v != exclude {
+			out = append(out, v)
+		}
+	}
+	// If we filtered it out, zero out the last item to prevent
+	// the GC from seeing it.
+	if len(in) != len(out) {
+		in[len(in)-1] = nil
+	}
+	return out
+}
+
+// noDialClientConnPool is an implementation of http2.ClientConnPool
+// which never dials.  We let the HTTP/1.1 client dial and use its TLS
+// connection instead.
+type noDialClientConnPool struct{ *clientConnPool }
+
+func (p noDialClientConnPool) GetClientConn(req *http.Request, addr string) (*ClientConn, error) {
+	return p.getClientConn(req, addr, noDialOnMiss)
+}
diff --git a/vendor/golang.org/x/net/http2/configure_transport.go b/vendor/golang.org/x/net/http2/configure_transport.go
new file mode 100644
index 00000000..4f720f53
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/configure_transport.go
@@ -0,0 +1,80 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build go1.6
+
+package http2
+
+import (
+	"crypto/tls"
+	"fmt"
+	"net/http"
+)
+
+func configureTransport(t1 *http.Transport) (*Transport, error) {
+	connPool := new(clientConnPool)
+	t2 := &Transport{
+		ConnPool: noDialClientConnPool{connPool},
+		t1:       t1,
+	}
+	connPool.t = t2
+	if err := registerHTTPSProtocol(t1, noDialH2RoundTripper{t2}); err != nil {
+		return nil, err
+	}
+	if t1.TLSClientConfig == nil {
+		t1.TLSClientConfig = new(tls.Config)
+	}
+	if !strSliceContains(t1.TLSClientConfig.NextProtos, "h2") {
+		t1.TLSClientConfig.NextProtos = append([]string{"h2"}, t1.TLSClientConfig.NextProtos...)
+	}
+	if !strSliceContains(t1.TLSClientConfig.NextProtos, "http/1.1") {
+		t1.TLSClientConfig.NextProtos = append(t1.TLSClientConfig.NextProtos, "http/1.1")
+	}
+	upgradeFn := func(authority string, c *tls.Conn) http.RoundTripper {
+		addr := authorityAddr("https", authority)
+		if used, err := connPool.addConnIfNeeded(addr, t2, c); err != nil {
+			go c.Close()
+			return erringRoundTripper{err}
+		} else if !used {
+			// Turns out we don't need this c.
+			// For example, two goroutines made requests to the same host
+			// at the same time, both kicking off TCP dials. (since protocol
+			// was unknown)
+			go c.Close()
+		}
+		return t2
+	}
+	if m := t1.TLSNextProto; len(m) == 0 {
+		t1.TLSNextProto = map[string]func(string, *tls.Conn) http.RoundTripper{
+			"h2": upgradeFn,
+		}
+	} else {
+		m["h2"] = upgradeFn
+	}
+	return t2, nil
+}
+
+// registerHTTPSProtocol calls Transport.RegisterProtocol but
+// convering panics into errors.
+func registerHTTPSProtocol(t *http.Transport, rt http.RoundTripper) (err error) {
+	defer func() {
+		if e := recover(); e != nil {
+			err = fmt.Errorf("%v", e)
+		}
+	}()
+	t.RegisterProtocol("https", rt)
+	return nil
+}
+
+// noDialH2RoundTripper is a RoundTripper which only tries to complete the request
+// if there's already has a cached connection to the host.
+type noDialH2RoundTripper struct{ t *Transport }
+
+func (rt noDialH2RoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	res, err := rt.t.RoundTrip(req)
+	if err == ErrNoCachedConn {
+		return nil, http.ErrSkipAltProtocol
+	}
+	return res, err
+}
diff --git a/vendor/golang.org/x/net/http2/errors.go b/vendor/golang.org/x/net/http2/errors.go
index 1f8de65e..20fd7626 100644
--- a/vendor/golang.org/x/net/http2/errors.go
+++ b/vendor/golang.org/x/net/http2/errors.go
@@ -4,7 +4,10 @@
 
 package http2
 
-import "fmt"
+import (
+	"errors"
+	"fmt"
+)
 
 // An ErrCode is an unsigned 32-bit error code as defined in the HTTP/2 spec.
 type ErrCode uint32
@@ -61,9 +64,17 @@ func (e ConnectionError) Error() string { return fmt.Sprintf("connection error:
 type StreamError struct {
 	StreamID uint32
 	Code     ErrCode
+	Cause    error // optional additional detail
+}
+
+func streamError(id uint32, code ErrCode) StreamError {
+	return StreamError{StreamID: id, Code: code}
 }
 
 func (e StreamError) Error() string {
+	if e.Cause != nil {
+		return fmt.Sprintf("stream error: stream ID %d; %v; %v", e.StreamID, e.Code, e.Cause)
+	}
 	return fmt.Sprintf("stream error: stream ID %d; %v", e.StreamID, e.Code)
 }
 
@@ -75,3 +86,45 @@ func (e StreamError) Error() string {
 type goAwayFlowError struct{}
 
 func (goAwayFlowError) Error() string { return "connection exceeded flow control window size" }
+
+// connErrorReason wraps a ConnectionError with an informative error about why it occurs.
+
+// Errors of this type are only returned by the frame parser functions
+// and converted into ConnectionError(ErrCodeProtocol).
+type connError struct {
+	Code   ErrCode
+	Reason string
+}
+
+func (e connError) Error() string {
+	return fmt.Sprintf("http2: connection error: %v: %v", e.Code, e.Reason)
+}
+
+type pseudoHeaderError string
+
+func (e pseudoHeaderError) Error() string {
+	return fmt.Sprintf("invalid pseudo-header %q", string(e))
+}
+
+type duplicatePseudoHeaderError string
+
+func (e duplicatePseudoHeaderError) Error() string {
+	return fmt.Sprintf("duplicate pseudo-header %q", string(e))
+}
+
+type headerFieldNameError string
+
+func (e headerFieldNameError) Error() string {
+	return fmt.Sprintf("invalid header field name %q", string(e))
+}
+
+type headerFieldValueError string
+
+func (e headerFieldValueError) Error() string {
+	return fmt.Sprintf("invalid header field value %q", string(e))
+}
+
+var (
+	errMixPseudoHeaderTypes = errors.New("mix of request and response pseudo headers")
+	errPseudoAfterRegular   = errors.New("pseudo header field after regular")
+)
diff --git a/vendor/golang.org/x/net/http2/frame.go b/vendor/golang.org/x/net/http2/frame.go
index 30c333a1..c9b09bb6 100644
--- a/vendor/golang.org/x/net/http2/frame.go
+++ b/vendor/golang.org/x/net/http2/frame.go
@@ -10,7 +10,12 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"log"
+	"strings"
 	"sync"
+
+	"golang.org/x/net/http2/hpack"
+	"golang.org/x/net/lex/httplex"
 )
 
 const frameHeaderLen = 9
@@ -171,6 +176,12 @@ func (h FrameHeader) Header() FrameHeader { return h }
 func (h FrameHeader) String() string {
 	var buf bytes.Buffer
 	buf.WriteString("[FrameHeader ")
+	h.writeDebug(&buf)
+	buf.WriteByte(']')
+	return buf.String()
+}
+
+func (h FrameHeader) writeDebug(buf *bytes.Buffer) {
 	buf.WriteString(h.Type.String())
 	if h.Flags != 0 {
 		buf.WriteString(" flags=")
@@ -187,15 +198,14 @@ func (h FrameHeader) String() string {
 			if name != "" {
 				buf.WriteString(name)
 			} else {
-				fmt.Fprintf(&buf, "0x%x", 1<<i)
+				fmt.Fprintf(buf, "0x%x", 1<<i)
 			}
 		}
 	}
 	if h.StreamID != 0 {
-		fmt.Fprintf(&buf, " stream=%d", h.StreamID)
+		fmt.Fprintf(buf, " stream=%d", h.StreamID)
 	}
-	fmt.Fprintf(&buf, " len=%d]", h.Length)
-	return buf.String()
+	fmt.Fprintf(buf, " len=%d", h.Length)
 }
 
 func (h *FrameHeader) checkValid() {
@@ -255,6 +265,11 @@ type Frame interface {
 type Framer struct {
 	r         io.Reader
 	lastFrame Frame
+	errDetail error
+
+	// lastHeaderStream is non-zero if the last frame was an
+	// unfinished HEADERS/CONTINUATION.
+	lastHeaderStream uint32
 
 	maxReadSize uint32
 	headerBuf   [frameHeaderLen]byte
@@ -271,18 +286,48 @@ type Framer struct {
 	wbuf []byte
 
 	// AllowIllegalWrites permits the Framer's Write methods to
-	// write frames that do not conform to the HTTP/2 spec.  This
+	// write frames that do not conform to the HTTP/2 spec. This
 	// permits using the Framer to test other HTTP/2
 	// implementations' conformance to the spec.
 	// If false, the Write methods will prefer to return an error
 	// rather than comply.
 	AllowIllegalWrites bool
 
+	// AllowIllegalReads permits the Framer's ReadFrame method
+	// to return non-compliant frames or frame orders.
+	// This is for testing and permits using the Framer to test
+	// other HTTP/2 implementations' conformance to the spec.
+	// It is not compatible with ReadMetaHeaders.
+	AllowIllegalReads bool
+
+	// ReadMetaHeaders if non-nil causes ReadFrame to merge
+	// HEADERS and CONTINUATION frames together and return
+	// MetaHeadersFrame instead.
+	ReadMetaHeaders *hpack.Decoder
+
+	// MaxHeaderListSize is the http2 MAX_HEADER_LIST_SIZE.
+	// It's used only if ReadMetaHeaders is set; 0 means a sane default
+	// (currently 16MB)
+	// If the limit is hit, MetaHeadersFrame.Truncated is set true.
+	MaxHeaderListSize uint32
+
 	// TODO: track which type of frame & with which flags was sent
 	// last.  Then return an error (unless AllowIllegalWrites) if
 	// we're in the middle of a header block and a
 	// non-Continuation or Continuation on a different stream is
 	// attempted to be written.
+
+	logReads bool
+
+	debugFramer    *Framer // only use for logging written writes
+	debugFramerBuf *bytes.Buffer
+}
+
+func (fr *Framer) maxHeaderListSize() uint32 {
+	if fr.MaxHeaderListSize == 0 {
+		return 16 << 20 // sane default, per docs
+	}
+	return fr.MaxHeaderListSize
 }
 
 func (f *Framer) startWrite(ftype FrameType, flags Flags, streamID uint32) {
@@ -310,6 +355,10 @@ func (f *Framer) endWrite() error {
 		byte(length>>16),
 		byte(length>>8),
 		byte(length))
+	if logFrameWrites {
+		f.logWrite()
+	}
+
 	n, err := f.w.Write(f.wbuf)
 	if err == nil && n != len(f.wbuf) {
 		err = io.ErrShortWrite
@@ -317,6 +366,24 @@ func (f *Framer) endWrite() error {
 	return err
 }
 
+func (f *Framer) logWrite() {
+	if f.debugFramer == nil {
+		f.debugFramerBuf = new(bytes.Buffer)
+		f.debugFramer = NewFramer(nil, f.debugFramerBuf)
+		f.debugFramer.logReads = false // we log it ourselves, saying "wrote" below
+		// Let us read anything, even if we accidentally wrote it
+		// in the wrong order:
+		f.debugFramer.AllowIllegalReads = true
+	}
+	f.debugFramerBuf.Write(f.wbuf)
+	fr, err := f.debugFramer.ReadFrame()
+	if err != nil {
+		log.Printf("http2: Framer %p: failed to decode just-written frame", f)
+		return
+	}
+	log.Printf("http2: Framer %p: wrote %v", f, summarizeFrame(fr))
+}
+
 func (f *Framer) writeByte(v byte)     { f.wbuf = append(f.wbuf, v) }
 func (f *Framer) writeBytes(v []byte)  { f.wbuf = append(f.wbuf, v...) }
 func (f *Framer) writeUint16(v uint16) { f.wbuf = append(f.wbuf, byte(v>>8), byte(v)) }
@@ -332,8 +399,9 @@ const (
 // NewFramer returns a Framer that writes frames to w and reads them from r.
 func NewFramer(w io.Writer, r io.Reader) *Framer {
 	fr := &Framer{
-		w: w,
-		r: r,
+		w:        w,
+		r:        r,
+		logReads: logFrameReads,
 	}
 	fr.getReadBuf = func(size uint32) []byte {
 		if cap(fr.readBuf) >= int(size) {
@@ -357,15 +425,39 @@ func (fr *Framer) SetMaxReadFrameSize(v uint32) {
 	fr.maxReadSize = v
 }
 
+// ErrorDetail returns a more detailed error of the last error
+// returned by Framer.ReadFrame. For instance, if ReadFrame
+// returns a StreamError with code PROTOCOL_ERROR, ErrorDetail
+// will say exactly what was invalid. ErrorDetail is not guaranteed
+// to return a non-nil value and like the rest of the http2 package,
+// its return value is not protected by an API compatibility promise.
+// ErrorDetail is reset after the next call to ReadFrame.
+func (fr *Framer) ErrorDetail() error {
+	return fr.errDetail
+}
+
 // ErrFrameTooLarge is returned from Framer.ReadFrame when the peer
 // sends a frame that is larger than declared with SetMaxReadFrameSize.
 var ErrFrameTooLarge = errors.New("http2: frame too large")
 
+// terminalReadFrameError reports whether err is an unrecoverable
+// error from ReadFrame and no other frames should be read.
+func terminalReadFrameError(err error) bool {
+	if _, ok := err.(StreamError); ok {
+		return false
+	}
+	return err != nil
+}
+
 // ReadFrame reads a single frame. The returned Frame is only valid
 // until the next call to ReadFrame.
-// If the frame is larger than previously set with SetMaxReadFrameSize,
-// the returned error is ErrFrameTooLarge.
+//
+// If the frame is larger than previously set with SetMaxReadFrameSize, the
+// returned error is ErrFrameTooLarge. Other errors may be of type
+// ConnectionError, StreamError, or anything else from the underlying
+// reader.
 func (fr *Framer) ReadFrame() (Frame, error) {
+	fr.errDetail = nil
 	if fr.lastFrame != nil {
 		fr.lastFrame.invalidate()
 	}
@@ -382,12 +474,71 @@ func (fr *Framer) ReadFrame() (Frame, error) {
 	}
 	f, err := typeFrameParser(fh.Type)(fh, payload)
 	if err != nil {
+		if ce, ok := err.(connError); ok {
+			return nil, fr.connError(ce.Code, ce.Reason)
+		}
 		return nil, err
 	}
-	fr.lastFrame = f
+	if err := fr.checkFrameOrder(f); err != nil {
+		return nil, err
+	}
+	if fr.logReads {
+		log.Printf("http2: Framer %p: read %v", fr, summarizeFrame(f))
+	}
+	if fh.Type == FrameHeaders && fr.ReadMetaHeaders != nil {
+		return fr.readMetaFrame(f.(*HeadersFrame))
+	}
 	return f, nil
 }
 
+// connError returns ConnectionError(code) but first
+// stashes away a public reason to the caller can optionally relay it
+// to the peer before hanging up on them. This might help others debug
+// their implementations.
+func (fr *Framer) connError(code ErrCode, reason string) error {
+	fr.errDetail = errors.New(reason)
+	return ConnectionError(code)
+}
+
+// checkFrameOrder reports an error if f is an invalid frame to return
+// next from ReadFrame. Mostly it checks whether HEADERS and
+// CONTINUATION frames are contiguous.
+func (fr *Framer) checkFrameOrder(f Frame) error {
+	last := fr.lastFrame
+	fr.lastFrame = f
+	if fr.AllowIllegalReads {
+		return nil
+	}
+
+	fh := f.Header()
+	if fr.lastHeaderStream != 0 {
+		if fh.Type != FrameContinuation {
+			return fr.connError(ErrCodeProtocol,
+				fmt.Sprintf("got %s for stream %d; expected CONTINUATION following %s for stream %d",
+					fh.Type, fh.StreamID,
+					last.Header().Type, fr.lastHeaderStream))
+		}
+		if fh.StreamID != fr.lastHeaderStream {
+			return fr.connError(ErrCodeProtocol,
+				fmt.Sprintf("got CONTINUATION for stream %d; expected stream %d",
+					fh.StreamID, fr.lastHeaderStream))
+		}
+	} else if fh.Type == FrameContinuation {
+		return fr.connError(ErrCodeProtocol, fmt.Sprintf("unexpected CONTINUATION for stream %d", fh.StreamID))
+	}
+
+	switch fh.Type {
+	case FrameHeaders, FrameContinuation:
+		if fh.Flags.Has(FlagHeadersEndHeaders) {
+			fr.lastHeaderStream = 0
+		} else {
+			fr.lastHeaderStream = fh.StreamID
+		}
+	}
+
+	return nil
+}
+
 // A DataFrame conveys arbitrary, variable-length sequences of octets
 // associated with a stream.
 // See http://http2.github.io/http2-spec/#rfc.section.6.1
@@ -416,7 +567,7 @@ func parseDataFrame(fh FrameHeader, payload []byte) (Frame, error) {
 		// field is 0x0, the recipient MUST respond with a
 		// connection error (Section 5.4.1) of type
 		// PROTOCOL_ERROR.
-		return nil, ConnectionError(ErrCodeProtocol)
+		return nil, connError{ErrCodeProtocol, "DATA frame with stream ID 0"}
 	}
 	f := &DataFrame{
 		FrameHeader: fh,
@@ -434,13 +585,21 @@ func parseDataFrame(fh FrameHeader, payload []byte) (Frame, error) {
 		// length of the frame payload, the recipient MUST
 		// treat this as a connection error.
 		// Filed: https://github.com/http2/http2-spec/issues/610
-		return nil, ConnectionError(ErrCodeProtocol)
+		return nil, connError{ErrCodeProtocol, "pad size larger than data payload"}
 	}
 	f.data = payload[:len(payload)-int(padSize)]
 	return f, nil
 }
 
-var errStreamID = errors.New("invalid streamid")
+var (
+	errStreamID    = errors.New("invalid stream ID")
+	errDepStreamID = errors.New("invalid dependent stream ID")
+	errPadLength   = errors.New("pad length too large")
+)
+
+func validStreamIDOrZero(streamID uint32) bool {
+	return streamID&(1<<31) == 0
+}
 
 func validStreamID(streamID uint32) bool {
 	return streamID != 0 && streamID&(1<<31) == 0
@@ -449,18 +608,40 @@ func validStreamID(streamID uint32) bool {
 // WriteData writes a DATA frame.
 //
 // It will perform exactly one Write to the underlying Writer.
-// It is the caller's responsibility to not call other Write methods concurrently.
+// It is the caller's responsibility not to violate the maximum frame size
+// and to not call other Write methods concurrently.
 func (f *Framer) WriteData(streamID uint32, endStream bool, data []byte) error {
-	// TODO: ignoring padding for now. will add when somebody cares.
+	return f.WriteDataPadded(streamID, endStream, data, nil)
+}
+
+// WriteData writes a DATA frame with optional padding.
+//
+// If pad is nil, the padding bit is not sent.
+// The length of pad must not exceed 255 bytes.
+//
+// It will perform exactly one Write to the underlying Writer.
+// It is the caller's responsibility not to violate the maximum frame size
+// and to not call other Write methods concurrently.
+func (f *Framer) WriteDataPadded(streamID uint32, endStream bool, data, pad []byte) error {
 	if !validStreamID(streamID) && !f.AllowIllegalWrites {
 		return errStreamID
 	}
+	if len(pad) > 255 {
+		return errPadLength
+	}
 	var flags Flags
 	if endStream {
 		flags |= FlagDataEndStream
 	}
+	if pad != nil {
+		flags |= FlagDataPadded
+	}
 	f.startWrite(FrameData, flags, streamID)
+	if pad != nil {
+		f.wbuf = append(f.wbuf, byte(len(pad)))
+	}
 	f.wbuf = append(f.wbuf, data...)
+	f.wbuf = append(f.wbuf, pad...)
 	return f.endWrite()
 }
 
@@ -574,6 +755,8 @@ type PingFrame struct {
 	Data [8]byte
 }
 
+func (f *PingFrame) IsAck() bool { return f.Flags.Has(FlagPingAck) }
+
 func parsePingFrame(fh FrameHeader, payload []byte) (Frame, error) {
 	if len(payload) != 8 {
 		return nil, ConnectionError(ErrCodeFrameSize)
@@ -680,7 +863,7 @@ func parseWindowUpdateFrame(fh FrameHeader, p []byte) (Frame, error) {
 		if fh.StreamID == 0 {
 			return nil, ConnectionError(ErrCodeProtocol)
 		}
-		return nil, StreamError{fh.StreamID, ErrCodeProtocol}
+		return nil, streamError(fh.StreamID, ErrCodeProtocol)
 	}
 	return &WindowUpdateFrame{
 		FrameHeader: fh,
@@ -739,7 +922,7 @@ func parseHeadersFrame(fh FrameHeader, p []byte) (_ Frame, err error) {
 		// is received whose stream identifier field is 0x0, the recipient MUST
 		// respond with a connection error (Section 5.4.1) of type
 		// PROTOCOL_ERROR.
-		return nil, ConnectionError(ErrCodeProtocol)
+		return nil, connError{ErrCodeProtocol, "HEADERS frame with stream ID 0"}
 	}
 	var padLength uint8
 	if fh.Flags.Has(FlagHeadersPadded) {
@@ -761,7 +944,7 @@ func parseHeadersFrame(fh FrameHeader, p []byte) (_ Frame, err error) {
 		}
 	}
 	if len(p)-int(padLength) <= 0 {
-		return nil, StreamError{fh.StreamID, ErrCodeProtocol}
+		return nil, streamError(fh.StreamID, ErrCodeProtocol)
 	}
 	hf.headerFragBuf = p[:len(p)-int(padLength)]
 	return hf, nil
@@ -825,8 +1008,8 @@ func (f *Framer) WriteHeaders(p HeadersFrameParam) error {
 	}
 	if !p.Priority.IsZero() {
 		v := p.Priority.StreamDep
-		if !validStreamID(v) && !f.AllowIllegalWrites {
-			return errors.New("invalid dependent stream id")
+		if !validStreamIDOrZero(v) && !f.AllowIllegalWrites {
+			return errDepStreamID
 		}
 		if p.Priority.Exclusive {
 			v |= 1 << 31
@@ -869,10 +1052,10 @@ func (p PriorityParam) IsZero() bool {
 
 func parsePriorityFrame(fh FrameHeader, payload []byte) (Frame, error) {
 	if fh.StreamID == 0 {
-		return nil, ConnectionError(ErrCodeProtocol)
+		return nil, connError{ErrCodeProtocol, "PRIORITY frame with stream ID 0"}
 	}
 	if len(payload) != 5 {
-		return nil, ConnectionError(ErrCodeFrameSize)
+		return nil, connError{ErrCodeFrameSize, fmt.Sprintf("PRIORITY frame payload size was %d; want 5", len(payload))}
 	}
 	v := binary.BigEndian.Uint32(payload[:4])
 	streamID := v & 0x7fffffff // mask off high bit
@@ -894,6 +1077,9 @@ func (f *Framer) WritePriority(streamID uint32, p PriorityParam) error {
 	if !validStreamID(streamID) && !f.AllowIllegalWrites {
 		return errStreamID
 	}
+	if !validStreamIDOrZero(p.StreamDep) {
+		return errDepStreamID
+	}
 	f.startWrite(FramePriority, 0, streamID)
 	v := p.StreamDep
 	if p.Exclusive {
@@ -942,13 +1128,12 @@ type ContinuationFrame struct {
 }
 
 func parseContinuationFrame(fh FrameHeader, p []byte) (Frame, error) {
+	if fh.StreamID == 0 {
+		return nil, connError{ErrCodeProtocol, "CONTINUATION frame with stream ID 0"}
+	}
 	return &ContinuationFrame{fh, p}, nil
 }
 
