diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/transport/http2_client.go')
| -rw-r--r-- | vendor/google.golang.org/grpc/transport/http2_client.go | 953 |
1 files changed, 953 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/transport/http2_client.go b/vendor/google.golang.org/grpc/transport/http2_client.go new file mode 100644 index 0000000..e624f8d --- /dev/null +++ b/vendor/google.golang.org/grpc/transport/http2_client.go @@ -0,0 +1,953 @@ +/* + * + * Copyright 2014, Google Inc. + * 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 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 transport + +import ( + "bytes" + "io" + "math" + "net" + "strings" + "sync" + "time" + + "golang.org/x/net/context" + "golang.org/x/net/http2" + "golang.org/x/net/http2/hpack" + "google.golang.org/grpc/codes" + "google.golang.org/grpc/credentials" + "google.golang.org/grpc/grpclog" + "google.golang.org/grpc/metadata" + "google.golang.org/grpc/peer" +) + +// http2Client implements the ClientTransport interface with HTTP2. +type http2Client struct { + target string // server name/addr + userAgent string + conn net.Conn // underlying communication channel + authInfo credentials.AuthInfo // auth info about the connection + nextID uint32 // the next stream ID to be used + + // writableChan synchronizes write access to the transport. + // A writer acquires the write lock by sending a value on writableChan + // and releases it by receiving from writableChan. + writableChan chan int + // shutdownChan is closed when Close is called. + // Blocking operations should select on shutdownChan to avoid + // blocking forever after Close. + // TODO(zhaoq): Maybe have a channel context? + shutdownChan chan struct{} + // errorChan is closed to notify the I/O error to the caller. + errorChan chan struct{} + + framer *framer + hBuf *bytes.Buffer // the buffer for HPACK encoding + hEnc *hpack.Encoder // HPACK encoder + + // controlBuf delivers all the control related tasks (e.g., window + // updates, reset streams, and various settings) to the controller. + controlBuf *recvBuffer + fc *inFlow + // sendQuotaPool provides flow control to outbound message. + sendQuotaPool *quotaPool + // streamsQuota limits the max number of concurrent streams. + streamsQuota *quotaPool + + // The scheme used: https if TLS is on, http otherwise. + scheme string + + authCreds []credentials.Credentials + + mu sync.Mutex // guard the following variables + state transportState // the state of underlying connection + activeStreams map[uint32]*Stream + // The max number of concurrent streams + maxStreams int + // the per-stream outbound flow control window size set by the peer. + streamSendQuota uint32 +} + +// newHTTP2Client constructs a connected ClientTransport to addr based on HTTP2 +// and starts to receive messages on it. Non-nil error returns if construction +// fails. +func newHTTP2Client(addr string, opts *ConnectOptions) (_ ClientTransport, err error) { + if opts.Dialer == nil { + // Set the default Dialer. + opts.Dialer = func(addr string, timeout time.Duration) (net.Conn, error) { + return net.DialTimeout("tcp", addr, timeout) + } + } + scheme := "http" + startT := time.Now() + timeout := opts.Timeout + conn, connErr := opts.Dialer(addr, timeout) + if connErr != nil { + return nil, ConnectionErrorf("transport: %v", connErr) + } + var authInfo credentials.AuthInfo + for _, c := range opts.AuthOptions { + if ccreds, ok := c.