diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/transport')
| -rw-r--r-- | vendor/google.golang.org/grpc/transport/control.go | 210 | ||||
| -rw-r--r-- | vendor/google.golang.org/grpc/transport/handler_server.go | 393 | ||||
| -rw-r--r-- | vendor/google.golang.org/grpc/transport/http2_client.go | 953 | ||||
| -rw-r--r-- | vendor/google.golang.org/grpc/transport/http2_server.go | 743 | ||||
| -rw-r--r-- | vendor/google.golang.org/grpc/transport/http_util.go | 422 | ||||
| -rw-r--r-- | vendor/google.golang.org/grpc/transport/transport.go | 513 |
6 files changed, 3234 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/transport/control.go b/vendor/google.golang.org/grpc/transport/control.go new file mode 100644 index 0000000..7e9bdf3 --- /dev/null +++ b/vendor/google.golang.org/grpc/transport/control.go @@ -0,0 +1,210 @@ +/* + * + * 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 ( + "fmt" + "sync" + + "golang.org/x/net/http2" +) + +const ( + // The default value of flow control window size in HTTP2 spec. + defaultWindowSize = 65535 + // The initial window size for flow control. + initialWindowSize = defaultWindowSize // for an RPC + initialConnWindowSize = defaultWindowSize * 16 // for a connection +) + +// The following defines various control items which could flow through +// the control buffer of transport. They represent different aspects of +// control tasks, e.g., flow control, settings, streaming resetting, etc. +type windowUpdate struct { + streamID uint32 + increment uint32 +} + +func (*windowUpdate) item() {} + +type settings struct { + ack bool + ss []http2.Setting +} + +func (*settings) item() {} + +type resetStream struct { + streamID uint32 + code http2.ErrCode +} + +func (*resetStream) item() {} + +type flushIO struct { +} + +func (*flushIO) item() {} + +type ping struct { + ack bool + data [8]byte +} + +func (*ping) item() {} + +// quotaPool is a pool which accumulates the quota and sends it to acquire() +// when it is available. +type quotaPool struct { + c chan int + + mu sync.Mutex + quota int +} + +// newQuotaPool creates a quotaPool which has quota q available to consume. +func newQuotaPool(q int) *quotaPool { + qb := "aPool{ + c: make(chan int, 1), + } + if q > 0 { + qb.c <- q + } else { + qb.quota = q + } + return qb +} + +// add adds n to the available quota and tries to send it on acquire. +func (qb *quotaPool) add(n int) { + qb.mu.Lock() + defer qb.mu.Unlock() + qb.quota += n + if qb.quota <= 0 { + return + } + select { + case qb.c <- qb.quota: + qb.quota = 0 + default: + } +} + +// cancel cancels the pending quota sent on acquire, if any. +func (qb *quotaPool) cancel() { + qb.mu.Lock() + defer qb.mu.Unlock() + select { + case n := <-qb.c: + qb.quota += n + default: + } +} + +// reset cancels the pending quota sent on acquired, incremented by v and sends +// it back on acquire. +func (qb *quotaPool) reset(v int) { + qb.mu.Lock() + defer qb.mu.Unlock() + select { + case n := <-qb.c: + qb.quota += n + default: + } + qb.quota += v + if qb.quota <= 0 { + return + } + select { + case qb.c <- qb.quota: + qb.quota = 0 + default: + } +} + +// acquire returns the channel on which available quota amounts are sent. +func (qb *quotaPool) acquire() <-chan int { + return qb.c +} + +// inFlow deals with inbound flow control +type inFlow struct { + // The inbound flow control limit for pending data. + limit uint32 + + mu sync.Mutex + // pendingData is the overall data which have been received but not been + // consumed by applications. + pendingData uint32 + // The amount of data the application has consumed but grpc has not sent + // window update for them. Used to reduce window update