-func (f *ContinuationFrame) StreamEnded() bool {
-	return f.FrameHeader.Flags.Has(FlagDataEndStream)
-}
-
 func (f *ContinuationFrame) HeaderBlockFragment() []byte {
 	f.checkValid()
 	return f.headerFragBuf
@@ -1110,3 +1295,245 @@ type streamEnder interface {
 type headersEnder interface {
 	HeadersEnded() bool
 }
+
+type headersOrContinuation interface {
+	headersEnder
+	HeaderBlockFragment() []byte
+}
+
+// A MetaHeadersFrame is the representation of one HEADERS frame and
+// zero or more contiguous CONTINUATION frames and the decoding of
+// their HPACK-encoded contents.
+//
+// This type of frame does not appear on the wire and is only returned
+// by the Framer when Framer.ReadMetaHeaders is set.
+type MetaHeadersFrame struct {
+	*HeadersFrame
+
+	// Fields are the fields contained in the HEADERS and
+	// CONTINUATION frames. The underlying slice is owned by the
+	// Framer and must not be retained after the next call to
+	// ReadFrame.
+	//
+	// Fields are guaranteed to be in the correct http2 order and
+	// not have unknown pseudo header fields or invalid header
+	// field names or values. Required pseudo header fields may be
+	// missing, however. Use the MetaHeadersFrame.Pseudo accessor
+	// method access pseudo headers.
+	Fields []hpack.HeaderField
+
+	// Truncated is whether the max header list size limit was hit
+	// and Fields is incomplete. The hpack decoder state is still
+	// valid, however.
+	Truncated bool
+}
+
+// PseudoValue returns the given pseudo header field's value.
+// The provided pseudo field should not contain the leading colon.
+func (mh *MetaHeadersFrame) PseudoValue(pseudo string) string {
+	for _, hf := range mh.Fields {
+		if !hf.IsPseudo() {
+			return ""
+		}
+		if hf.Name[1:] == pseudo {
+			return hf.Value
+		}
+	}
+	return ""
+}
+
+// RegularFields returns the regular (non-pseudo) header fields of mh.
+// The caller does not own the returned slice.
+func (mh *MetaHeadersFrame) RegularFields() []hpack.HeaderField {
+	for i, hf := range mh.Fields {
+		if !hf.IsPseudo() {
+			return mh.Fields[i:]
+		}
+	}
+	return nil
+}
+
+// PseudoFields returns the pseudo header fields of mh.
+// The caller does not own the returned slice.
+func (mh *MetaHeadersFrame) PseudoFields() []hpack.HeaderField {
+	for i, hf := range mh.Fields {
+		if !hf.IsPseudo() {
+			return mh.Fields[:i]
+		}
+	}
+	return mh.Fields
+}
+
+func (mh *MetaHeadersFrame) checkPseudos() error {
+	var isRequest, isResponse bool
+	pf := mh.PseudoFields()
+	for i, hf := range pf {
+		switch hf.Name {
+		case ":method", ":path", ":scheme", ":authority":
+			isRequest = true
+		case ":status":
+			isResponse = true
+		default:
+			return pseudoHeaderError(hf.Name)
+		}
+		// Check for duplicates.
+		// This would be a bad algorithm, but N is 4.
+		// And this doesn't allocate.
+		for _, hf2 := range pf[:i] {
+			if hf.Name == hf2.Name {
+				return duplicatePseudoHeaderError(hf.Name)
+			}
+		}
+	}
+	if isRequest && isResponse {
+		return errMixPseudoHeaderTypes
+	}
+	return nil
+}
+
+func (fr *Framer) maxHeaderStringLen() int {
+	v := fr.maxHeaderListSize()
+	if uint32(int(v)) == v {
+		return int(v)
+	}
+	// They had a crazy big number for MaxHeaderBytes anyway,
+	// so give them unlimited header lengths:
+	return 0
+}
+
+// readMetaFrame returns 0 or more CONTINUATION frames from fr and
+// merge them into into the provided hf and returns a MetaHeadersFrame
+// with the decoded hpack values.
+func (fr *Framer) readMetaFrame(hf *HeadersFrame) (*MetaHeadersFrame, error) {
+	if fr.AllowIllegalReads {
+		return nil, errors.New("illegal use of AllowIllegalReads with ReadMetaHeaders")
+	}
+	mh := &MetaHeadersFrame{
+		HeadersFrame: hf,
+	}
+	var remainSize = fr.maxHeaderListSize()
+	var sawRegular bool
+
+	var invalid error // pseudo header field errors
+	hdec := fr.ReadMetaHeaders
+	hdec.SetEmitEnabled(true)
+	hdec.SetMaxStringLength(fr.maxHeaderStringLen())
+	hdec.SetEmitFunc(func(hf hpack.HeaderField) {
+		if VerboseLogs && logFrameReads {
+			log.Printf("http2: decoded hpack field %+v", hf)
+		}
+		if !httplex.ValidHeaderFieldValue(hf.Value) {
+			invalid = headerFieldValueError(hf.Value)
+		}
+		isPseudo := strings.HasPrefix(hf.Name, ":")
+		if isPseudo {
+			if sawRegular {
+				invalid = errPseudoAfterRegular
+			}
+		} else {
+			sawRegular = true
+			if !validWireHeaderFieldName(hf.Name) {
+				invalid = headerFieldNameError(hf.Name)
+			}
+		}
+
+		if invalid != nil {
+			hdec.SetEmitEnabled(false)
+			return
+		}
+
+		size := hf.Size()
+		if size > remainSize {
+			hdec.SetEmitEnabled(false)
+			mh.Truncated = true
+			return
+		}
+		remainSize -= size
+
+		mh.Fields = append(mh.Fields, hf)
+	})
+	// Lose reference to MetaHeadersFrame:
+	defer hdec.SetEmitFunc(func(hf hpack.HeaderField) {})
+
+	var hc headersOrContinuation = hf
+	for {
+		frag := hc.HeaderBlockFragment()
+		if _, err := hdec.Write(frag); err != nil {
+			return nil, ConnectionError(ErrCodeCompression)
+		}
+
+		if hc.HeadersEnded() {
+			break
+		}
+		if f, err := fr.ReadFrame(); err != nil {
+			return nil, err
+		} else {
+			hc = f.(*ContinuationFrame) // guaranteed by checkFrameOrder
+		}
+	}
+
+	mh.HeadersFrame.headerFragBuf = nil
+	mh.HeadersFrame.invalidate()
+
+	if err := hdec.Close(); err != nil {
+		return nil, ConnectionError(ErrCodeCompression)
+	}
+	if invalid != nil {
+		fr.errDetail = invalid
+		if VerboseLogs {
+			log.Printf("http2: invalid header: %v", invalid)
+		}
+		return nil, StreamError{mh.StreamID, ErrCodeProtocol, invalid}
+	}
+	if err := mh.checkPseudos(); err != nil {
+		fr.errDetail = err
+		if VerboseLogs {
+			log.Printf("http2: invalid pseudo headers: %v", err)
+		}
+		return nil, StreamError{mh.StreamID, ErrCodeProtocol, err}
+	}
+	return mh, nil
+}
+
+func summarizeFrame(f Frame) string {
+	var buf bytes.Buffer
+	f.Header().writeDebug(&buf)
+	switch f := f.(type) {
+	case *SettingsFrame:
+		n := 0
+		f.ForeachSetting(func(s Setting) error {
+			n++
+			if n == 1 {
+				buf.WriteString(", settings:")
+			}
+			fmt.Fprintf(&buf, " %v=%v,", s.ID, s.Val)
+			return nil
+		})
+		if n > 0 {
+			buf.Truncate(buf.Len() - 1) // remove trailing comma
+		}
+	case *DataFrame:
+		data := f.Data()
+		const max = 256
+		if len(data) > max {
+			data = data[:max]
+		}
+		fmt.Fprintf(&buf, " data=%q", data)
+		if len(f.Data()) > max {
+			fmt.Fprintf(&buf, " (%d bytes omitted)", len(f.Data())-max)
+		}
+	case *WindowUpdateFrame:
+		if f.StreamID == 0 {
+			buf.WriteString(" (conn)")
+		}
+		fmt.Fprintf(&buf, " incr=%v", f.Increment)
+	case *PingFrame:
+		fmt.Fprintf(&buf, " ping=%q", f.Data[:])
+	case *GoAwayFrame:
+		fmt.Fprintf(&buf, " LastStreamID=%v ErrCode=%v Debug=%q",
+			f.LastStreamID, f.ErrCode, f.debugData)
+	case *RSTStreamFrame:
+		fmt.Fprintf(&buf, " ErrCode=%v", f.ErrCode)
+	}
+	return buf.String()
+}
diff --git a/vendor/golang.org/x/net/http2/go16.go b/vendor/golang.org/x/net/http2/go16.go
new file mode 100644
index 00000000..2b72855f
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/go16.go
@@ -0,0 +1,43 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build go1.6
+
+package http2
+
+import (
+	"crypto/tls"
+	"net/http"
+	"time"
+)
+
+func transportExpectContinueTimeout(t1 *http.Transport) time.Duration {
+	return t1.ExpectContinueTimeout
+}
+
+// isBadCipher reports whether the cipher is blacklisted by the HTTP/2 spec.
+func isBadCipher(cipher uint16) bool {
+	switch cipher {
+	case tls.TLS_RSA_WITH_RC4_128_SHA,
+		tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
+		tls.TLS_RSA_WITH_AES_128_CBC_SHA,
+		tls.TLS_RSA_WITH_AES_256_CBC_SHA,
+		tls.TLS_RSA_WITH_AES_128_GCM_SHA256,
+		tls.TLS_RSA_WITH_AES_256_GCM_SHA384,
+		tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
+		tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
+		tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
+		tls.TLS_ECDHE_RSA_WITH_RC4_128_SHA,
+		tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
+		tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
+		tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:
+		// Reject cipher suites from Appendix A.
+		// "This list includes those cipher suites that do not
+		// offer an ephemeral key exchange and those that are
+		// based on the TLS null, stream or block cipher type"
+		return true
+	default:
+		return false
+	}
+}
diff --git a/vendor/golang.org/x/net/http2/go17.go b/vendor/golang.org/x/net/http2/go17.go
new file mode 100644
index 00000000..730319dd
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/go17.go
@@ -0,0 +1,94 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build go1.7
+
+package http2
+
+import (
+	"context"
+	"net"
+	"net/http"
+	"net/http/httptrace"
+	"time"
+)
+
+type contextContext interface {
+	context.Context
+}
+
+func serverConnBaseContext(c net.Conn, opts *ServeConnOpts) (ctx contextContext, cancel func()) {
+	ctx, cancel = context.WithCancel(context.Background())
+	ctx = context.WithValue(ctx, http.LocalAddrContextKey, c.LocalAddr())
+	if hs := opts.baseConfig(); hs != nil {
+		ctx = context.WithValue(ctx, http.ServerContextKey, hs)
+	}
+	return
+}
+
+func contextWithCancel(ctx contextContext) (_ contextContext, cancel func()) {
+	return context.WithCancel(ctx)
+}
+
+func requestWithContext(req *http.Request, ctx contextContext) *http.Request {
+	return req.WithContext(ctx)
+}
+
+type clientTrace httptrace.ClientTrace
+
+func reqContext(r *http.Request) context.Context { return r.Context() }
+
+func setResponseUncompressed(res *http.Response) { res.Uncompressed = true }
+
+func traceGotConn(req *http.Request, cc *ClientConn) {
+	trace := httptrace.ContextClientTrace(req.Context())
+	if trace == nil || trace.GotConn == nil {
+		return
+	}
+	ci := httptrace.GotConnInfo{Conn: cc.tconn}
+	cc.mu.Lock()
+	ci.Reused = cc.nextStreamID > 1
+	ci.WasIdle = len(cc.streams) == 0 && ci.Reused
+	if ci.WasIdle && !cc.lastActive.IsZero() {
+		ci.IdleTime = time.Now().Sub(cc.lastActive)
+	}
+	cc.mu.Unlock()
+
+	trace.GotConn(ci)
+}
+
+func traceWroteHeaders(trace *clientTrace) {
+	if trace != nil && trace.WroteHeaders != nil {
+		trace.WroteHeaders()
+	}
+}
+
+func traceGot100Continue(trace *clientTrace) {
+	if trace != nil && trace.Got100Continue != nil {
+		trace.Got100Continue()
+	}
+}
+
+func traceWait100Continue(trace *clientTrace) {
+	if trace != nil && trace.Wait100Continue != nil {
+		trace.Wait100Continue()
+	}
+}
+
+func traceWroteRequest(trace *clientTrace, err error) {
+	if trace != nil && trace.WroteRequest != nil {
+		trace.WroteRequest(httptrace.WroteRequestInfo{Err: err})
+	}
+}
+
+func traceFirstResponseByte(trace *clientTrace) {
+	if trace != nil && trace.GotFirstResponseByte != nil {
+		trace.GotFirstResponseByte()
+	}
+}
+
+func requestTrace(req *http.Request) *clientTrace {
+	trace := httptrace.ContextClientTrace(req.Context())
+	return (*clientTrace)(trace)
+}
diff --git a/vendor/golang.org/x/net/http2/h2demo/.gitignore b/vendor/golang.org/x/net/http2/h2demo/.gitignore
deleted file mode 100644
index 0de86ddb..00000000
--- a/vendor/golang.org/x/net/http2/h2demo/.gitignore
+++ /dev/null
@@ -1,5 +0,0 @@
-h2demo
-h2demo.linux
-client-id.dat
-client-secret.dat
-token.dat
diff --git a/vendor/golang.org/x/net/http2/h2demo/Makefile b/vendor/golang.org/x/net/http2/h2demo/Makefile
deleted file mode 100644
index 3a77cf07..00000000
--- a/vendor/golang.org/x/net/http2/h2demo/Makefile
+++ /dev/null
@@ -1,5 +0,0 @@
-h2demo.linux: h2demo.go
-	GOOS=linux go build --tags=h2demo -o h2demo.linux .
-
-upload: h2demo.linux
-	cat h2demo.linux | go run launch.go --write_object=http2-demo-server-tls/h2demo --write_object_is_public
diff --git a/vendor/golang.org/x/net/http2/h2demo/README b/vendor/golang.org/x/net/http2/h2demo/README
deleted file mode 100644
index 212a96f3..00000000
--- a/vendor/golang.org/x/net/http2/h2demo/README
+++ /dev/null
@@ -1,16 +0,0 @@
-
-Client:
- -- Firefox nightly with about:config network.http.spdy.enabled.http2draft set true
- -- Chrome: go to chrome://flags/#enable-spdy4, save and restart (button at bottom)
-
-Make CA:
-$ openssl genrsa -out rootCA.key 2048
-$ openssl req -x509 -new -nodes -key rootCA.key -days 1024 -out rootCA.pem
-... install that to Firefox
-
-Make cert:
-$ openssl genrsa -out server.key 2048
-$ openssl req -new -key server.key -out server.csr
-$ openssl x509 -req -in server.csr -CA rootCA.pem -CAkey rootCA.key -CAcreateserial -out server.crt -days 500
-
-
diff --git a/vendor/golang.org/x/net/http2/h2demo/h2demo.go b/vendor/golang.org/x/net/http2/h2demo/h2demo.go
deleted file mode 100644
index 84b89e2b..00000000
--- a/vendor/golang.org/x/net/http2/h2demo/h2demo.go
+++ /dev/null
@@ -1,436 +0,0 @@
-// Copyright 2014 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build h2demo
-
-package main
-
-import (
-	"bytes"
-	"crypto/tls"
-	"flag"
-	"fmt"
-	"hash/crc32"
-	"image"
-	"image/jpeg"
-	"io"
-	"io/ioutil"
-	"log"
-	"net"
-	"net/http"
-	"path"
-	"regexp"
-	"runtime"
-	"strconv"
-	"strings"
-	"sync"
-	"time"
-
-	"camlistore.org/pkg/googlestorage"
-	"camlistore.org/pkg/singleflight"
-	"golang.org/x/net/http2"
-)
-
-var (
-	prod = flag.Bool("prod", false, "Whether to configure itself to be the production http2.golang.org server.")
-
-	httpsAddr = flag.String("https_addr", "localhost:4430", "TLS address to listen on ('host:port' or ':port'). Required.")
-	httpAddr  = flag.String("http_addr", "", "Plain HTTP address to listen on ('host:port', or ':port'). Empty means no HTTP.")
-
-	hostHTTP  = flag.String("http_host", "", "Optional host or host:port to use for http:// links to this service. By default, this is implied from -http_addr.")
-	hostHTTPS = flag.String("https_host", "", "Optional host or host:port to use for http:// links to this service. By default, this is implied from -https_addr.")
-)
-
-func homeOldHTTP(w http.ResponseWriter, r *http.Request) {
-	io.WriteString(w, `<html>
-<body>
-<h1>Go + HTTP/2</h1>
-<p>Welcome to <a href="https://golang.org/">the Go language</a>'s <a href="https://http2.github.io/">HTTP/2</a> demo & interop server.</p>
-<p>Unfortunately, you're <b>not</b> using HTTP/2 right now. To do so:</p>
-<ul>
-   <li>Use Firefox Nightly or go to <b>about:config</b> and enable "network.http.spdy.enabled.http2draft"</li>
-   <li>Use Google Chrome Canary and/or go to <b>chrome://flags/#enable-spdy4</b> to <i>Enable SPDY/4</i> (Chrome's name for HTTP/2)</li>
-</ul>
-<p>See code & instructions for connecting at <a href="https://github.com/golang/net/tree/master/http2">https://github.com/golang/net/tree/master/http2</a>.</p>
-
-</body></html>`)
-}
-
-func home(w http.ResponseWriter, r *http.Request) {
-	if r.URL.Path != "/" {
-		http.NotFound(w, r)
-		return
-	}
-	io.WriteString(w, `<html>
-<body>
-<h1>Go + HTTP/2</h1>
-
-<p>Welcome to <a href="https://golang.org/">the Go language</a>'s <a
-href="https://http2.github.io/">HTTP/2</a> demo & interop server.</p>
-
-<p>Congratulations, <b>you're using HTTP/2 right now</b>.</p>
-
-<p>This server exists for others in the HTTP/2 community to test their HTTP/2 client implementations and point out flaws in our server.</p>
-
-<p> The code is currently at <a
-href="https://golang.org/x/net/http2">golang.org/x/net/http2</a>
-but will move to the Go standard library at some point in the future
-(enabled by default, without users needing to change their code).</p>
-
-<p>Contact info: <i>bradfitz@golang.org</i>, or <a
-href="https://golang.org/issues">file a bug</a>.</p>
-
-<h2>Handlers for testing</h2>
-<ul>
-  <li>GET <a href="/reqinfo">/reqinfo</a> to dump the request + headers received</li>
-  <li>GET <a href="/clockstream">/clockstream</a> streams the current time every second</li>
-  <li>GET <a href="/gophertiles">/gophertiles</a> to see a page with a bunch of images</li>
-  <li>GET <a href="/file/gopher.png">/file/gopher.png</a> for a small file (does If-Modified-Since, Content-Range, etc)</li>
-  <li>GET <a href="/file/go.src.tar.gz">/file/go.src.tar.gz</a> for a larger file (~10 MB)</li>
-  <li>GET <a href="/redirect">/redirect</a> to redirect back to / (this page)</li>
-  <li>GET <a href="/goroutines">/goroutines</a> to see all active goroutines in this server</li>
-  <li>PUT something to <a href="/crc32">/crc32</a> to get a count of number of bytes and its CRC-32</li>
-</ul>
-
-</body></html>`)
-}
-
-func reqInfoHandler(w http.ResponseWriter, r *http.Request) {
-	w.Header().Set("Content-Type", "text/plain")
-	fmt.Fprintf(w, "Method: %s\n", r.Method)
-	fmt.Fprintf(w, "Protocol: %s\n", r.Proto)
-	fmt.Fprintf(w, "Host: %s\n", r.Host)
-	fmt.Fprintf(w, "RemoteAddr: %s\n", r.RemoteAddr)
-	fmt.Fprintf(w, "RequestURI: %q\n", r.RequestURI)
-	fmt.Fprintf(w, "URL: %#v\n", r.URL)
-	fmt.Fprintf(w, "Body.ContentLength: %d (-1 means unknown)\n", r.ContentLength)
-	fmt.Fprintf(w, "Close: %v (relevant for HTTP/1 only)\n", r.Close)
-	fmt.Fprintf(w, "TLS: %#v\n", r.TLS)
-	fmt.Fprintf(w, "\nHeaders:\n")
-	r.Header.Write(w)
-}
-
-func crcHandler(w http.ResponseWriter, r *http.Request) {
-	if r.Method != "PUT" {
-		http.Error(w, "PUT required.", 400)
-		return
-	}
-	crc := crc32.NewIEEE()
-	n, err := io.Copy(crc, r.Body)
-	if err == nil {
-		w.Header().Set("Content-Type", "text/plain")
-		fmt.Fprintf(w, "bytes=%d, CRC32=%x", n, crc.Sum(nil))
-	}
-}
-
-var (
-	fsGrp   singleflight.Group
-	fsMu    sync.Mutex // guards fsCache
-	fsCache = map[string]http.Handler{}
-)
-
-// fileServer returns a file-serving handler that proxies URL.
-// It lazily fetches URL on the first access and caches its contents forever.
-func fileServer(url string) http.Handler {
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		hi, err := fsGrp.Do(url, func() (interface{}, error) {
-			fsMu.Lock()
-			if h, ok := fsCache[url]; ok {
-				fsMu.Unlock()
-				return h, nil
-			}
-			fsMu.Unlock()
-
-			res, err := http.Get(url)
-			if err != nil {
-				return nil, err
-			}
-			defer res.Body.Close()
-			slurp, err := ioutil.ReadAll(res.Body)
-			if err != nil {
-				return nil, err
-			}
-
-			modTime := time.Now()
-			var h http.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-				http.ServeContent(w, r, path.Base(url), modTime, bytes.NewReader(slurp))
-			})
-			fsMu.Lock()
-			fsCache[url] = h
-			fsMu.Unlock()
-			return h, nil
-		})
-		if err != nil {
-			http.Error(w, err.Error(), 500)
-			return
-		}
-		hi.(http.Handler).ServeHTTP(w, r)
-	})
-}
-
-func clockStreamHandler(w http.ResponseWriter, r *http.Request) {
-	clientGone := w.(http.CloseNotifier).CloseNotify()
-	w.Header().Set("Content-Type", "text/plain")
-	ticker := time.NewTicker(1 * time.Second)
-	defer ticker.Stop()
-	fmt.Fprintf(w, "# ~1KB of junk to force browsers to start rendering immediately: \n")
-	io.WriteString(w, strings.Repeat("# xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx\n", 13))
-
-	for {
-		fmt.Fprintf(w, "%v\n", time.Now())
-		w.(http.Flusher).Flush()
-		select {
-		case <-ticker.C:
-		case <-clientGone:
-			log.Printf("Client %v disconnected from the clock", r.RemoteAddr)
-			return
-		}
-	}
-}
-
-func registerHandlers() {
-	tiles := newGopherTilesHandler()
-
-	mux2 := http.NewServeMux()
-	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		if r.TLS == nil {
-			if r.URL.Path == "/gophertiles" {
-				tiles.ServeHTTP(w, r)
-				return
-			}
-			http.Redirect(w, r, "https://"+httpsHost()+"/", http.StatusFound)
-			return
-		}
-		if r.ProtoMajor == 1 {
-			if r.URL.Path == "/reqinfo" {
-				reqInfoHandler(w, r)
-				return
-			}
-			homeOldHTTP(w, r)
-			return
-		}
-		mux2.ServeHTTP(w, r)
-	})
-	mux2.HandleFunc("/", home)
-	mux2.Handle("/file/gopher.png", fileServer("https://golang.org/doc/gopher/frontpage.png"))
-	mux2.Handle("/file/go.src.tar.gz", fileServer("https://storage.googleapis.com/golang/go1.4.1.src.tar.gz"))
-	mux2.HandleFunc("/reqinfo", reqInfoHandler)
-	mux2.HandleFunc("/crc32", crcHandler)
-	mux2.HandleFunc("/clockstream", clockStreamHandler)
-	mux2.Handle("/gophertiles", tiles)
-	mux2.HandleFunc("/redirect", func(w http.ResponseWriter, r *http.Request) {
-		http.Redirect(w, r, "/", http.StatusFound)
-	})
-	stripHomedir := regexp.MustCompile(`/(Users|home)/\w+`)
-	mux2.HandleFunc("/goroutines", func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-		buf := make([]byte, 2<<20)
-		w.Write(stripHomedir.ReplaceAll(buf[:runtime.Stack(buf, true)], nil))
-	})
-}
-
-func newGopherTilesHandler() http.Handler {
-	const gopherURL = "https://blog.golang.org/go-programming-language-turns-two_gophers.jpg"
-	res, err := http.Get(gopherURL)
-	if err != nil {
-		log.Fatal(err)
-	}
-	if res.StatusCode != 200 {
-		log.Fatalf("Error fetching %s: %v", gopherURL, res.Status)
-	}
-	slurp, err := ioutil.ReadAll(res.Body)
-	res.Body.Close()
-	if err != nil {
-		log.Fatal(err)
-	}
-	im, err := jpeg.Decode(bytes.NewReader(slurp))
-	if err != nil {
-		if len(slurp) > 1024 {
-			slurp = slurp[:1024]
-		}
-		log.Fatalf("Failed to decode gopher image: %v (got %q)", err, slurp)
-	}
-
-	type subImager interface {
-		SubImage(image.Rectangle) image.Image
-	}
-	const tileSize = 32
-	xt := im.Bounds().Max.X / tileSize
-	yt := im.Bounds().Max.Y / tileSize
-	var tile [][][]byte // y -> x -> jpeg bytes
-	for yi := 0; yi < yt; yi++ {
-		var row [][]byte
-		for xi := 0; xi < xt; xi++ {
-			si := im.(subImager).SubImage(image.Rectangle{
-				Min: image.Point{xi * tileSize, yi * tileSize},
-				Max: image.Point{(xi + 1) * tileSize, (yi + 1) * tileSize},
-			})
-			buf := new(bytes.Buffer)
-			if err := jpeg.Encode(buf, si, &jpeg.Options{Quality: 90}); err != nil {
-				log.Fatal(err)
-			}
-			row = append(row, buf.Bytes())
-		}
-		tile = append(tile, row)
-	}
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		ms, _ := strconv.Atoi(r.FormValue("latency"))
-		const nanosPerMilli = 1e6
-		if r.FormValue("x") != "" {
-			x, _ := strconv.Atoi(r.FormValue("x"))
-			y, _ := strconv.Atoi(r.FormValue("y"))
-			if ms <= 1000 {
-				time.Sleep(time.Duration(ms) * nanosPerMilli)
-			}
-			if x >= 0 && x < xt && y >= 0 && y < yt {
-				http.ServeContent(w, r, "", time.Time{}, bytes.NewReader(tile[y][x]))
-				return
-			}
-		}
-		io.WriteString(w, "<html><body onload='showtimes()'>")
-		fmt.Fprintf(w, "A grid of %d tiled images is below. Compare:<p>", xt*yt)
-		for _, ms := range []int{0, 30, 200, 1000} {
-			d := time.Duration(ms) * nanosPerMilli
-			fmt.Fprintf(w, "[<a href='https://%s/gophertiles?latency=%d'>HTTP/2, %v latency</a>] [<a href='http://%s/gophertiles?latency=%d'>HTTP/1, %v latency</a>]<br>\n",
-				httpsHost(), ms, d,
-				httpHost(), ms, d,
-			)
-		}
-		io.WriteString(w, "<p>\n")
-		cacheBust := time.Now().UnixNano()
-		for y := 0; y < yt; y++ {
-			for x := 0; x < xt; x++ {
-				fmt.Fprintf(w, "<img width=%d height=%d src='/gophertiles?x=%d&y=%d&cachebust=%d&latency=%d'>",
-					tileSize, tileSize, x, y, cacheBust, ms)
-			}
-			io.WriteString(w, "<br/>\n")
-		}
-		io.WriteString(w, `<p><div id='loadtimes'></div></p>
-<script>
-function showtimes() {
-	var times = 'Times from connection start:<br>'
-	times += 'DOM loaded: ' + (window.performance.timing.domContentLoadedEventEnd - window.performance.timing.connectStart) + 'ms<br>'
-	times += 'DOM complete (images loaded): ' + (window.performance.timing.domComplete - window.performance.timing.connectStart) + 'ms<br>'
-	document.getElementById('loadtimes').innerHTML = times
-}
-</script>
-<hr><a href='/'>&lt;&lt Back to Go HTTP/2 demo server</a></body></html>`)
-	})
-}
-
-func httpsHost() string {
-	if *hostHTTPS != "" {
-		return *hostHTTPS
-	}
-	if v := *httpsAddr; strings.HasPrefix(v, ":") {
-		return "localhost" + v
-	} else {
-		return v
-	}
-}
-
-func httpHost() string {
-	if *hostHTTP != "" {
-		return *hostHTTP
-	}
-	if v := *httpAddr; strings.HasPrefix(v, ":") {
-		return "localhost" + v
-	} else {
-		return v
-	}
-}
-
-func serveProdTLS() error {
-	c, err := googlestorage.NewServiceClient()
-	if err != nil {
-		return err
-	}
-	slurp := func(key string) ([]byte, error) {
-		const bucket = "http2-demo-server-tls"
-		rc, _, err := c.GetObject(&googlestorage.Object{
-			Bucket: bucket,
-			Key:    key,
-		})
-		if err != nil {
-			return nil, fmt.Errorf("Error fetching GCS object %q in bucket %q: %v", key, bucket, err)
-		}
-		defer rc.Close()
-		return ioutil.ReadAll(rc)
-	}
-	certPem, err := slurp("http2.golang.org.chained.pem")
-	if err != nil {
-		return err
-	}
-	keyPem, err := slurp("http2.golang.org.key")
-	if err != nil {
-		return err
-	}
-	cert, err := tls.X509KeyPair(certPem, keyPem)
-	if err != nil {
-		return err
-	}
-	srv := &http.Server{
-		TLSConfig: &tls.Config{
-			Certificates: []tls.Certificate{cert},
-		},
-	}
-	http2.ConfigureServer(srv, &http2.Server{})
-	ln, err := net.Listen("tcp", ":443")
-	if err != nil {
-		return err
-	}
-	return srv.Serve(tls.NewListener(tcpKeepAliveListener{ln.(*net.TCPListener)}, srv.TLSConfig))
-}
-
-type tcpKeepAliveListener struct {
-	*net.TCPListener
-}
-
-func (ln tcpKeepAliveListener) Accept() (c net.Conn, err error) {
-	tc, err := ln.AcceptTCP()
-	if err != nil {
-		return
-	}
-	tc.SetKeepAlive(true)
-	tc.SetKeepAlivePeriod(3 * time.Minute)
-	return tc, nil
-}
-
-func serveProd() error {
-	errc := make(chan error, 2)
-	go func() { errc <- http.ListenAndServe(":80", nil) }()
-	go func() { errc <- serveProdTLS() }()
-	return <-errc
-}
-
-func main() {
-	var srv http.Server
-	flag.BoolVar(&http2.VerboseLogs, "verbose", false, "Verbose HTTP/2 debugging.")
-	flag.Parse()
-	srv.Addr = *httpsAddr
-
-	registerHandlers()
-
-	if *prod {
-		*hostHTTP = "http2.golang.org"
-		*hostHTTPS = "http2.golang.org"
-		log.Fatal(serveProd())
-	}
-
-	url := "https://" + httpsHost() + "/"
-	log.Printf("Listening on " + url)
-	http2.ConfigureServer(&srv, &http2.Server{})
-
-	if *httpAddr != "" {
-		go func() {
-			log.Printf("Listening on http://" + httpHost() + "/ (for unencrypted HTTP/1)")
-			log.Fatal(http.ListenAndServe(*httpAddr, nil))
-		}()
-	}
-
-	go func() {
-		log.Fatal(srv.ListenAndServeTLS("server.crt", "server.key"))
-	}()
-	select {}
-}
diff --git a/vendor/golang.org/x/net/http2/h2demo/launch.go b/vendor/golang.org/x/net/http2/h2demo/launch.go
deleted file mode 100644
index 74666154..00000000
--- a/vendor/golang.org/x/net/http2/h2demo/launch.go
+++ /dev/null
@@ -1,302 +0,0 @@
-// Copyright 2014 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build ignore
-
-package main
-
-import (
-	"bufio"
-	"bytes"
-	"encoding/json"
-	"flag"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"log"
-	"net/http"
-	"os"
-	"strings"
-	"time"
-
-	"golang.org/x/oauth2"
-	"golang.org/x/oauth2/google"
-	compute "google.golang.org/api/compute/v1"
-)
-
-var (
-	proj     = flag.String("project", "symbolic-datum-552", "name of Project")
-	zone     = flag.String("zone", "us-central1-a", "GCE zone")
-	mach     = flag.String("machinetype", "n1-standard-1", "Machine type")
-	instName = flag.String("instance_name", "http2-demo", "Name of VM instance.")
-	sshPub   = flag.String("ssh_public_key", "", "ssh public key file to authorize. Can modify later in Google's web UI anyway.")
-	staticIP = flag.String("static_ip", "130.211.116.44", "Static IP to use. If empty, automatic.")
-
-	writeObject  = flag.String("write_object", "", "If non-empty, a VM isn't created and the flag value is Google Cloud Storage bucket/object to write. The contents from stdin.")
-	publicObject = flag.Bool("write_object_is_public", false, "Whether the object created by --write_object should be public.")
-)
-
-func readFile(v string) string {
-	slurp, err := ioutil.ReadFile(v)
-	if err != nil {
-		log.Fatalf("Error reading %s: %v", v, err)
-	}
-	return strings.TrimSpace(string(slurp))
-}
-
-var config = &oauth2.Config{
-	// The client-id and secret should be for an "Installed Application" when using
-	// the CLI. Later we'll use a web application with a callback.
-	ClientID:     readFile("client-id.dat"),
-	ClientSecret: readFile("client-secret.dat"),
-	Endpoint:     google.Endpoint,
-	Scopes: []string{
-		compute.DevstorageFull_controlScope,
-		compute.ComputeScope,
-		"https://www.googleapis.com/auth/sqlservice",
-		"https://www.googleapis.com/auth/sqlservice.admin",
-	},
-	RedirectURL: "urn:ietf:wg:oauth:2.0:oob",
-}
-
-const baseConfig = `#cloud-config
-coreos:
-  units:
-    - name: h2demo.service
-      command: start
-      content: |
-        [Unit]
-        Description=HTTP2 Demo
-        
-        [Service]
-        ExecStartPre=/bin/bash -c 'mkdir -p /opt/bin && curl -s -o /opt/bin/h2demo http://storage.googleapis.com/http2-demo-server-tls/h2demo && chmod +x /opt/bin/h2demo'
-        ExecStart=/opt/bin/h2demo --prod
-        RestartSec=5s
-        Restart=always
-        Type=simple
-        
-        [Install]
-        WantedBy=multi-user.target
-`
-
-func main() {
-	flag.Parse()
-	if *proj == "" {
-		log.Fatalf("Missing --project flag")
-	}
-	prefix := "https://www.googleapis.com/compute/v1/projects/" + *proj
-	machType := prefix + "/zones/" + *zone + "/machineTypes/" + *mach
-
-	const tokenFileName = "token.dat"
-	tokenFile := tokenCacheFile(tokenFileName)
-	tokenSource := oauth2.ReuseTokenSource(nil, tokenFile)
-	token, err := tokenSource.Token()
-	if err != nil {
-		if *writeObject != "" {
-			log.Fatalf("Can't use --write_object without a valid token.dat file already cached.")
