+++ /dev/null
-// 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"
- "log"
- "net/http"
- "net/url"
- "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.
-type writeFramer interface {
- writeFrame(writeContext) error
-
- // staysWithinBuffer reports whether this writer promises that
- // it will only write less than or equal to size bytes, and it
- // won't Flush the write context.
- staysWithinBuffer(size int) bool
-}
-
-// 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: 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
- CloseConn() error
- // HeaderEncoder returns an HPACK encoder that writes to the
- // returned buffer.
- HeaderEncoder() (*hpack.Encoder, *bytes.Buffer)
-}
-
-// writeEndsStream reports whether w writes a frame that will transition
-// the stream to a half-closed local state. This returns false for RST_STREAM,
-// which closes the entire stream (not just the local half).
-func writeEndsStream(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("writeEndsStream called on nil writeFramer")
- }
- return false
-}
-
-type flushFrameWriter struct{}
-
-func (flushFrameWriter) writeFrame(ctx writeContext) error {
- return ctx.Flush()
-}
-
-func (flushFrameWriter) staysWithinBuffer(max int) bool { return false }
-
-type writeSettings []Setting
-
-func (s writeSettings) staysWithinBuffer(max int) bool {
- const settingSize = 6 // uint16 + uint32
- return frameHeaderLen+settingSize*len(s) <= max
-
-}
-
-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
-}
-
-func (*writeGoAway) staysWithinBuffer(max int) bool { return false } // flushes
-
-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 (w *writeData) staysWithinBuffer(max int) bool {
- return frameHeaderLen+len(w.p) <= max
-}
-
-// 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 (hp handlerPanicRST) staysWithinBuffer(max int) bool { return frameHeaderLen+4 <= max }
-
-func (se StreamError) writeFrame(ctx writeContext) error {
- return ctx.Framer().WriteRSTStream(se.StreamID, se.Code)
-}
-
-func (se StreamError) staysWithinBuffer(max int) bool { return frameHeaderLen+4 <= max }
-
-type writePingAck struct{ pf *PingFrame }
-
-func (w writePingAck) writeFrame(ctx writeContext) error {
- return ctx.Framer().WritePing(true, w.pf.Data)
-}
-
-func (w writePingAck) staysWithinBuffer(max int) bool { return frameHeaderLen+len(w.pf.Data) <= max }
-
-type writeSettingsAck struct{}
-
-func (writeSettingsAck) writeFrame(ctx writeContext) error {
- return ctx.Framer().WriteSettingsAck()
-}
-
-func (writeSettingsAck) staysWithinBuffer(max int) bool { return frameHeaderLen <= max }
-
-// splitHeaderBlock splits headerBlock into fragments so that each fragment fits
-// in a single frame, then calls fn for each fragment. firstFrag/lastFrag are true
-// for the first/last fragment, respectively.
-func splitHeaderBlock(ctx writeContext, headerBlock []byte, fn func(ctx writeContext, frag []byte, firstFrag, lastFrag bool) error) error {
- // 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):]
- if err := fn(ctx, frag, first, len(headerBlock) == 0); err != nil {
- return err
- }
- first = false
- }
- return nil
-}
-
-// writeResHeaders is a request to write a HEADERS and 0+ CONTINUATION frames
-// for HTTP response headers or trailers from a server handler.
-type writeResHeaders struct {
- streamID uint32
- 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) staysWithinBuffer(max int) bool {
- // TODO: this is a common one. It'd be nice to return true
- // here and get into the fast path if we could be clever and
- // calculate the size fast enough, or at least a conservative
- // uppper bound that usually fires. (Maybe if w.h and
- // w.trailers are nil, so we don't need to enumerate it.)
- // Otherwise I'm afraid that just calculating the length to
- // answer this question would be slower than the ~2µs benefit.
