break inflight management out into a module

5 files changed, 145 insertions, 0 deletions

diff --git a/node_modules/inflight/LICENSE b/node_modules/inflight/LICENSE
new file mode 100644
index 000000000..05eeeb88c
--- /dev/null
+++ b/node_modules/inflight/LICENSE
@@ -0,0 +1,15 @@
+The ISC License
+
+Copyright (c) Isaac Z. Schlueter
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
diff --git a/node_modules/inflight/README.md b/node_modules/inflight/README.md
new file mode 100644
index 000000000..6dc892917
--- /dev/null
+++ b/node_modules/inflight/README.md
@@ -0,0 +1,37 @@
+# inflight
+
+Add callbacks to requests in flight to avoid async duplication
+
+## USAGE
+
+```javascript
+var inflight = require('inflight')
+
+// some request that does some stuff
+function req(key, callback) {
+  // key is any random string.  like a url or filename or whatever.
+  //
+  // will return either a falsey value, indicating that the
+  // request for this key is already in flight, or a new callback
+  // which when called will call all callbacks passed to inflightk
+  // with the same key
+  callback = inflight(key, callback)
+
+  // If we got a falsey value back, then there's already a req going
+  if (!callback) return
+
+  // this is where you'd fetch the url or whatever
+  // callback is also once()-ified, so it can safely be assigned
+  // to multiple events etc.  First call wins.
+  setTimeout(function() {
+    callback(null, key)
+  }, 100)
+}
+
+// only assigns a single setTimeout
+// when it dings, all cbs get called
+req('foo', cb1)
+req('foo', cb2)
+req('foo', cb3)
+req('foo', cb4)
+```
diff --git a/node_modules/inflight/inflight.js b/node_modules/inflight/inflight.js
new file mode 100644
index 000000000..1fe279f9a
--- /dev/null
+++ b/node_modules/inflight/inflight.js
@@ -0,0 +1,25 @@
+module.exports = inflight
+
+var reqs = Object.create(null)
+var once = require('once')
+
+function inflight (key, cb) {
+  if (reqs[key]) {
+    reqs[key].push(cb)
+    return null
+  } else {
+    reqs[key] = [cb]
+    return makeres(key)
+  }
+}
+
+function makeres(key) {
+  return once(res)
+  function res(error,  data) {
+    var cbs = reqs[key]
+    delete reqs[key]
+    cbs.forEach(function(cb) {
+      cb(error, data)
+    })
+  }
+}
diff --git a/node_modules/inflight/package.json b/node_modules/inflight/package.json
new file mode 100644
index 000000000..263cc9872
--- /dev/null
+++ b/node_modules/inflight/package.json
@@ -0,0 +1,35 @@
+{
+  "name": "inflight",
+  "version": "1.0.1",
+  "description": "Add callbacks to requests in flight to avoid async duplication",
+  "main": "inflight.js",
+  "dependencies": {
+    "once": "^1.3.0"
+  },
+  "devDependencies": {
+    "tap": "^0.4.10"
+  },
+  "scripts": {
+    "test": "tap test.js"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git://github.com/isaacs/inflight"
+  },
+  "author": {
+    "name": "Isaac Z. Schlueter",
+    "email": "i@izs.me",
+    "url": "http://blog.izs.me/"
+  },
+  "bugs": {
+    "url": "https://github.com/isaacs/inflight/issues"
+  },
+  "homepage": "https://github.com/isaacs/inflight",
+  "license": "ISC",
+  "readme": "# inflight\n\nAdd callbacks to requests in flight to avoid async duplication\n\n## USAGE\n\n```javascript\nvar inflight = require('inflight')\n\n// some request that does some stuff\nfunction req(key, callback) {\n  // key is any random string.  like a url or filename or whatever.\n  //\n  // will return either a falsey value, indicating that the\n  // request for this key is already in flight, or a new callback\n  // which when called will call all callbacks passed to inflightk\n  // with the same key\n  callback = inflight(key, callback)\n\n  // If we got a falsey value back, then there's already a req going\n  if (!callback) return\n\n  // this is where you'd fetch the url or whatever\n  // callback is also once()-ified, so it can safely be assigned\n  // to multiple events etc.  First call wins.\n  setTimeout(function() {\n    callback(null, key)\n  }, 100)\n}\n\n// only assigns a single setTimeout\n// when it dings, all cbs get called\nreq('foo', cb1)\nreq('foo', cb2)\nreq('foo', cb3)\nreq('foo', cb4)\n```\n",
+  "readmeFilename": "README.md",
+  "_id": "inflight@1.0.1",
+  "_shasum": "01f6911821535243c790ac0f998f54e9023ffb6f",
+  "_from": "inflight@",
+  "_resolved": "https://registry.npmjs.org/inflight/-/inflight-1.0.1.tgz"
+}
diff --git a/node_modules/inflight/test.js b/node_modules/inflight/test.js
new file mode 100644
index 000000000..28fc14503
--- /dev/null
+++ b/node_modules/inflight/test.js
@@ -0,0 +1,33 @@
+var test = require('tap').test
+var inf = require('./inflight.js')
+
+
+function req (key, cb) {
+  cb = inf(key, cb)
+  if (cb) setTimeout(function () {
+    cb(key)
+    cb(key)
+  })
+  return cb
+}
+
+test('basic', function (t) {
+  var calleda = false
+  var a = req('key', function (k) {
+    t.notOk(calleda)
+    calleda = true
+    t.equal(k, 'key')
+    if (calledb) t.end()
+  })
+  t.ok(a, 'first returned cb function')
+
+  var calledb = false
+  var b = req('key', function (k) {
+    t.notOk(calledb)
+    calledb = true
+    t.equal(k, 'key')
+    if (calleda) t.end()
+  })
+
+  t.notOk(b, 'second should get falsey inflight response')
+})