-		}
-		log.Printf("Error getting token from %s: %v", tokenFileName, err)
-		log.Printf("Get auth code from %v", config.AuthCodeURL("my-state"))
-		fmt.Print("\nEnter auth code: ")
-		sc := bufio.NewScanner(os.Stdin)
-		sc.Scan()
-		authCode := strings.TrimSpace(sc.Text())
-		token, err = config.Exchange(oauth2.NoContext, authCode)
-		if err != nil {
-			log.Fatalf("Error exchanging auth code for a token: %v", err)
-		}
-		if err := tokenFile.WriteToken(token); err != nil {
-			log.Fatalf("Error writing to %s: %v", tokenFileName, err)
-		}
-		tokenSource = oauth2.ReuseTokenSource(token, nil)
-	}
-
-	oauthClient := oauth2.NewClient(oauth2.NoContext, tokenSource)
-
-	if *writeObject != "" {
-		writeCloudStorageObject(oauthClient)
-		return
-	}
-
-	computeService, _ := compute.New(oauthClient)
-
-	natIP := *staticIP
-	if natIP == "" {
-		// Try to find it by name.
-		aggAddrList, err := computeService.Addresses.AggregatedList(*proj).Do()
-		if err != nil {
-			log.Fatal(err)
-		}
-		// http://godoc.org/code.google.com/p/google-api-go-client/compute/v1#AddressAggregatedList
-	IPLoop:
-		for _, asl := range aggAddrList.Items {
-			for _, addr := range asl.Addresses {
-				if addr.Name == *instName+"-ip" && addr.Status == "RESERVED" {
-					natIP = addr.Address
-					break IPLoop
-				}
-			}
-		}
-	}
-
-	cloudConfig := baseConfig
-	if *sshPub != "" {
-		key := strings.TrimSpace(readFile(*sshPub))
-		cloudConfig += fmt.Sprintf("\nssh_authorized_keys:\n    - %s\n", key)
-	}
-	if os.Getenv("USER") == "bradfitz" {
-		cloudConfig += fmt.Sprintf("\nssh_authorized_keys:\n    - %s\n", "ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAwks9dwWKlRC+73gRbvYtVg0vdCwDSuIlyt4z6xa/YU/jTDynM4R4W10hm2tPjy8iR1k8XhDv4/qdxe6m07NjG/By1tkmGpm1mGwho4Pr5kbAAy/Qg+NLCSdAYnnE00FQEcFOC15GFVMOW2AzDGKisReohwH9eIzHPzdYQNPRWXE= bradfitz@papag.bradfitz.com")
-	}
-	const maxCloudConfig = 32 << 10 // per compute API docs
-	if len(cloudConfig) > maxCloudConfig {
-		log.Fatalf("cloud config length of %d bytes is over %d byte limit", len(cloudConfig), maxCloudConfig)
-	}
-
-	instance := &compute.Instance{
-		Name:        *instName,
-		Description: "Go Builder",
-		MachineType: machType,
-		Disks:       []*compute.AttachedDisk{instanceDisk(computeService)},
-		Tags: &compute.Tags{
-			Items: []string{"http-server", "https-server"},
-		},
-		Metadata: &compute.Metadata{
-			Items: []*compute.MetadataItems{
-				{
-					Key:   "user-data",
-					Value: cloudConfig,
-				},
-			},
-		},
-		NetworkInterfaces: []*compute.NetworkInterface{
-			&compute.NetworkInterface{
-				AccessConfigs: []*compute.AccessConfig{
-					&compute.AccessConfig{
-						Type:  "ONE_TO_ONE_NAT",
-						Name:  "External NAT",
-						NatIP: natIP,
-					},
-				},
-				Network: prefix + "/global/networks/default",
-			},
-		},
-		ServiceAccounts: []*compute.ServiceAccount{
-			{
-				Email: "default",
-				Scopes: []string{
-					compute.DevstorageFull_controlScope,
-					compute.ComputeScope,
-				},
-			},
-		},
-	}
-
-	log.Printf("Creating instance...")
-	op, err := computeService.Instances.Insert(*proj, *zone, instance).Do()
-	if err != nil {
-		log.Fatalf("Failed to create instance: %v", err)
-	}
-	opName := op.Name
-	log.Printf("Created. Waiting on operation %v", opName)
-OpLoop:
-	for {
-		time.Sleep(2 * time.Second)
-		op, err := computeService.ZoneOperations.Get(*proj, *zone, opName).Do()
-		if err != nil {
-			log.Fatalf("Failed to get op %s: %v", opName, err)
-		}
-		switch op.Status {
-		case "PENDING", "RUNNING":
-			log.Printf("Waiting on operation %v", opName)
-			continue
-		case "DONE":
-			if op.Error != nil {
-				for _, operr := range op.Error.Errors {
-					log.Printf("Error: %+v", operr)
-				}
-				log.Fatalf("Failed to start.")
-			}
-			log.Printf("Success. %+v", op)
-			break OpLoop
-		default:
-			log.Fatalf("Unknown status %q: %+v", op.Status, op)
-		}
-	}
-
-	inst, err := computeService.Instances.Get(*proj, *zone, *instName).Do()
-	if err != nil {
-		log.Fatalf("Error getting instance after creation: %v", err)
-	}
-	ij, _ := json.MarshalIndent(inst, "", "    ")
-	log.Printf("Instance: %s", ij)
-}
-
-func instanceDisk(svc *compute.Service) *compute.AttachedDisk {
-	const imageURL = "https://www.googleapis.com/compute/v1/projects/coreos-cloud/global/images/coreos-stable-444-5-0-v20141016"
-	diskName := *instName + "-disk"
-
-	return &compute.AttachedDisk{
-		AutoDelete: true,
-		Boot:       true,
-		Type:       "PERSISTENT",
-		InitializeParams: &compute.AttachedDiskInitializeParams{
-			DiskName:    diskName,
-			SourceImage: imageURL,
-			DiskSizeGb:  50,
-		},
-	}
-}
-
-func writeCloudStorageObject(httpClient *http.Client) {
-	content := os.Stdin
-	const maxSlurp = 1 << 20
-	var buf bytes.Buffer
-	n, err := io.CopyN(&buf, content, maxSlurp)
-	if err != nil && err != io.EOF {
-		log.Fatalf("Error reading from stdin: %v, %v", n, err)
-	}
-	contentType := http.DetectContentType(buf.Bytes())
-
-	req, err := http.NewRequest("PUT", "https://storage.googleapis.com/"+*writeObject, io.MultiReader(&buf, content))
-	if err != nil {
-		log.Fatal(err)
-	}
-	req.Header.Set("x-goog-api-version", "2")
-	if *publicObject {
-		req.Header.Set("x-goog-acl", "public-read")
-	}
-	req.Header.Set("Content-Type", contentType)
-	res, err := httpClient.Do(req)
-	if err != nil {
-		log.Fatal(err)
-	}
-	if res.StatusCode != 200 {
-		res.Write(os.Stderr)
-		log.Fatalf("Failed.")
-	}
-	log.Printf("Success.")
-	os.Exit(0)
-}
-
-type tokenCacheFile string
-
-func (f tokenCacheFile) Token() (*oauth2.Token, error) {
-	slurp, err := ioutil.ReadFile(string(f))
-	if err != nil {
-		return nil, err
-	}
-	t := new(oauth2.Token)
-	if err := json.Unmarshal(slurp, t); err != nil {
-		return nil, err
-	}
-	return t, nil
-}
-
-func (f tokenCacheFile) WriteToken(t *oauth2.Token) error {
-	jt, err := json.Marshal(t)
-	if err != nil {
-		return err
-	}
-	return ioutil.WriteFile(string(f), jt, 0600)
-}
diff --git a/vendor/golang.org/x/net/http2/h2demo/rootCA.key b/vendor/golang.org/x/net/http2/h2demo/rootCA.key
deleted file mode 100644
index a15a6aba..00000000
--- a/vendor/golang.org/x/net/http2/h2demo/rootCA.key
+++ /dev/null
@@ -1,27 +0,0 @@
------BEGIN RSA PRIVATE KEY-----
-MIIEowIBAAKCAQEAt5fAjp4fTcekWUTfzsp0kyih1OYbsGL0KX1eRbSSR8Od0+9Q
-62Hyny+GFwMTb4A/KU8mssoHvcceSAAbwfbxFK/+s51TobqUnORZrOoTZjkUygby
-XDSK99YBbcR1Pip8vwMTm4XKuLtCigeBBdjjAQdgUO28LENGlsMnmeYkJfODVGnV
-mr5Ltb9ANA8IKyTfsnHJ4iOCS/PlPbUj2q7YnoVLposUBMlgUb/CykX3mOoLb4yJ
-JQyA/iST6ZxiIEj36D4yWZ5lg7YJl+UiiBQHGCnPdGyipqV06ex0heYWcaiW8LWZ
-SUQ93jQ+WVCH8hT7DQO1dmsvUmXlq/JeAlwQ/QIDAQABAoIBAFFHV7JMAqPWnMYA
-nezY6J81v9+XN+7xABNWM2Q8uv4WdksbigGLTXR3/680Z2hXqJ7LMeC5XJACFT/e
-/Gr0vmpgOCygnCPfjGehGKpavtfksXV3edikUlnCXsOP1C//c1bFL+sMYmFCVgTx
-qYdDK8yKzXNGrKYT6q5YG7IglyRNV1rsQa8lM/5taFYiD1Ck/3tQi3YIq8Lcuser
-hrxsMABcQ6mi+EIvG6Xr4mfJug0dGJMHG4RG1UGFQn6RXrQq2+q53fC8ZbVUSi0j
-NQ918aKFzktwv+DouKU0ME4I9toks03gM860bAL7zCbKGmwR3hfgX/TqzVCWpG9E
-LDVfvekCgYEA8fk9N53jbBRmULUGEf4qWypcLGiZnNU0OeXWpbPV9aa3H0VDytA7
-8fCN2dPAVDPqlthMDdVe983NCNwp2Yo8ZimDgowyIAKhdC25s1kejuaiH9OAPj3c
-0f8KbriYX4n8zNHxFwK6Ae3pQ6EqOLJVCUsziUaZX9nyKY5aZlyX6xcCgYEAwjws
-K62PjC64U5wYddNLp+kNdJ4edx+a7qBb3mEgPvSFT2RO3/xafJyG8kQB30Mfstjd
-bRxyUV6N0vtX1zA7VQtRUAvfGCecpMo+VQZzcHXKzoRTnQ7eZg4Lmj5fQ9tOAKAo
-QCVBoSW/DI4PZL26CAMDcAba4Pa22ooLapoRIQsCgYA6pIfkkbxLNkpxpt2YwLtt
-Kr/590O7UaR9n6k8sW/aQBRDXNsILR1KDl2ifAIxpf9lnXgZJiwE7HiTfCAcW7c1
-nzwDCI0hWuHcMTS/NYsFYPnLsstyyjVZI3FY0h4DkYKV9Q9z3zJLQ2hz/nwoD3gy
-b2pHC7giFcTts1VPV4Nt8wKBgHeFn4ihHJweg76vZz3Z78w7VNRWGFklUalVdDK7
-gaQ7w2y/ROn/146mo0OhJaXFIFRlrpvdzVrU3GDf2YXJYDlM5ZRkObwbZADjksev
-WInzcgDy3KDg7WnPasRXbTfMU4t/AkW2p1QKbi3DnSVYuokDkbH2Beo45vxDxhKr
-C69RAoGBAIyo3+OJenoZmoNzNJl2WPW5MeBUzSh8T/bgyjFTdqFHF5WiYRD/lfHj
-x9Glyw2nutuT4hlOqHvKhgTYdDMsF2oQ72fe3v8Q5FU7FuKndNPEAyvKNXZaShVA
-hnlhv5DjXKb0wFWnt5PCCiQLtzG0yyHaITrrEme7FikkIcTxaX/Y
------END RSA PRIVATE KEY-----
diff --git a/vendor/golang.org/x/net/http2/h2demo/rootCA.pem b/vendor/golang.org/x/net/http2/h2demo/rootCA.pem
deleted file mode 100644
index 3a323e77..00000000
--- a/vendor/golang.org/x/net/http2/h2demo/rootCA.pem
+++ /dev/null
@@ -1,26 +0,0 @@
------BEGIN CERTIFICATE-----
-MIIEWjCCA0KgAwIBAgIJALfRlWsI8YQHMA0GCSqGSIb3DQEBBQUAMHsxCzAJBgNV
-BAYTAlVTMQswCQYDVQQIEwJDQTEWMBQGA1UEBxMNU2FuIEZyYW5jaXNjbzEUMBIG
-A1UEChMLQnJhZGZpdHppbmMxEjAQBgNVBAMTCWxvY2FsaG9zdDEdMBsGCSqGSIb3
-DQEJARYOYnJhZEBkYW5nYS5jb20wHhcNMTQwNzE1MjA0NjA1WhcNMTcwNTA0MjA0
-NjA1WjB7MQswCQYDVQQGEwJVUzELMAkGA1UECBMCQ0ExFjAUBgNVBAcTDVNhbiBG
-cmFuY2lzY28xFDASBgNVBAoTC0JyYWRmaXR6aW5jMRIwEAYDVQQDEwlsb2NhbGhv
-c3QxHTAbBgkqhkiG9w0BCQEWDmJyYWRAZGFuZ2EuY29tMIIBIjANBgkqhkiG9w0B
-AQEFAAOCAQ8AMIIBCgKCAQEAt5fAjp4fTcekWUTfzsp0kyih1OYbsGL0KX1eRbSS
-R8Od0+9Q62Hyny+GFwMTb4A/KU8mssoHvcceSAAbwfbxFK/+s51TobqUnORZrOoT
-ZjkUygbyXDSK99YBbcR1Pip8vwMTm4XKuLtCigeBBdjjAQdgUO28LENGlsMnmeYk
-JfODVGnVmr5Ltb9ANA8IKyTfsnHJ4iOCS/PlPbUj2q7YnoVLposUBMlgUb/CykX3
-mOoLb4yJJQyA/iST6ZxiIEj36D4yWZ5lg7YJl+UiiBQHGCnPdGyipqV06ex0heYW
-caiW8LWZSUQ93jQ+WVCH8hT7DQO1dmsvUmXlq/JeAlwQ/QIDAQABo4HgMIHdMB0G
-A1UdDgQWBBRcAROthS4P4U7vTfjByC569R7E6DCBrQYDVR0jBIGlMIGigBRcAROt
-hS4P4U7vTfjByC569R7E6KF/pH0wezELMAkGA1UEBhMCVVMxCzAJBgNVBAgTAkNB
-MRYwFAYDVQQHEw1TYW4gRnJhbmNpc2NvMRQwEgYDVQQKEwtCcmFkZml0emluYzES
-MBAGA1UEAxMJbG9jYWxob3N0MR0wGwYJKoZIhvcNAQkBFg5icmFkQGRhbmdhLmNv
-bYIJALfRlWsI8YQHMAwGA1UdEwQFMAMBAf8wDQYJKoZIhvcNAQEFBQADggEBAG6h
-U9f9sNH0/6oBbGGy2EVU0UgITUQIrFWo9rFkrW5k/XkDjQm+3lzjT0iGR4IxE/Ao
-eU6sQhua7wrWeFEn47GL98lnCsJdD7oZNhFmQ95Tb/LnDUjs5Yj9brP0NWzXfYU4
-UK2ZnINJRcJpB8iRCaCxE8DdcUF0XqIEq6pA272snoLmiXLMvNl3kYEdm+je6voD
-58SNVEUsztzQyXmJEhCpwVI0A6QCjzXj+qvpmw3ZZHi8JwXei8ZZBLTSFBki8Z7n
-sH9BBH38/SzUmAN4QHSPy1gjqm00OAE8NaYDkh/bzE4d7mLGGMWp/WE3KPSu82HF
-kPe6XoSbiLm/kxk32T0=
------END CERTIFICATE-----
diff --git a/vendor/golang.org/x/net/http2/h2demo/rootCA.srl b/vendor/golang.org/x/net/http2/h2demo/rootCA.srl
deleted file mode 100644
index 6db38918..00000000
--- a/vendor/golang.org/x/net/http2/h2demo/rootCA.srl
+++ /dev/null
@@ -1 +0,0 @@
-E2CE26BF3285059C
diff --git a/vendor/golang.org/x/net/http2/h2demo/server.crt b/vendor/golang.org/x/net/http2/h2demo/server.crt
deleted file mode 100644
index c59059bd..00000000
--- a/vendor/golang.org/x/net/http2/h2demo/server.crt
+++ /dev/null
@@ -1,20 +0,0 @@
------BEGIN CERTIFICATE-----
-MIIDPjCCAiYCCQDizia/MoUFnDANBgkqhkiG9w0BAQUFADB7MQswCQYDVQQGEwJV
-UzELMAkGA1UECBMCQ0ExFjAUBgNVBAcTDVNhbiBGcmFuY2lzY28xFDASBgNVBAoT
-C0JyYWRmaXR6aW5jMRIwEAYDVQQDEwlsb2NhbGhvc3QxHTAbBgkqhkiG9w0BCQEW
-DmJyYWRAZGFuZ2EuY29tMB4XDTE0MDcxNTIwNTAyN1oXDTE1MTEyNzIwNTAyN1ow
-RzELMAkGA1UEBhMCVVMxCzAJBgNVBAgTAkNBMQswCQYDVQQHEwJTRjEeMBwGA1UE
-ChMVYnJhZGZpdHogaHR0cDIgc2VydmVyMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8A
-MIIBCgKCAQEAs1Y9CyLFrdL8VQWN1WaifDqaZFnoqjHhCMlc1TfG2zA+InDifx2l
-gZD3o8FeNnAcfM2sPlk3+ZleOYw9P/CklFVDlvqmpCv9ss/BEp/dDaWvy1LmJ4c2
-dbQJfmTxn7CV1H3TsVJvKdwFmdoABb41NoBp6+NNO7OtDyhbIMiCI0pL3Nefb3HL
-A7hIMo3DYbORTtJLTIH9W8YKrEWL0lwHLrYFx/UdutZnv+HjdmO6vCN4na55mjws
-/vjKQUmc7xeY7Xe20xDEG2oDKVkL2eD7FfyrYMS3rO1ExP2KSqlXYG/1S9I/fz88
-F0GK7HX55b5WjZCl2J3ERVdnv/0MQv+sYQIDAQABMA0GCSqGSIb3DQEBBQUAA4IB
-AQC0zL+n/YpRZOdulSu9tS8FxrstXqGWoxfe+vIUgqfMZ5+0MkjJ/vW0FqlLDl2R
-rn4XaR3e7FmWkwdDVbq/UB6lPmoAaFkCgh9/5oapMaclNVNnfF3fjCJfRr+qj/iD
-EmJStTIN0ZuUjAlpiACmfnpEU55PafT5Zx+i1yE4FGjw8bJpFoyD4Hnm54nGjX19
-KeCuvcYFUPnBm3lcL0FalF2AjqV02WTHYNQk7YF/oeO7NKBoEgvGvKG3x+xaOeBI
-dwvdq175ZsGul30h+QjrRlXhH/twcuaT3GSdoysDl9cCYE8f1Mk8PD6gan3uBCJU
-90p6/CbU71bGbfpM2PHot2fm
------END CERTIFICATE-----
diff --git a/vendor/golang.org/x/net/http2/h2demo/server.key b/vendor/golang.org/x/net/http2/h2demo/server.key
deleted file mode 100644
index f329c142..00000000
--- a/vendor/golang.org/x/net/http2/h2demo/server.key
+++ /dev/null
@@ -1,27 +0,0 @@
------BEGIN RSA PRIVATE KEY-----
-MIIEowIBAAKCAQEAs1Y9CyLFrdL8VQWN1WaifDqaZFnoqjHhCMlc1TfG2zA+InDi
-fx2lgZD3o8FeNnAcfM2sPlk3+ZleOYw9P/CklFVDlvqmpCv9ss/BEp/dDaWvy1Lm
-J4c2dbQJfmTxn7CV1H3TsVJvKdwFmdoABb41NoBp6+NNO7OtDyhbIMiCI0pL3Nef
-b3HLA7hIMo3DYbORTtJLTIH9W8YKrEWL0lwHLrYFx/UdutZnv+HjdmO6vCN4na55
-mjws/vjKQUmc7xeY7Xe20xDEG2oDKVkL2eD7FfyrYMS3rO1ExP2KSqlXYG/1S9I/
-fz88F0GK7HX55b5WjZCl2J3ERVdnv/0MQv+sYQIDAQABAoIBADQ2spUwbY+bcz4p
-3M66ECrNQTBggP40gYl2XyHxGGOu2xhZ94f9ELf1hjRWU2DUKWco1rJcdZClV6q3
-qwmXvcM2Q/SMS8JW0ImkNVl/0/NqPxGatEnj8zY30d/L8hGFb0orzFu/XYA5gCP4
-NbN2WrXgk3ZLeqwcNxHHtSiJWGJ/fPyeDWAu/apy75u9Xf2GlzBZmV6HYD9EfK80
-LTlI60f5FO487CrJnboL7ovPJrIHn+k05xRQqwma4orpz932rTXnTjs9Lg6KtbQN
-a7PrqfAntIISgr11a66Mng3IYH1lYqJsWJJwX/xHT4WLEy0EH4/0+PfYemJekz2+
-Co62drECgYEA6O9zVJZXrLSDsIi54cfxA7nEZWm5CAtkYWeAHa4EJ+IlZ7gIf9sL
-W8oFcEfFGpvwVqWZ+AsQ70dsjXAv3zXaG0tmg9FtqWp7pzRSMPidifZcQwWkKeTO
-gJnFmnVyed8h6GfjTEu4gxo1/S5U0V+mYSha01z5NTnN6ltKx1Or3b0CgYEAxRgm
-S30nZxnyg/V7ys61AZhst1DG2tkZXEMcA7dYhabMoXPJAP/EfhlWwpWYYUs/u0gS
-Wwmf5IivX5TlYScgmkvb/NYz0u4ZmOXkLTnLPtdKKFXhjXJcHjUP67jYmOxNlJLp
-V4vLRnFxTpffAV+OszzRxsXX6fvruwZBANYJeXUCgYBVouLFsFgfWGYp2rpr9XP4
-KK25kvrBqF6JKOIDB1zjxNJ3pUMKrl8oqccCFoCyXa4oTM2kUX0yWxHfleUjrMq4
-yimwQKiOZmV7fVLSSjSw6e/VfBd0h3gb82ygcplZkN0IclkwTY5SNKqwn/3y07V5
-drqdhkrgdJXtmQ6O5YYECQKBgATERcDToQ1USlI4sKrB/wyv1AlG8dg/IebiVJ4e
-ZAyvcQmClFzq0qS+FiQUnB/WQw9TeeYrwGs1hxBHuJh16srwhLyDrbMvQP06qh8R
-48F8UXXSRec22dV9MQphaROhu2qZdv1AC0WD3tqov6L33aqmEOi+xi8JgbT/PLk5
-c/c1AoGBAI1A/02ryksW6/wc7/6SP2M2rTy4m1sD/GnrTc67EHnRcVBdKO6qH2RY
-nqC8YcveC2ZghgPTDsA3VGuzuBXpwY6wTyV99q6jxQJ6/xcrD9/NUG6Uwv/xfCxl
-IJLeBYEqQundSSny3VtaAUK8Ul1nxpTvVRNwtcyWTo8RHAAyNPWd
------END RSA PRIVATE KEY-----
diff --git a/vendor/golang.org/x/net/http2/h2i/README.md b/vendor/golang.org/x/net/http2/h2i/README.md
deleted file mode 100644
index fb5c5efb..00000000
--- a/vendor/golang.org/x/net/http2/h2i/README.md
+++ /dev/null
@@ -1,97 +0,0 @@
-# h2i
-
-**h2i** is an interactive HTTP/2 ("h2") console debugger. Miss the good ol'
-days of telnetting to your HTTP/1.n servers? We're bringing you
-back.
-
-Features:
-- send raw HTTP/2 frames
- - PING
- - SETTINGS
- - HEADERS
- - etc
-- type in HTTP/1.n and have it auto-HPACK/frame-ify it for HTTP/2
-- pretty print all received HTTP/2 frames from the peer (including HPACK decoding)
-- tab completion of commands, options
-
-Not yet features, but soon:
-- unnecessary CONTINUATION frames on short boundaries, to test peer implementations 
-- request bodies (DATA frames)
-- send invalid frames for testing server implementations (supported by underlying Framer)
-
-Later:
-- act like a server
-
-## Installation
-
-```
-$ go get golang.org/x/net/http2/h2i
-$ h2i <host>
-```
-
-## Demo
-
-```
-$ h2i
-Usage: h2i <hostname>
-  
-  -insecure
-        Whether to skip TLS cert validation
-  -nextproto string
-        Comma-separated list of NPN/ALPN protocol names to negotiate. (default "h2,h2-14")
-
-$ h2i google.com
-Connecting to google.com:443 ...
-Connected to 74.125.224.41:443
-Negotiated protocol "h2-14"
-[FrameHeader SETTINGS len=18]
-  [MAX_CONCURRENT_STREAMS = 100]
-  [INITIAL_WINDOW_SIZE = 1048576]
-  [MAX_FRAME_SIZE = 16384]
-[FrameHeader WINDOW_UPDATE len=4]
-  Window-Increment = 983041
-  
-h2i> PING h2iSayHI
-[FrameHeader PING flags=ACK len=8]
-  Data = "h2iSayHI"
-h2i> headers
-(as HTTP/1.1)> GET / HTTP/1.1
-(as HTTP/1.1)> Host: ip.appspot.com
-(as HTTP/1.1)> User-Agent: h2i/brad-n-blake
-(as HTTP/1.1)>  
-Opening Stream-ID 1:
- :authority = ip.appspot.com
- :method = GET
- :path = /
- :scheme = https
- user-agent = h2i/brad-n-blake
-[FrameHeader HEADERS flags=END_HEADERS stream=1 len=77]
-  :status = "200"
-  alternate-protocol = "443:quic,p=1"
-  content-length = "15"
-  content-type = "text/html"
-  date = "Fri, 01 May 2015 23:06:56 GMT"
-  server = "Google Frontend"
-[FrameHeader DATA flags=END_STREAM stream=1 len=15]
-  "173.164.155.78\n"
-[FrameHeader PING len=8]
-  Data = "\x00\x00\x00\x00\x00\x00\x00\x00"
-h2i> ping  
-[FrameHeader PING flags=ACK len=8]  
-  Data = "h2i_ping"  
-h2i> ping  
-[FrameHeader PING flags=ACK len=8]
-  Data = "h2i_ping"
-h2i> ping
-[FrameHeader GOAWAY len=22]
-  Last-Stream-ID = 1; Error-Code = PROTOCOL_ERROR (1)
-
-ReadFrame: EOF
-```
-
-## Status
-
-Quick few hour hack. So much yet to do. Feel free to file issues for
-bugs or wishlist items, but [@bmizerany](https://github.com/bmizerany/)
-and I aren't yet accepting pull requests until things settle down.
-
diff --git a/vendor/golang.org/x/net/http2/h2i/h2i.go b/vendor/golang.org/x/net/http2/h2i/h2i.go
deleted file mode 100644
index ac262084..00000000
--- a/vendor/golang.org/x/net/http2/h2i/h2i.go
+++ /dev/null
@@ -1,486 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-/*
-The h2i command is an interactive HTTP/2 console.
-
-Usage:
-  $ h2i [flags] <hostname>
-
-Interactive commands in the console: (all parts case-insensitive)
-
-  ping [data]
-  settings ack
-  settings FOO=n BAR=z
-  headers      (open a new stream by typing HTTP/1.1)
-*/
-package main
-
-import (
-	"bufio"
-	"bytes"
-	"crypto/tls"
-	"errors"
-	"flag"
-	"fmt"
-	"io"
-	"log"
-	"net"
-	"net/http"
-	"os"
-	"regexp"
-	"strconv"
-	"strings"
-
-	"golang.org/x/crypto/ssh/terminal"
-	"golang.org/x/net/http2"
-	"golang.org/x/net/http2/hpack"
-)
-
-// Flags
-var (
-	flagNextProto = flag.String("nextproto", "h2,h2-14", "Comma-separated list of NPN/ALPN protocol names to negotiate.")
-	flagInsecure  = flag.Bool("insecure", false, "Whether to skip TLS cert validation")
-)
-
-type command struct {
-	run func(*h2i, []string) error // required
-
-	// complete optionally specifies tokens (case-insensitive) which are
-	// valid for this subcommand.
-	complete func() []string
-}
-
-var commands = map[string]command{
-	"ping": command{run: (*h2i).cmdPing},
-	"settings": command{
-		run: (*h2i).cmdSettings,
-		complete: func() []string {
-			return []string{
-				"ACK",
-				http2.SettingHeaderTableSize.String(),
-				http2.SettingEnablePush.String(),
-				http2.SettingMaxConcurrentStreams.String(),
-				http2.SettingInitialWindowSize.String(),
-				http2.SettingMaxFrameSize.String(),
-				http2.SettingMaxHeaderListSize.String(),
-			}
-		},
-	},
-	"quit":    command{run: (*h2i).cmdQuit},
-	"headers": command{run: (*h2i).cmdHeaders},
-}
-
-func usage() {
-	fmt.Fprintf(os.Stderr, "Usage: h2i <hostname>\n\n")
-	flag.PrintDefaults()
-	os.Exit(1)
-}
-
-// withPort adds ":443" if another port isn't already present.
-func withPort(host string) string {
-	if _, _, err := net.SplitHostPort(host); err != nil {
-		return net.JoinHostPort(host, "443")
-	}
-	return host
-}
-
-// h2i is the app's state.
-type h2i struct {
-	host   string
-	tc     *tls.Conn
-	framer *http2.Framer
-	term   *terminal.Terminal
-
-	// owned by the command loop:
-	streamID uint32
-	hbuf     bytes.Buffer
-	henc     *hpack.Encoder
-
-	// owned by the readFrames loop:
-	peerSetting map[http2.SettingID]uint32
-	hdec        *hpack.Decoder
-}
-
-func main() {
-	flag.Usage = usage
-	flag.Parse()
-	if flag.NArg() != 1 {
-		usage()
-	}
-	log.SetFlags(0)
-
-	host := flag.Arg(0)
-	app := &h2i{
-		host:        host,
-		peerSetting: make(map[http2.SettingID]uint32),
-	}
-	app.henc = hpack.NewEncoder(&app.hbuf)
-
-	if err := app.Main(); err != nil {
-		if app.term != nil {
-			app.logf("%v\n", err)
-		} else {
-			fmt.Fprintf(os.Stderr, "%v\n", err)
-		}
-		os.Exit(1)
-	}
-	fmt.Fprintf(os.Stdout, "\n")
-}
-
-func (app *h2i) Main() error {
-	cfg := &tls.Config{
-		ServerName:         app.host,
-		NextProtos:         strings.Split(*flagNextProto, ","),
-		InsecureSkipVerify: *flagInsecure,
-	}
-
-	hostAndPort := withPort(app.host)
-	log.Printf("Connecting to %s ...", hostAndPort)
-	tc, err := tls.Dial("tcp", hostAndPort, cfg)
-	if err != nil {
-		return fmt.Errorf("Error dialing %s: %v", withPort(app.host), err)
-	}
-	log.Printf("Connected to %v", tc.RemoteAddr())
-	defer tc.Close()
-
-	if err := tc.Handshake(); err != nil {
-		return fmt.Errorf("TLS handshake: %v", err)
-	}
-	if !*flagInsecure {
-		if err := tc.VerifyHostname(app.host); err != nil {
-			return fmt.Errorf("VerifyHostname: %v", err)
-		}
-	}
-	state := tc.ConnectionState()
-	log.Printf("Negotiated protocol %q", state.NegotiatedProtocol)
-	if !state.NegotiatedProtocolIsMutual || state.NegotiatedProtocol == "" {
-		return fmt.Errorf("Could not negotiate protocol mutually")
-	}
-
-	if _, err := io.WriteString(tc, http2.ClientPreface); err != nil {
-		return err
-	}
-
-	app.framer = http2.NewFramer(tc, tc)
-
-	oldState, err := terminal.MakeRaw(0)
-	if err != nil {
-		return err
-	}
-	defer terminal.Restore(0, oldState)
-
-	var screen = struct {
-		io.Reader
-		io.Writer
-	}{os.Stdin, os.Stdout}
-
-	app.term = terminal.NewTerminal(screen, "h2i> ")
-	lastWord := regexp.MustCompile(`.+\W(\w+)$`)
-	app.term.AutoCompleteCallback = func(line string, pos int, key rune) (newLine string, newPos int, ok bool) {
-		if key != '\t' {
-			return
-		}
-		if pos != len(line) {
-			// TODO: we're being lazy for now, only supporting tab completion at the end.
-			return
-		}
-		// Auto-complete for the command itself.
-		if !strings.Contains(line, " ") {
-			var name string
-			name, _, ok = lookupCommand(line)
-			if !ok {
-				return
-			}
-			return name, len(name), true
-		}
-		_, c, ok := lookupCommand(line[:strings.IndexByte(line, ' ')])
-		if !ok || c.complete == nil {
-			return
-		}
-		if strings.HasSuffix(line, " ") {
-			app.logf("%s", strings.Join(c.complete(), " "))
-			return line, pos, true
-		}
-		m := lastWord.FindStringSubmatch(line)
-		if m == nil {
-			return line, len(line), true
-		}
-		soFar := m[1]
-		var match []string
-		for _, cand := range c.complete() {
-			if len(soFar) > len(cand) || !strings.EqualFold(cand[:len(soFar)], soFar) {
-				continue
-			}
-			match = append(match, cand)
-		}
-		if len(match) == 0 {
-			return
-		}
-		if len(match) > 1 {
-			// TODO: auto-complete any common prefix
-			app.logf("%s", strings.Join(match, " "))
-			return line, pos, true
-		}
-		newLine = line[:len(line)-len(soFar)] + match[0]
-		return newLine, len(newLine), true
-
-	}
-
-	errc := make(chan error, 2)
-	go func() { errc <- app.readFrames() }()
-	go func() { errc <- app.readConsole() }()
-	return <-errc
-}
-
-func (app *h2i) logf(format string, args ...interface{}) {
-	fmt.Fprintf(app.term, format+"\n", args...)
-}
-
-func (app *h2i) readConsole() error {
-	for {
-		line, err := app.term.ReadLine()
-		if err == io.EOF {
-			return nil
-		}
-		if err != nil {
-			return fmt.Errorf("terminal.ReadLine: %v", err)
-		}
-		f := strings.Fields(line)
-		if len(f) == 0 {
-			continue
-		}
-		cmd, args := f[0], f[1:]
-		if _, c, ok := lookupCommand(cmd); ok {
-			err = c.run(app, args)
-		} else {
-			app.logf("Unknown command %q", line)
-		}
-		if err == errExitApp {
-			return nil
-		}
-		if err != nil {
-			return err
-		}
-	}
-}
-
-func lookupCommand(prefix string) (name string, c command, ok bool) {
-	prefix = strings.ToLower(prefix)
-	if c, ok = commands[prefix]; ok {
-		return prefix, c, ok
-	}
-
-	for full, candidate := range commands {
-		if strings.HasPrefix(full, prefix) {
-			if c.run != nil {
-				return "", command{}, false // ambiguous
-			}
-			c = candidate
-			name = full
-		}
-	}
-	return name, c, c.run != nil
-}
-
-var errExitApp = errors.New("internal sentinel error value to quit the console reading loop")
-
-func (a *h2i) cmdQuit(args []string) error {
-	if len(args) > 0 {
-		a.logf("the QUIT command takes no argument")
-		return nil
-	}
-	return errExitApp
-}
-
-func (a *h2i) cmdSettings(args []string) error {
-	if len(args) == 1 && strings.EqualFold(args[0], "ACK") {
-		return a.framer.WriteSettingsAck()
-	}
-	var settings []http2.Setting
-	for _, arg := range args {
-		if strings.EqualFold(arg, "ACK") {
-			a.logf("Error: ACK must be only argument with the SETTINGS command")
-			return nil
-		}
-		eq := strings.Index(arg, "=")
-		if eq == -1 {
-			a.logf("Error: invalid argument %q (expected SETTING_NAME=nnnn)", arg)
-			return nil
-		}
-		sid, ok := settingByName(arg[:eq])
-		if !ok {
-			a.logf("Error: unknown setting name %q", arg[:eq])
-			return nil
-		}
-		val, err := strconv.ParseUint(arg[eq+1:], 10, 32)
-		if err != nil {
-			a.logf("Error: invalid argument %q (expected SETTING_NAME=nnnn)", arg)
-			return nil
-		}
-		settings = append(settings, http2.Setting{
-			ID:  sid,
-			Val: uint32(val),
-		})
-	}
-	a.logf("Sending: %v", settings)
-	return a.framer.WriteSettings(settings...)
-}
-
-func settingByName(name string) (http2.SettingID, bool) {
-	for _, sid := range [...]http2.SettingID{
-		http2.SettingHeaderTableSize,
-		http2.SettingEnablePush,
-		http2.SettingMaxConcurrentStreams,
-		http2.SettingInitialWindowSize,
-		http2.SettingMaxFrameSize,
-		http2.SettingMaxHeaderListSize,
-	} {
-		if strings.EqualFold(sid.String(), name) {
-			return sid, true
-		}
-	}
-	return 0, false
-}
-
-func (app *h2i) cmdPing(args []string) error {
-	if len(args) > 1 {
-		app.logf("invalid PING usage: only accepts 0 or 1 args")
-		return nil // nil means don't end the program
-	}
-	var data [8]byte
-	if len(args) == 1 {
-		copy(data[:], args[0])
-	} else {
-		copy(data[:], "h2i_ping")
-	}
-	return app.framer.WritePing(false, data)
-}
-
-func (app *h2i) cmdHeaders(args []string) error {
-	if len(args) > 0 {
-		app.logf("Error: HEADERS doesn't yet take arguments.")
-		// TODO: flags for restricting window size, to force CONTINUATION
-		// frames.
-		return nil
-	}
-	var h1req bytes.Buffer
-	app.term.SetPrompt("(as HTTP/1.1)> ")
-	defer app.term.SetPrompt("h2i> ")
-	for {
-		line, err := app.term.ReadLine()
-		if err != nil {
-			return err
-		}
-		h1req.WriteString(line)
-		h1req.WriteString("\r\n")
-		if line == "" {
-			break
-		}
-	}
-	req, err := http.ReadRequest(bufio.NewReader(&h1req))
-	if err != nil {
-		app.logf("Invalid HTTP/1.1 request: %v", err)
-		return nil
-	}
-	if app.streamID == 0 {
-		app.streamID = 1
-	} else {
-		app.streamID += 2
-	}
-	app.logf("Opening Stream-ID %d:", app.streamID)
-	hbf := app.encodeHeaders(req)
-	if len(hbf) > 16<<10 {
-		app.logf("TODO: h2i doesn't yet write CONTINUATION frames. Copy it from transport.go")
-		return nil
-	}
-	return app.framer.WriteHeaders(http2.HeadersFrameParam{
-		StreamID:      app.streamID,
-		BlockFragment: hbf,
-		EndStream:     req.Method == "GET" || req.Method == "HEAD", // good enough for now
-		EndHeaders:    true,                                        // for now
-	})
-}
-
-func (app *h2i) readFrames() error {
-	for {
-		f, err := app.framer.ReadFrame()
-		if err != nil {
-			return fmt.Errorf("ReadFrame: %v", err)
-		}
-		app.logf("%v", f)
-		switch f := f.(type) {
-		case *http2.PingFrame:
-			app.logf("  Data = %q", f.Data)
-		case *http2.SettingsFrame:
-			f.ForeachSetting(func(s http2.Setting) error {
-				app.logf("  %v", s)
-				app.peerSetting[s.ID] = s.Val
-				return nil
-			})
-		case *http2.WindowUpdateFrame:
-			app.logf("  Window-Increment = %v\n", f.Increment)
-		case *http2.GoAwayFrame:
-			app.logf("  Last-Stream-ID = %d; Error-Code = %v (%d)\n", f.LastStreamID, f.ErrCode, f.ErrCode)
-		case *http2.DataFrame:
-			app.logf("  %q", f.Data())
-		case *http2.HeadersFrame:
-			if f.HasPriority() {
-				app.logf("  PRIORITY = %v", f.Priority)
-			}
-			if app.hdec == nil {
-				// TODO: if the user uses h2i to send a SETTINGS frame advertising
-				// something larger, we'll need to respect SETTINGS_HEADER_TABLE_SIZE
-				// and stuff here instead of using the 4k default. But for now:
-				tableSize := uint32(4 << 10)
-				app.hdec = hpack.NewDecoder(tableSize, app.onNewHeaderField)
-			}
-			app.hdec.Write(f.HeaderBlockFragment())
-		}
-	}
-}
-
-// called from readLoop
-func (app *h2i) onNewHeaderField(f hpack.HeaderField) {
-	if f.Sensitive {
-		app.logf("  %s = %q (SENSITIVE)", f.Name, f.Value)
-	}
-	app.logf("  %s = %q", f.Name, f.Value)
-}
-
-func (app *h2i) encodeHeaders(req *http.Request) []byte {
-	app.hbuf.Reset()
-
-	// TODO(bradfitz): figure out :authority-vs-Host stuff between http2 and Go
-	host := req.Host
-	if host == "" {
-		host = req.URL.Host
-	}
-
-	path := req.URL.Path
-	if path == "" {
-		path = "/"
-	}
-
-	app.writeHeader(":authority", host) // probably not right for all sites
-	app.writeHeader(":method", req.Method)
-	app.writeHeader(":path", path)
-	app.writeHeader(":scheme", "https")
-
-	for k, vv := range req.Header {
-		lowKey := strings.ToLower(k)
-		if lowKey == "host" {
-			continue
-		}
-		for _, v := range vv {
-			app.writeHeader(lowKey, v)
-		}
-	}
-	return app.hbuf.Bytes()
-}
-
-func (app *h2i) writeHeader(name, value string) {
-	app.henc.WriteField(hpack.HeaderField{Name: name, Value: value})
-	app.logf(" %s = %s", name, value)
-}
diff --git a/vendor/golang.org/x/net/http2/headermap.go b/vendor/golang.org/x/net/http2/headermap.go
index 014f7896..c2805f6a 100644
--- a/vendor/golang.org/x/net/http2/headermap.go
+++ b/vendor/golang.org/x/net/http2/headermap.go
@@ -57,6 +57,7 @@ func init() {
 		"server",
 		"set-cookie",
 		"strict-transport-security",
+		"trailer",
 		"transfer-encoding",
 		"user-agent",
 		"vary",
diff --git a/vendor/golang.org/x/net/http2/hpack/encode.go b/vendor/golang.org/x/net/http2/hpack/encode.go
index 80d621cf..f9bb0339 100644
--- a/vendor/golang.org/x/net/http2/hpack/encode.go
+++ b/vendor/golang.org/x/net/http2/hpack/encode.go
@@ -144,7 +144,7 @@ func (e *Encoder) SetMaxDynamicTableSizeLimit(v uint32) {
 
