diff options
Diffstat (limited to 'vendor/golang.org/x/net/http2/write.go')
-rw-r--r-- | vendor/golang.org/x/net/http2/write.go | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/http2/write.go b/vendor/golang.org/x/net/http2/write.go new file mode 100644 index 00000000..9050bebb --- /dev/null +++ b/vendor/golang.org/x/net/http2/write.go @@ -0,0 +1,206 @@ +// 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. + +package http2 + +import ( + "bytes" + "fmt" + "net/http" + "time" + + "golang.org/x/net/http2/hpack" +) + +// writeFramer is implemented by any type that is used to write frames. +type writeFramer interface { + writeFrame(writeContext) error +} + +// writeContext is the interface needed by the various frame writer +// types below. All the writeFrame methods below are scheduled via the +// 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. +type writeContext interface { + Framer() *Framer + Flush() error + CloseConn() error + // HeaderEncoder returns an HPACK encoder that writes to the + // returned buffer. + HeaderEncoder() (*hpack.Encoder, *bytes.Buffer) +} + +// endsStream reports whether the given frame writer w will locally +// close the stream. +func endsStream(w writeFramer) bool { + switch v := w.(type) { + case *writeData: + return v.endStream + case *writeResHeaders: + return v.endStream + case nil: + // This can only happen if the caller reuses w after it's + // been intentionally nil'ed out to prevent use. Keep this + // here to catch future refactoring breaking it. + panic("endsStream called on nil writeFramer") + } + return false +} + +type flushFrameWriter struct{} + +func (flushFrameWriter) writeFrame(ctx writeContext) error { + return ctx.Flush() +} + +type writeSettings []Setting + +func (s writeSettings) writeFrame(ctx writeContext) error { + return ctx.Framer().WriteSettings([]Setting(s)...) +} + +type writeGoAway struct { + maxStreamID uint32 + code ErrCode +} + +func (p *writeGoAway) writeFrame(ctx writeContext) error { + err := ctx.Framer().WriteGoAway(p.maxStreamID, p.code, nil) + if p.code != 0 { + ctx.Flush() // ignore error: we're hanging up on them anyway + time.Sleep(50 * time.Millisecond) + ctx.CloseConn() + } + return err +} + +type writeData struct { + streamID uint32 + p []byte + endStream bool +} + +func (w *writeData) String() string { + return fmt.Sprintf("writeData(stream=%d, p=%d, endStream=%v)", w.streamID, len(w.p), w.endStream) +} + +func (w *writeData) writeFrame(ctx writeContext) error { + return ctx.Framer().WriteData(w.streamID, w.endStream, w.p) +} + +func (se StreamError) writeFrame(ctx writeContext) error { + return ctx.Framer().WriteRSTStream(se.StreamID, se.Code) +} + +type writePingAck struct{ pf *PingFrame } + +func (w writePingAck) writeFrame(ctx writeContext) error { + return ctx.Framer().WritePing(true, w.pf.Data) +} + +type writeSettingsAck struct{} + +func (writeSettingsAck) writeFrame(ctx writeContext) error { + return ctx.Framer().WriteSettingsAck() +} + +// writeResHeaders is a request to write a HEADERS and 0+ CONTINUATION frames +// for HTTP response headers from a server handler. +type writeResHeaders struct { + streamID uint32 + httpResCode int + h http.Header // may be nil + endStream bool + + contentType string + contentLength string +} + +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.contentType != "" { + enc.WriteField(hpack.HeaderField{Name: "content-type", Value: w.contentType}) + } + if w.contentLength != "" { + enc.WriteField(hpack.HeaderField{Name: "content-length", Value: w.contentLength}) + } + + headerBlock := buf.Bytes() + if len(headerBlock) == 0 { + panic("unexpected empty hpack") + } + + // For now we're lazy and just pick the minimum MAX_FRAME_SIZE + // that all peers must support (16KB). Later we could care + // more and send larger frames if the peer advertised it, but + // there's little point. Most headers are small anyway (so we + // generally won't have CONTINUATION frames), and extra frames + // only waste 9 bytes anyway. + const maxFrameSize = 16384 + + first := true + for len(headerBlock) > 0 { + frag := headerBlock + if len(frag) > maxFrameSize { + frag = frag[:maxFrameSize] + } + headerBlock = headerBlock[len(frag):] + endHeaders := len(headerBlock) == 0 + var err error + if first { + first = false + err = ctx.Framer().WriteHeaders(HeadersFrameParam{ + StreamID: w.streamID, + BlockFragment: frag, + EndStream: w.endStream, + EndHeaders: endHeaders, + }) + } else { + err = ctx.Framer().WriteContinuation(w.streamID, endHeaders, frag) + } + if err != nil { + return err + } + } + return nil +} + +type write100ContinueHeadersFrame struct { + streamID uint32 +} + +func (w write100ContinueHeadersFrame) writeFrame(ctx writeContext) error { + enc, buf := ctx.HeaderEncoder() + buf.Reset() + enc.WriteField(hpack.HeaderField{Name: ":status", Value: "100"}) + return ctx.Framer().WriteHeaders(HeadersFrameParam{ + StreamID: w.streamID, + BlockFragment: buf.Bytes(), + EndStream: false, + EndHeaders: true, + }) +} + +type writeWindowUpdate struct { + streamID uint32 // or 0 for conn-level + n uint32 +} + +func (wu writeWindowUpdate) writeFrame(ctx writeContext) error { + return ctx.Framer().WriteWindowUpdate(wu.streamID, wu.n) +} |