(credentials.TransportAuthenticator); ok { + scheme = "https" + // TODO(zhaoq): Now the first TransportAuthenticator is used if there are + // multiple ones provided. Revisit this if it is not appropriate. Probably + // place the ClientTransport construction into a separate function to make + // things clear. + if timeout > 0 { + timeout -= time.Since(startT) + } + conn, authInfo, connErr = ccreds.ClientHandshake(addr, conn, timeout) + break + } + } + if connErr != nil { + return nil, ConnectionErrorf("transport: %v", connErr) + } + defer func() { + if err != nil { + conn.Close() + } + }() + ua := primaryUA + if opts.UserAgent != "" { + ua = opts.UserAgent + " " + ua + } + var buf bytes.Buffer + t := &http2Client{ + target: addr, + userAgent: ua, + conn: conn, + authInfo: authInfo, + // The client initiated stream id is odd starting from 1. + nextID: 1, + writableChan: make(chan int, 1), + shutdownChan: make(chan struct{}), + errorChan: make(chan struct{}), + framer: newFramer(conn), + hBuf: &buf, + hEnc: hpack.NewEncoder(&buf), + controlBuf: newRecvBuffer(), + fc: &inFlow{limit: initialConnWindowSize}, + sendQuotaPool: newQuotaPool(defaultWindowSize), + scheme: scheme, + state: reachable, + activeStreams: make(map[uint32]*Stream), + authCreds: opts.AuthOptions, + maxStreams: math.MaxInt32, + streamSendQuota: defaultWindowSize, + } + // Start the reader goroutine for incoming message. Each transport has + // a dedicated goroutine which reads HTTP2 frame from network. Then it + // dispatches the frame to the corresponding stream entity. + go t.reader() + // Send connection preface to server. + n, err := t.conn.Write(clientPreface) + if err != nil { + t.Close() + return nil, ConnectionErrorf("transport: %v", err) + } + if n != len(clientPreface) { + t.Close() + return nil, ConnectionErrorf("transport: preface mismatch, wrote %d bytes; want %d", n, len(clientPreface)) + } + if initialWindowSize != defaultWindowSize { + err = t.framer.writeSettings(true, http2.Setting{http2.SettingInitialWindowSize, uint32(initialWindowSize)}) + } else { + err = t.framer.writeSettings(true) + } + if err != nil { + t.Close() + return nil, ConnectionErrorf("transport: %v", err) + } + // Adjust the connection flow control window if needed. + if delta := uint32(initialConnWindowSize - defaultWindowSize); delta > 0 { + if err := t.framer.writeWindowUpdate(true, 0, delta); err != nil { + t.Close() + return nil, ConnectionErrorf("transport: %v", err) + } + } + go t.controller() + t.writableChan <- 0 + return t, nil +} + +func (t *http2Client) newStream(ctx context.Context, callHdr *CallHdr) *Stream { + // TODO(zhaoq): Handle uint32 overflow of Stream.id. + s := &Stream{ + id: t.nextID, + method: callHdr.Method, + sendCompress: callHdr.SendCompress, + buf: newRecvBuffer(), + fc: &inFlow{limit: initialWindowSize}, + sendQuotaPool: newQuotaPool(int(t.streamSendQuota)), + headerChan: make(chan struct{}), + } + t.nextID += 2 + s.windowHandler = func(n int) { + t.updateWindow(s, uint32(n)) + } + // Make a stream be able to cancel the pending operations by itself. + s.ctx, s.cancel = context.WithCancel(ctx) + s.dec = &recvBufferReader{ + ctx: s.ctx, + recv: s.buf, + } + return s +} + +// NewStream creates a stream and register it into the transport as "active" +// streams. +func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Stream, err error) { + // Record the timeout value on the context. + var timeout time.Duration + if dl, ok := ctx.Deadline(); ok { + timeout = dl.Sub(time.Now()) + } + select { + case <-ctx.Done(): + return nil, ContextErr(ctx.Err()) + default: + } + pr := &peer.Peer{ + Addr: t.conn.RemoteAddr(), + } + // Attach Auth info if there is any. + if t.authInfo != nil { + pr.AuthInfo = t.authInfo + } + ctx = peer.NewContext(ctx, pr) + authData := make(map[string]string) + for _, c := range t.authCreds { + // Construct URI required to get auth request metadata. + var port string + if pos := strings.LastIndex(t.target, ":"); pos != -1 { + // Omit port if it is the default one. + if t.target[pos+1:] != "443" { + port = ":" + t.target[pos+1:] + } + } + pos := strings.LastIndex(callHdr.Method, "/") + if pos == -1 { + return nil, StreamErrorf(codes.InvalidArgument, "transport: malformed method name: %q", callHdr.Method) + } + audience := "https://" + callHdr.Host + port + callHdr.Method[:pos] + data, err := c.GetRequestMetadata(ctx, audience) + if err != nil { + return nil, StreamErrorf(codes.InvalidArgument, "transport: %v", err) + } + for k, v := range data { + authData[k] = v + } + } + t.mu.Lock() + if t.activeStreams == nil { + t.mu.Unlock() + return nil, ErrConnClosing + } + if t.state != reachable { + t.mu.Unlock() + return nil, ErrConnClosing + } + checkStreamsQuota := t.streamsQuota != nil + t.mu.Unlock() + if checkStreamsQuota { + sq, err := wait(ctx, t.shutdownChan, t.streamsQuota.acquire()) + if err != nil { + return nil, err + } + // Returns the quota balance back. + if sq > 1 { + t.streamsQuota.add(sq - 1) + } + } + if _, err := wait(ctx, t.shutdownChan, t.writableChan); err != nil { + // Return the quota back now because there is no stream returned to the caller. + if _, ok := err.(StreamError); ok && checkStreamsQuota { + t.streamsQuota.add(1) + } + return nil, err + } + t.mu.Lock() + if t.state != reachable { + t.mu.Unlock() + return nil, ErrConnClosing + } + s := t.newStream(ctx, callHdr) + t.activeStreams[s.id] = s + + // This stream is not counted when applySetings(...) initialize t.streamsQuota. + // Reset t.streamsQuota to the right value. + var reset bool + if !checkStreamsQuota && t.streamsQuota != nil { + reset = true + } + t.mu.Unlock() + if reset { + t.streamsQuota.reset(-1) + } + + // HPACK encodes various headers. Note that once WriteField(...) is + // called, the corresponding headers/continuation frame has to be sent + // because hpack.Encoder is stateful. + t.hBuf.Reset() + t.hEnc.WriteField(hpack.HeaderField{Name: ":method", Value: "POST"}) + t.hEnc.WriteField(hpack.HeaderField{Name: ":scheme", Value: t.scheme}) + t.hEnc.WriteField(hpack.HeaderField{Name: ":path", Value: callHdr.Method}) + t.hEnc.WriteField(hpack.HeaderField{Name: ":authority", Value: callHdr.Host}) + t.hEnc.WriteField(hpack.HeaderField{Name: "content-type", Value: "application/grpc"}) + t.hEnc.WriteField(hpack.HeaderField{Name: "user-agent", Value: t.userAgent}) + t.hEnc.WriteField(hpack.HeaderField{Name: "te", Value: "trailers"}) + + if callHdr.SendCompress != "" { + t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-encoding", Value: callHdr.SendCompress}) + } + if timeout > 0 { + t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-timeout", Value: timeoutEncode(timeout)}) + } + for k, v := range authData { + // Capital header names are illegal in HTTP/2. + k = strings.ToLower(k) + t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: v}) + } + var ( + hasMD bool + endHeaders bool + ) + if md, ok := metadata.FromContext(ctx); ok { + hasMD = true + for k, v := range md { + // HTTP doesn't allow you to set pseudoheaders after non pseudoheaders were set. + if isReservedHeader(k) { + continue + } + for _, entry := range v { + t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: entry}) + } + } + } + first := true + // Sends the headers in a single batch even when they span multiple frames. + for !endHeaders { + size := t.hBuf.Len() + if size > http2MaxFrameLen { + size = http2MaxFrameLen + } else { + endHeaders = true + } + var flush bool + if endHeaders && (hasMD || callHdr.Flush) { + flush = true + } + if first { + // Sends a HeadersFrame to server to start a new stream. + p := http2.HeadersFrameParam{ + StreamID: s.id, + BlockFragment: t.hBuf.Next(size), + EndStream: false, + EndHeaders: endHeaders, + } + // Do a force flush for the buffered frames iff it is the last headers frame + // and there is header metadata to be sent. Otherwise, there is flushing until + // the corresponding data frame is written. + err = t.framer.writeHeaders(flush, p) + first = false + } else { + // Sends Continuation frames for the leftover headers. + err = t.framer.writeContinuation(flush, s.id, endHeaders, t.hBuf.Next(size)) + } + if err != nil { + t.notifyError(err) + return nil, ConnectionErrorf("transport: %v", err) + } + } + t.writableChan <- 0 + return s, nil +} + +// CloseStream clears the footprint of a stream when the stream is not needed any more. +// This must not be executed in reader's goroutine. +func (t *http2Client) CloseStream(s *Stream, err error) { + var updateStreams bool + t.mu.Lock() + if t.activeStreams == nil { + t.mu.Unlock() + return + } + if t.streamsQuota != nil { + updateStreams = true + } + if t.state == draining && len(t.activeStreams) == 1 { + // The transport is draining and s is the last live stream on t. + t.mu.Unlock() + t.Close() + return + } + delete(t.activeStreams, s.id) + t.mu.Unlock() + if updateStreams { + t.streamsQuota.add(1) + } + // In case stream sending and receiving are invoked in separate + // goroutines (e.g., bi-directional streaming), the caller needs + // to call cancel on the stream to interrupt the blocking on + // other goroutines. + s.cancel() + s.mu.Lock() + if q := s.fc.resetPendingData(); q > 0 { + if n := t.fc.onRead(q); n > 0 { + t.controlBuf.put(&windowUpdate{0, n}) + } + } + if s.state == streamDone { + s.mu.Unlock() + return + } + if !s.headerDone { + close(s.headerChan) + s.headerDone = true + } + s.state = streamDone + s.mu.Unlock() + if _, ok := err.(StreamError); ok { + t.controlBuf.put(&resetStream{s.id, http2.ErrCodeCancel}) + } +} + +// Close kicks off the shutdown process of the transport. This should be called +// only once on a transport. Once it is called, the transport should not be +// accessed any more. +func (t *http2Client) Close() (err error) { + t.mu.Lock() + if t.state == reachable { + close(t.errorChan) + } + if t.state == closing { + t.mu.Unlock() + return + } + t.state = closing + t.mu.Unlock() + close(t.shutdownChan) + err = t.conn.Close() + t.mu.Lock() + streams := t.activeStreams + t.activeStreams = nil + t.mu.Unlock() + // Notify all active streams. + for _, s := range streams { + s.mu.Lock() + if !s.headerDone { + close(s.headerChan) + s.headerDone = true + } + s.mu.Unlock() + s.write(recvMsg{err: ErrConnClosing}) + } + return +} + +func (t *http2Client) GracefulClose() error { + t.mu.Lock() + if t.state == closing { + t.mu.Unlock() + return nil + } + if t.state == draining { + t.mu.Unlock() + return nil + } + t.state = draining + active := len(t.activeStreams) + t.mu.Unlock() + if active == 0 { + return t.Close() + } + return nil +} + +// Write formats the data into HTTP2 data frame(s) and sends it out. The caller +// should proceed only if Write returns nil. +// TODO(zhaoq): opts.Delay is ignored in this implementation. Support it later +// if it improves the performance. +func (t *http2Client) Write(s *Stream, data []byte, opts *Options) error { + r := bytes.NewBuffer(data) + for { + var p []byte + if r.Len() > 0 { + size := http2MaxFrameLen + s.sendQuotaPool.add(0) + // Wait until the stream has some quota to send the data. + sq, err := wait(s.ctx, t.shutdownChan, s.sendQuotaPool.acquire()) + if err != nil { + return err + } + t.sendQuotaPool.add(0) + // Wait until the transport has some quota to send the data. + tq, err := wait(s.ctx, t.shutdownChan, t.sendQuotaPool.acquire()) + if err != nil { + if _, ok := err.