 // shouldIndex reports whether f should be indexed.
 func (e *Encoder) shouldIndex(f HeaderField) bool {
-	return !f.Sensitive && f.size() <= e.dynTab.maxSize
+	return !f.Sensitive && f.Size() <= e.dynTab.maxSize
 }
 
 // appendIndexed appends index i, as encoded in "Indexed Header Field"
diff --git a/vendor/golang.org/x/net/http2/hpack/hpack.go b/vendor/golang.org/x/net/http2/hpack/hpack.go
index 8e9b2f2e..8aa197ad 100644
--- a/vendor/golang.org/x/net/http2/hpack/hpack.go
+++ b/vendor/golang.org/x/net/http2/hpack/hpack.go
@@ -41,7 +41,24 @@ type HeaderField struct {
 	Sensitive bool
 }
 
-func (hf *HeaderField) size() uint32 {
+// IsPseudo reports whether the header field is an http2 pseudo header.
+// That is, it reports whether it starts with a colon.
+// It is not otherwise guaranteed to be a valid pseudo header field,
+// though.
+func (hf HeaderField) IsPseudo() bool {
+	return len(hf.Name) != 0 && hf.Name[0] == ':'
+}
+
+func (hf HeaderField) String() string {
+	var suffix string
+	if hf.Sensitive {
+		suffix = " (sensitive)"
+	}
+	return fmt.Sprintf("header field %q = %q%s", hf.Name, hf.Value, suffix)
+}
+
+// Size returns the size of an entry per RFC 7540 section 5.2.
+func (hf HeaderField) Size() uint32 {
 	// http://http2.github.io/http2-spec/compression.html#rfc.section.4.1
 	// "The size of the dynamic table is the sum of the size of
 	// its entries.  The size of an entry is the sum of its name's
@@ -102,6 +119,13 @@ func (d *Decoder) SetMaxStringLength(n int) {
 	d.maxStrLen = n
 }
 
+// SetEmitFunc changes the callback used when new header fields
+// are decoded.
+// It must be non-nil. It does not affect EmitEnabled.
+func (d *Decoder) SetEmitFunc(emitFunc func(f HeaderField)) {
+	d.emit = emitFunc
+}
+
 // SetEmitEnabled controls whether the emitFunc provided to NewDecoder
 // should be called. The default is true.
 //
@@ -156,7 +180,7 @@ func (dt *dynamicTable) setMaxSize(v uint32) {
 
 func (dt *dynamicTable) add(f HeaderField) {
 	dt.ents = append(dt.ents, f)
-	dt.size += f.size()
+	dt.size += f.Size()
 	dt.evict()
 }
 
@@ -164,7 +188,7 @@ func (dt *dynamicTable) add(f HeaderField) {
 func (dt *dynamicTable) evict() {
 	base := dt.ents // keep base pointer of slice
 	for dt.size > dt.maxSize {
-		dt.size -= dt.ents[0].size()
+		dt.size -= dt.ents[0].Size()
 		dt.ents = dt.ents[1:]
 	}
 
diff --git a/vendor/golang.org/x/net/http2/hpack/huffman.go b/vendor/golang.org/x/net/http2/hpack/huffman.go
index eb4b1f05..8850e394 100644
--- a/vendor/golang.org/x/net/http2/hpack/huffman.go
+++ b/vendor/golang.org/x/net/http2/hpack/huffman.go
@@ -48,12 +48,16 @@ var ErrInvalidHuffman = errors.New("hpack: invalid Huffman-encoded data")
 // maxLen bytes will return ErrStringLength.
 func huffmanDecode(buf *bytes.Buffer, maxLen int, v []byte) error {
 	n := rootHuffmanNode
-	cur, nbits := uint(0), uint8(0)
+	// cur is the bit buffer that has not been fed into n.
+	// cbits is the number of low order bits in cur that are valid.
+	// sbits is the number of bits of the symbol prefix being decoded.
+	cur, cbits, sbits := uint(0), uint8(0), uint8(0)
 	for _, b := range v {
 		cur = cur<<8 | uint(b)
-		nbits += 8
-		for nbits >= 8 {
-			idx := byte(cur >> (nbits - 8))
+		cbits += 8
+		sbits += 8
+		for cbits >= 8 {
+			idx := byte(cur >> (cbits - 8))
 			n = n.children[idx]
 			if n == nil {
 				return ErrInvalidHuffman
@@ -63,22 +67,40 @@ func huffmanDecode(buf *bytes.Buffer, maxLen int, v []byte) error {
 					return ErrStringLength
 				}
 				buf.WriteByte(n.sym)
-				nbits -= n.codeLen
+				cbits -= n.codeLen
 				n = rootHuffmanNode
+				sbits = cbits
 			} else {
-				nbits -= 8
+				cbits -= 8
 			}
 		}
 	}
-	for nbits > 0 {
-		n = n.children[byte(cur<<(8-nbits))]
-		if n.children != nil || n.codeLen > nbits {
+	for cbits > 0 {
+		n = n.children[byte(cur<<(8-cbits))]
+		if n == nil {
+			return ErrInvalidHuffman
+		}
+		if n.children != nil || n.codeLen > cbits {
 			break
 		}
+		if maxLen != 0 && buf.Len() == maxLen {
+			return ErrStringLength
+		}
 		buf.WriteByte(n.sym)
-		nbits -= n.codeLen
+		cbits -= n.codeLen
 		n = rootHuffmanNode
+		sbits = cbits
+	}
+	if sbits > 7 {
+		// Either there was an incomplete symbol, or overlong padding.
+		// Both are decoding errors per RFC 7541 section 5.2.
+		return ErrInvalidHuffman
 	}
+	if mask := uint(1<<cbits - 1); cur&mask != mask {
+		// Trailing bits must be a prefix of EOS per RFC 7541 section 5.2.
+		return ErrInvalidHuffman
+	}
+
 	return nil
 }
 
diff --git a/vendor/golang.org/x/net/http2/http2.go b/vendor/golang.org/x/net/http2/http2.go
index 03ad05cc..a9053eec 100644
--- a/vendor/golang.org/x/net/http2/http2.go
+++ b/vendor/golang.org/x/net/http2/http2.go
@@ -4,25 +4,51 @@
 
 // Package http2 implements the HTTP/2 protocol.
 //
-// This is a work in progress. This package is low-level and intended
-// to be used directly by very few people. Most users will use it
-// indirectly through integration with the net/http package. See
-// ConfigureServer. That ConfigureServer call will likely be automatic
-// or available via an empty import in the future.
+// This package is low-level and intended to be used directly by very
+// few people. Most users will use it indirectly through the automatic
+// use by the net/http package (from Go 1.6 and later).
+// For use in earlier Go versions see ConfigureServer. (Transport support
+// requires Go 1.6 or later)
+//
+// See https://http2.github.io/ for more information on HTTP/2.
+//
+// See https://http2.golang.org/ for a test server running this code.
 //
-// See http://http2.github.io/
 package http2
 
 import (
 	"bufio"
+	"crypto/tls"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
+	"os"
+	"sort"
 	"strconv"
+	"strings"
 	"sync"
+
+	"golang.org/x/net/lex/httplex"
+)
+
+var (
+	VerboseLogs    bool
+	logFrameWrites bool
+	logFrameReads  bool
 )
 
-var VerboseLogs = false
+func init() {
+	e := os.Getenv("GODEBUG")
+	if strings.Contains(e, "http2debug=1") {
+		VerboseLogs = true
+	}
+	if strings.Contains(e, "http2debug=2") {
+		VerboseLogs = true
+		logFrameWrites = true
+		logFrameReads = true
+	}
+}
 
 const (
 	// ClientPreface is the string that must be sent by new
@@ -138,17 +164,28 @@ func (s SettingID) String() string {
 	return fmt.Sprintf("UNKNOWN_SETTING_%d", uint16(s))
 }
 
-func validHeader(v string) bool {
+var (
+	errInvalidHeaderFieldName  = errors.New("http2: invalid header field name")
+	errInvalidHeaderFieldValue = errors.New("http2: invalid header field value")
+)
+
+// validWireHeaderFieldName reports whether v is a valid header field
+// name (key). See httplex.ValidHeaderName for the base rules.
+//
+// Further, http2 says:
+//   "Just as in HTTP/1.x, header field names are strings of ASCII
+//   characters that are compared in a case-insensitive
+//   fashion. However, header field names MUST be converted to
+//   lowercase prior to their encoding in HTTP/2. "
+func validWireHeaderFieldName(v string) bool {
 	if len(v) == 0 {
 		return false
 	}
 	for _, r := range v {
-		// "Just as in HTTP/1.x, header field names are
-		// strings of ASCII characters that are compared in a
-		// case-insensitive fashion. However, header field
-		// names MUST be converted to lowercase prior to their
-		// encoding in HTTP/2. "
-		if r >= 127 || ('A' <= r && r <= 'Z') {
+		if !httplex.IsTokenRune(r) {
+			return false
+		}
+		if 'A' <= r && r <= 'Z' {
 			return false
 		}
 	}
@@ -251,3 +288,65 @@ func mustUint31(v int32) uint32 {
 	}
 	return uint32(v)
 }
+
+// bodyAllowedForStatus reports whether a given response status code
+// permits a body. See RFC 2616, section 4.4.
+func bodyAllowedForStatus(status int) bool {
+	switch {
+	case status >= 100 && status <= 199:
+		return false
+	case status == 204:
+		return false
+	case status == 304:
+		return false
+	}
+	return true
+}
+
+type httpError struct {
+	msg     string
+	timeout bool
+}
+
+func (e *httpError) Error() string   { return e.msg }
+func (e *httpError) Timeout() bool   { return e.timeout }
+func (e *httpError) Temporary() bool { return true }
+
+var errTimeout error = &httpError{msg: "http2: timeout awaiting response headers", timeout: true}
+
+type connectionStater interface {
+	ConnectionState() tls.ConnectionState
+}
+
+var sorterPool = sync.Pool{New: func() interface{} { return new(sorter) }}
+
+type sorter struct {
+	v []string // owned by sorter
+}
+
+func (s *sorter) Len() int           { return len(s.v) }
+func (s *sorter) Swap(i, j int)      { s.v[i], s.v[j] = s.v[j], s.v[i] }
+func (s *sorter) Less(i, j int) bool { return s.v[i] < s.v[j] }
+
+// Keys returns the sorted keys of h.
+//
+// The returned slice is only valid until s used again or returned to
+// its pool.
+func (s *sorter) Keys(h http.Header) []string {
+	keys := s.v[:0]
+	for k := range h {
+		keys = append(keys, k)
+	}
+	s.v = keys
+	sort.Sort(s)
+	return keys
+}
+
+func (s *sorter) SortStrings(ss []string) {
+	// Our sorter works on s.v, which sorter owners, so
+	// stash it away while we sort the user's buffer.
+	save := s.v
+	s.v = ss
+	sort.Sort(s)
+	s.v = save
+}
diff --git a/vendor/golang.org/x/net/http2/not_go16.go b/vendor/golang.org/x/net/http2/not_go16.go
new file mode 100644
index 00000000..efd2e128
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/not_go16.go
@@ -0,0 +1,46 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !go1.6
+
+package http2
+
+import (
+	"crypto/tls"
+	"net/http"
+	"time"
+)
+
+func configureTransport(t1 *http.Transport) (*Transport, error) {
+	return nil, errTransportVersion
+}
+
+func transportExpectContinueTimeout(t1 *http.Transport) time.Duration {
+	return 0
+
+}
+
+// isBadCipher reports whether the cipher is blacklisted by the HTTP/2 spec.
+func isBadCipher(cipher uint16) bool {
+	switch cipher {
+	case tls.TLS_RSA_WITH_RC4_128_SHA,
+		tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
+		tls.TLS_RSA_WITH_AES_128_CBC_SHA,
+		tls.TLS_RSA_WITH_AES_256_CBC_SHA,
+		tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
+		tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
+		tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
+		tls.TLS_ECDHE_RSA_WITH_RC4_128_SHA,
+		tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
+		tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
+		tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:
+		// Reject cipher suites from Appendix A.
+		// "This list includes those cipher suites that do not
+		// offer an ephemeral key exchange and those that are
+		// based on the TLS null, stream or block cipher type"
+		return true
+	default:
+		return false
+	}
+}
diff --git a/vendor/golang.org/x/net/http2/not_go17.go b/vendor/golang.org/x/net/http2/not_go17.go
new file mode 100644
index 00000000..28df0c16
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/not_go17.go
@@ -0,0 +1,51 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !go1.7
+
+package http2
+
+import (
+	"net"
+	"net/http"
+)
+
+type contextContext interface{}
+
+type fakeContext struct{}
+
+func (fakeContext) Done() <-chan struct{} { return nil }
+func (fakeContext) Err() error            { panic("should not be called") }
+
+func reqContext(r *http.Request) fakeContext {
+	return fakeContext{}
+}
+
+func setResponseUncompressed(res *http.Response) {
+	// Nothing.
+}
+
+type clientTrace struct{}
+
+func requestTrace(*http.Request) *clientTrace { return nil }
+func traceGotConn(*http.Request, *ClientConn) {}
+func traceFirstResponseByte(*clientTrace)     {}
+func traceWroteHeaders(*clientTrace)          {}
+func traceWroteRequest(*clientTrace, error)   {}
+func traceGot100Continue(trace *clientTrace)  {}
+func traceWait100Continue(trace *clientTrace) {}
+
+func nop() {}
+
+func serverConnBaseContext(c net.Conn, opts *ServeConnOpts) (ctx contextContext, cancel func()) {
+	return nil, nop
+}
+
+func contextWithCancel(ctx contextContext) (_ contextContext, cancel func()) {
+	return ctx, nop
+}
+
+func requestWithContext(req *http.Request, ctx contextContext) *http.Request {
+	return req
+}
diff --git a/vendor/golang.org/x/net/http2/pipe.go b/vendor/golang.org/x/net/http2/pipe.go
index 96a3eb8d..53b7a1da 100644
--- a/vendor/golang.org/x/net/http2/pipe.go
+++ b/vendor/golang.org/x/net/http2/pipe.go
@@ -14,10 +14,13 @@ import (
 // io.Pipe except there are no PipeReader/PipeWriter halves, and the
 // underlying buffer is an interface. (io.Pipe is always unbuffered)
 type pipe struct {
-	mu  sync.Mutex
-	c   sync.Cond // c.L must point to
-	b   pipeBuffer
-	err error // read error once empty. non-nil means closed.
+	mu       sync.Mutex
+	c        sync.Cond // c.L lazily initialized to &p.mu
+	b        pipeBuffer
+	err      error         // read error once empty. non-nil means closed.
+	breakErr error         // immediate read error (caller doesn't see rest of b)
+	donec    chan struct{} // closed on error
+	readFn   func()        // optional code to run in Read before error
 }
 
 type pipeBuffer interface {
@@ -26,6 +29,12 @@ type pipeBuffer interface {
 	io.Reader
 }
 
+func (p *pipe) Len() int {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	return p.b.Len()
+}
+
 // Read waits until data is available and copies bytes
 // from the buffer into p.
 func (p *pipe) Read(d []byte) (n int, err error) {
@@ -35,10 +44,17 @@ func (p *pipe) Read(d []byte) (n int, err error) {
 		p.c.L = &p.mu
 	}
 	for {
+		if p.breakErr != nil {
+			return 0, p.breakErr
+		}
 		if p.b.Len() > 0 {
 			return p.b.Read(d)
 		}
 		if p.err != nil {
+			if p.readFn != nil {
+				p.readFn()     // e.g. copy trailers
+				p.readFn = nil // not sticky like p.err
+			}
 			return 0, p.err
 		}
 		p.c.Wait()
@@ -62,13 +78,25 @@ func (p *pipe) Write(d []byte) (n int, err error) {
 	return p.b.Write(d)
 }
 
-// CloseWithError causes Reads to wake up and return the
-// provided err after all data has been read.
+// CloseWithError causes the next Read (waking up a current blocked
+// Read if needed) to return the provided err after all data has been
+// read.
 //
 // The error must be non-nil.
-func (p *pipe) CloseWithError(err error) {
+func (p *pipe) CloseWithError(err error) { p.closeWithError(&p.err, err, nil) }
+
+// BreakWithError causes the next Read (waking up a current blocked
+// Read if needed) to return the provided err immediately, without
+// waiting for unread data.
+func (p *pipe) BreakWithError(err error) { p.closeWithError(&p.breakErr, err, nil) }
+
+// closeWithErrorAndCode is like CloseWithError but also sets some code to run
+// in the caller's goroutine before returning the error.
+func (p *pipe) closeWithErrorAndCode(err error, fn func()) { p.closeWithError(&p.err, err, fn) }
+
+func (p *pipe) closeWithError(dst *error, err error, fn func()) {
 	if err == nil {
-		panic("CloseWithError must be non-nil")
+		panic("err must be non-nil")
 	}
 	p.mu.Lock()
 	defer p.mu.Unlock()
@@ -76,15 +104,50 @@ func (p *pipe) CloseWithError(err error) {
 		p.c.L = &p.mu
 	}
 	defer p.c.Signal()
-	if p.err == nil {
-		p.err = err
+	if *dst != nil {
+		// Already been done.
+		return
 	}
+	p.readFn = fn
+	*dst = err
+	p.closeDoneLocked()
 }
 
-// Err returns the error (if any) first set with CloseWithError.
-// This is the error which will be returned after the reader is exhausted.
+// requires p.mu be held.
+func (p *pipe) closeDoneLocked() {
+	if p.donec == nil {
+		return
+	}
+	// Close if unclosed. This isn't racy since we always
+	// hold p.mu while closing.
+	select {
+	case <-p.donec:
+	default:
+		close(p.donec)
+	}
+}
+
+// Err returns the error (if any) first set by BreakWithError or CloseWithError.
 func (p *pipe) Err() error {
 	p.mu.Lock()
 	defer p.mu.Unlock()
+	if p.breakErr != nil {
+		return p.breakErr
+	}
 	return p.err
 }
+
+// Done returns a channel which is closed if and when this pipe is closed
+// with CloseWithError.
+func (p *pipe) Done() <-chan struct{} {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if p.donec == nil {
+		p.donec = make(chan struct{})
+		if p.err != nil || p.breakErr != nil {
+			// Already hit an error.
+			p.closeDoneLocked()
+		}
+	}
+	return p.donec
+}
diff --git a/vendor/golang.org/x/net/http2/server.go b/vendor/golang.org/x/net/http2/server.go
index 7405cdab..8206fa79 100644
--- a/vendor/golang.org/x/net/http2/server.go
+++ b/vendor/golang.org/x/net/http2/server.go
@@ -6,8 +6,8 @@
 // instead, and make sure that on close we close all open
 // streams. then remove doneServing?
 
-// TODO: finish GOAWAY support. Consider each incoming frame type and
-// whether it should be ignored during a shutdown race.
+// TODO: re-audit GOAWAY support. Consider each incoming frame type and
+// whether it should be ignored during graceful shutdown.
 
 // TODO: disconnect idle clients. GFE seems to do 4 minutes. make
 // configurable?  or maximum number of idle clients and remove the
@@ -46,7 +46,11 @@ import (
 	"log"
 	"net"
 	"net/http"
+	"net/textproto"
 	"net/url"
+	"os"
+	"reflect"
+	"runtime"
 	"strconv"
 	"strings"
 	"sync"
@@ -190,28 +194,80 @@ func ConfigureServer(s *http.Server, conf *Server) error {
 		if testHookOnConn != nil {
 			testHookOnConn()
 		}
-		conf.handleConn(hs, c, h)
+		conf.ServeConn(c, &ServeConnOpts{
+			Handler:    h,
+			BaseConfig: hs,
+		})
 	}
 	s.TLSNextProto[NextProtoTLS] = protoHandler
 	s.TLSNextProto["h2-14"] = protoHandler // temporary; see above.
 	return nil
 }
 
-func (srv *Server) handleConn(hs *http.Server, c net.Conn, h http.Handler) {
+// ServeConnOpts are options for the Server.ServeConn method.
+type ServeConnOpts struct {
+	// BaseConfig optionally sets the base configuration
+	// for values. If nil, defaults are used.
+	BaseConfig *http.Server
+
+	// Handler specifies which handler to use for processing
+	// requests. If nil, BaseConfig.Handler is used. If BaseConfig
+	// or BaseConfig.Handler is nil, http.DefaultServeMux is used.
+	Handler http.Handler
+}
+
+func (o *ServeConnOpts) baseConfig() *http.Server {
+	if o != nil && o.BaseConfig != nil {
+		return o.BaseConfig
+	}
+	return new(http.Server)
+}
+
+func (o *ServeConnOpts) handler() http.Handler {
+	if o != nil {
+		if o.Handler != nil {
+			return o.Handler
+		}
+		if o.BaseConfig != nil && o.BaseConfig.Handler != nil {
+			return o.BaseConfig.Handler
+		}
+	}
+	return http.DefaultServeMux
+}
+
+// ServeConn serves HTTP/2 requests on the provided connection and
+// blocks until the connection is no longer readable.
+//
+// ServeConn starts speaking HTTP/2 assuming that c has not had any
+// reads or writes. It writes its initial settings frame and expects
+// to be able to read the preface and settings frame from the
+// client. If c has a ConnectionState method like a *tls.Conn, the
+// ConnectionState is used to verify the TLS ciphersuite and to set
+// the Request.TLS field in Handlers.
+//
+// ServeConn does not support h2c by itself. Any h2c support must be
+// implemented in terms of providing a suitably-behaving net.Conn.
+//
+// The opts parameter is optional. If nil, default values are used.
+func (s *Server) ServeConn(c net.Conn, opts *ServeConnOpts) {
+	baseCtx, cancel := serverConnBaseContext(c, opts)
+	defer cancel()
+
 	sc := &serverConn{
-		srv:              srv,
-		hs:               hs,
+		srv:              s,
+		hs:               opts.baseConfig(),
 		conn:             c,
+		baseCtx:          baseCtx,
 		remoteAddrStr:    c.RemoteAddr().String(),
 		bw:               newBufferedWriter(c),
-		handler:          h,
+		handler:          opts.handler(),
 		streams:          make(map[uint32]*stream),
 		readFrameCh:      make(chan readFrameResult),
 		wantWriteFrameCh: make(chan frameWriteMsg, 8),
 		wroteFrameCh:     make(chan frameWriteResult, 1), // buffered; one send in writeFrameAsync
 		bodyReadCh:       make(chan bodyReadMsg),         // buffering doesn't matter either way
 		doneServing:      make(chan struct{}),
-		advMaxStreams:    srv.maxConcurrentStreams(),
+		advMaxStreams:    s.maxConcurrentStreams(),
 		writeSched: writeScheduler{
 			maxFrameSize: initialMaxFrameSize,
 		},
@@ -220,17 +276,18 @@ func (srv *Server) handleConn(hs *http.Server, c net.Conn, h http.Handler) {
 		serveG:            newGoroutineLock(),
 		pushEnabled:       true,
 	}
+
 	sc.flow.add(initialWindowSize)
 	sc.inflow.add(initialWindowSize)
 	sc.hpackEncoder = hpack.NewEncoder(&sc.headerWriteBuf)
-	sc.hpackDecoder = hpack.NewDecoder(initialHeaderTableSize, sc.onNewHeaderField)
-	sc.hpackDecoder.SetMaxStringLength(sc.maxHeaderStringLen())
 
 	fr := NewFramer(sc.bw, c)
-	fr.SetMaxReadFrameSize(srv.maxReadFrameSize())
+	fr.ReadMetaHeaders = hpack.NewDecoder(initialHeaderTableSize, nil)
+	fr.MaxHeaderListSize = sc.maxHeaderListSize()
+	fr.SetMaxReadFrameSize(s.maxReadFrameSize())
 	sc.framer = fr
 
-	if tc, ok := c.(*tls.Conn); ok {
+	if tc, ok := c.(connectionStater); ok {
 		sc.tlsState = new(tls.ConnectionState)
 		*sc.tlsState = tc.ConnectionState()
 		// 9.2 Use of TLS Features
@@ -260,7 +317,7 @@ func (srv *Server) handleConn(hs *http.Server, c net.Conn, h http.Handler) {
 			// So for now, do nothing here again.
 		}
 
-		if !srv.PermitProhibitedCipherSuites && isBadCipher(sc.tlsState.CipherSuite) {
+		if !s.PermitProhibitedCipherSuites && isBadCipher(sc.tlsState.CipherSuite) {
 			// "Endpoints MAY choose to generate a connection error
 			// (Section 5.4.1) of type INADEQUATE_SECURITY if one of
 			// the prohibited cipher suites are negotiated."
@@ -282,32 +339,8 @@ func (srv *Server) handleConn(hs *http.Server, c net.Conn, h http.Handler) {
 	sc.serve()
 }
 
-// isBadCipher reports whether the cipher is blacklisted by the HTTP/2 spec.
-func isBadCipher(cipher uint16) bool {
-	switch cipher {
-	case tls.TLS_RSA_WITH_RC4_128_SHA,
-		tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
-		tls.TLS_RSA_WITH_AES_128_CBC_SHA,
-		tls.TLS_RSA_WITH_AES_256_CBC_SHA,
-		tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
-		tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
-		tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
-		tls.TLS_ECDHE_RSA_WITH_RC4_128_SHA,
-		tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
-		tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
-		tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:
-		// Reject cipher suites from Appendix A.
-		// "This list includes those cipher suites that do not
-		// offer an ephemeral key exchange and those that are
-		// based on the TLS null, stream or block cipher type"
-		return true
-	default:
-		return false
-	}
-}
-
 func (sc *serverConn) rejectConn(err ErrCode, debug string) {
-	sc.vlogf("REJECTING conn: %v, %s", err, debug)
+	sc.vlogf("http2: server rejecting conn: %v, %s", err, debug)
 	// ignoring errors. hanging up anyway.
 	sc.framer.WriteGoAway(0, err, []byte(debug))
 	sc.bw.Flush()
@@ -321,8 +354,8 @@ type serverConn struct {
 	conn             net.Conn
 	bw               *bufferedWriter // writing to conn
 	handler          http.Handler
+	baseCtx          contextContext
 	framer           *Framer
-	hpackDecoder     *hpack.Decoder
 	doneServing      chan struct{}         // closed when serverConn.serve ends
 	readFrameCh      chan readFrameResult  // written by serverConn.readFrames
 	wantWriteFrameCh chan frameWriteMsg    // from handlers -> serve
@@ -349,7 +382,6 @@ type serverConn struct {
 	headerTableSize       uint32
 	peerMaxHeaderListSize uint32            // zero means unknown (default)
 	canonHeader           map[string]string // http2-lower-case -> Go-Canonical-Case
-	req                   requestParam      // non-zero while reading request headers
 	writingFrame          bool              // started write goroutine but haven't heard back on wroteFrameCh
 	needsFrameFlush       bool              // last frame write wasn't a flush
 	writeSched            writeScheduler
@@ -358,22 +390,13 @@ type serverConn struct {
 	goAwayCode            ErrCode
 	shutdownTimerCh       <-chan time.Time // nil until used
 	shutdownTimer         *time.Timer      // nil until used
+	freeRequestBodyBuf    []byte           // if non-nil, a free initialWindowSize buffer for getRequestBodyBuf
 
 	// Owned by the writeFrameAsync goroutine:
 	headerWriteBuf bytes.Buffer
 	hpackEncoder   *hpack.Encoder
 }
 
-func (sc *serverConn) maxHeaderStringLen() int {
-	v := sc.maxHeaderListSize()
-	if uint32(int(v)) == v {
-		return int(v)
-	}
-	// They had a crazy big number for MaxHeaderBytes anyway,
-	// so give them unlimited header lengths:
-	return 0
-}
-
 func (sc *serverConn) maxHeaderListSize() uint32 {
 	n := sc.hs.MaxHeaderBytes
 	if n <= 0 {
@@ -386,21 +409,6 @@ func (sc *serverConn) maxHeaderListSize() uint32 {
 	return uint32(n + typicalHeaders*perFieldOverhead)
 }
 
-// requestParam is the state of the next request, initialized over
-// potentially several frames HEADERS + zero or more CONTINUATION
-// frames.
-type requestParam struct {
-	// stream is non-nil if we're reading (HEADER or CONTINUATION)
-	// frames for a request (but not DATA).
-	stream            *stream
-	header            http.Header
-	method, path      string
-	scheme, authority string
-	sawRegularHeader  bool  // saw a non-pseudo header already
-	invalidHeader     bool  // an invalid header was seen
-	headerListSize    int64 // actually uint32, but easier math this way
-}
-
 // stream represents a stream. This is the minimal metadata needed by
 // the serve goroutine. Most of the actual stream state is owned by
 // the http.Handler's goroutine in the responseWriter. Because the
@@ -410,20 +418,30 @@ type requestParam struct {
 // responseWriter's state field.
 type stream struct {
 	// immutable:
-	id   uint32
-	body *pipe       // non-nil if expecting DATA frames
-	cw   closeWaiter // closed wait stream transitions to closed state
+	sc        *serverConn
+	id        uint32
+	body      *pipe       // non-nil if expecting DATA frames
+	cw        closeWaiter // closed wait stream transitions to closed state
+	ctx       contextContext
+	cancelCtx func()
 
 	// owned by serverConn's serve loop:
-	bodyBytes     int64   // body bytes seen so far
-	declBodyBytes int64   // or -1 if undeclared
-	flow          flow    // limits writing from Handler to client
-	inflow        flow    // what the client is allowed to POST/etc to us
-	parent        *stream // or nil
-	weight        uint8
-	state         streamState
-	sentReset     bool // only true once detached from streams map
-	gotReset      bool // only true once detacted from streams map
+	bodyBytes        int64   // body bytes seen so far
+	declBodyBytes    int64   // or -1 if undeclared
+	flow             flow    // limits writing from Handler to client
+	inflow           flow    // what the client is allowed to POST/etc to us
+	parent           *stream // or nil
+	numTrailerValues int64
+	weight           uint8
+	state            streamState
+	sentReset        bool // only true once detached from streams map
+	gotReset         bool // only true once detacted from streams map
+	gotTrailerHeader bool // HEADER frame for trailers was seen
+	wroteHeaders     bool // whether we wrote headers (not status 100)
+	reqBuf           []byte
+
+	trailer    http.Header // accumulated trailers
+	reqTrailer http.Header // handler's Request.Trailer
 }
 
 func (sc *serverConn) Framer() *Framer  { return sc.framer }
@@ -474,12 +492,55 @@ func (sc *serverConn) logf(format string, args ...interface{}) {
 	}
 }
 
+// errno returns v's underlying uintptr, else 0.
+//
+// TODO: remove this helper function once http2 can use build
+// tags. See comment in isClosedConnError.
+func errno(v error) uintptr {
+	if rv := reflect.ValueOf(v); rv.Kind() == reflect.Uintptr {
+		return uintptr(rv.Uint())
+	}
+	return 0
+}
+
+// isClosedConnError reports whether err is an error from use of a closed
+// network connection.
+func isClosedConnError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	// TODO: remove this string search and be more like the Windows
+	// case below. That might involve modifying the standard library
+	// to return better error types.
+	str := err.Error()
+	if strings.Contains(str, "use of closed network connection") {
+		return true
+	}
+
+	// TODO(bradfitz): x/tools/cmd/bundle doesn't really support
+	// build tags, so I can't make an http2_windows.go file with
+	// Windows-specific stuff. Fix that and move this, once we
+	// have a way to bundle this into std's net/http somehow.
+	if runtime.GOOS == "windows" {
+		if oe, ok := err.(*net.OpError); ok && oe.Op == "read" {
+			if se, ok := oe.Err.(*os.SyscallError); ok && se.Syscall == "wsarecv" {
+				const WSAECONNABORTED = 10053
+				const WSAECONNRESET = 10054
+				if n := errno(se.Err); n == WSAECONNRESET || n == WSAECONNABORTED {
+					return true
+				}
+			}
+		}
+	}
+	return false
+}
+
 func (sc *serverConn) condlogf(err error, format string, args ...interface{}) {
 	if err == nil {
 		return
 	}
-	str := err.Error()
-	if err == io.EOF || strings.Contains(str, "use of closed network connection") {
+	if err == io.EOF || err == io.ErrUnexpectedEOF || isClosedConnError(err) {
 		// Boring, expected errors.
 		sc.vlogf(format, args...)
 	} else {
@@ -487,55 +548,6 @@ func (sc *serverConn) condlogf(err error, format string, args ...interface{}) {
 	}
 }
 
-func (sc *serverConn) onNewHeaderField(f hpack.HeaderField) {
-	sc.serveG.check()
-	sc.vlogf("got header field %+v", f)
-	switch {
-	case !validHeader(f.Name):
-		sc.req.invalidHeader = true
-	case strings.HasPrefix(f.Name, ":"):
-		if sc.req.sawRegularHeader {
-			sc.logf("pseudo-header after regular header")
-			sc.req.invalidHeader = true
-			return
-		}
-		var dst *string
-		switch f.Name {
-		case ":method":
-			dst = &sc.req.method
-		case ":path":
-			dst = &sc.req.path
-		case ":scheme":
-			dst = &sc.req.scheme
-		case ":authority":
-			dst = &sc.req.authority
-		default:
-			// 8.1.2.1 Pseudo-Header Fields
-			// "Endpoints MUST treat a request or response
-			// that contains undefined or invalid
-			// pseudo-header fields as malformed (Section
-			// 8.1.2.6)."
-			sc.logf("invalid pseudo-header %q", f.Name)
-			sc.req.invalidHeader = true
-			return
-		}
-		if *dst != "" {
-			sc.logf("duplicate pseudo-header %q sent", f.Name)
-			sc.req.invalidHeader = true
-			return
-		}
-		*dst = f.Value
-	default:
-		sc.req.sawRegularHeader = true
-		sc.req.header.Add(sc.canonicalHeader(f.Name), f.Value)
-		const headerFieldOverhead = 32 // per spec
-		sc.req.headerListSize += int64(len(f.Name)) + int64(len(f.Value)) + headerFieldOverhead
-		if sc.req.headerListSize > int64(sc.maxHeaderListSize()) {
-			sc.hpackDecoder.SetEmitEnabled(false)
-		}
-	}
-}
-
 func (sc *serverConn) canonicalHeader(v string) string {
 	sc.serveG.check()
 	cv, ok := commonCanonHeader[v]
@@ -570,10 +582,11 @@ type readFrameResult struct {
 // It's run on its own goroutine.
 func (sc *serverConn) readFrames() {
 	gate := make(gate)
+	gateDone := gate.Done
 	for {
 		f, err := sc.framer.ReadFrame()
 		select {
-		case sc.readFrameCh <- readFrameResult{f, err, gate.Done}:
+		case sc.readFrameCh <- readFrameResult{f, err, gateDone}:
 		case <-sc.doneServing:
 			return
 		}
@@ -582,6 +595,9 @@ func (sc *serverConn) readFrames() {
 		case <-sc.doneServing:
 			return
 		}
+		if terminalReadFrameError(err) {
+			return
+		}
 	}
 }
 
@@ -615,6 +631,7 @@ func (sc *serverConn) stopShutdownTimer() {
 }
 
 func (sc *serverConn) notePanic() {
+	// Note: this is for serverConn.serve panicking, not http.Handler code.
 	if testHookOnPanicMu != nil {
 		testHookOnPanicMu.Lock()
 		defer testHookOnPanicMu.Unlock()
@@ -636,7 +653,9 @@ func (sc *serverConn) serve() {
 	defer sc.stopShutdownTimer()
 	defer close(sc.doneServing) // unblocks handlers trying to send
 