- return false
-}
-
-func (w *writeResHeaders) writeFrame(ctx writeContext) error {
- enc, buf := ctx.HeaderEncoder()
- buf.Reset()
-
- if w.httpResCode != 0 {
- encKV(enc, ":status", httpCodeString(w.httpResCode))
- }
-
- encodeHeaders(enc, w.h, w.trailers)
-
- if w.contentType != "" {
- encKV(enc, "content-type", w.contentType)
- }
- if w.contentLength != "" {
- encKV(enc, "content-length", w.contentLength)
- }
- if w.date != "" {
- encKV(enc, "date", w.date)
- }
-
- headerBlock := buf.Bytes()
- if len(headerBlock) == 0 && w.trailers == nil {
- panic("unexpected empty hpack")
- }
-
- return splitHeaderBlock(ctx, headerBlock, w.writeHeaderBlock)
-}
-
-func (w *writeResHeaders) writeHeaderBlock(ctx writeContext, frag []byte, firstFrag, lastFrag bool) error {
- if firstFrag {
- return ctx.Framer().WriteHeaders(HeadersFrameParam{
- StreamID: w.streamID,
- BlockFragment: frag,
- EndStream: w.endStream,
- EndHeaders: lastFrag,
- })
- } else {
- return ctx.Framer().WriteContinuation(w.streamID, lastFrag, frag)
- }
-}
-
-// writePushPromise is a request to write a PUSH_PROMISE and 0+ CONTINUATION frames.
-type writePushPromise struct {
- streamID uint32 // pusher stream
- method string // for :method
- url *url.URL // for :scheme, :authority, :path
- h http.Header
-
- // Creates an ID for a pushed stream. This runs on serveG just before
- // the frame is written. The returned ID is copied to promisedID.
- allocatePromisedID func() (uint32, error)
- promisedID uint32
-}
-
-func (w *writePushPromise) staysWithinBuffer(max int) bool {
- // TODO: see writeResHeaders.staysWithinBuffer
- return false
-}
-
-func (w *writePushPromise) writeFrame(ctx writeContext) error {
- enc, buf := ctx.HeaderEncoder()
- buf.Reset()
-
- encKV(enc, ":method", w.method)
- encKV(enc, ":scheme", w.url.Scheme)
- encKV(enc, ":authority", w.url.Host)
- encKV(enc, ":path", w.url.RequestURI())
- encodeHeaders(enc, w.h, nil)
-
- headerBlock := buf.Bytes()
- if len(headerBlock) == 0 {
- panic("unexpected empty hpack")
- }
-
- return splitHeaderBlock(ctx, headerBlock, w.writeHeaderBlock)
-}
-
-func (w *writePushPromise) writeHeaderBlock(ctx writeContext, frag []byte, firstFrag, lastFrag bool) error {
- if firstFrag {
- return ctx.Framer().WritePushPromise(PushPromiseParam{
- StreamID: w.streamID,
- PromiseID: w.promisedID,
- BlockFragment: frag,
- EndHeaders: lastFrag,
- })
- } else {
- return ctx.Framer().WriteContinuation(w.streamID, lastFrag, frag)
- }
-}
-
-type write100ContinueHeadersFrame struct {
- streamID uint32
-}
-
-func (w write100ContinueHeadersFrame) writeFrame(ctx writeContext) error {
- enc, buf := ctx.HeaderEncoder()
- buf.Reset()
- encKV(enc, ":status", "100")
- return ctx.Framer().WriteHeaders(HeadersFrameParam{
- StreamID: w.streamID,
- BlockFragment: buf.Bytes(),
- EndStream: false,
- EndHeaders: true,
- })
-}
-
-func (w write100ContinueHeadersFrame) staysWithinBuffer(max int) bool {
- // Sloppy but conservative:
- return 9+2*(len(":status")+len("100")) <= max
-}
-
-type writeWindowUpdate struct {
- streamID uint32 // or 0 for conn-level
- n uint32
-}
-
-func (wu writeWindowUpdate) staysWithinBuffer(max int) bool { return frameHeaderLen+4 <= max }
-
-func (wu writeWindowUpdate) writeFrame(ctx writeContext) error {
- return ctx.Framer().WriteWindowUpdate(wu.streamID, wu.n)
-}
-
-// encodeHeaders encodes an http.Header. If keys is not nil, then (k, h[k])
-// is encoded only only if k is in keys.
-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)
- }
- }
-}
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