(StreamError); ok { + t.sendQuotaPool.cancel() + } + return err + } + if sq < size { + size = sq + } + if tq < size { + size = tq + } + p = r.Next(size) + ps := len(p) + if ps < sq { + // Overbooked stream quota. Return it back. + s.sendQuotaPool.add(sq - ps) + } + if ps < tq { + // Overbooked transport quota. Return it back. + t.sendQuotaPool.add(tq - ps) + } + } + var ( + endStream bool + forceFlush bool + ) + if opts.Last && r.Len() == 0 { + endStream = true + } + // Indicate there is a writer who is about to write a data frame. + t.framer.adjustNumWriters(1) + // Got some quota. Try to acquire writing privilege on the transport. + if _, err := wait(s.ctx, t.shutdownChan, t.writableChan); err != nil { + if _, ok := err.(StreamError); ok { + // Return the connection quota back. + t.sendQuotaPool.add(len(p)) + } + if t.framer.adjustNumWriters(-1) == 0 { + // This writer is the last one in this batch and has the + // responsibility to flush the buffered frames. It queues + // a flush request to controlBuf instead of flushing directly + // in order to avoid the race with other writing or flushing. + t.controlBuf.put(&flushIO{}) + } + return err + } + select { + case <-s.ctx.Done(): + t.sendQuotaPool.add(len(p)) + if t.framer.adjustNumWriters(-1) == 0 { + t.controlBuf.put(&flushIO{}) + } + t.writableChan <- 0 + return ContextErr(s.ctx.Err()) + default: + } + if r.Len() == 0 && t.framer.adjustNumWriters(0) == 1 { + // Do a force flush iff this is last frame for the entire gRPC message + // and the caller is the only writer at this moment. + forceFlush = true + } + // If WriteData fails, all the pending streams will be handled + // by http2Client.Close(). No explicit CloseStream() needs to be + // invoked. + if err := t.framer.writeData(forceFlush, s.id, endStream, p); err != nil { + t.notifyError(err) + return ConnectionErrorf("transport: %v", err) + } + if t.framer.adjustNumWriters(-1) == 0 { + t.framer.flushWrite() + } + t.writableChan <- 0 + if r.Len() == 0 { + break + } + } + if !opts.Last { + return nil + } + s.mu.Lock() + if s.state != streamDone { + if s.state == streamReadDone { + s.state = streamDone + } else { + s.state = streamWriteDone + } + } + s.mu.Unlock() + return nil +} + +func (t *http2Client) getStream(f http2.Frame) (*Stream, bool) { + t.mu.Lock() + defer t.mu.Unlock() + s, ok := t.activeStreams[f.Header().StreamID] + return s, ok +} + +// updateWindow adjusts the inbound quota for the stream and the transport. +// Window updates will deliver to the controller for sending when +// the cumulative quota exceeds the corresponding threshold. +func (t *http2Client) updateWindow(s *Stream, n uint32) { + s.mu.Lock() + defer s.mu.Unlock() + if s.state == streamDone { + return + } + if w := t.fc.onRead(n); w > 0 { + t.controlBuf.put(&windowUpdate{0, w}) + } + if w := s.fc.onRead(n); w > 0 { + t.controlBuf.put(&windowUpdate{s.id, w}) + } +} + +func (t *http2Client) handleData(f *http2.DataFrame) { + size := len(f.Data()) + if err := t.fc.onData(uint32(size)); err != nil { + t.notifyError(ConnectionErrorf("%v", err)) + return + } + // Select the right stream to dispatch. + s, ok := t.getStream(f) + if !ok { + if w := t.fc.onRead(uint32(size)); w > 0 { + t.controlBuf.put(&windowUpdate{0, w}) + } + return + } + if size > 0 { + s.mu.Lock() + if s.state == streamDone { + s.mu.Unlock() + // The stream has been closed. Release the corresponding quota. + if w := t.fc.onRead(uint32(size)); w > 0 { + t.controlBuf.put(&windowUpdate{0, w}) + } + return + } + if err := s.fc.onData(uint32(size)); err != nil { + s.state = streamDone + s.statusCode = codes.Internal + s.statusDesc = err.Error() + s.mu.Unlock() + s.write(recvMsg{err: io.EOF}) + t.controlBuf.put(&resetStream{s.id, http2.ErrCodeFlowControl}) + return + } + s.mu.Unlock() + // TODO(bradfitz, zhaoq): A copy is required here because there is no + // guarantee f.Data() is consumed before the arrival of next frame. + // Can this copy be eliminated? + data := make([]byte, size) + copy(data, f.Data()) + s.write(recvMsg{data: data}) + } + // The server has closed the stream without sending trailers. Record that + // the read direction is closed, and set the status appropriately. + if f.FrameHeader.Flags.Has(http2.FlagDataEndStream) { + s.mu.Lock() + if s.state == streamWriteDone { + s.state = streamDone + } else { + s.state = streamReadDone + } + s.statusCode = codes.Internal + s.statusDesc = "server closed the stream without sending trailers" + s.mu.Unlock() + s.write(recvMsg{err: io.EOF}) + } +} + +func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) { + s, ok := t.getStream(f) + if !ok { + return + } + s.mu.Lock() + if s.state == streamDone { + s.mu.Unlock() + return + } + s.state = streamDone + if !s.headerDone { + close(s.headerChan) + s.headerDone = true + } + s.statusCode, ok = http2ErrConvTab[http2.ErrCode(f.ErrCode)] + if !ok { + grpclog.Println("transport: http2Client.handleRSTStream found no mapped gRPC status for the received http2 error ", f.ErrCode) + s.statusCode = codes.Unknown + } + s.mu.Unlock() + s.write(recvMsg{err: io.EOF}) +} + +func (t *http2Client) handleSettings(f *http2.SettingsFrame) { + if f.IsAck() { + return + } + var ss []http2.Setting + f.ForeachSetting(func(s http2.Setting) error { + ss = append(ss, s) + return nil + }) + // The settings will be applied once the ack is sent. + t.controlBuf.put(&settings{ack: true, ss: ss}) +} + +func (t *http2Client) handlePing(f *http2.PingFrame) { + pingAck := &ping{ack: true} + copy(pingAck.data[:], f.Data[:]) + t.controlBuf.put(pingAck) +} + +func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) { + // TODO(zhaoq): GoAwayFrame handler to be implemented +} + +func (t *http2Client) handleWindowUpdate(f *http2.WindowUpdateFrame) { + id := f.Header().StreamID + incr := f.Increment + if id == 0 { + t.sendQuotaPool.add(int(incr)) + return + } + if s, ok := t.getStream(f); ok { + s.sendQuotaPool.add(int(incr)) + } +} + +// operateHeaders takes action on the decoded headers. +func (t *http2Client) operateHeaders(frame *http2.MetaHeadersFrame) { + s, ok := t.getStream(frame) + if !ok { + return + } + var state decodeState + for _, hf := range frame.Fields { + state.processHeaderField(hf) + } + if state.err != nil { + s.write(recvMsg{err: state.err}) + // Something wrong. Stops reading even when there is remaining. + return + } + + endStream := frame.StreamEnded() + + s.mu.Lock() + if !endStream { + s.recvCompress = state.encoding + } + if !s.headerDone { + if !endStream && len(state.mdata) > 0 { + s.header = state.mdata + } + close(s.headerChan) + s.headerDone = true + } + if !endStream || s.state == streamDone { + s.mu.Unlock() + return + } + + if len(state.mdata) > 0 { + s.trailer = state.mdata + } + s.state = streamDone + s.statusCode = state.statusCode + s.statusDesc = state.statusDesc + s.mu.Unlock() + + s.write(recvMsg{err: io.EOF}) +} + +func handleMalformedHTTP2(s *Stream, err error) { + s.mu.Lock() + if !s.headerDone { + close(s.headerChan) + s.headerDone = true + } + s.mu.Unlock() + s.write(recvMsg{err: err}) +} + +// reader runs as a separate goroutine in charge of reading data from network +// connection. +// +// TODO(zhaoq): currently one reader per transport. Investigate whether this is +// optimal. +// TODO(zhaoq): Check the validity of the incoming frame sequence. +func (t *http2Client) reader() { + // Check the validity of server preface. + frame, err := t.framer.readFrame() + if err != nil { + t.notifyError(err) + return + } + sf, ok := frame.