-	sc.vlogf("HTTP/2 connection from %v on %p", sc.conn.RemoteAddr(), sc.hs)
+	if VerboseLogs {
+		sc.vlogf("http2: server connection from %v on %p", sc.conn.RemoteAddr(), sc.hs)
+	}
 
 	sc.writeFrame(frameWriteMsg{
 		write: writeSettings{
@@ -653,7 +672,7 @@ func (sc *serverConn) serve() {
 	sc.unackedSettings++
 
 	if err := sc.readPreface(); err != nil {
-		sc.condlogf(err, "error reading preface from client %v: %v", sc.conn.RemoteAddr(), err)
+		sc.condlogf(err, "http2: server: error reading preface from client %v: %v", sc.conn.RemoteAddr(), err)
 		return
 	}
 	// Now that we've got the preface, get us out of the
@@ -719,7 +738,9 @@ func (sc *serverConn) readPreface() error {
 		return errors.New("timeout waiting for client preface")
 	case err := <-errc:
 		if err == nil {
-			sc.vlogf("client %v said hello", sc.conn.RemoteAddr())
+			if VerboseLogs {
+				sc.vlogf("http2: server: client %v said hello", sc.conn.RemoteAddr())
+			}
 		}
 		return err
 	}
@@ -804,7 +825,23 @@ func (sc *serverConn) writeFrameFromHandler(wm frameWriteMsg) error {
 // If you're not on the serve goroutine, use writeFrameFromHandler instead.
 func (sc *serverConn) writeFrame(wm frameWriteMsg) {
 	sc.serveG.check()
-	sc.writeSched.add(wm)
+
+	var ignoreWrite bool
+
+	// Don't send a 100-continue response if we've already sent headers.
+	// See golang.org/issue/14030.
+	switch wm.write.(type) {
+	case *writeResHeaders:
+		wm.stream.wroteHeaders = true
+	case write100ContinueHeadersFrame:
+		if wm.stream.wroteHeaders {
+			ignoreWrite = true
+		}
+	}
+
+	if !ignoreWrite {
+		sc.writeSched.add(wm)
+	}
 	sc.scheduleFrameWrite()
 }
 
@@ -837,6 +874,11 @@ func (sc *serverConn) startFrameWrite(wm frameWriteMsg) {
 	go sc.writeFrameAsync(wm)
 }
 
+// errHandlerPanicked is the error given to any callers blocked in a read from
+// Request.Body when the main goroutine panics. Since most handlers read in the
+// the main ServeHTTP goroutine, this will show up rarely.
+var errHandlerPanicked = errors.New("http2: handler panicked")
+
 // wroteFrame is called on the serve goroutine with the result of
 // whatever happened on writeFrameAsync.
 func (sc *serverConn) wroteFrame(res frameWriteResult) {
@@ -851,6 +893,10 @@ func (sc *serverConn) wroteFrame(res frameWriteResult) {
 
 	closeStream := endsStream(wm.write)
 
+	if _, ok := wm.write.(handlerPanicRST); ok {
+		sc.closeStream(st, errHandlerPanicked)
+	}
+
 	// Reply (if requested) to the blocked ServeHTTP goroutine.
 	if ch := wm.done; ch != nil {
 		select {
@@ -876,7 +922,7 @@ func (sc *serverConn) wroteFrame(res frameWriteResult) {
 			// state here anyway, after telling the peer
 			// we're hanging up on them.
 			st.state = stateHalfClosedLocal // won't last long, but necessary for closeStream via resetStream
-			errCancel := StreamError{st.id, ErrCodeCancel}
+			errCancel := streamError(st.id, ErrCodeCancel)
 			sc.resetStream(errCancel)
 		case stateHalfClosedRemote:
 			sc.closeStream(st, errHandlerComplete)
@@ -963,18 +1009,6 @@ func (sc *serverConn) resetStream(se StreamError) {
 	}
 }
 
-// curHeaderStreamID returns the stream ID of the header block we're
-// currently in the middle of reading. If this returns non-zero, the
-// next frame must be a CONTINUATION with this stream id.
-func (sc *serverConn) curHeaderStreamID() uint32 {
-	sc.serveG.check()
-	st := sc.req.stream
-	if st == nil {
-		return 0
-	}
-	return st.id
-}
-
 // processFrameFromReader processes the serve loop's read from readFrameCh from the
 // frame-reading goroutine.
 // processFrameFromReader returns whether the connection should be kept open.
@@ -986,7 +1020,7 @@ func (sc *serverConn) processFrameFromReader(res readFrameResult) bool {
 			sc.goAway(ErrCodeFrameSize)
 			return true // goAway will close the loop
 		}
-		clientGone := err == io.EOF || strings.Contains(err.Error(), "use of closed network connection")
+		clientGone := err == io.EOF || err == io.ErrUnexpectedEOF || isClosedConnError(err)
 		if clientGone {
 			// TODO: could we also get into this state if
 			// the peer does a half close
@@ -1000,7 +1034,9 @@ func (sc *serverConn) processFrameFromReader(res readFrameResult) bool {
 		}
 	} else {
 		f := res.f
-		sc.vlogf("got %v: %#v", f.Header(), f)
+		if VerboseLogs {
+			sc.vlogf("http2: server read frame %v", summarizeFrame(f))
+		}
 		err = sc.processFrame(f)
 		if err == nil {
 			return true
@@ -1015,14 +1051,14 @@ func (sc *serverConn) processFrameFromReader(res readFrameResult) bool {
 		sc.goAway(ErrCodeFlowControl)
 		return true
 	case ConnectionError:
-		sc.logf("%v: %v", sc.conn.RemoteAddr(), ev)
+		sc.logf("http2: server connection error from %v: %v", sc.conn.RemoteAddr(), ev)
 		sc.goAway(ErrCode(ev))
 		return true // goAway will handle shutdown
 	default:
 		if res.err != nil {
-			sc.logf("disconnecting; error reading frame from client %s: %v", sc.conn.RemoteAddr(), err)
+			sc.vlogf("http2: server closing client connection; error reading frame from client %s: %v", sc.conn.RemoteAddr(), err)
 		} else {
-			sc.logf("disconnection due to other error: %v", err)
+			sc.logf("http2: server closing client connection: %v", err)
 		}
 		return false
 	}
@@ -1039,21 +1075,11 @@ func (sc *serverConn) processFrame(f Frame) error {
 		sc.sawFirstSettings = true
 	}
 
-	if s := sc.curHeaderStreamID(); s != 0 {
-		if cf, ok := f.(*ContinuationFrame); !ok {
-			return ConnectionError(ErrCodeProtocol)
-		} else if cf.Header().StreamID != s {
-			return ConnectionError(ErrCodeProtocol)
-		}
-	}
-
 	switch f := f.(type) {
 	case *SettingsFrame:
 		return sc.processSettings(f)
-	case *HeadersFrame:
+	case *MetaHeadersFrame:
 		return sc.processHeaders(f)
-	case *ContinuationFrame:
-		return sc.processContinuation(f)
 	case *WindowUpdateFrame:
 		return sc.processWindowUpdate(f)
 	case *PingFrame:
@@ -1069,14 +1095,14 @@ func (sc *serverConn) processFrame(f Frame) error {
 		// frame as a connection error (Section 5.4.1) of type PROTOCOL_ERROR.
 		return ConnectionError(ErrCodeProtocol)
 	default:
-		sc.vlogf("Ignoring frame: %v", f.Header())
+		sc.vlogf("http2: server ignoring frame: %v", f.Header())
 		return nil
 	}
 }
 
 func (sc *serverConn) processPing(f *PingFrame) error {
 	sc.serveG.check()
-	if f.Flags.Has(FlagSettingsAck) {
+	if f.IsAck() {
 		// 6.7 PING: " An endpoint MUST NOT respond to PING frames
 		// containing this flag."
 		return nil
@@ -1107,7 +1133,7 @@ func (sc *serverConn) processWindowUpdate(f *WindowUpdateFrame) error {
 			return nil
 		}
 		if !st.flow.add(int32(f.Increment)) {
-			return StreamError{f.StreamID, ErrCodeFlowControl}
+			return streamError(f.StreamID, ErrCodeFlowControl)
 		}
 	default: // connection-level flow control
 		if !sc.flow.add(int32(f.Increment)) {
@@ -1132,7 +1158,8 @@ func (sc *serverConn) processResetStream(f *RSTStreamFrame) error {
 	}
 	if st != nil {
 		st.gotReset = true
-		sc.closeStream(st, StreamError{f.StreamID, f.ErrCode})
+		st.cancelCtx()
+		sc.closeStream(st, streamError(f.StreamID, f.ErrCode))
 	}
 	return nil
 }
@@ -1149,10 +1176,26 @@ func (sc *serverConn) closeStream(st *stream, err error) {
 	}
 	delete(sc.streams, st.id)
 	if p := st.body; p != nil {
+		// Return any buffered unread bytes worth of conn-level flow control.
+		// See golang.org/issue/16481
+		sc.sendWindowUpdate(nil, p.Len())
+
 		p.CloseWithError(err)
 	}
 	st.cw.Close() // signals Handler's CloseNotifier, unblocks writes, etc
 	sc.writeSched.forgetStream(st.id)
+	if st.reqBuf != nil {
+		// Stash this request body buffer (64k) away for reuse
+		// by a future POST/PUT/etc.
+		//
+		// TODO(bradfitz): share on the server? sync.Pool?
+		// Server requires locks and might hurt contention.
+		// sync.Pool might work, or might be worse, depending
+		// on goroutine CPU migrations. (get and put on
+		// separate CPUs).  Maybe a mix of strategies. But
+		// this is an easy win for now.
+		sc.freeRequestBodyBuf = st.reqBuf
+	}
 }
 
 func (sc *serverConn) processSettings(f *SettingsFrame) error {
@@ -1180,7 +1223,9 @@ func (sc *serverConn) processSetting(s Setting) error {
 	if err := s.Valid(); err != nil {
 		return err
 	}
-	sc.vlogf("processing setting %v", s)
+	if VerboseLogs {
+		sc.vlogf("http2: server processing setting %v", s)
+	}
 	switch s.ID {
 	case SettingHeaderTableSize:
 		sc.headerTableSize = s.Val
@@ -1199,6 +1244,9 @@ func (sc *serverConn) processSetting(s Setting) error {
 		// Unknown setting: "An endpoint that receives a SETTINGS
 		// frame with any unknown or unsupported identifier MUST
 		// ignore that setting."
+		if VerboseLogs {
+			sc.vlogf("http2: server ignoring unknown setting %v", s)
+		}
 	}
 	return nil
 }
@@ -1233,57 +1281,103 @@ func (sc *serverConn) processSettingInitialWindowSize(val uint32) error {
 
 func (sc *serverConn) processData(f *DataFrame) error {
 	sc.serveG.check()
+	data := f.Data()
+
 	// "If a DATA frame is received whose stream is not in "open"
 	// or "half closed (local)" state, the recipient MUST respond
 	// with a stream error (Section 5.4.2) of type STREAM_CLOSED."
 	id := f.Header().StreamID
 	st, ok := sc.streams[id]
-	if !ok || st.state != stateOpen {
+	if !ok || st.state != stateOpen || st.gotTrailerHeader {
 		// This includes sending a RST_STREAM if the stream is
 		// in stateHalfClosedLocal (which currently means that
 		// the http.Handler returned, so it's done reading &
 		// done writing). Try to stop the client from sending
 		// more DATA.
-		return StreamError{id, ErrCodeStreamClosed}
+
+		// But still enforce their connection-level flow control,
+		// and return any flow control bytes since we're not going
+		// to consume them.
+		if sc.inflow.available() < int32(f.Length) {
+			return streamError(id, ErrCodeFlowControl)
+		}
+		// Deduct the flow control from inflow, since we're
+		// going to immediately add it back in
+		// sendWindowUpdate, which also schedules sending the
+		// frames.
+		sc.inflow.take(int32(f.Length))
+		sc.sendWindowUpdate(nil, int(f.Length)) // conn-level
+
+		return streamError(id, ErrCodeStreamClosed)
 	}
 	if st.body == nil {
 		panic("internal error: should have a body in this state")
 	}
-	data := f.Data()
 
 	// Sender sending more than they'd declared?
 	if st.declBodyBytes != -1 && st.bodyBytes+int64(len(data)) > st.declBodyBytes {
 		st.body.CloseWithError(fmt.Errorf("sender tried to send more than declared Content-Length of %d bytes", st.declBodyBytes))
-		return StreamError{id, ErrCodeStreamClosed}
+		return streamError(id, ErrCodeStreamClosed)
 	}
-	if len(data) > 0 {
+	if f.Length > 0 {
 		// Check whether the client has flow control quota.
-		if int(st.inflow.available()) < len(data) {
-			return StreamError{id, ErrCodeFlowControl}
+		if st.inflow.available() < int32(f.Length) {
+			return streamError(id, ErrCodeFlowControl)
 		}
-		st.inflow.take(int32(len(data)))
-		wrote, err := st.body.Write(data)
-		if err != nil {
-			return StreamError{id, ErrCodeStreamClosed}
+		st.inflow.take(int32(f.Length))
+
+		if len(data) > 0 {
+			wrote, err := st.body.Write(data)
+			if err != nil {
+				return streamError(id, ErrCodeStreamClosed)
+			}
+			if wrote != len(data) {
+				panic("internal error: bad Writer")
+			}
+			st.bodyBytes += int64(len(data))
 		}
-		if wrote != len(data) {
-			panic("internal error: bad Writer")
+
+		// Return any padded flow control now, since we won't
+		// refund it later on body reads.
+		if pad := int32(f.Length) - int32(len(data)); pad > 0 {
+			sc.sendWindowUpdate32(nil, pad)
+			sc.sendWindowUpdate32(st, pad)
 		}
-		st.bodyBytes += int64(len(data))
 	}
 	if f.StreamEnded() {
-		if st.declBodyBytes != -1 && st.declBodyBytes != st.bodyBytes {
-			st.body.CloseWithError(fmt.Errorf("request declared a Content-Length of %d but only wrote %d bytes",
-				st.declBodyBytes, st.bodyBytes))
-		} else {
-			st.body.CloseWithError(io.EOF)
-		}
-		st.state = stateHalfClosedRemote
+		st.endStream()
 	}
 	return nil
 }
 
-func (sc *serverConn) processHeaders(f *HeadersFrame) error {
+// endStream closes a Request.Body's pipe. It is called when a DATA
+// frame says a request body is over (or after trailers).
+func (st *stream) endStream() {
+	sc := st.sc
+	sc.serveG.check()
+
+	if st.declBodyBytes != -1 && st.declBodyBytes != st.bodyBytes {
+		st.body.CloseWithError(fmt.Errorf("request declared a Content-Length of %d but only wrote %d bytes",
+			st.declBodyBytes, st.bodyBytes))
+	} else {
+		st.body.closeWithErrorAndCode(io.EOF, st.copyTrailersToHandlerRequest)
+		st.body.CloseWithError(io.EOF)
+	}
+	st.state = stateHalfClosedRemote
+}
+
+// copyTrailersToHandlerRequest is run in the Handler's goroutine in
+// its Request.Body.Read just before it gets io.EOF.
+func (st *stream) copyTrailersToHandlerRequest() {
+	for k, vv := range st.trailer {
+		if _, ok := st.reqTrailer[k]; ok {
+			// Only copy it over it was pre-declared.
+			st.reqTrailer[k] = vv
+		}
+	}
+}
+
+func (sc *serverConn) processHeaders(f *MetaHeadersFrame) error {
 	sc.serveG.check()
 	id := f.Header().StreamID
 	if sc.inGoAway {
@@ -1291,22 +1385,39 @@ func (sc *serverConn) processHeaders(f *HeadersFrame) error {
 		return nil
 	}
 	// http://http2.github.io/http2-spec/#rfc.section.5.1.1
-	if id%2 != 1 || id <= sc.maxStreamID || sc.req.stream != nil {
-		// Streams initiated by a client MUST use odd-numbered
-		// stream identifiers. [...] The identifier of a newly
-		// established stream MUST be numerically greater than all
-		// streams that the initiating endpoint has opened or
-		// reserved. [...]  An endpoint that receives an unexpected
-		// stream identifier MUST respond with a connection error
-		// (Section 5.4.1) of type PROTOCOL_ERROR.
+	// Streams initiated by a client MUST use odd-numbered stream
+	// identifiers. [...] An endpoint that receives an unexpected
+	// stream identifier MUST respond with a connection error
+	// (Section 5.4.1) of type PROTOCOL_ERROR.
+	if id%2 != 1 {
 		return ConnectionError(ErrCodeProtocol)
 	}
-	if id > sc.maxStreamID {
-		sc.maxStreamID = id
+	// A HEADERS frame can be used to create a new stream or
+	// send a trailer for an open one. If we already have a stream
+	// open, let it process its own HEADERS frame (trailers at this
+	// point, if it's valid).
+	st := sc.streams[f.Header().StreamID]
+	if st != nil {
+		return st.processTrailerHeaders(f)
+	}
+
+	// [...] The identifier of a newly established stream MUST be
+	// numerically greater than all streams that the initiating
+	// endpoint has opened or reserved. [...]  An endpoint that
+	// receives an unexpected stream identifier MUST respond with
+	// a connection error (Section 5.4.1) of type PROTOCOL_ERROR.
+	if id <= sc.maxStreamID {
+		return ConnectionError(ErrCodeProtocol)
 	}
-	st := &stream{
-		id:    id,
-		state: stateOpen,
+	sc.maxStreamID = id
+
+	ctx, cancelCtx := contextWithCancel(sc.baseCtx)
+	st = &stream{
+		sc:        sc,
+		id:        id,
+		state:     stateOpen,
+		ctx:       ctx,
+		cancelCtx: cancelCtx,
 	}
 	if f.StreamEnded() {
 		st.state = stateHalfClosedRemote
@@ -1326,35 +1437,6 @@ func (sc *serverConn) processHeaders(f *HeadersFrame) error {
 	if sc.curOpenStreams == 1 {
 		sc.setConnState(http.StateActive)
 	}
-	sc.req = requestParam{
-		stream: st,
-		header: make(http.Header),
-	}
-	sc.hpackDecoder.SetEmitEnabled(true)
-	return sc.processHeaderBlockFragment(st, f.HeaderBlockFragment(), f.HeadersEnded())
-}
-
-func (sc *serverConn) processContinuation(f *ContinuationFrame) error {
-	sc.serveG.check()
-	st := sc.streams[f.Header().StreamID]
-	if st == nil || sc.curHeaderStreamID() != st.id {
-		return ConnectionError(ErrCodeProtocol)
-	}
-	return sc.processHeaderBlockFragment(st, f.HeaderBlockFragment(), f.HeadersEnded())
-}
-
-func (sc *serverConn) processHeaderBlockFragment(st *stream, frag []byte, end bool) error {
-	sc.serveG.check()
-	if _, err := sc.hpackDecoder.Write(frag); err != nil {
-		return ConnectionError(ErrCodeCompression)
-	}
-	if !end {
-		return nil
-	}
-	if err := sc.hpackDecoder.Close(); err != nil {
-		return ConnectionError(ErrCodeCompression)
-	}
-	defer sc.resetPendingRequest()
 	if sc.curOpenStreams > sc.advMaxStreams {
 		// "Endpoints MUST NOT exceed the limit set by their
 		// peer. An endpoint that receives a HEADERS frame
@@ -1364,33 +1446,69 @@ func (sc *serverConn) processHeaderBlockFragment(st *stream, frag []byte, end bo
 		// REFUSED_STREAM."
 		if sc.unackedSettings == 0 {
 			// They should know better.
-			return StreamError{st.id, ErrCodeProtocol}
+			return streamError(st.id, ErrCodeProtocol)
 		}
 		// Assume it's a network race, where they just haven't
 		// received our last SETTINGS update. But actually
 		// this can't happen yet, because we don't yet provide
 		// a way for users to adjust server parameters at
 		// runtime.
-		return StreamError{st.id, ErrCodeRefusedStream}
+		return streamError(st.id, ErrCodeRefusedStream)
 	}
 
-	rw, req, err := sc.newWriterAndRequest()
+	rw, req, err := sc.newWriterAndRequest(st, f)
 	if err != nil {
 		return err
 	}
+	st.reqTrailer = req.Trailer
+	if st.reqTrailer != nil {
+		st.trailer = make(http.Header)
+	}
 	st.body = req.Body.(*requestBody).pipe // may be nil
 	st.declBodyBytes = req.ContentLength
 
 	handler := sc.handler.ServeHTTP
-	if !sc.hpackDecoder.EmitEnabled() {
+	if f.Truncated {
 		// Their header list was too long. Send a 431 error.
 		handler = handleHeaderListTooLong
+	} else if err := checkValidHTTP2Request(req); err != nil {
+		handler = new400Handler(err)
 	}
 
 	go sc.runHandler(rw, req, handler)
 	return nil
 }
 
+func (st *stream) processTrailerHeaders(f *MetaHeadersFrame) error {
+	sc := st.sc
+	sc.serveG.check()
+	if st.gotTrailerHeader {
+		return ConnectionError(ErrCodeProtocol)
+	}
+	st.gotTrailerHeader = true
+	if !f.StreamEnded() {
+		return streamError(st.id, ErrCodeProtocol)
+	}
+
+	if len(f.PseudoFields()) > 0 {
+		return streamError(st.id, ErrCodeProtocol)
+	}
+	if st.trailer != nil {
+		for _, hf := range f.RegularFields() {
+			key := sc.canonicalHeader(hf.Name)
+			if !ValidTrailerHeader(key) {
+				// TODO: send more details to the peer somehow. But http2 has
+				// no way to send debug data at a stream level. Discuss with
+				// HTTP folk.
+				return streamError(st.id, ErrCodeProtocol)
+			}
+			st.trailer[key] = append(st.trailer[key], hf.Value)
+		}
+	}
+	st.endStream()
+	return nil
+}
+
 func (sc *serverConn) processPriority(f *PriorityFrame) error {
 	adjustStreamPriority(sc.streams, f.StreamID, f.PriorityParam)
 	return nil
@@ -1432,19 +1550,21 @@ func adjustStreamPriority(streams map[uint32]*stream, streamID uint32, priority
 	}
 }
 
-// resetPendingRequest zeros out all state related to a HEADERS frame
-// and its zero or more CONTINUATION frames sent to start a new
-// request.
-func (sc *serverConn) resetPendingRequest() {
+func (sc *serverConn) newWriterAndRequest(st *stream, f *MetaHeadersFrame) (*responseWriter, *http.Request, error) {
 	sc.serveG.check()
-	sc.req = requestParam{}
-}
 
-func (sc *serverConn) newWriterAndRequest() (*responseWriter, *http.Request, error) {
-	sc.serveG.check()
-	rp := &sc.req
-	if rp.invalidHeader || rp.method == "" || rp.path == "" ||
-		(rp.scheme != "https" && rp.scheme != "http") {
+	method := f.PseudoValue("method")
+	path := f.PseudoValue("path")
+	scheme := f.PseudoValue("scheme")
+	authority := f.PseudoValue("authority")
+
+	isConnect := method == "CONNECT"
+	if isConnect {
+		if path != "" || scheme != "" || authority == "" {
+			return nil, nil, streamError(f.StreamID, ErrCodeProtocol)
+		}
+	} else if method == "" || path == "" ||
+		(scheme != "https" && scheme != "http") {
 		// See 8.1.2.6 Malformed Requests and Responses:
 		//
 		// Malformed requests or responses that are detected
@@ -1455,55 +1575,100 @@ func (sc *serverConn) newWriterAndRequest() (*responseWriter, *http.Request, err
 		// "All HTTP/2 requests MUST include exactly one valid
 		// value for the :method, :scheme, and :path
 		// pseudo-header fields"
-		return nil, nil, StreamError{rp.stream.id, ErrCodeProtocol}
+		return nil, nil, streamError(f.StreamID, ErrCodeProtocol)
+	}
+
+	bodyOpen := !f.StreamEnded()
+	if method == "HEAD" && bodyOpen {
+		// HEAD requests can't have bodies
+		return nil, nil, streamError(f.StreamID, ErrCodeProtocol)
 	}
 	var tlsState *tls.ConnectionState // nil if not scheme https
-	if rp.scheme == "https" {
+
+	if scheme == "https" {
 		tlsState = sc.tlsState
 	}
-	authority := rp.authority
+
+	header := make(http.Header)
+	for _, hf := range f.RegularFields() {
+		header.Add(sc.canonicalHeader(hf.Name), hf.Value)
+	}
+
 	if authority == "" {
-		authority = rp.header.Get("Host")
+		authority = header.Get("Host")
 	}
-	needsContinue := rp.header.Get("Expect") == "100-continue"
+	needsContinue := header.Get("Expect") == "100-continue"
 	if needsContinue {
-		rp.header.Del("Expect")
+		header.Del("Expect")
 	}
 	// Merge Cookie headers into one "; "-delimited value.
-	if cookies := rp.header["Cookie"]; len(cookies) > 1 {
-		rp.header.Set("Cookie", strings.Join(cookies, "; "))
+	if cookies := header["Cookie"]; len(cookies) > 1 {
+		header.Set("Cookie", strings.Join(cookies, "; "))
+	}
+
+	// Setup Trailers
+	var trailer http.Header
+	for _, v := range header["Trailer"] {
+		for _, key := range strings.Split(v, ",") {
+			key = http.CanonicalHeaderKey(strings.TrimSpace(key))
+			switch key {
+			case "Transfer-Encoding", "Trailer", "Content-Length":
+				// Bogus. (copy of http1 rules)
+				// Ignore.
+			default:
+				if trailer == nil {
+					trailer = make(http.Header)
+				}
+				trailer[key] = nil
+			}
+		}
 	}
-	bodyOpen := rp.stream.state == stateOpen
+	delete(header, "Trailer")
+
 	body := &requestBody{
 		conn:          sc,
-		stream:        rp.stream,
+		stream:        st,
 		needsContinue: needsContinue,
 	}
-	// TODO: handle asterisk '*' requests + test
-	url, err := url.ParseRequestURI(rp.path)
-	if err != nil {
-		// TODO: find the right error code?
-		return nil, nil, StreamError{rp.stream.id, ErrCodeProtocol}
+	var url_ *url.URL
+	var requestURI string
+	if isConnect {
+		url_ = &url.URL{Host: authority}
+		requestURI = authority // mimic HTTP/1 server behavior
+	} else {
+		var err error
+		url_, err = url.ParseRequestURI(path)
+		if err != nil {
+			return nil, nil, streamError(f.StreamID, ErrCodeProtocol)
+		}
+		requestURI = path
 	}
 	req := &http.Request{
-		Method:     rp.method,
-		URL:        url,
+		Method:     method,
+		URL:        url_,
 		RemoteAddr: sc.remoteAddrStr,
-		Header:     rp.header,
-		RequestURI: rp.path,
+		Header:     header,
+		RequestURI: requestURI,
 		Proto:      "HTTP/2.0",
 		ProtoMajor: 2,
 		ProtoMinor: 0,
 		TLS:        tlsState,
 		Host:       authority,
 		Body:       body,
+		Trailer:    trailer,
 	}
+	req = requestWithContext(req, st.ctx)
 	if bodyOpen {
+		// Disabled, per golang.org/issue/14960:
+		// st.reqBuf = sc.getRequestBodyBuf()
+		// TODO: remove this 64k of garbage per request (again, but without a data race):
+		buf := make([]byte, initialWindowSize)
+
 		body.pipe = &pipe{
-			b: &fixedBuffer{buf: make([]byte, initialWindowSize)}, // TODO: share/remove XXX
+			b: &fixedBuffer{buf: buf},
 		}
 
-		if vv, ok := rp.header["Content-Length"]; ok {
+		if vv, ok := header["Content-Length"]; ok {
 			req.ContentLength, _ = strconv.ParseInt(vv[0], 10, 64)
 		} else {
 			req.ContentLength = -1
@@ -1516,7 +1681,7 @@ func (sc *serverConn) newWriterAndRequest() (*responseWriter, *http.Request, err
 	rws.conn = sc
 	rws.bw = bwSave
 	rws.bw.Reset(chunkWriter{rws})
-	rws.stream = rp.stream
+	rws.stream = st
 	rws.req = req
 	rws.body = body
 
@@ -1524,11 +1689,37 @@ func (sc *serverConn) newWriterAndRequest() (*responseWriter, *http.Request, err
 	return rw, req, nil
 }
 
+func (sc *serverConn) getRequestBodyBuf() []byte {
+	sc.serveG.check()
+	if buf := sc.freeRequestBodyBuf; buf != nil {
+		sc.freeRequestBodyBuf = nil
+		return buf
+	}
+	return make([]byte, initialWindowSize)
+}
+
 // Run on its own goroutine.
 func (sc *serverConn) runHandler(rw *responseWriter, req *http.Request, handler func(http.ResponseWriter, *http.Request)) {
-	defer rw.handlerDone()
-	// TODO: catch panics like net/http.Server
+	didPanic := true
+	defer func() {
+		rw.rws.stream.cancelCtx()
+		if didPanic {
+			e := recover()
+			// Same as net/http:
+			const size = 64 << 10
+			buf := make([]byte, size)
+			buf = buf[:runtime.Stack(buf, false)]
+			sc.writeFrameFromHandler(frameWriteMsg{
+				write:  handlerPanicRST{rw.rws.stream.id},
+				stream: rw.rws.stream,
+			})
+			sc.logf("http2: panic serving %v: %v\n%s", sc.conn.RemoteAddr(), e, buf)
+			return
+		}
+		rw.handlerDone()
+	}()
 	handler(rw, req)
+	didPanic = false
 }
 
 func handleHeaderListTooLong(w http.ResponseWriter, r *http.Request) {
@@ -1664,7 +1855,7 @@ type requestBody struct {
 
 func (b *requestBody) Close() error {
 	if b.pipe != nil {
-		b.pipe.CloseWithError(errClosedBody)
+		b.pipe.BreakWithError(errClosedBody)
 	}
 	b.closed = true
 	return nil
@@ -1715,11 +1906,15 @@ type responseWriterState struct {
 	// mutated by http.Handler goroutine:
 	handlerHeader http.Header // nil until called
 	snapHeader    http.Header // snapshot of handlerHeader at WriteHeader time
+	trailers      []string    // set in writeChunk
 	status        int         // status code passed to WriteHeader
 	wroteHeader   bool        // WriteHeader called (explicitly or implicitly). Not necessarily sent to user yet.
 	sentHeader    bool        // have we sent the header frame?
 	handlerDone   bool        // handler has finished
 
+	sentContentLen int64 // non-zero if handler set a Content-Length header
+	wroteBytes     int64
+
 	closeNotifierMu sync.Mutex // guards closeNotifierCh
 	closeNotifierCh chan bool  // nil until first used
 }
@@ -1728,6 +1923,23 @@ type chunkWriter struct{ rws *responseWriterState }
 
 func (cw chunkWriter) Write(p []byte) (n int, err error) { return cw.rws.writeChunk(p) }
 
+func (rws *responseWriterState) hasTrailers() bool { return len(rws.trailers) != 0 }
+
+// declareTrailer is called for each Trailer header when the
+// response header is written. It notes that a header will need to be
+// written in the trailers at the end of the response.
+func (rws *responseWriterState) declareTrailer(k string) {
+	k = http.CanonicalHeaderKey(k)
+	if !ValidTrailerHeader(k) {
+		// Forbidden by RFC 2616 14.40.
+		rws.conn.logf("ignoring invalid trailer %q", k)
+		return
+	}
+	if !strSliceContains(rws.trailers, k) {
+		rws.trailers = append(rws.trailers, k)
+	}
+}
+
 // writeChunk writes chunks from the bufio.Writer. But because
 // bufio.Writer may bypass its chunking, sometimes p may be
 // arbitrarily large.
@@ -1738,16 +1950,38 @@ func (rws *responseWriterState) writeChunk(p []byte) (n int, err error) {
 	if !rws.wroteHeader {
 		rws.writeHeader(200)
 	}
+
+	isHeadResp := rws.req.Method == "HEAD"
 	if !rws.sentHeader {
 		rws.sentHeader = true
-		var ctype, clen string // implicit ones, if we can calculate it
-		if rws.handlerDone && rws.snapHeader.Get("Content-Length") == "" {
+		var ctype, clen string
+		if clen = rws.snapHeader.Get("Content-Length"); clen != "" {
+			rws.snapHeader.Del("Content-Length")
+			clen64, err := strconv.ParseInt(clen, 10, 64)
+			if err == nil && clen64 >= 0 {
+				rws.sentContentLen = clen64
+			} else {
+				clen = ""
+			}
+		}
+		if clen == "" && rws.handlerDone && bodyAllowedForStatus(rws.status) && (len(p) > 0 || !isHeadResp) {
 			clen = strconv.Itoa(len(p))
 		}
-		if rws.snapHeader.Get("Content-Type") == "" {
+		_, hasContentType := rws.snapHeader["Content-Type"]
+		if !hasContentType && bodyAllowedForStatus(rws.status) {
 			ctype = http.DetectContentType(p)
 		}
-		endStream := rws.handlerDone && len(p) == 0
+		var date string
+		if _, ok := rws.snapHeader["Date"]; !ok {
+			// TODO(bradfitz): be faster here, like net/http? measure.
+			date = time.Now().UTC().Format(http.TimeFormat)
+		}
+
+		for _, v := range rws.snapHeader["Trailer"] {
+			foreachHeaderElement(v, rws.declareTrailer)
+		}
+
+		endStream := (rws.handlerDone && !rws.hasTrailers() && len(p) == 0) || isHeadResp
 		err = rws.conn.writeHeaders(rws.stream, &writeResHeaders{
 			streamID:      rws.stream.id,
 			httpResCode:   rws.status,
@@ -1755,6 +1989,7 @@ func (rws *responseWriterState) writeChunk(p []byte) (n int, err error) {
 			endStream:     endStream,
 			contentType:   ctype,
 			contentLength: clen,
+			date:          date,
 		})
 		if err != nil {
 			return 0, err
@@ -1763,16 +1998,89 @@ func (rws *responseWriterState) writeChunk(p []byte) (n int, err error) {
 			return 0, nil
 		}
 	}
+	if isHeadResp {
+		return len(p), nil
+	}
 	if len(p) == 0 && !rws.handlerDone {
 		return 0, nil
 	}
 
-	if err := rws.conn.writeDataFromHandler(rws.stream, p, rws.handlerDone); err != nil {
-		return 0, err
+	if rws.handlerDone {
+		rws.promoteUndeclaredTrailers()
+	}
+
+	endStream := rws.handlerDone && !rws.hasTrailers()
+	if len(p) > 0 || endStream {
+		// only send a 0 byte DATA frame if we're ending the stream.
+		if err := rws.conn.writeDataFromHandler(rws.stream, p, endStream); err != nil {
+			return 0, err
+		}
+	}
+
+	if rws.handlerDone && rws.hasTrailers() {
+		err = rws.conn.writeHeaders(rws.stream, &writeResHeaders{
+			streamID:  rws.stream.id,
+			h:         rws.handlerHeader,
+			trailers:  rws.trailers,
+			endStream: true,
+		})
+		return len(p), err
 	}
 	return len(p), nil
 }
 
+// TrailerPrefix is a magic prefix for ResponseWriter.Header map keys
+// that, if present, signals that the map entry is actually for
+// the response trailers, and not the response headers. The prefix
+// is stripped after the ServeHTTP call finishes and the values are
+// sent in the trailers.
+//
+// This mechanism is intended only for trailers that are not known
+// prior to the headers being written. If the set of trailers is fixed
+// or known before the header is written, the normal Go trailers mechanism
+// is preferred:
+//    https://golang.org/pkg/net/http/#ResponseWriter
+//    https://golang.org/pkg/net/http/#example_ResponseWriter_trailers
+const TrailerPrefix = "Trailer:"
+
+// promoteUndeclaredTrailers permits http.Handlers to set trailers
+// after the header has already been flushed. Because the Go
+// ResponseWriter interface has no way to set Trailers (only the
+// Header), and because we didn't want to expand the ResponseWriter
+// interface, and because nobody used trailers, and because RFC 2616
+// says you SHOULD (but not must) predeclare any trailers in the
+// header, the official ResponseWriter rules said trailers in Go must
+// be predeclared, and then we reuse the same ResponseWriter.Header()
+// map to mean both Headers and Trailers.  When it's time to write the
+// Trailers, we pick out the fields of Headers that were declared as
+// trailers. That worked for a while, until we found the first major
+// user of Trailers in the wild: gRPC (using them only over http2),
+// and gRPC libraries permit setting trailers mid-stream without
+// predeclarnig them. So: change of plans. We still permit the old
+// way, but we also permit this hack: if a Header() key begins with
+// "Trailer:", the suffix of that key is a Trailer. Because ':' is an
+// invalid token byte anyway, there is no ambiguity. (And it's already
+// filtered out) It's mildly hacky, but not terrible.
+//
+// This method runs after the Handler is done and promotes any Header
+// fields to be trailers.
+func (rws *responseWriterState) promoteUndeclaredTrailers() {
+	for k, vv := range rws.handlerHeader {
+		if !strings.HasPrefix(k, TrailerPrefix) {
+			continue
+		}
+		trailerKey := strings.TrimPrefix(k, TrailerPrefix)
+		rws.declareTrailer(trailerKey)
+		rws.handlerHeader[http.CanonicalHeaderKey(trailerKey)] = vv
+	}
+
+	if len(rws.trailers) > 1 {
+		sorter := sorterPool.Get().(*sorter)
+		sorter.SortStrings(rws.trailers)
+		sorterPool.Put(sorter)
+	}
+}
+
 func (w *responseWriter) Flush() {
 	rws := w.rws
 	if rws == nil {
@@ -1875,6 +2183,15 @@ func (w *responseWriter) write(lenData int, dataB []byte, dataS string) (n int,
 	if !rws.wroteHeader {
 		w.WriteHeader(200)
 	}
+	if !bodyAllowedForStatus(rws.status) {
+		return 0, http.ErrBodyNotAllowed
+	}
+	rws.wroteBytes += int64(len(dataB)) + int64(len(dataS)) // only one can be set
+	if rws.sentContentLen != 0 && rws.wroteBytes > rws.sentContentLen {
+		// TODO: send a RST_STREAM
+		return 0, errors.New("http2: handler wrote more than declared Content-Length")
+	}
+
 	if dataB != nil {
 		return rws.bw.Write(dataB)
 	} else {
@@ -1884,11 +2201,92 @@ func (w *responseWriter) write(lenData int, dataB []byte, dataS string) (n int,
 
 func (w *responseWriter) handlerDone() {
 	rws := w.rws
-	if rws == nil {
-		panic("handlerDone called twice")
-	}
 	rws.handlerDone = true
 	w.Flush()
 	w.rws = nil
 	responseWriterStatePool.Put(rws)
 }
+
+// foreachHeaderElement splits v according to the "#rule" construction
+// in RFC 2616 section 2.1 and calls fn for each non-empty element.
+func foreachHeaderElement(v string, fn func(string)) {
+	v = textproto.TrimString(v)
+	if v == "" {
+		return
+	}
+	if !strings.Contains(v, ",") {
+		fn(v)
+		return
+	}
+	for _, f := range strings.Split(v, ",") {
+		if f = textproto.TrimString(f); f != "" {
+			fn(f)
+		}
+	}
+}
+
+// From http://httpwg.org/specs/rfc7540.html#rfc.section.8.1.2.2
+var connHeaders = []string{
+	"Connection",
+	"Keep-Alive",
+	"Proxy-Connection",
+	"Transfer-Encoding",
+	"Upgrade",
+}
+
+// checkValidHTTP2Request checks whether req is a valid HTTP/2 request,
+// per RFC 7540 Section 8.1.2.2.
+// The returned error is reported to users.
+func checkValidHTTP2Request(req *http.Request) error {
+	for _, h := range connHeaders {
+		if _, ok := req.Header[h]; ok {
+			return fmt.Errorf("request header %q is not valid in HTTP/2", h)
+		}
+	}
+	te := req.Header["Te"]
+	if len(te) > 0 && (len(te) > 1 || (te[0] != "trailers" && te[0] != "")) {
+		return errors.New(`request header "TE" may only be "trailers" in HTTP/2`)
+	}
+	return nil
+}
+
+func new400Handler(err error) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+	}
+}
+
+// ValidTrailerHeader reports whether name is a valid header field name to appear
+// in trailers.
+// See: http://tools.ietf.org/html/rfc7230#section-4.1.2
+func ValidTrailerHeader(name string) bool {
+	name = http.CanonicalHeaderKey(name)
+	if strings.HasPrefix(name, "If-") || badTrailer[name] {
+		return false
+	}
+	return true
+}
+
+var badTrailer = map[string]bool{
+	"Authorization":       true,
+	"Cache-Control":       true,
+	"Connection":          true,
+	"Content-Encoding":    true,
+	"Content-Length":      true,
+	"Content-Range":       true,
+	"Content-Type":        true,
+	"Expect":              true,
+	"Host":                true,
+	"Keep-Alive":          true,
+	"Max-Forwards":        true,
+	"Pragma":              true,
+	"Proxy-Authenticate":  true,
+	"Proxy-Authorization": true,
+	"Proxy-Connection":    true,
+	"Range":               true,
+	"Realm":               true,
+	"Te":                  true,
+	"Trailer":             true,
+	"Transfer-Encoding":   true,
+	"Www-Authenticate":    true,
+}
diff --git a/vendor/golang.org/x/net/http2/transport.go b/vendor/golang.org/x/net/http2/transport.go
index 6f0d1256..3cefc22a 100644
--- a/vendor/golang.org/x/net/http2/transport.go
+++ b/vendor/golang.org/x/net/http2/transport.go
@@ -9,19 +9,24 @@ package http2
 import (
 	"bufio"
 	"bytes"
+	"compress/gzip"
 	"crypto/tls"
 	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
 	"log"
+	"math"
 	"net"
 	"net/http"
+	"sort"
 	"strconv"
 	"strings"
 	"sync"
+	"time"
 
 	"golang.org/x/net/http2/hpack"
+	"golang.org/x/net/lex/httplex"
 )
 
 const (
@@ -37,6 +42,8 @@ const (
 	// transportDefaultStreamMinRefresh is the minimum number of bytes we'll send
 	// a stream-level WINDOW_UPDATE for at a time.
 	transportDefaultStreamMinRefresh = 4 << 10
+
+	defaultUserAgent = "Go-http-client/2.0"
 )
 
 // Transport is an HTTP/2 Transport.
@@ -57,74 +64,195 @@ type Transport struct {
 	// tls.Client. If nil, the default configuration is used.
 	TLSClientConfig *tls.Config
 
-	// TODO: switch to RWMutex
-	// TODO: add support for sharing conns based on cert names
-	// (e.g. share conn for googleapis.com and appspot.com)
-	connMu sync.Mutex
-	conns  map[string][]*clientConn // key is host:port
+	// ConnPool optionally specifies an alternate connection pool to use.
+	// If nil, the default is used.
+	ConnPool ClientConnPool
+
+	// DisableCompression, if true, prevents the Transport from
+	// requesting compression with an "Accept-Encoding: gzip"
+	// request header when the Request contains no existing
+	// Accept-Encoding value. If the Transport requests gzip on
+	// its own and gets a gzipped response, it's transparently
+	// decoded in the Response.Body. However, if the user
+	// explicitly requested gzip it is not automatically
+	// uncompressed.
+	DisableCompression bool
+
+	// AllowHTTP, if true, permits HTTP/2 requests using the insecure,
+	// plain-text "http" scheme. Note that this does not enable h2c support.
+	AllowHTTP bool
+
+	// MaxHeaderListSize is the http2 SETTINGS_MAX_HEADER_LIST_SIZE to
+	// send in the initial settings frame. It is how many bytes
+	// of response headers are allow. Unlike the http2 spec, zero here
+	// means to use a default limit (currently 10MB). If you actually
+	// want to advertise an ulimited value to the peer, Transport
+	// interprets the highest possible value here (0xffffffff or 1<<32-1)
+	// to mean no limit.
+	MaxHeaderListSize uint32
+
+	// t1, if non-nil, is the standard library Transport using
+	// this transport. Its settings are used (but not its
+	// RoundTrip method, etc).
+	t1 *http.Transport
+
+	connPoolOnce  sync.Once
+	connPoolOrDef ClientConnPool // non-nil version of ConnPool
+}
+
+func (t *Transport) maxHeaderListSize() uint32 {
+	if t.MaxHeaderListSize == 0 {
+		return 10 << 20
+	}
+	if t.MaxHeaderListSize == 0xffffffff {
+		return 0
+	}
+	return t.MaxHeaderListSize
+}
+
+func (t *Transport) disableCompression() bool {
+	return t.DisableCompression || (t.t1 != nil && t.t1.DisableCompression)
+}
+
+var errTransportVersion = errors.New("http2: ConfigureTransport is only supported starting at Go 1.6")
+
+// ConfigureTransport configures a net/http HTTP/1 Transport to use HTTP/2.
+// It requires Go 1.6 or later and returns an error if the net/http package is too old
+// or if t1 has already been HTTP/2-enabled.
+func ConfigureTransport(t1 *http.Transport) error {
+	_, err := configureTransport(t1) // in configure_transport.go (go1.6) or not_go16.go
+	return err
+}
+
+func (t *Transport) connPool() ClientConnPool {
+	t.connPoolOnce.Do(t.initConnPool)
+	return t.connPoolOrDef
 }
 
-// clientConn is the state of a single HTTP/2 client connection to an
+func (t *Transport) initConnPool() {
+	if t.ConnPool != nil {
+		t.connPoolOrDef = t.ConnPool
+	} else {
+		t.connPoolOrDef = &clientConnPool{t: t}
+	}
+}
+
+// ClientConn is the state of a single HTTP/2 client connection to an
 // HTTP/2 server.
-type clientConn struct {
-	t        *Transport
-	tconn    net.Conn
-	tlsState *tls.ConnectionState
-	connKey  []string // key(s) this connection is cached in, in t.conns
+type ClientConn struct {
+	t         *Transport
+	tconn     net.Conn             // usually *tls.Conn, except specialized impls
+	tlsState  *tls.ConnectionState // nil only for specialized impls
+	singleUse bool                 // whether being used for a single http.Request
 
 	// readLoop goroutine fields:
 	readerDone chan struct{} // closed on error
 	readerErr  error         // set before readerDone is closed
 
-	mu           sync.Mutex // guards following
-	cond         *sync.Cond // hold mu; broadcast on flow/closed changes
-	flow         flow       // our conn-level flow control quota (cs.flow is per stream)
-	inflow       flow       // peer's conn-level flow control
-	closed       bool
-	goAway       *GoAwayFrame             // if non-nil, the GoAwayFrame we received
-	streams      map[uint32]*clientStream // client-initiated
-	nextStreamID uint32
-	bw           *bufio.Writer
-	br           *bufio.Reader
-	fr           *Framer
-	// Settings from peer:
+	mu              sync.Mutex // guards following
+	cond            *sync.Cond // hold mu; broadcast on flow/closed changes
+	flow            flow       // our conn-level flow control quota (cs.flow is per stream)
+	inflow          flow       // peer's conn-level flow control
+	closed          bool
+	wantSettingsAck bool                     // we sent a SETTINGS frame and haven't heard back
+	goAway          *GoAwayFrame             // if non-nil, the GoAwayFrame we received
+	goAwayDebug     string                   // goAway frame's debug data, retained as a string
+	streams         map[uint32]*clientStream // client-initiated
+	nextStreamID    uint32
+	bw              *bufio.Writer
+	br              *bufio.Reader
+	fr              *Framer
+	lastActive      time.Time
+	// Settings from peer: (also guarded by mu)
 	maxFrameSize         uint32
 	maxConcurrentStreams uint32
 	initialWindowSize    uint32
-	hbuf                 bytes.Buffer // HPACK encoder writes into this
-	henc                 *hpack.Encoder
-	freeBuf              [][]byte
 
-	wmu  sync.Mutex // held while writing; acquire AFTER wmu if holding both
+	hbuf    bytes.Buffer // HPACK encoder writes into this
+	henc    *hpack.Encoder
+	freeBuf [][]byte
+
+	wmu  sync.Mutex // held while writing; acquire AFTER mu if holding both
 	werr error      // first write error that has occurred
 }
 
 // clientStream is the state for a single HTTP/2 stream. One of these
 // is created for each Transport.RoundTrip call.
 type clientStream struct {
-	cc      *clientConn
-	ID      uint32
-	resc    chan resAndError
-	bufPipe pipe // buffered pipe with the flow-controlled response payload
-
-	flow   flow // guarded by cc.mu
-	inflow flow // guarded by cc.mu
+	cc            *ClientConn
+	req           *http.Request
+	trace         *clientTrace // or nil
+	ID            uint32
+	resc          chan resAndError
+	bufPipe       pipe // buffered pipe with the flow-controlled response payload
+	requestedGzip bool
+	on100         func() // optional code to run if get a 100 continue response
+
+	flow        flow  // guarded by cc.mu
+	inflow      flow  // guarded by cc.mu
+	bytesRemain int64 // -1 means unknown; owned by transportResponseBody.Read
+	readErr     error // sticky read error; owned by transportResponseBody.Read
+	stopReqBody error // if non-nil, stop writing req body; guarded by cc.mu
 
 	peerReset chan struct{} // closed on peer reset
 	resetErr  error         // populated before peerReset is closed
+
+	done chan struct{} // closed when stream remove from cc.streams map; close calls guarded by cc.mu
+
+	// owned by clientConnReadLoop:
+	firstByte    bool // got the first response byte
+	pastHeaders  bool // got first MetaHeadersFrame (actual headers)
+	pastTrailers bool // got optional second MetaHeadersFrame (trailers)
+
+	trailer    http.Header  // accumulated trailers
+	resTrailer *http.Header // client's Response.Trailer
 }
 
-// checkReset reports any error sent in a RST_STREAM frame by the
-// server.
-func (cs *clientStream) checkReset() error {
+// awaitRequestCancel runs in its own goroutine and waits for the user
+// to cancel a RoundTrip request, its context to expire, or for the
+// request to be done (any way it might be removed from the cc.streams
+// map: peer reset, successful completion, TCP connection breakage,
+// etc)
+func (cs *clientStream) awaitRequestCancel(req *http.Request) {
+	ctx := reqContext(req)
+	if req.Cancel == nil && ctx.Done() == nil {
+		return
+	}
+	select {
+	case <-req.Cancel:
+		cs.bufPipe.CloseWithError(errRequestCanceled)
+		cs.cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
+	case <-ctx.Done():
+		cs.bufPipe.CloseWithError(ctx.Err())
+		cs.cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
+	case <-cs.done:
+	}
+}
+
+// checkResetOrDone reports any error sent in a RST_STREAM frame by the
+// server, or errStreamClosed if the stream is complete.
+func (cs *clientStream) checkResetOrDone() error {
 	select {
 	case <-cs.peerReset:
 		return cs.resetErr
+	case <-cs.done:
+		return errStreamClosed
 	default:
 		return nil
 	}
 }
 
+func (cs *clientStream) abortRequestBodyWrite(err error) {
+	if err == nil {
+		panic("nil error")
+	}
+	cc := cs.cc
+	cc.mu.Lock()
+	cs.stopReqBody = err
+	cc.cond.Broadcast()
+	cc.mu.Unlock()
+}
+
 type stickyErrWriter struct {
 	w   io.Writer
 	err *error
@@ -139,27 +267,54 @@ func (sew stickyErrWriter) Write(p []byte) (n int, err error) {
 	return
 }
 
+var ErrNoCachedConn = errors.New("http2: no cached connection was available")
+
+// RoundTripOpt are options for the Transport.RoundTripOpt method.
+type RoundTripOpt struct {
+	// OnlyCachedConn controls whether RoundTripOpt may
+	// create a new TCP connection. If set true and
+	// no cached connection is available, RoundTripOpt
+	// will return ErrNoCachedConn.
+	OnlyCachedConn bool
+}
+
 func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
-	if req.URL.Scheme != "https" {
-		return nil, errors.New("http2: unsupported scheme")
+	return t.RoundTripOpt(req, RoundTripOpt{})
+}
+
+// authorityAddr returns a given authority (a host/IP, or host:port / ip:port)
+// and returns a host:port. The port 443 is added if needed.
+func authorityAddr(scheme string, authority string) (addr string) {
+	if _, _, err := net.SplitHostPort(authority); err == nil {
+		return authority
+	}
+	port := "443"
+	if scheme == "http" {
+		port = "80"
 	}
+	return net.JoinHostPort(authority, port)
+}
 
-	host, port, err := net.SplitHostPort(req.URL.Host)
-	if err != nil {
-		host = req.URL.Host
-		port = "443"
+// RoundTripOpt is like RoundTrip, but takes options.
+func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Response, error) {
+	if !(req.URL.Scheme == "https" || (req.URL.Scheme == "http" && t.AllowHTTP)) {
+		return nil, errors.New("http2: unsupported scheme")
 	}
 
+	addr := authorityAddr(req.URL.Scheme, req.URL.Host)
 	for {
-		cc, err := t.getClientConn(host, port)
+		cc, err := t.connPool().GetClientConn(req, addr)
 		if err != nil {
+			t.vlogf("http2: Transport failed to get client conn for %s: %v", addr, err)
 			return nil, err
 		}
-		res, err := cc.roundTrip(req)
-		if shouldRetryRequest(err) { // TODO: or clientconn is overloaded (too many outstanding requests)?
+		traceGotConn(req, cc)
+		res, err := cc.RoundTrip(req)
+		if shouldRetryRequest(req, err) {
 			continue
 		}
 		if err != nil {
+			t.vlogf("RoundTrip failure: %v", err)
 			return nil, err
 		}
 		return res, nil
@@ -170,113 +325,32 @@ func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
 // connected from previous requests but are now sitting idle.
 // It does not interrupt any connections currently in use.
 func (t *Transport) CloseIdleConnections() {
-	t.connMu.Lock()
-	defer t.connMu.Unlock()
-	for _, vv := range t.conns {
-		for _, cc := range vv {
-			cc.closeIfIdle()
-		}
-	}
-}
-
-var errClientConnClosed = errors.New("http2: client conn is closed")
-
-func shouldRetryRequest(err error) bool {
-	// TODO: or GOAWAY graceful shutdown stuff
-	return err == errClientConnClosed
-}
-
-func (t *Transport) removeClientConn(cc *clientConn) {
-	t.connMu.Lock()
-	defer t.connMu.Unlock()
-	for _, key := range cc.connKey {
-		vv, ok := t.conns[key]
-		if !ok {
-			continue
-		}
-		newList := filterOutClientConn(vv, cc)
-		if len(newList) > 0 {
-			t.conns[key] = newList
-		} else {
-			delete(t.conns, key)
-		}
-	}
-}
-
-func filterOutClientConn(in []*clientConn, exclude *clientConn) []*clientConn {
-	out := in[:0]
-	for _, v := range in {
-		if v != exclude {
-			out = append(out, v)
-		}
-	}
-	// If we filtered it out, zero out the last item to prevent
-	// the GC from seeing it.
-	if len(in) != len(out) {
-		in[len(in)-1] = nil
+	if cp, ok := t.connPool().(clientConnPoolIdleCloser); ok {
+		cp.closeIdleConnections()
 	}
-	return out
 }
 
-// AddIdleConn adds c as an idle conn for Transport.
-// It assumes that c has not yet exchanged SETTINGS frames.
-// The addr maybe be either "host" or "host:port".
-func (t *Transport) AddIdleConn(addr string, c *tls.Conn) error {
-	var key string
-	_, _, err := net.SplitHostPort(addr)
-	if err == nil {
-		key = addr
-	} else {
-		key = addr + ":443"
-	}
-	cc, err := t.newClientConn(key, c)
-	if err != nil {
-		return err
-	}
-
-	t.addConn(key, cc)
-	return nil
-}
+var (
+	errClientConnClosed   = errors.New("http2: client conn is closed")
+	errClientConnUnusable = errors.New("http2: client conn not usable")
+)
 
-func (t *Transport) addConn(key string, cc *clientConn) {
-	t.connMu.Lock()
-	defer t.connMu.Unlock()
-	if t.conns == nil {
-		t.conns = make(map[string][]*clientConn)
-	}
-	t.conns[key] = append(t.conns[key], cc)
+func shouldRetryRequest(req *http.Request, err error) bool {
+	// TODO: retry GET requests (no bodies) more aggressively, if shutdown
+	// before response.
+	return err == errClientConnUnusable
 }
 
-func (t *Transport) getClientConn(host, port string) (*clientConn, error) {
-	key := net.JoinHostPort(host, port)
-
-	t.connMu.Lock()
-	for _, cc := range t.conns[key] {
-		if cc.canTakeNewRequest() {
-			t.connMu.Unlock()
-			return cc, nil
-		}
-	}
-	t.connMu.Unlock()
-
-	// TODO(bradfitz): use a singleflight.Group to only lock once per 'key'.
-	// Probably need to vendor it in as github.com/golang/sync/singleflight
-	// though, since the net package already uses it? Also lines up with
-	// sameer, bcmills, et al wanting to open source some sync stuff.
-	cc, err := t.dialClientConn(host, port, key)
+func (t *Transport) dialClientConn(addr string, singleUse bool) (*ClientConn, error) {
+	host, _, err := net.SplitHostPort(addr)
 	if err != nil {
 		return nil, err
 	}
-	t.addConn(key, cc)
-	return cc, nil
-}
-
-func (t *Transport) dialClientConn(host, port, key string) (*clientConn, error) {
-	tconn, err := t.dialTLS()("tcp", net.JoinHostPort(host, port), t.newTLSConfig(host))
+	tconn, err := t.dialTLS()("tcp", addr, t.newTLSConfig(host))
 	if err != nil {
 		return nil, err
 	}
-	return t.newClientConn(key, tconn)
+	return t.newClientConn(tconn, singleUse)
 }
 
 func (t *Transport) newTLSConfig(host string) *tls.Config {
@@ -284,8 +358,12 @@ func (t *Transport) newTLSConfig(host string) *tls.Config {
 	if t.TLSClientConfig != nil {
 		*cfg = *t.TLSClientConfig
 	}
-	cfg.NextProtos = []string{NextProtoTLS} // TODO: don't override if already in list
-	cfg.ServerName = host
+	if !strSliceContains(cfg.NextProtos, NextProtoTLS) {
+		cfg.NextProtos = append([]string{NextProtoTLS}, cfg.NextProtos...)
+	}
+	if cfg.ServerName == "" {
+		cfg.ServerName = host
+	}
 	return cfg
 }
 
@@ -319,44 +397,70 @@ func (t *Transport) dialTLSDefault(network, addr string, cfg *tls.Config) (net.C
 	return cn, nil
 }
 
-func (t *Transport) newClientConn(key string, tconn net.Conn) (*clientConn, error) {
-	if _, err := tconn.Write(clientPreface); err != nil {
-		return nil, err
+// disableKeepAlives reports whether connections should be closed as
+// soon as possible after handling the first request.
+func (t *Transport) disableKeepAlives() bool {
+	return t.t1 != nil && t.t1.DisableKeepAlives
+}
+
+func (t *Transport) expectContinueTimeout() time.Duration {
+	if t.t1 == nil {
+		return 0
 	}
+	return transportExpectContinueTimeout(t.t1)
+}
+
+func (t *Transport) NewClientConn(c net.Conn) (*ClientConn, error) {
+	return t.newClientConn(c, false)
+}
 
-	cc := &clientConn{
+func (t *Transport) newClientConn(c net.Conn, singleUse bool) (*ClientConn, error) {
+	cc := &ClientConn{
 		t:                    t,
-		tconn:                tconn,
-		connKey:              []string{key}, // TODO: cert's validated hostnames too
+		tconn:                c,
 		readerDone:           make(chan struct{}),
 		nextStreamID:         1,
 		maxFrameSize:         16 << 10, // spec default
 		initialWindowSize:    65535,    // spec default
 		maxConcurrentStreams: 1000,     // "infinite", per spec. 1000 seems good enough.
 		streams:              make(map[uint32]*clientStream),
+		singleUse:            singleUse,
+		wantSettingsAck:      true,
 	}
+	if VerboseLogs {
+		t.vlogf("http2: Transport creating client conn %p to %v", cc, c.RemoteAddr())
+	}
+
 	cc.cond = sync.NewCond(&cc.mu)
 	cc.flow.add(int32(initialWindowSize))
 
 	// TODO: adjust this writer size to account for frame size +
 	// MTU + crypto/tls record padding.
-	cc.bw = bufio.NewWriter(stickyErrWriter{tconn, &cc.werr})
-	cc.br = bufio.NewReader(tconn)
+	cc.bw = bufio.NewWriter(stickyErrWriter{c, &cc.werr})
+	cc.br = bufio.NewReader(c)
 	cc.fr = NewFramer(cc.bw, cc.br)
+	cc.fr.ReadMetaHeaders = hpack.NewDecoder(initialHeaderTableSize, nil)
+	cc.fr.MaxHeaderListSize = t.maxHeaderListSize()
+
+	// TODO: SetMaxDynamicTableSize, SetMaxDynamicTableSizeLimit on
+	// henc in response to SETTINGS frames?
 	cc.henc = hpack.NewEncoder(&cc.hbuf)
 
-	type connectionStater interface {
-		ConnectionState() tls.ConnectionState
-	}
-	if cs, ok := tconn.(connectionStater); ok {
+	if cs, ok := c.(connectionStater); ok {
 		state := cs.ConnectionState()
 		cc.tlsState = &state
 	}
 
-	cc.fr.WriteSettings(
-		Setting{ID: SettingEnablePush, Val: 0},
-		Setting{ID: SettingInitialWindowSize, Val: transportDefaultStreamFlow},
-	)
+	initialSettings := []Setting{
+		{ID: SettingEnablePush, Val: 0},
+		{ID: SettingInitialWindowSize, Val: transportDefaultStreamFlow},
+	}
+	if max := t.maxHeaderListSize(); max != 0 {
+		initialSettings = append(initialSettings, Setting{ID: SettingMaxHeaderListSize, Val: max})
+	}
+
+	cc.bw.Write(clientPreface)
+	cc.fr.WriteSettings(initialSettings...)
 	cc.fr.WriteWindowUpdate(0, transportDefaultConnFlow)
 	cc.inflow.add(transportDefaultConnFlow + initialWindowSize)
 	cc.bw.Flush()
@@ -364,61 +468,55 @@ func (t *Transport) newClientConn(key string, tconn net.Conn) (*clientConn, erro
 		return nil, cc.werr
 	}
 
-	// Read the obligatory SETTINGS frame
-	f, err := cc.fr.ReadFrame()
-	if err != nil {
-		return nil, err
-	}
-	sf, ok := f.(*SettingsFrame)
-	if !ok {
-		return nil, fmt.Errorf("expected settings frame, got: %T", f)
-	}
-	cc.fr.WriteSettingsAck()
-	cc.bw.Flush()
-
-	sf.ForeachSetting(func(s Setting) error {
-		switch s.ID {
-		case SettingMaxFrameSize:
-			cc.maxFrameSize = s.Val
-		case SettingMaxConcurrentStreams:
-			cc.maxConcurrentStreams = s.Val
-		case SettingInitialWindowSize:
-			cc.initialWindowSize = s.Val
-		default:
-			// TODO(bradfitz): handle more
-			t.vlogf("Unhandled Setting: %v", s)
-		}
-		return nil
-	})
-
 	go cc.readLoop()
 	return cc, nil
 }
 
-func (cc *clientConn) setGoAway(f *GoAwayFrame) {
+func (cc *ClientConn) setGoAway(f *GoAwayFrame) {
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
+
+	old := cc.goAway
 	cc.goAway = f
+
+	// Merge the previous and current GoAway error frames.
+	if cc.goAwayDebug == "" {
+		cc.goAwayDebug = string(f.DebugData())
+	}
+	if old != nil && old.ErrCode != ErrCodeNo {
+		cc.goAway.ErrCode = old.ErrCode
+	}
 }
 
-func (cc *clientConn) canTakeNewRequest() bool {
+func (cc *ClientConn) CanTakeNewRequest() bool {
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
-	return cc.goAway == nil &&
+	return cc.canTakeNewRequestLocked()
+}
+
+func (cc *ClientConn) canTakeNewRequestLocked() bool {
+	if cc.singleUse && cc.nextStreamID > 1 {
+		return false
+	}
+	return cc.goAway == nil && !cc.closed &&
 		int64(len(cc.streams)+1) < int64(cc.maxConcurrentStreams) &&
-		cc.nextStreamID < 2147483647
+		cc.nextStreamID < math.MaxInt32
 }
 
-func (cc *clientConn) closeIfIdle() {
+func (cc *ClientConn) closeIfIdle() {
 	cc.mu.Lock()
 	if len(cc.streams) > 0 {
 		cc.mu.Unlock()
 		return
 	}
 	cc.closed = true
+	nextID := cc.nextStreamID
 	// TODO: do clients send GOAWAY too? maybe? Just Close:
 	cc.mu.Unlock()
 
+	if VerboseLogs {
+		cc.vlogf("http2: Transport closing idle conn %p (forSingleUse=%v, maxStream=%v)", cc, cc.singleUse, nextID-2)
+	}
 	cc.tconn.Close()
 }
 
@@ -428,7 +526,7 @@ const maxAllocFrameSize = 512 << 10
 // They're capped at the min of the peer's max frame size or 512KB
 // (kinda arbitrarily), but definitely capped so we don't allocate 4GB
 // bufers.
-func (cc *clientConn) frameScratchBuffer() []byte {
+func (cc *ClientConn) frameScratchBuffer() []byte {
 	cc.mu.Lock()
 	size := cc.maxFrameSize
 	if size > maxAllocFrameSize {
@@ -445,7 +543,7 @@ func (cc *clientConn) frameScratchBuffer() []byte {
 	return make([]byte, size)
 }
 
-func (cc *clientConn) putFrameScratchBuffer(buf []byte) {
+func (cc *ClientConn) putFrameScratchBuffer(buf []byte) {
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
 	const maxBufs = 4 // arbitrary; 4 concurrent requests per conn? investigate.
@@ -462,121 +560,352 @@ func (cc *clientConn) putFrameScratchBuffer(buf []byte) {
 	// forget about it.
 }
 
-func (cc *clientConn) roundTrip(req *http.Request) (*http.Response, error) {
-	cc.mu.Lock()
+// errRequestCanceled is a copy of net/http's errRequestCanceled because it's not
+// exported. At least they'll be DeepEqual for h1-vs-h2 comparisons tests.
+var errRequestCanceled = errors.New("net/http: request canceled")
+
+func commaSeparatedTrailers(req *http.Request) (string, error) {
+	keys := make([]string, 0, len(req.Trailer))
+	for k := range req.Trailer {
+		k = http.CanonicalHeaderKey(k)
+		switch k {
+		case "Transfer-Encoding", "Trailer", "Content-Length":
+			return "", &badStringError{"invalid Trailer key", k}
+		}
+		keys = append(keys, k)
+	}
+	if len(keys) > 0 {
+		sort.Strings(keys)
+		// TODO: could do better allocation-wise here, but trailers are rare,
+		// so being lazy for now.
+		return strings.Join(keys, ","), nil
+	}
+	return "", nil
+}
+
+func (cc *ClientConn) responseHeaderTimeout() time.Duration {
+	if cc.t.t1 != nil {
+		return cc.t.t1.ResponseHeaderTimeout
+	}
+	// No way to do this (yet?) with just an http2.Transport. Probably
+	// no need. Request.Cancel this is the new way. We only need to support
+	// this for compatibility with the old http.Transport fields when
+	// we're doing transparent http2.
+	return 0
+}
+
+// checkConnHeaders checks whether req has any invalid connection-level headers.
+// per RFC 7540 section 8.1.2.2: Connection-Specific Header Fields.
+// Certain headers are special-cased as okay but not transmitted later.
+func checkConnHeaders(req *http.Request) error {
+	if v := req.Header.Get("Upgrade"); v != "" {
+		return errors.New("http2: invalid Upgrade request header")
+	}
+	if v := req.Header.Get("Transfer-Encoding"); (v != "" && v != "chunked") || len(req.Header["Transfer-Encoding"]) > 1 {
+		return errors.New("http2: invalid Transfer-Encoding request header")
+	}
+	if v := req.Header.Get("Connection"); (v != "" && v != "close" && v != "keep-alive") || len(req.Header["Connection"]) > 1 {
+		return errors.New("http2: invalid Connection request header")
+	}
+	return nil
+}
+
+func bodyAndLength(req *http.Request) (body io.Reader, contentLen int64) {
+	body = req.Body
+	if body == nil {
+		return nil, 0
+	}
+	if req.ContentLength != 0 {
+		return req.Body, req.ContentLength
+	}
+
+	// We have a body but a zero content length. Test to see if
+	// it's actually zero or just unset.
+	var buf [1]byte
+	n, rerr := io.ReadFull(body, buf[:])
+	if rerr != nil && rerr != io.EOF {
+		return errorReader{rerr}, -1
+	}
+	if n == 1 {
+		// Oh, guess there is data in this Body Reader after all.
+		// The ContentLength field just wasn't set.
+		// Stich the Body back together again, re-attaching our
+		// consumed byte.
+		return io.MultiReader(bytes.NewReader(buf[:]), body), -1
+	}
+	// Body is actually zero bytes.
+	return nil, 0
+}
+
+func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
+	if err := checkConnHeaders(req); err != nil {
+		return nil, err
+	}
+
+	trailers, err := commaSeparatedTrailers(req)
+	if err != nil {
+		return nil, err
+	}
+	hasTrailers := trailers != ""
+
+	body, contentLen := bodyAndLength(req)
+	hasBody := body != nil
 