(*http2.SettingsFrame) + if !ok { + t.notifyError(err) + return + } + t.handleSettings(sf) + + // loop to keep reading incoming messages on this transport. + for { + frame, err := t.framer.readFrame() + if err != nil { + // Abort an active stream if the http2.Framer returns a + // http2.StreamError. This can happen only if the server's response + // is malformed http2. + if se, ok := err.(http2.StreamError); ok { + t.mu.Lock() + s := t.activeStreams[se.StreamID] + t.mu.Unlock() + if s != nil { + // use error detail to provide better err message + handleMalformedHTTP2(s, StreamErrorf(http2ErrConvTab[se.Code], "%v", t.framer.errorDetail())) + } + continue + } else { + // Transport error. + t.notifyError(err) + return + } + } + switch frame := frame.(type) { + case *http2.MetaHeadersFrame: + t.operateHeaders(frame) + case *http2.DataFrame: + t.handleData(frame) + case *http2.RSTStreamFrame: + t.handleRSTStream(frame) + case *http2.SettingsFrame: + t.handleSettings(frame) + case *http2.PingFrame: + t.handlePing(frame) + case *http2.GoAwayFrame: + t.handleGoAway(frame) + case *http2.WindowUpdateFrame: + t.handleWindowUpdate(frame) + default: + grpclog.Printf("transport: http2Client.reader got unhandled frame type %v.", frame) + } + } +} + +func (t *http2Client) applySettings(ss []http2.Setting) { + for _, s := range ss { + switch s.ID { + case http2.SettingMaxConcurrentStreams: + // TODO(zhaoq): This is a hack to avoid significant refactoring of the + // code to deal with the unrealistic int32 overflow. Probably will try + // to find a better way to handle this later. + if s.Val > math.MaxInt32 { + s.Val = math.MaxInt32 + } + t.mu.Lock() + reset := t.streamsQuota != nil + if !reset { + t.streamsQuota = newQuotaPool(int(s.Val) - len(t.activeStreams)) + } + ms := t.maxStreams + t.maxStreams = int(s.Val) + t.mu.Unlock() + if reset { + t.streamsQuota.reset(int(s.Val) - ms) + } + case http2.SettingInitialWindowSize: + t.mu.Lock() + for _, stream := range t.activeStreams { + // Adjust the sending quota for each stream. + stream.sendQuotaPool.reset(int(s.Val - t.streamSendQuota)) + } + t.streamSendQuota = s.Val + t.mu.Unlock() + } + } +} + +// controller running in a separate goroutine takes charge of sending control +// frames (e.g., window update, reset stream, setting, etc.) to the server. +func (t *http2Client) controller() { + for { + select { + case i := <-t.controlBuf.get(): + t.controlBuf.load() + select { + case <-t.writableChan: + switch i := i.(type) { + case *windowUpdate: + t.framer.writeWindowUpdate(true, i.streamID, i.increment) + case *settings: + if i.ack { + t.framer.writeSettingsAck(true) + t.applySettings(i.ss) + } else { + t.framer.writeSettings(true, i.ss...) + } + case *resetStream: + t.framer.writeRSTStream(true, i.streamID, i.code) + case *flushIO: + t.framer.flushWrite() + case *ping: + t.framer.writePing(true, i.ack, i.data) + default: + grpclog.Printf("transport: http2Client.controller got unexpected item type %v\n", i) + } + t.writableChan <- 0 + continue + case <-t.shutdownChan: + return + } + case <-t.shutdownChan: + return + } + } +} + +func (t *http2Client) Error() <-chan struct{} { + return t.errorChan +} + +func (t *http2Client) notifyError(err error) { + t.mu.Lock() + defer t.mu.Unlock() + // make sure t.errorChan is closed only once. + if t.state == reachable { + t.state = unreachable + close(t.errorChan) + grpclog.Printf("transport: http2Client.notifyError got notified that the client transport was broken %v.", err) + } +} |