-	if cc.closed {
+	cc.mu.Lock()
+	cc.lastActive = time.Now()
+	if cc.closed || !cc.canTakeNewRequestLocked() {
+		cc.mu.Unlock()
+		return nil, errClientConnUnusable
+	}
+
+	// TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere?
+	var requestedGzip bool
+	if !cc.t.disableCompression() &&
+		req.Header.Get("Accept-Encoding") == "" &&
+		req.Header.Get("Range") == "" &&
+		req.Method != "HEAD" {
+		// Request gzip only, not deflate. Deflate is ambiguous and
+		// not as universally supported anyway.
+		// See: http://www.gzip.org/zlib/zlib_faq.html#faq38
+		//
+		// Note that we don't request this for HEAD requests,
+		// due to a bug in nginx:
+		//   http://trac.nginx.org/nginx/ticket/358
+		//   https://golang.org/issue/5522
+		//
+		// We don't request gzip if the request is for a range, since
+		// auto-decoding a portion of a gzipped document will just fail
+		// anyway. See https://golang.org/issue/8923
+		requestedGzip = true
+	}
+
+	// we send: HEADERS{1}, CONTINUATION{0,} + DATA{0,} (DATA is
+	// sent by writeRequestBody below, along with any Trailers,
+	// again in form HEADERS{1}, CONTINUATION{0,})
+	hdrs, err := cc.encodeHeaders(req, requestedGzip, trailers, contentLen)
+	if err != nil {
 		cc.mu.Unlock()
-		return nil, errClientConnClosed
+		return nil, err
 	}
 
 	cs := cc.newStream()
-	hasBody := req.Body != nil
-
-	// we send: HEADERS[+CONTINUATION] + (DATA?)
-	hdrs := cc.encodeHeaders(req)
-	first := true
+	cs.req = req
+	cs.trace = requestTrace(req)
+	cs.requestedGzip = requestedGzip
+	bodyWriter := cc.t.getBodyWriterState(cs, body)
+	cs.on100 = bodyWriter.on100
 
 	cc.wmu.Lock()
-	frameSize := int(cc.maxFrameSize)
-	for len(hdrs) > 0 && cc.werr == nil {
-		chunk := hdrs
-		if len(chunk) > frameSize {
-			chunk = chunk[:frameSize]
-		}
-		hdrs = hdrs[len(chunk):]
-		endHeaders := len(hdrs) == 0
-		if first {
-			cc.fr.WriteHeaders(HeadersFrameParam{
-				StreamID:      cs.ID,
-				BlockFragment: chunk,
-				EndStream:     !hasBody,
-				EndHeaders:    endHeaders,
-			})
-			first = false
-		} else {
-			cc.fr.WriteContinuation(cs.ID, endHeaders, chunk)
-		}
-	}
-	cc.bw.Flush()
-	werr := cc.werr
+	endStream := !hasBody && !hasTrailers
+	werr := cc.writeHeaders(cs.ID, endStream, hdrs)
 	cc.wmu.Unlock()
+	traceWroteHeaders(cs.trace)
 	cc.mu.Unlock()
 
 	if werr != nil {
+		if hasBody {
+			req.Body.Close() // per RoundTripper contract
+			bodyWriter.cancel()
+		}
+		cc.forgetStreamID(cs.ID)
+		// Don't bother sending a RST_STREAM (our write already failed;
+		// no need to keep writing)
+		traceWroteRequest(cs.trace, werr)
 		return nil, werr
 	}
 
-	var bodyCopyErrc chan error
-	var gotResHeaders chan struct{} // closed on resheaders
+	var respHeaderTimer <-chan time.Time
 	if hasBody {
-		bodyCopyErrc = make(chan error, 1)
-		gotResHeaders = make(chan struct{})
-		go func() {
-			bodyCopyErrc <- cs.writeRequestBody(req.Body, gotResHeaders)
-		}()
+		bodyWriter.scheduleBodyWrite()
+	} else {
+		traceWroteRequest(cs.trace, nil)
+		if d := cc.responseHeaderTimeout(); d != 0 {
+			timer := time.NewTimer(d)
+			defer timer.Stop()
+			respHeaderTimer = timer.C
+		}
+	}
+
+	readLoopResCh := cs.resc
+	bodyWritten := false
+	ctx := reqContext(req)
+
+	handleReadLoopResponse := func(re resAndError) (*http.Response, error) {
+		res := re.res
+		if re.err != nil || res.StatusCode > 299 {
+			// On error or status code 3xx, 4xx, 5xx, etc abort any
+			// ongoing write, assuming that the server doesn't care
+			// about our request body. If the server replied with 1xx or
+			// 2xx, however, then assume the server DOES potentially
+			// want our body (e.g. full-duplex streaming:
+			// golang.org/issue/13444). If it turns out the server
+			// doesn't, they'll RST_STREAM us soon enough.  This is a
+			// heuristic to avoid adding knobs to Transport.  Hopefully
+			// we can keep it.
+			bodyWriter.cancel()
+			cs.abortRequestBodyWrite(errStopReqBodyWrite)
+		}
+		if re.err != nil {
+			cc.forgetStreamID(cs.ID)
+			return nil, re.err
+		}
+		res.Request = req
+		res.TLS = cc.tlsState
+		return res, nil
 	}
 
 	for {
 		select {
-		case re := <-cs.resc:
-			if gotResHeaders != nil {
-				close(gotResHeaders)
+		case re := <-readLoopResCh:
+			return handleReadLoopResponse(re)
+		case <-respHeaderTimer:
+			cc.forgetStreamID(cs.ID)
+			if !hasBody || bodyWritten {
+				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
+			} else {
+				bodyWriter.cancel()
+				cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
 			}
-			if re.err != nil {
-				return nil, re.err
+			return nil, errTimeout
+		case <-ctx.Done():
+			cc.forgetStreamID(cs.ID)
+			if !hasBody || bodyWritten {
+				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
+			} else {
+				bodyWriter.cancel()
+				cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
+			}
+			return nil, ctx.Err()
+		case <-req.Cancel:
+			cc.forgetStreamID(cs.ID)
+			if !hasBody || bodyWritten {
+				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
+			} else {
+				bodyWriter.cancel()
+				cs.abortRequestBodyWrite(errStopReqBodyWriteAndCancel)
+			}
+			return nil, errRequestCanceled
+		case <-cs.peerReset:
+			// processResetStream already removed the
+			// stream from the streams map; no need for
+			// forgetStreamID.
+			return nil, cs.resetErr
+		case err := <-bodyWriter.resc:
+			// Prefer the read loop's response, if available. Issue 16102.
+			select {
+			case re := <-readLoopResCh:
+				return handleReadLoopResponse(re)
+			default:
 			}
-			res := re.res
-			res.Request = req
-			res.TLS = cc.tlsState
-			return res, nil
-		case err := <-bodyCopyErrc:
 			if err != nil {
 				return nil, err
 			}
+			bodyWritten = true
+			if d := cc.responseHeaderTimeout(); d != 0 {
+				timer := time.NewTimer(d)
+				defer timer.Stop()
+				respHeaderTimer = timer.C
+			}
 		}
 	}
 }
 
-var errServerResponseBeforeRequestBody = errors.New("http2: server sent response while still writing request body")
+// requires cc.wmu be held
+func (cc *ClientConn) writeHeaders(streamID uint32, endStream bool, hdrs []byte) error {
+	first := true // first frame written (HEADERS is first, then CONTINUATION)
+	frameSize := int(cc.maxFrameSize)
+	for len(hdrs) > 0 && cc.werr == nil {
+		chunk := hdrs
+		if len(chunk) > frameSize {
+			chunk = chunk[:frameSize]
+		}
+		hdrs = hdrs[len(chunk):]
+		endHeaders := len(hdrs) == 0
+		if first {
+			cc.fr.WriteHeaders(HeadersFrameParam{
+				StreamID:      streamID,
+				BlockFragment: chunk,
+				EndStream:     endStream,
+				EndHeaders:    endHeaders,
+			})
+			first = false
+		} else {
+			cc.fr.WriteContinuation(streamID, endHeaders, chunk)
+		}
+	}
+	// TODO(bradfitz): this Flush could potentially block (as
+	// could the WriteHeaders call(s) above), which means they
+	// wouldn't respond to Request.Cancel being readable. That's
+	// rare, but this should probably be in a goroutine.
+	cc.bw.Flush()
+	return cc.werr
+}
 
-func (cs *clientStream) writeRequestBody(body io.Reader, gotResHeaders <-chan struct{}) error {
+// internal error values; they don't escape to callers
+var (
+	// abort request body write; don't send cancel
+	errStopReqBodyWrite = errors.New("http2: aborting request body write")
+
+	// abort request body write, but send stream reset of cancel.
+	errStopReqBodyWriteAndCancel = errors.New("http2: canceling request")
+)
+
+func (cs *clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) (err error) {
 	cc := cs.cc
 	sentEnd := false // whether we sent the final DATA frame w/ END_STREAM
 	buf := cc.frameScratchBuffer()
 	defer cc.putFrameScratchBuffer(buf)
 
-	for !sentEnd {
-		var sawEOF bool
-		n, err := io.ReadFull(body, buf)
-		if err == io.ErrUnexpectedEOF {
+	defer func() {
+		traceWroteRequest(cs.trace, err)
+		// TODO: write h12Compare test showing whether
+		// Request.Body is closed by the Transport,
+		// and in multiple cases: server replies <=299 and >299
+		// while still writing request body
+		cerr := bodyCloser.Close()
+		if err == nil {
+			err = cerr
+		}
+	}()
+
+	req := cs.req
+	hasTrailers := req.Trailer != nil
+
+	var sawEOF bool
+	for !sawEOF {
+		n, err := body.Read(buf)
+		if err == io.EOF {
 			sawEOF = true
 			err = nil
-		} else if err == io.EOF {
-			break
 		} else if err != nil {
 			return err
 		}
 
-		toWrite := buf[:n]
-		for len(toWrite) > 0 && err == nil {
+		remain := buf[:n]
+		for len(remain) > 0 && err == nil {
 			var allowed int32
-			allowed, err = cs.awaitFlowControl(int32(len(toWrite)))
-			if err != nil {
+			allowed, err = cs.awaitFlowControl(len(remain))
+			switch {
+			case err == errStopReqBodyWrite:
+				return err
+			case err == errStopReqBodyWriteAndCancel:
+				cc.writeStreamReset(cs.ID, ErrCodeCancel, nil)
+				return err
+			case err != nil:
 				return err
 			}
-
 			cc.wmu.Lock()
-			select {
-			case <-gotResHeaders:
-				err = errServerResponseBeforeRequestBody
-			case <-cs.peerReset:
-				err = cs.resetErr
-			default:
-				data := toWrite[:allowed]
-				toWrite = toWrite[allowed:]
-				sentEnd = sawEOF && len(toWrite) == 0
-				err = cc.fr.WriteData(cs.ID, sentEnd, data)
+			data := remain[:allowed]
+			remain = remain[allowed:]
+			sentEnd = sawEOF && len(remain) == 0 && !hasTrailers
+			err = cc.fr.WriteData(cs.ID, sentEnd, data)
+			if err == nil {
+				// TODO(bradfitz): this flush is for latency, not bandwidth.
+				// Most requests won't need this. Make this opt-in or opt-out?
+				// Use some heuristic on the body type? Nagel-like timers?
+				// Based on 'n'? Only last chunk of this for loop, unless flow control
+				// tokens are low? For now, always:
+				err = cc.bw.Flush()
 			}
 			cc.wmu.Unlock()
 		}
@@ -585,17 +914,26 @@ func (cs *clientStream) writeRequestBody(body io.Reader, gotResHeaders <-chan st
 		}
 	}
 
-	var err error
+	var trls []byte
+	if !sentEnd && hasTrailers {
+		cc.mu.Lock()
+		defer cc.mu.Unlock()
+		trls = cc.encodeTrailers(req)
+	}
 
 	cc.wmu.Lock()
-	if !sentEnd {
+	defer cc.wmu.Unlock()
+
+	// Avoid forgetting to send an END_STREAM if the encoded
+	// trailers are 0 bytes. Both results produce and END_STREAM.
+	if len(trls) > 0 {
+		err = cc.writeHeaders(cs.ID, true, trls)
+	} else {
 		err = cc.fr.WriteData(cs.ID, true, nil)
 	}
 	if ferr := cc.bw.Flush(); ferr != nil && err == nil {
 		err = ferr
 	}
-	cc.wmu.Unlock()
-
 	return err
 }
 
@@ -603,7 +941,7 @@ func (cs *clientStream) writeRequestBody(body io.Reader, gotResHeaders <-chan st
 // control tokens from the server.
 // It returns either the non-zero number of tokens taken or an error
 // if the stream is dead.
-func (cs *clientStream) awaitFlowControl(maxBytes int32) (taken int32, err error) {
+func (cs *clientStream) awaitFlowControl(maxBytes int) (taken int32, err error) {
 	cc := cs.cc
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
@@ -611,13 +949,17 @@ func (cs *clientStream) awaitFlowControl(maxBytes int32) (taken int32, err error
 		if cc.closed {
 			return 0, errClientConnClosed
 		}
-		if err := cs.checkReset(); err != nil {
+		if cs.stopReqBody != nil {
+			return 0, cs.stopReqBody
+		}
+		if err := cs.checkResetOrDone(); err != nil {
 			return 0, err
 		}
 		if a := cs.flow.available(); a > 0 {
 			take := a
-			if take > maxBytes {
-				take = maxBytes
+			if int(take) > maxBytes {
+
+				take = int32(maxBytes) // can't truncate int; take is int32
 			}
 			if take > int32(cc.maxFrameSize) {
 				take = int32(cc.maxFrameSize)
@@ -629,31 +971,124 @@ func (cs *clientStream) awaitFlowControl(maxBytes int32) (taken int32, err error
 	}
 }
 
+type badStringError struct {
+	what string
+	str  string
+}
+
+func (e *badStringError) Error() string { return fmt.Sprintf("%s %q", e.what, e.str) }
+
 // requires cc.mu be held.
-func (cc *clientConn) encodeHeaders(req *http.Request) []byte {
+func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trailers string, contentLength int64) ([]byte, error) {
 	cc.hbuf.Reset()
 
-	// TODO(bradfitz): figure out :authority-vs-Host stuff between http2 and Go
 	host := req.Host
 	if host == "" {
 		host = req.URL.Host
 	}
 
+	// Check for any invalid headers and return an error before we
+	// potentially pollute our hpack state. (We want to be able to
+	// continue to reuse the hpack encoder for future requests)
+	for k, vv := range req.Header {
+		if !httplex.ValidHeaderFieldName(k) {
+			return nil, fmt.Errorf("invalid HTTP header name %q", k)
+		}
+		for _, v := range vv {
+			if !httplex.ValidHeaderFieldValue(v) {
+				return nil, fmt.Errorf("invalid HTTP header value %q for header %q", v, k)
+			}
+		}
+	}
+
 	// 8.1.2.3 Request Pseudo-Header Fields
 	// The :path pseudo-header field includes the path and query parts of the
 	// target URI (the path-absolute production and optionally a '?' character
 	// followed by the query production (see Sections 3.3 and 3.4 of
 	// [RFC3986]).
-	cc.writeHeader(":authority", host) // probably not right for all sites
+	cc.writeHeader(":authority", host)
 	cc.writeHeader(":method", req.Method)
-	cc.writeHeader(":path", req.URL.RequestURI())
-	cc.writeHeader(":scheme", "https")
+	if req.Method != "CONNECT" {
+		cc.writeHeader(":path", req.URL.RequestURI())
+		cc.writeHeader(":scheme", "https")
+	}
+	if trailers != "" {
+		cc.writeHeader("trailer", trailers)
+	}
 
+	var didUA bool
 	for k, vv := range req.Header {
 		lowKey := strings.ToLower(k)
-		if lowKey == "host" {
+		switch lowKey {
+		case "host", "content-length":
+			// Host is :authority, already sent.
+			// Content-Length is automatic, set below.
+			continue
+		case "connection", "proxy-connection", "transfer-encoding", "upgrade", "keep-alive":
+			// Per 8.1.2.2 Connection-Specific Header
+			// Fields, don't send connection-specific
+			// fields. We have already checked if any
+			// are error-worthy so just ignore the rest.
 			continue
+		case "user-agent":
+			// Match Go's http1 behavior: at most one
+			// User-Agent. If set to nil or empty string,
+			// then omit it. Otherwise if not mentioned,
+			// include the default (below).
+			didUA = true
+			if len(vv) < 1 {
+				continue
+			}
+			vv = vv[:1]
+			if vv[0] == "" {
+				continue
+			}
+		}
+		for _, v := range vv {
+			cc.writeHeader(lowKey, v)
 		}
+	}
+	if shouldSendReqContentLength(req.Method, contentLength) {
+		cc.writeHeader("content-length", strconv.FormatInt(contentLength, 10))
+	}
+	if addGzipHeader {
+		cc.writeHeader("accept-encoding", "gzip")
+	}
+	if !didUA {
+		cc.writeHeader("user-agent", defaultUserAgent)
+	}
+	return cc.hbuf.Bytes(), nil
+}
+
+// shouldSendReqContentLength reports whether the http2.Transport should send
+// a "content-length" request header. This logic is basically a copy of the net/http
+// transferWriter.shouldSendContentLength.
+// The contentLength is the corrected contentLength (so 0 means actually 0, not unknown).
+// -1 means unknown.
+func shouldSendReqContentLength(method string, contentLength int64) bool {
+	if contentLength > 0 {
+		return true
+	}
+	if contentLength < 0 {
+		return false
+	}
+	// For zero bodies, whether we send a content-length depends on the method.
+	// It also kinda doesn't matter for http2 either way, with END_STREAM.
+	switch method {
+	case "POST", "PUT", "PATCH":
+		return true
+	default:
+		return false
+	}
+}
+
+// requires cc.mu be held.
+func (cc *ClientConn) encodeTrailers(req *http.Request) []byte {
+	cc.hbuf.Reset()
+	for k, vv := range req.Trailer {
+		// Transfer-Encoding, etc.. have already been filter at the
+		// start of RoundTrip
+		lowKey := strings.ToLower(k)
 		for _, v := range vv {
 			cc.writeHeader(lowKey, v)
 		}
@@ -661,7 +1096,10 @@ func (cc *clientConn) encodeHeaders(req *http.Request) []byte {
 	return cc.hbuf.Bytes()
 }
 
-func (cc *clientConn) writeHeader(name, value string) {
+func (cc *ClientConn) writeHeader(name, value string) {
+	if VerboseLogs {
+		log.Printf("http2: Transport encoding header %q = %q", name, value)
+	}
 	cc.henc.WriteField(hpack.HeaderField{Name: name, Value: value})
 }
 
@@ -671,12 +1109,13 @@ type resAndError struct {
 }
 
 // requires cc.mu be held.
-func (cc *clientConn) newStream() *clientStream {
+func (cc *ClientConn) newStream() *clientStream {
 	cs := &clientStream{
 		cc:        cc,
 		ID:        cc.nextStreamID,
 		resc:      make(chan resAndError, 1),
 		peerReset: make(chan struct{}),
+		done:      make(chan struct{}),
 	}
 	cs.flow.add(int32(cc.initialWindowSize))
 	cs.flow.setConnFlow(&cc.flow)
@@ -687,41 +1126,36 @@ func (cc *clientConn) newStream() *clientStream {
 	return cs
 }
 
-func (cc *clientConn) streamByID(id uint32, andRemove bool) *clientStream {
+func (cc *ClientConn) forgetStreamID(id uint32) {
+	cc.streamByID(id, true)
+}
+
+func (cc *ClientConn) streamByID(id uint32, andRemove bool) *clientStream {
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
 	cs := cc.streams[id]
-	if andRemove {
+	if andRemove && cs != nil && !cc.closed {
+		cc.lastActive = time.Now()
 		delete(cc.streams, id)
+		close(cs.done)
+		cc.cond.Broadcast() // wake up checkResetOrDone via clientStream.awaitFlowControl
 	}
 	return cs
 }
 
 // clientConnReadLoop is the state owned by the clientConn's frame-reading readLoop.
 type clientConnReadLoop struct {
-	cc        *clientConn
-	activeRes map[uint32]*clientStream // keyed by streamID
-
-	// continueStreamID is the stream ID we're waiting for
-	// continuation frames for.
-	continueStreamID uint32
-
-	hdec *hpack.Decoder
-
-	// Fields reset on each HEADERS:
-	nextRes      *http.Response
-	sawRegHeader bool  // saw non-pseudo header
-	reqMalformed error // non-nil once known to be malformed
+	cc            *ClientConn
+	activeRes     map[uint32]*clientStream // keyed by streamID
+	closeWhenIdle bool
 }
 
 // readLoop runs in its own goroutine and reads and dispatches frames.
-func (cc *clientConn) readLoop() {
+func (cc *ClientConn) readLoop() {
 	rl := &clientConnReadLoop{
 		cc:        cc,
 		activeRes: make(map[uint32]*clientStream),
 	}
-	// TODO: figure out henc size
-	rl.hdec = hpack.NewDecoder(initialHeaderTableSize, rl.onNewHeaderField)
 
 	defer rl.cleanup()
 	cc.readerErr = rl.run()
@@ -732,20 +1166,47 @@ func (cc *clientConn) readLoop() {
 	}
 }
 
+// GoAwayError is returned by the Transport when the server closes the
+// TCP connection after sending a GOAWAY frame.
+type GoAwayError struct {
+	LastStreamID uint32
+	ErrCode      ErrCode
+	DebugData    string
+}
+
+func (e GoAwayError) Error() string {
+	return fmt.Sprintf("http2: server sent GOAWAY and closed the connection; LastStreamID=%v, ErrCode=%v, debug=%q",
+		e.LastStreamID, e.ErrCode, e.DebugData)
+}
+
+func isEOFOrNetReadError(err error) bool {
+	if err == io.EOF {
+		return true
+	}
+	ne, ok := err.(*net.OpError)
+	return ok && ne.Op == "read"
+}
+
 func (rl *clientConnReadLoop) cleanup() {
 	cc := rl.cc
 	defer cc.tconn.Close()
-	defer cc.t.removeClientConn(cc)
+	defer cc.t.connPool().MarkDead(cc)
 	defer close(cc.readerDone)
 
 	// Close any response bodies if the server closes prematurely.
 	// TODO: also do this if we've written the headers but not
 	// gotten a response yet.
 	err := cc.readerErr
-	if err == io.EOF {
+	cc.mu.Lock()
+	if cc.goAway != nil && isEOFOrNetReadError(err) {
+		err = GoAwayError{
+			LastStreamID: cc.goAway.LastStreamID,
+			ErrCode:      cc.goAway.ErrCode,
+			DebugData:    cc.goAwayDebug,
+		}
+	} else if err == io.EOF {
 		err = io.ErrUnexpectedEOF
 	}
-	cc.mu.Lock()
 	for _, cs := range rl.activeRes {
 		cs.bufPipe.CloseWithError(err)
 	}
@@ -754,6 +1215,7 @@ func (rl *clientConnReadLoop) cleanup() {
 		case cs.resc <- resAndError{err: err}:
 		default:
 		}
+		close(cs.done)
 	}
 	cc.closed = true
 	cc.cond.Broadcast()
@@ -762,114 +1224,239 @@ func (rl *clientConnReadLoop) cleanup() {
 
 func (rl *clientConnReadLoop) run() error {
 	cc := rl.cc
+	rl.closeWhenIdle = cc.t.disableKeepAlives() || cc.singleUse
+	gotReply := false // ever saw a HEADERS reply
+	gotSettings := false
 	for {
 		f, err := cc.fr.ReadFrame()
+		if err != nil {
+			cc.vlogf("http2: Transport readFrame error on conn %p: (%T) %v", cc, err, err)
+		}
 		if se, ok := err.(StreamError); ok {
-			// TODO: deal with stream errors from the framer.
-			return se
+			if cs := cc.streamByID(se.StreamID, true /*ended; remove it*/); cs != nil {
+				cs.cc.writeStreamReset(cs.ID, se.Code, err)
+				if se.Cause == nil {
+					se.Cause = cc.fr.errDetail
+				}
+				rl.endStreamError(cs, se)
+			}
+			continue
 		} else if err != nil {
 			return err
 		}
-		cc.vlogf("Transport received %v: %#v", f.Header(), f)
-
-		streamID := f.Header().StreamID
-
-		_, isContinue := f.(*ContinuationFrame)
-		if isContinue {
-			if streamID != rl.continueStreamID {
-				cc.logf("Protocol violation: got CONTINUATION with id %d; want %d", streamID, rl.continueStreamID)
+		if VerboseLogs {
+			cc.vlogf("http2: Transport received %s", summarizeFrame(f))
+		}
+		if !gotSettings {
+			if _, ok := f.(*SettingsFrame); !ok {
+				cc.logf("protocol error: received %T before a SETTINGS frame", f)
 				return ConnectionError(ErrCodeProtocol)
 			}
-		} else if rl.continueStreamID != 0 {
-			// Continue frames need to be adjacent in the stream
-			// and we were in the middle of headers.
-			cc.logf("Protocol violation: got %T for stream %d, want CONTINUATION for %d", f, streamID, rl.continueStreamID)
-			return ConnectionError(ErrCodeProtocol)
+			gotSettings = true
 		}
+		maybeIdle := false // whether frame might transition us to idle
 
 		switch f := f.(type) {
-		case *HeadersFrame:
+		case *MetaHeadersFrame:
 			err = rl.processHeaders(f)
-		case *ContinuationFrame:
-			err = rl.processContinuation(f)
+			maybeIdle = true
+			gotReply = true
 		case *DataFrame:
 			err = rl.processData(f)
+			maybeIdle = true
 		case *GoAwayFrame:
 			err = rl.processGoAway(f)
+			maybeIdle = true
 		case *RSTStreamFrame:
 			err = rl.processResetStream(f)
+			maybeIdle = true
 		case *SettingsFrame:
 			err = rl.processSettings(f)
 		case *PushPromiseFrame:
 			err = rl.processPushPromise(f)
 		case *WindowUpdateFrame:
 			err = rl.processWindowUpdate(f)
+		case *PingFrame:
+			err = rl.processPing(f)
 		default:
 			cc.logf("Transport: unhandled response frame type %T", f)
 		}
 		if err != nil {
+			if VerboseLogs {
+				cc.vlogf("http2: Transport conn %p received error from processing frame %v: %v", cc, summarizeFrame(f), err)
+			}
 			return err
 		}
+		if rl.closeWhenIdle && gotReply && maybeIdle && len(rl.activeRes) == 0 {
+			cc.closeIfIdle()
+		}
 	}
 }
 
-func (rl *clientConnReadLoop) processHeaders(f *HeadersFrame) error {
-	rl.sawRegHeader = false
-	rl.reqMalformed = nil
-	rl.nextRes = &http.Response{
-		Proto:      "HTTP/2.0",
-		ProtoMajor: 2,
-		Header:     make(http.Header),
-	}
-	return rl.processHeaderBlockFragment(f.HeaderBlockFragment(), f.StreamID, f.HeadersEnded(), f.StreamEnded())
-}
-
-func (rl *clientConnReadLoop) processContinuation(f *ContinuationFrame) error {
-	return rl.processHeaderBlockFragment(f.HeaderBlockFragment(), f.StreamID, f.HeadersEnded(), f.StreamEnded())
-}
-
-func (rl *clientConnReadLoop) processHeaderBlockFragment(frag []byte, streamID uint32, headersEnded, streamEnded bool) error {
+func (rl *clientConnReadLoop) processHeaders(f *MetaHeadersFrame) error {
 	cc := rl.cc
-	cs := cc.streamByID(streamID, streamEnded)
+	cs := cc.streamByID(f.StreamID, f.StreamEnded())
 	if cs == nil {
-		// We could return a ConnectionError(ErrCodeProtocol)
-		// here, except that in the case of us canceling
-		// client requests, we may also delete from the
-		// streams map, in which case we forgot that we sent
-		// this request. So, just ignore any responses for
-		// now.  They might've been in-flight before the
-		// server got our RST_STREAM.
+		// We'd get here if we canceled a request while the
+		// server had its response still in flight. So if this
+		// was just something we canceled, ignore it.
 		return nil
 	}
-	_, err := rl.hdec.Write(frag)
+	if !cs.firstByte {
+		if cs.trace != nil {
+			// TODO(bradfitz): move first response byte earlier,
+			// when we first read the 9 byte header, not waiting
+			// until all the HEADERS+CONTINUATION frames have been
+			// merged. This works for now.
+			traceFirstResponseByte(cs.trace)
+		}
+		cs.firstByte = true
+	}
+	if !cs.pastHeaders {
+		cs.pastHeaders = true
+	} else {
+		return rl.processTrailers(cs, f)
+	}
+
+	res, err := rl.handleResponse(cs, f)
 	if err != nil {
-		return err
+		if _, ok := err.(ConnectionError); ok {
+			return err
+		}
+		// Any other error type is a stream error.
+		cs.cc.writeStreamReset(f.StreamID, ErrCodeProtocol, err)
+		cs.resc <- resAndError{err: err}
+		return nil // return nil from process* funcs to keep conn alive
 	}
-	if !headersEnded {
-		rl.continueStreamID = cs.ID
+	if res == nil {
+		// (nil, nil) special case. See handleResponse docs.
 		return nil
 	}
+	if res.Body != noBody {
+		rl.activeRes[cs.ID] = cs
+	}
+	cs.resTrailer = &res.Trailer
+	cs.resc <- resAndError{res: res}
+	return nil
+}
+
+// may return error types nil, or ConnectionError. Any other error value
+// is a StreamError of type ErrCodeProtocol. The returned error in that case
+// is the detail.
+//
+// As a special case, handleResponse may return (nil, nil) to skip the
+// frame (currently only used for 100 expect continue). This special
+// case is going away after Issue 13851 is fixed.
+func (rl *clientConnReadLoop) handleResponse(cs *clientStream, f *MetaHeadersFrame) (*http.Response, error) {
+	if f.Truncated {
+		return nil, errResponseHeaderListSize
+	}
 
-	// HEADERS (or CONTINUATION) are now over.
-	rl.continueStreamID = 0
+	status := f.PseudoValue("status")
+	if status == "" {
+		return nil, errors.New("missing status pseudo header")
+	}
+	statusCode, err := strconv.Atoi(status)
+	if err != nil {
+		return nil, errors.New("malformed non-numeric status pseudo header")
+	}
 
-	if rl.reqMalformed != nil {
-		cs.resc <- resAndError{err: rl.reqMalformed}
-		rl.cc.writeStreamReset(cs.ID, ErrCodeProtocol, rl.reqMalformed)
-		return nil
+	if statusCode == 100 {
+		traceGot100Continue(cs.trace)
+		if cs.on100 != nil {
+			cs.on100() // forces any write delay timer to fire
+		}
+		cs.pastHeaders = false // do it all again
+		return nil, nil
 	}
 
-	res := rl.nextRes
-	if streamEnded {
+	header := make(http.Header)
+	res := &http.Response{
+		Proto:      "HTTP/2.0",
+		ProtoMajor: 2,
+		Header:     header,
+		StatusCode: statusCode,
+		Status:     status + " " + http.StatusText(statusCode),
+	}
+	for _, hf := range f.RegularFields() {
+		key := http.CanonicalHeaderKey(hf.Name)
+		if key == "Trailer" {
+			t := res.Trailer
+			if t == nil {
+				t = make(http.Header)
+				res.Trailer = t
+			}
+			foreachHeaderElement(hf.Value, func(v string) {
+				t[http.CanonicalHeaderKey(v)] = nil
+			})
+		} else {
+			header[key] = append(header[key], hf.Value)
+		}
+	}
+
+	streamEnded := f.StreamEnded()
+	isHead := cs.req.Method == "HEAD"
+	if !streamEnded || isHead {
+		res.ContentLength = -1
+		if clens := res.Header["Content-Length"]; len(clens) == 1 {
+			if clen64, err := strconv.ParseInt(clens[0], 10, 64); err == nil {
+				res.ContentLength = clen64
+			} else {
+				// TODO: care? unlike http/1, it won't mess up our framing, so it's
+				// more safe smuggling-wise to ignore.
+			}
+		} else if len(clens) > 1 {
+			// TODO: care? unlike http/1, it won't mess up our framing, so it's
+			// more safe smuggling-wise to ignore.
+		}
+	}
+
+	if streamEnded || isHead {
 		res.Body = noBody
-	} else {
-		buf := new(bytes.Buffer) // TODO(bradfitz): recycle this garbage
-		cs.bufPipe = pipe{b: buf}
-		res.Body = transportResponseBody{cs}
+		return res, nil
 	}
-	rl.activeRes[cs.ID] = cs
-	cs.resc <- resAndError{res: res}
-	rl.nextRes = nil // unused now; will be reset next HEADERS frame
+
+	buf := new(bytes.Buffer) // TODO(bradfitz): recycle this garbage
+	cs.bufPipe = pipe{b: buf}
+	cs.bytesRemain = res.ContentLength
+	res.Body = transportResponseBody{cs}
+	go cs.awaitRequestCancel(cs.req)
+
+	if cs.requestedGzip && res.Header.Get("Content-Encoding") == "gzip" {
+		res.Header.Del("Content-Encoding")
+		res.Header.Del("Content-Length")
+		res.ContentLength = -1
+		res.Body = &gzipReader{body: res.Body}
+		setResponseUncompressed(res)
+	}
+	return res, nil
+}
+
+func (rl *clientConnReadLoop) processTrailers(cs *clientStream, f *MetaHeadersFrame) error {
+	if cs.pastTrailers {
+		// Too many HEADERS frames for this stream.
+		return ConnectionError(ErrCodeProtocol)
+	}
+	cs.pastTrailers = true
+	if !f.StreamEnded() {
+		// We expect that any headers for trailers also
+		// has END_STREAM.
+		return ConnectionError(ErrCodeProtocol)
+	}
+	if len(f.PseudoFields()) > 0 {
+		// No pseudo header fields are defined for trailers.
+		// TODO: ConnectionError might be overly harsh? Check.
+		return ConnectionError(ErrCodeProtocol)
+	}
+
+	trailer := make(http.Header)
+	for _, hf := range f.RegularFields() {
+		key := http.CanonicalHeaderKey(hf.Name)
+		trailer[key] = append(trailer[key], hf.Value)
+	}
+	cs.trailer = trailer
+
+	rl.endStream(cs)
 	return nil
 }
 
@@ -881,13 +1468,35 @@ type transportResponseBody struct {
 }
 
 func (b transportResponseBody) Read(p []byte) (n int, err error) {
+	cs := b.cs
+	cc := cs.cc
+
+	if cs.readErr != nil {
+		return 0, cs.readErr
+	}
 	n, err = b.cs.bufPipe.Read(p)
+	if cs.bytesRemain != -1 {
+		if int64(n) > cs.bytesRemain {
+			n = int(cs.bytesRemain)
+			if err == nil {
+				err = errors.New("net/http: server replied with more than declared Content-Length; truncated")
+				cc.writeStreamReset(cs.ID, ErrCodeProtocol, err)
+			}
+			cs.readErr = err
+			return int(cs.bytesRemain), err
+		}
+		cs.bytesRemain -= int64(n)
+		if err == io.EOF && cs.bytesRemain > 0 {
+			err = io.ErrUnexpectedEOF
+			cs.readErr = err
+			return n, err
+		}
+	}
 	if n == 0 {
+		// No flow control tokens to send back.
 		return
 	}
 
-	cs := b.cs
-	cc := cs.cc
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
 
@@ -898,8 +1507,12 @@ func (b transportResponseBody) Read(p []byte) (n int, err error) {
 		cc.inflow.add(connAdd)
 	}
 	if err == nil { // No need to refresh if the stream is over or failed.
-		if v := cs.inflow.available(); v < transportDefaultStreamFlow-transportDefaultStreamMinRefresh {
-			streamAdd = transportDefaultStreamFlow - v
+		// Consider any buffered body data (read from the conn but not
+		// consumed by the client) when computing flow control for this
+		// stream.
+		v := int(cs.inflow.available()) + cs.bufPipe.Len()
+		if v < transportDefaultStreamFlow-transportDefaultStreamMinRefresh {
+			streamAdd = int32(transportDefaultStreamFlow - v)
 			cs.inflow.add(streamAdd)
 		}
 	}
@@ -917,49 +1530,147 @@ func (b transportResponseBody) Read(p []byte) (n int, err error) {
 	return
 }
 
+var errClosedResponseBody = errors.New("http2: response body closed")
+
 func (b transportResponseBody) Close() error {
-	if b.cs.bufPipe.Err() != io.EOF {
-		// TODO: write test for this
-		b.cs.cc.writeStreamReset(b.cs.ID, ErrCodeCancel, nil)
+	cs := b.cs
+	cc := cs.cc
+
+	serverSentStreamEnd := cs.bufPipe.Err() == io.EOF
+	unread := cs.bufPipe.Len()
+
+	if unread > 0 || !serverSentStreamEnd {
+		cc.mu.Lock()
+		cc.wmu.Lock()
+		if !serverSentStreamEnd {
+			cc.fr.WriteRSTStream(cs.ID, ErrCodeCancel)
+		}
+		// Return connection-level flow control.
+		if unread > 0 {
+			cc.inflow.add(int32(unread))
+			cc.fr.WriteWindowUpdate(0, uint32(unread))
+		}
+		cc.bw.Flush()
+		cc.wmu.Unlock()
+		cc.mu.Unlock()
 	}
+
+	cs.bufPipe.BreakWithError(errClosedResponseBody)
 	return nil
 }
 
 func (rl *clientConnReadLoop) processData(f *DataFrame) error {
 	cc := rl.cc
 	cs := cc.streamByID(f.StreamID, f.StreamEnded())
+	data := f.Data()
 	if cs == nil {
+		cc.mu.Lock()
+		neverSent := cc.nextStreamID
+		cc.mu.Unlock()
+		if f.StreamID >= neverSent {
+			// We never asked for this.
+			cc.logf("http2: Transport received unsolicited DATA frame; closing connection")
+			return ConnectionError(ErrCodeProtocol)
+		}
+		// We probably did ask for this, but canceled. Just ignore it.
+		// TODO: be stricter here? only silently ignore things which
+		// we canceled, but not things which were closed normally
+		// by the peer? Tough without accumulating too much state.
+
+		// But at least return their flow control:
+		if f.Length > 0 {
+			cc.mu.Lock()
+			cc.inflow.add(int32(f.Length))
+			cc.mu.Unlock()
+
+			cc.wmu.Lock()
+			cc.fr.WriteWindowUpdate(0, uint32(f.Length))
+			cc.bw.Flush()
+			cc.wmu.Unlock()
+		}
 		return nil
 	}
-	data := f.Data()
-	if VerboseLogs {
-		rl.cc.logf("DATA: %q", data)
-	}
+	if f.Length > 0 {
+		if len(data) > 0 && cs.bufPipe.b == nil {
+			// Data frame after it's already closed?
+			cc.logf("http2: Transport received DATA frame for closed stream; closing connection")
+			return ConnectionError(ErrCodeProtocol)
+		}
 
-	// Check connection-level flow control.
-	cc.mu.Lock()
-	if cs.inflow.available() >= int32(len(data)) {
-		cs.inflow.take(int32(len(data)))
-	} else {
+		// Check connection-level flow control.
+		cc.mu.Lock()
+		if cs.inflow.available() >= int32(f.Length) {
+			cs.inflow.take(int32(f.Length))
+		} else {
+			cc.mu.Unlock()
+			return ConnectionError(ErrCodeFlowControl)
+		}
+		// Return any padded flow control now, since we won't
+		// refund it later on body reads.
+		if pad := int32(f.Length) - int32(len(data)); pad > 0 {
+			cs.inflow.add(pad)
+			cc.inflow.add(pad)
+			cc.wmu.Lock()
+			cc.fr.WriteWindowUpdate(0, uint32(pad))
+			cc.fr.WriteWindowUpdate(cs.ID, uint32(pad))
+			cc.bw.Flush()
+			cc.wmu.Unlock()
+		}
 		cc.mu.Unlock()
-		return ConnectionError(ErrCodeFlowControl)
-	}
-	cc.mu.Unlock()
 
-	if _, err := cs.bufPipe.Write(data); err != nil {
-		return err
+		if len(data) > 0 {
+			if _, err := cs.bufPipe.Write(data); err != nil {
+				rl.endStreamError(cs, err)
+				return err
+			}
+		}
 	}
 
 	if f.StreamEnded() {
-		cs.bufPipe.CloseWithError(io.EOF)
-		delete(rl.activeRes, cs.ID)
+		rl.endStream(cs)
 	}
 	return nil
 }
 
+var errInvalidTrailers = errors.New("http2: invalid trailers")
+
+func (rl *clientConnReadLoop) endStream(cs *clientStream) {
+	// TODO: check that any declared content-length matches, like
+	// server.go's (*stream).endStream method.
+	rl.endStreamError(cs, nil)
+}
+
+func (rl *clientConnReadLoop) endStreamError(cs *clientStream, err error) {
+	var code func()
+	if err == nil {
+		err = io.EOF
+		code = cs.copyTrailers
+	}
+	cs.bufPipe.closeWithErrorAndCode(err, code)
+	delete(rl.activeRes, cs.ID)
+	if isConnectionCloseRequest(cs.req) {
+		rl.closeWhenIdle = true
+	}
+
+	select {
+	case cs.resc <- resAndError{err: err}:
+	default:
+	}
+}
+
+func (cs *clientStream) copyTrailers() {
+	for k, vv := range cs.trailer {
+		t := cs.resTrailer
+		if *t == nil {
+			*t = make(http.Header)
+		}
+		(*t)[k] = vv
+	}
+}
+
 func (rl *clientConnReadLoop) processGoAway(f *GoAwayFrame) error {
 	cc := rl.cc
-	cc.t.removeClientConn(cc)
+	cc.t.connPool().MarkDead(cc)
 	if f.ErrCode != 0 {
 		// TODO: deal with GOAWAY more. particularly the error code
 		cc.vlogf("transport got GOAWAY with error code = %v", f.ErrCode)
@@ -972,25 +1683,56 @@ func (rl *clientConnReadLoop) processSettings(f *SettingsFrame) error {
 	cc := rl.cc
 	cc.mu.Lock()
 	defer cc.mu.Unlock()
-	return f.ForeachSetting(func(s Setting) error {
+
+	if f.IsAck() {
+		if cc.wantSettingsAck {
+			cc.wantSettingsAck = false
+			return nil
+		}
+		return ConnectionError(ErrCodeProtocol)
+	}
+
+	err := f.ForeachSetting(func(s Setting) error {
 		switch s.ID {
 		case SettingMaxFrameSize:
 			cc.maxFrameSize = s.Val
 		case SettingMaxConcurrentStreams:
 			cc.maxConcurrentStreams = s.Val
 		case SettingInitialWindowSize:
-			// TODO: error if this is too large.
+			// Values above the maximum flow-control
+			// window size of 2^31-1 MUST be treated as a
+			// connection error (Section 5.4.1) of type
+			// FLOW_CONTROL_ERROR.
+			if s.Val > math.MaxInt32 {
+				return ConnectionError(ErrCodeFlowControl)
+			}
 
-			// TODO: adjust flow control of still-open
+			// Adjust flow control of currently-open
 			// frames by the difference of the old initial
 			// window size and this one.
+			delta := int32(s.Val) - int32(cc.initialWindowSize)
+			for _, cs := range cc.streams {
+				cs.flow.add(delta)
+			}
+			cc.cond.Broadcast()
+
 			cc.initialWindowSize = s.Val
 		default:
-			// TODO(bradfitz): handle more settings?
+			// TODO(bradfitz): handle more settings? SETTINGS_HEADER_TABLE_SIZE probably.
 			cc.vlogf("Unhandled Setting: %v", s)
 		}
 		return nil
 	})
+	if err != nil {
+		return err
+	}
+
+	cc.wmu.Lock()
+	defer cc.wmu.Unlock()
+
+	cc.fr.WriteSettingsAck()
+	cc.bw.Flush()
+	return cc.werr
 }
 
 func (rl *clientConnReadLoop) processWindowUpdate(f *WindowUpdateFrame) error {
@@ -1027,15 +1769,31 @@ func (rl *clientConnReadLoop) processResetStream(f *RSTStreamFrame) error {
 		// which closes this, so there
 		// isn't a race.
 	default:
-		err := StreamError{cs.ID, f.ErrCode}
+		err := streamError(cs.ID, f.ErrCode)
 		cs.resetErr = err
 		close(cs.peerReset)
 		cs.bufPipe.CloseWithError(err)
+		cs.cc.cond.Broadcast() // wake up checkResetOrDone via clientStream.awaitFlowControl
 	}
 	delete(rl.activeRes, cs.ID)
 	return nil
 }
 
+func (rl *clientConnReadLoop) processPing(f *PingFrame) error {
+	if f.IsAck() {
+		// 6.7 PING: " An endpoint MUST NOT respond to PING frames
+		// containing this flag."
+		return nil
+	}
+	cc := rl.cc
+	cc.wmu.Lock()
+	defer cc.wmu.Unlock()
+	if err := cc.fr.WritePing(true, f.Data); err != nil {
+		return err
+	}
+	return cc.bw.Flush()
+}
+
 func (rl *clientConnReadLoop) processPushPromise(f *PushPromiseFrame) error {
 	// We told the peer we don't want them.
 	// Spec says:
@@ -1047,53 +1805,27 @@ func (rl *clientConnReadLoop) processPushPromise(f *PushPromiseFrame) error {
 	return ConnectionError(ErrCodeProtocol)
 }
 
-func (cc *clientConn) writeStreamReset(streamID uint32, code ErrCode, err error) {
-	// TODO: do something with err? send it as a debug frame to the peer?
-	// But that's only in GOAWAY. Invent a new frame type? Is there one already?
+func (cc *ClientConn) writeStreamReset(streamID uint32, code ErrCode, err error) {
+	// TODO: map err to more interesting error codes, once the
+	// HTTP community comes up with some. But currently for
+	// RST_STREAM there's no equivalent to GOAWAY frame's debug
+	// data, and the error codes are all pretty vague ("cancel").
 	cc.wmu.Lock()
 	cc.fr.WriteRSTStream(streamID, code)
+	cc.bw.Flush()
 	cc.wmu.Unlock()
 }
 
-// onNewHeaderField runs on the readLoop goroutine whenever a new
-// hpack header field is decoded.
-func (rl *clientConnReadLoop) onNewHeaderField(f hpack.HeaderField) {
-	cc := rl.cc
-	if VerboseLogs {
-		cc.logf("Header field: %+v", f)
-	}
-	isPseudo := strings.HasPrefix(f.Name, ":")
-	if isPseudo {
-		if rl.sawRegHeader {
-			rl.reqMalformed = errors.New("http2: invalid pseudo header after regular header")
-			return
-		}
-		switch f.Name {
-		case ":status":
-			code, err := strconv.Atoi(f.Value)
-			if err != nil {
-				rl.reqMalformed = errors.New("http2: invalid :status")
-				return
-			}
-			rl.nextRes.Status = f.Value + " " + http.StatusText(code)
-			rl.nextRes.StatusCode = code
-		default:
-			// "Endpoints MUST NOT generate pseudo-header
-			// fields other than those defined in this
-			// document."
-			rl.reqMalformed = fmt.Errorf("http2: unknown response pseudo header %q", f.Name)
-		}
-	} else {
-		rl.sawRegHeader = true
-		rl.nextRes.Header.Add(http.CanonicalHeaderKey(f.Name), f.Value)
-	}
-}
+var (
+	errResponseHeaderListSize = errors.New("http2: response header list larger than advertised limit")
+	errPseudoTrailers         = errors.New("http2: invalid pseudo header in trailers")
+)
 
-func (cc *clientConn) logf(format string, args ...interface{}) {
+func (cc *ClientConn) logf(format string, args ...interface{}) {
 	cc.t.logf(format, args...)
 }
 
-func (cc *clientConn) vlogf(format string, args ...interface{}) {
+func (cc *ClientConn) vlogf(format string, args ...interface{}) {
 	cc.t.vlogf(format, args...)
 }
 
@@ -1108,3 +1840,128 @@ func (t *Transport) logf(format string, args ...interface{}) {
 }
 
 var noBody io.ReadCloser = ioutil.NopCloser(bytes.NewReader(nil))
+
+func strSliceContains(ss []string, s string) bool {
+	for _, v := range ss {
+		if v == s {
+			return true
+		}
+	}
+	return false
+}
+
+type erringRoundTripper struct{ err error }
+
+func (rt erringRoundTripper) RoundTrip(*http.Request) (*http.Response, error) { return nil, rt.err }
+
+// gzipReader wraps a response body so it can lazily
+// call gzip.NewReader on the first call to Read
+type gzipReader struct {
+	body io.ReadCloser // underlying Response.Body
+	zr   *gzip.Reader  // lazily-initialized gzip reader
+	zerr error         // sticky error
+}
+
+func (gz *gzipReader) Read(p []byte) (n int, err error) {
+	if gz.zerr != nil {
+		return 0, gz.zerr
+	}
+	if gz.zr == nil {
+		gz.zr, err = gzip.NewReader(gz.body)
+		if err != nil {
+			gz.zerr = err
+			return 0, err
+		}
+	}
+	return gz.zr.Read(p)
+}
+
+func (gz *gzipReader) Close() error {
+	return gz.body.Close()
+}
+
+type errorReader struct{ err error }
+
+func (r errorReader) Read(p []byte) (int, error) { return 0, r.err }
+
+// bodyWriterState encapsulates various state around the Transport's writing
+// of the request body, particularly regarding doing delayed writes of the body
+// when the request contains "Expect: 100-continue".
+type bodyWriterState struct {
+	cs     *clientStream
+	timer  *time.Timer   // if non-nil, we're doing a delayed write
+	fnonce *sync.Once    // to call fn with
+	fn     func()        // the code to run in the goroutine, writing the body
+	resc   chan error    // result of fn's execution
+	delay  time.Duration // how long we should delay a delayed write for
+}
+
+func (t *Transport) getBodyWriterState(cs *clientStream, body io.Reader) (s bodyWriterState) {
+	s.cs = cs
+	if body == nil {
+		return
+	}
+	resc := make(chan error, 1)
+	s.resc = resc
+	s.fn = func() {
+		resc <- cs.writeRequestBody(body, cs.req.Body)
+	}
+	s.delay = t.expectContinueTimeout()
+	if s.delay == 0 ||
+		!httplex.HeaderValuesContainsToken(
+			cs.req.Header["Expect"],
+			"100-continue") {
+		return
+	}
+	s.fnonce = new(sync.Once)
+
+	// Arm the timer with a very large duration, which we'll
+	// intentionally lower later. It has to be large now because
+	// we need a handle to it before writing the headers, but the
+	// s.delay value is defined to not start until after the
+	// request headers were written.
+	const hugeDuration = 365 * 24 * time.Hour
+	s.timer = time.AfterFunc(hugeDuration, func() {
+		s.fnonce.Do(s.fn)
+	})
+	return
+}
+
+func (s bodyWriterState) cancel() {
+	if s.timer != nil {
+		s.timer.Stop()
+	}
+}
+
+func (s bodyWriterState) on100() {
+	if s.timer == nil {
+		// If we didn't do a delayed write, ignore the server's
+		// bogus 100 continue response.
+		return
+	}
+	s.timer.Stop()
+	go func() { s.fnonce.Do(s.fn) }()
+}
+
+// scheduleBodyWrite starts writing the body, either immediately (in
+// the common case) or after the delay timeout. It should not be
+// called until after the headers have been written.
+func (s bodyWriterState) scheduleBodyWrite() {
+	if s.timer == nil {
+		// We're not doing a delayed write (see
+		// getBodyWriterState), so just start the writing
+		// goroutine immediately.
+		go s.fn()
+		return
+	}
+	traceWait100Continue(s.cs.trace)
+	if s.timer.Stop() {
+		s.timer.Reset(s.delay)
+	}
+}
+
+// isConnectionCloseRequest reports whether req should use its own
+// connection for a single request and then close the connection.
+func isConnectionCloseRequest(req *http.Request) bool {
+	return req.Close || httplex.HeaderValuesContainsToken(req.Header["Connection"], "close")
+}
diff --git a/vendor/golang.org/x/net/http2/write.go b/vendor/golang.org/x/net/http2/write.go
index 9050bebb..27ef0dd4 100644
--- a/vendor/golang.org/x/net/http2/write.go
+++ b/vendor/golang.org/x/net/http2/write.go
@@ -7,10 +7,12 @@ package http2
 import (
 	"bytes"
 	"fmt"
+	"log"
 	"net/http"
 	"time"
 
 	"golang.org/x/net/http2/hpack"
+	"golang.org/x/net/lex/httplex"
 )
 
 // writeFramer is implemented by any type that is used to write frames.
@@ -23,7 +25,11 @@ type writeFramer interface {
 // frame writing scheduler (see writeScheduler in writesched.go).
 //
 // This interface is implemented by *serverConn.
-// TODO: use it from the client code too, once it exists.
+//
+// TODO: decide whether to a) use this in the client code (which didn't
+// end up using this yet, because it has a simpler design, not
+// currently implementing priorities), or b) delete this and
+// make the server code a bit more concrete.
 type writeContext interface {
 	Framer() *Framer
 	Flush() error
@@ -91,6 +97,16 @@ func (w *writeData) writeFrame(ctx writeContext) error {
 	return ctx.Framer().WriteData(w.streamID, w.endStream, w.p)
 }
 
+// handlerPanicRST is the message sent from handler goroutines when
+// the handler panics.
+type handlerPanicRST struct {
+	StreamID uint32
+}
+
+func (hp handlerPanicRST) writeFrame(ctx writeContext) error {
+	return ctx.Framer().WriteRSTStream(hp.StreamID, ErrCodeInternal)
+}
+
 func (se StreamError) writeFrame(ctx writeContext) error {
 	return ctx.Framer().WriteRSTStream(se.StreamID, se.Code)
 }
@@ -108,40 +124,48 @@ func (writeSettingsAck) writeFrame(ctx writeContext) error {
 }
 
 // writeResHeaders is a request to write a HEADERS and 0+ CONTINUATION frames
-// for HTTP response headers from a server handler.
+// for HTTP response headers or trailers from a server handler.
 type writeResHeaders struct {
 	streamID    uint32
-	httpResCode int
+	httpResCode int         // 0 means no ":status" line
 	h           http.Header // may be nil
+	trailers    []string    // if non-nil, which keys of h to write. nil means all.
 	endStream   bool
 
+	date          string
 	contentType   string
 	contentLength string
 }
 
+func encKV(enc *hpack.Encoder, k, v string) {
+	if VerboseLogs {
+		log.Printf("http2: server encoding header %q = %q", k, v)
+	}
+	enc.WriteField(hpack.HeaderField{Name: k, Value: v})
+}
+
 func (w *writeResHeaders) writeFrame(ctx writeContext) error {
 	enc, buf := ctx.HeaderEncoder()
 	buf.Reset()
-	enc.WriteField(hpack.HeaderField{Name: ":status", Value: httpCodeString(w.httpResCode)})
-	for k, vv := range w.h {
-		k = lowerHeader(k)
-		for _, v := range vv {
-			// TODO: more of "8.1.2.2 Connection-Specific Header Fields"
-			if k == "transfer-encoding" && v != "trailers" {
-				continue
-			}
-			enc.WriteField(hpack.HeaderField{Name: k, Value: v})
-		}
+
+	if w.httpResCode != 0 {
+		encKV(enc, ":status", httpCodeString(w.httpResCode))
 	}
+
+	encodeHeaders(enc, w.h, w.trailers)
+
 	if w.contentType != "" {
-		enc.WriteField(hpack.HeaderField{Name: "content-type", Value: w.contentType})
+		encKV(enc, "content-type", w.contentType)
 	}
 	if w.contentLength != "" {
-		enc.WriteField(hpack.HeaderField{Name: "content-length", Value: w.contentLength})
+		encKV(enc, "content-length", w.contentLength)
+	}
+	if w.date != "" {
+		encKV(enc, "date", w.date)
 	}
 
 	headerBlock := buf.Bytes()
-	if len(headerBlock) == 0 {
+	if len(headerBlock) == 0 && w.trailers == nil {
 		panic("unexpected empty hpack")
 	}
 
@@ -187,7 +211,7 @@ type write100ContinueHeadersFrame struct {
 func (w write100ContinueHeadersFrame) writeFrame(ctx writeContext) error {
 	enc, buf := ctx.HeaderEncoder()
 	buf.Reset()
-	enc.WriteField(hpack.HeaderField{Name: ":status", Value: "100"})
+	encKV(enc, ":status", "100")
 	return ctx.Framer().WriteHeaders(HeadersFrameParam{
 		StreamID:      w.streamID,
 		BlockFragment: buf.Bytes(),
@@ -204,3 +228,37 @@ type writeWindowUpdate struct {
 func (wu writeWindowUpdate) writeFrame(ctx writeContext) error {
 	return ctx.Framer().WriteWindowUpdate(wu.streamID, wu.n)
 }
+
+func encodeHeaders(enc *hpack.Encoder, h http.Header, keys []string) {
+	if keys == nil {
+		sorter := sorterPool.Get().(*sorter)
+		// Using defer here, since the returned keys from the
+		// sorter.Keys method is only valid until the sorter
+		// is returned:
+		defer sorterPool.Put(sorter)
+		keys = sorter.Keys(h)
+	}
+	for _, k := range keys {
+		vv := h[k]
+		k = lowerHeader(k)
+		if !validWireHeaderFieldName(k) {
+			// Skip it as backup paranoia. Per
+			// golang.org/issue/14048, these should
+			// already be rejected at a higher level.
+			continue
+		}
+		isTE := k == "transfer-encoding"
+		for _, v := range vv {
+			if !httplex.ValidHeaderFieldValue(v) {
+				// TODO: return an error? golang.org/issue/14048
+				// For now just omit it.
+				continue
+			}
+			// TODO: more of "8.1.2.2 Connection-Specific Header Fields"
+			if isTE && v != "trailers" {
+				continue
+			}
+			encKV(enc, k, v)
+		}
+	}
+}
diff --git a/vendor/golang.org/x/net/lex/httplex/httplex.go b/vendor/golang.org/x/net/lex/httplex/httplex.go
new file mode 100644
index 00000000..bd0ec24f
--- /dev/null
+++ b/vendor/golang.org/x/net/lex/httplex/httplex.go
@@ -0,0 +1,312 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package httplex contains rules around lexical matters of various
+// HTTP-related specifications.
+//
+// This package is shared by the standard library (which vendors it)
+// and x/net/http2. It comes with no API stability promise.
+package httplex
+
+import (
+	"strings"
+	"unicode/utf8"
+)
+
+var isTokenTable = [127]bool{
+	'!':  true,
+	'#':  true,
+	'$':  true,
+	'%':  true,
+	'&':  true,
+	'\'': true,
+	'*':  true,
+	'+':  true,
+	'-':  true,
+	'.':  true,
+	'0':  true,
+	'1':  true,
+	'2':  true,
+	'3':  true,
+	'4':  true,
+	'5':  true,
+	'6':  true,
+	'7':  true,
+	'8':  true,
+	'9':  true,
+	'A':  true,
+	'B':  true,
+	'C':  true,
+	'D':  true,
+	'E':  true,
+	'F':  true,
+	'G':  true,
+	'H':  true,
+	'I':  true,
+	'J':  true,
+	'K':  true,
+	'L':  true,
+	'M':  true,
+	'N':  true,
+	'O':  true,
+	'P':  true,
+	'Q':  true,
+	'R':  true,
+	'S':  true,
+	'T':  true,
+	'U':  true,
+	'W':  true,
+	'V':  true,
+	'X':  true,
+	'Y':  true,
+	'Z':  true,
+	'^':  true,
+	'_':  true,
+	'`':  true,
+	'a':  true,
+	'b':  true,
+	'c':  true,
+	'd':  true,
+	'e':  true,
+	'f':  true,
+	'g':  true,
+	'h':  true,
+	'i':  true,
+	'j':  true,
+	'k':  true,
+	'l':  true,
+	'm':  true,
+	'n':  true,
+	'o':  true,
+	'p':  true,
+	'q':  true,
+	'r':  true,
+	's':  true,
+	't':  true,
+	'u':  true,
+	'v':  true,
+	'w':  true,
+	'x':  true,
+	'y':  true,
+	'z':  true,
+	'|':  true,
+	'~':  true,
+}
+
+func IsTokenRune(r rune) bool {
+	i := int(r)
+	return i < len(isTokenTable) && isTokenTable[i]
+}
+
+func isNotToken(r rune) bool {
+	return !IsTokenRune(r)
+}
+
+// HeaderValuesContainsToken reports whether any string in values
+// contains the provided token, ASCII case-insensitively.
+func HeaderValuesContainsToken(values []string, token string) bool {
+	for _, v := range values {
+		if headerValueContainsToken(v, token) {
+			return true
+		}
+	}
+	return false
+}
+
+// isOWS reports whether b is an optional whitespace byte, as defined
+// by RFC 7230 section 3.2.3.
+func isOWS(b byte) bool { return b == ' ' || b == '\t' }
+
+// trimOWS returns x with all optional whitespace removes from the
+// beginning and end.
+func trimOWS(x string) string {
+	// TODO: consider using strings.Trim(x, " \t") instead,
+	// if and when it's fast enough. See issue 10292.
+	// But this ASCII-only code will probably always beat UTF-8
+	// aware code.
+	for len(x) > 0 && isOWS(x[0]) {
+		x = x[1:]
+	}
+	for len(x) > 0 && isOWS(x[len(x)-1]) {
+		x = x[:len(x)-1]
+	}
+	return x
+}
+
+// headerValueContainsToken reports whether v (assumed to be a
+// 0#element, in the ABNF extension described in RFC 7230 section 7)
+// contains token amongst its comma-separated tokens, ASCII
+// case-insensitively.
+func headerValueContainsToken(v string, token string) bool {
+	v = trimOWS(v)
+	if comma := strings.IndexByte(v, ','); comma != -1 {
+		return tokenEqual(trimOWS(v[:comma]), token) || headerValueContainsToken(v[comma+1:], token)
+	}
+	return tokenEqual(v, token)
+}
+
+// lowerASCII returns the ASCII lowercase version of b.
+func lowerASCII(b byte) byte {
+	if 'A' <= b && b <= 'Z' {
+		return b + ('a' - 'A')
+	}
+	return b
+}
+
+// tokenEqual reports whether t1 and t2 are equal, ASCII case-insensitively.
+func tokenEqual(t1, t2 string) bool {
+	if len(t1) != len(t2) {
+		return false
+	}
+	for i, b := range t1 {
+		if b >= utf8.RuneSelf {
+			// No UTF-8 or non-ASCII allowed in tokens.
+			return false
+		}
+		if lowerASCII(byte(b)) != lowerASCII(t2[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// isLWS reports whether b is linear white space, according
+// to http://www.w3.org/Protocols/rfc2616/rfc2616-sec2.html#sec2.2
+//      LWS            = [CRLF] 1*( SP | HT )
+func isLWS(b byte) bool { return b == ' ' || b == '\t' }
+
+// isCTL reports whether b is a control byte, according
+// to http://www.w3.org/Protocols/rfc2616/rfc2616-sec2.html#sec2.2
+//      CTL            = <any US-ASCII control character
+//                       (octets 0 - 31) and DEL (127)>
+func isCTL(b byte) bool {
+	const del = 0x7f // a CTL
+	return b < ' ' || b == del
+}
+
+// ValidHeaderFieldName reports whether v is a valid HTTP/1.x header name.
+// HTTP/2 imposes the additional restriction that uppercase ASCII
+// letters are not allowed.
+//
+//  RFC 7230 says:
+//   header-field   = field-name ":" OWS field-value OWS
+//   field-name     = token
+//   token          = 1*tchar
+//   tchar = "!" / "#" / "$" / "%" / "&" / "'" / "*" / "+" / "-" / "." /
+//           "^" / "_" / "`" / "|" / "~" / DIGIT / ALPHA
+func ValidHeaderFieldName(v string) bool {
+	if len(v) == 0 {
+		return false
+	}
+	for _, r := range v {
+		if !IsTokenRune(r) {
+			return false
+		}
+	}
+	return true
+}
+
+// ValidHostHeader reports whether h is a valid host header.
+func ValidHostHeader(h string) bool {
+	// The latest spec is actually this:
+	//
+	// http://tools.ietf.org/html/rfc7230#section-5.4
+	//     Host = uri-host [ ":" port ]
+	//
+	// Where uri-host is:
+	//     http://tools.ietf.org/html/rfc3986#section-3.2.2
+	//
+	// But we're going to be much more lenient for now and just
+	// search for any byte that's not a valid byte in any of those
+	// expressions.
+	for i := 0; i < len(h); i++ {
+		if !validHostByte[h[i]] {
+			return false
+		}
+	}
+	return true
+}
+
+// See the validHostHeader comment.
+var validHostByte = [256]bool{
+	'0': true, '1': true, '2': true, '3': true, '4': true, '5': true, '6': true, '7': true,
+	'8': true, '9': true,
+
+	'a': true, 'b': true, 'c': true, 'd': true, 'e': true, 'f': true, 'g': true, 'h': true,
+	'i': true, 'j': true, 'k': true, 'l': true, 'm': true, 'n': true, 'o': true, 'p': true,
+	'q': true, 'r': true, 's': true, 't': true, 'u': true, 'v': true, 'w': true, 'x': true,
+	'y': true, 'z': true,
+
+	'A': true, 'B': true, 'C': true, 'D': true, 'E': true, 'F': true, 'G': true, 'H': true,
+	'I': true, 'J': true, 'K': true, 'L': true, 'M': true, 'N': true, 'O': true, 'P': true,
+	'Q': true, 'R': true, 'S': true, 'T': true, 'U': true, 'V': true, 'W': true, 'X': true,
+	'Y': true, 'Z': true,
+
+	'!':  true, // sub-delims
+	'$':  true, // sub-delims
+	'%':  true, // pct-encoded (and used in IPv6 zones)
+	'&':  true, // sub-delims
+	'(':  true, // sub-delims
+	')':  true, // sub-delims
+	'*':  true, // sub-delims
+	'+':  true, // sub-delims
+	',':  true, // sub-delims
+	'-':  true, // unreserved
+	'.':  true, // unreserved
+	':':  true, // IPv6address + Host expression's optional port
+	';':  true, // sub-delims
+	'=':  true, // sub-delims
+	'[':  true,
+	'\'': true, // sub-delims
+	']':  true,
+	'_':  true, // unreserved
+	'~':  true, // unreserved
+}
+
+// ValidHeaderFieldValue reports whether v is a valid "field-value" according to
+// http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2 :
+//
+//        message-header = field-name ":" [ field-value ]
+//        field-value    = *( field-content | LWS )
+//        field-content  = <the OCTETs making up the field-value
+//                         and consisting of either *TEXT or combinations
+//                         of token, separators, and quoted-string>
+//
+// http://www.w3.org/Protocols/rfc2616/rfc2616-sec2.html#sec2.2 :
+//
+//        TEXT           = <any OCTET except CTLs,
+//                          but including LWS>
+//        LWS            = [CRLF] 1*( SP | HT )
+//        CTL            = <any US-ASCII control character
+//                         (octets 0 - 31) and DEL (127)>
+//
+// RFC 7230 says:
+//  field-value    = *( field-content / obs-fold )
+//  obj-fold       =  N/A to http2, and deprecated
+//  field-content  = field-vchar [ 1*( SP / HTAB ) field-vchar ]
+//  field-vchar    = VCHAR / obs-text
+//  obs-text       = %x80-FF
+//  VCHAR          = "any visible [USASCII] character"
+//
+// http2 further says: "Similarly, HTTP/2 allows header field values
+// that are not valid. While most of the values that can be encoded
+// will not alter header field parsing, carriage return (CR, ASCII
+// 0xd), line feed (LF, ASCII 0xa), and the zero character (NUL, ASCII
+// 0x0) might be exploited by an attacker if they are translated
+// verbatim. Any request or response that contains a character not
+// permitted in a header field value MUST be treated as malformed
+// (Section 8.1.2.6). Valid characters are defined by the
+// field-content ABNF rule in Section 3.2 of [RFC7230]."
+//
+// This function does not (yet?) properly handle the rejection of
+// strings that begin or end with SP or HTAB.
+func ValidHeaderFieldValue(v string) bool {
+	for i := 0; i < len(v); i++ {
+		b := v[i]
+		if isCTL(b) && !isLWS(b) {
+			return false
+		}
+	}
+	return true
+}