frequency. + pendingUpdate uint32 +} + +// onData is invoked when some data frame is received. It updates pendingData. +func (f *inFlow) onData(n uint32) error { + f.mu.Lock() + defer f.mu.Unlock() + f.pendingData += n + if f.pendingData+f.pendingUpdate > f.limit { + return fmt.Errorf("received %d-bytes data exceeding the limit %d bytes", f.pendingData+f.pendingUpdate, f.limit) + } + return nil +} + +// onRead is invoked when the application reads the data. It returns the window size +// to be sent to the peer. +func (f *inFlow) onRead(n uint32) uint32 { + f.mu.Lock() + defer f.mu.Unlock() + if f.pendingData == 0 { + return 0 + } + f.pendingData -= n + f.pendingUpdate += n + if f.pendingUpdate >= f.limit/4 { + wu := f.pendingUpdate + f.pendingUpdate = 0 + return wu + } + return 0 +} + +func (f *inFlow) resetPendingData() uint32 { + f.mu.Lock() + defer f.mu.Unlock() + n := f.pendingData + f.pendingData = 0 + return n +} diff --git a/vendor/google.golang.org/grpc/transport/handler_server.go b/vendor/google.golang.org/grpc/transport/handler_server.go new file mode 100644 index 0000000..7a4ae07 --- /dev/null +++ b/vendor/google.golang.org/grpc/transport/handler_server.go @@ -0,0 +1,393 @@ +/* + * Copyright 2016, 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. + * + */ + +// This file is the implementation of a gRPC server using HTTP/2 which +// uses the standard Go http2 Server implementation (via the +// http.Handler interface), rather than speaking low-level HTTP/2 +// frames itself. It is the implementation of *grpc.Server.ServeHTTP. + +package transport + +import ( + "errors" + "fmt" + "io" + "net" + "net/http" + "strings" + "sync" + "time" + + "golang.org/x/net/context" + "golang.org/x/net/http2" + "google.golang.org/grpc/codes" + "google.golang.org/grpc/credentials" + "google.golang.org/grpc/metadata" + "google.golang.org/grpc/peer" +) + +// NewServerHandlerTransport returns a ServerTransport handling gRPC +// from inside an http.Handler. It requires that the http Server +// supports HTTP/2. +func NewServerHandlerTransport(w http.ResponseWriter, r *http.Request) (ServerTransport, error) { + if r.ProtoMajor != 2 { + return nil, errors.New("gRPC requires HTTP/2") + } + if r.Method != "POST" { + return nil, errors.New("invalid gRPC request method") + } + if !strings.Contains(r.Header.Get("Content-Type"), "application/grpc") { + return nil, errors.New("invalid gRPC request content-type") + } + if _, ok := w.(http.Flusher); !ok { + return nil, errors.New("gRPC requires a ResponseWriter supporting http.Flusher") + } + if _, ok := w.(http.CloseNotifier); !ok { + return nil, errors.New("gRPC requires a ResponseWriter supporting http.CloseNotifier") + } + + st := &serverHandlerTransport{ + rw: w, + req: r, + closedCh: make(chan struct{}), + writes: make(chan func()), + } + + if v := r.Header.Get("grpc-timeout"); v != "" { + to, err := timeoutDecode(v) + if err != nil { + return nil, StreamErrorf(codes.Internal, "malformed time-out: %v", err) + } + st.timeoutSet = true + st.timeout = to + } + + var metakv []string + if r.Host != "" { + metakv = append(metakv, ":authority", r.Host) + } + for k, vv := range r.Header { + k = strings.ToLower(k) + if isReservedHeader(k) && !isWhitelistedPseudoHeader(k){ + continue + } + for _, v := range vv { + if k == "user-agent" { + // user-agent is special. Copying logic of http_util.go. + if i := strings.LastIndex(v, " "); i == -1 { + // There is no application user agent string being set + continue + } else { + v = v[:i] + } + } + metakv = append(metakv, k, v) + } + } + st.headerMD = metadata.Pairs(metakv...) + + return st, nil +} + +// serverHandlerTransport is an implementation of ServerTransport +// which replies to exactly one gRPC request (exactly one HTTP request), +// using the net/http.Handler interface. This http.Handler is guaranteed +// at this point to be speaking over HTTP/2, so it's able to speak valid +// gRPC. +type serverHandlerTransport struct { + rw http.ResponseWriter + req *http.Request + timeoutSet bool + timeout time.Duration + didCommonHeaders bool + + headerMD metadata.MD + + closeOnce sync.Once + closedCh chan struct{} // closed on Close + + // writes is a channel of code to run serialized in the + // ServeHTTP (HandleStreams) goroutine. The channel is closed + // when WriteStatus is called. + writes chan func() +} + +func (ht *serverHandlerTransport) Close() error { + ht.closeOnce.Do(ht.closeCloseChanOnce) + return nil +} + +func (ht *serverHandlerTransport) closeCloseChanOnce() { close(ht.closedCh) } + +func (ht *serverHandlerTransport) RemoteAddr() net.Addr { return strAddr(ht.req.RemoteAddr) } + +// strAddr is a net.Addr backed by either a TCP "ip:port" string, or +// the empty string if unknown. +type strAddr string + +func (a strAddr) Network() string { + if a != "" { + // Per the documentation on net/http.Request.RemoteAddr, if this is + // set, it's set to the IP:port of the peer (hence, TCP): + // https://golang.org/pkg/net/http/#Request + // + // If we want to support Unix sockets later, we can + // add our own grpc-specific convention within the + // grpc codebase to set RemoteAddr to a different + // format, or probably better: we can attach it to the + // context and use that from serverHandlerTransport.RemoteAddr. + return "tcp" + } + return "" +} + +func (a strAddr) String() string { return string(a) } + +// do runs fn in the ServeHTTP goroutine. +func (ht *serverHandlerTransport) do(fn func()) error { + select { + case ht.writes <- fn: + return nil + case <-ht.closedCh: + return ErrConnClosing + } +} + +func (ht *serverHandlerTransport) WriteStatus(s *Stream, statusCode codes.Code, statusDesc string) error { + err := ht.do(func() { + ht.writeCommonHeaders(s) + + // And flush, in case no header or body has been sent yet. + // This forces a separation of headers and trailers if this is the + // first call (for example, in end2end tests's TestNoService). + ht.rw.(http.Flusher).Flush() + + h := ht.rw.Header() + h.Set("Grpc-Status", fmt.Sprintf("%d", statusCode)) + if statusDesc != "" { + h.Set("Grpc-Message", statusDesc) + } + if md := s.Trailer(); len(md) > 0 { + for k, vv := range md { + // Clients don't tolerate reading restricted headers after some non restricted ones were sent. + if isReservedHeader(k) { + continue + } + for _, v := range vv { + // http2 ResponseWriter mechanism to + // send undeclared Trailers after the + // headers have possibly been written. + h.Add(http2.TrailerPrefix+k, v) + } + } + } + }) + close(ht.writes) + return err +} + +// writeCommonHeaders sets common headers on the first write +// call (Write, WriteHeader, or WriteStatus). +func (ht *serverHandlerTransport) writeCommonHeaders(s *Stream) { + if ht.didCommonHeaders { + return + } + ht.didCommonHeaders = true + + h := ht.rw.Header() + h["Date"] = nil // suppress Date to make tests happy; TODO: restore + h.Set("Content-Type", "application/grpc") + + // Predeclare trailers we'll set later in WriteStatus (after the body). + // This is a SHOULD in the HTTP RFC, and the way you add (known) + // Trailers per the net/http.ResponseWriter contract. + // See https://golang.org/pkg/net/http/#ResponseWriter + // and https://golang.org/pkg/net/http/#example_ResponseWriter_trailers + h.Add("Trailer", "Grpc-Status") + h.Add("Trailer", "Grpc-Message") + + if s.sendCompress != "" { + h.Set("Grpc-Encoding", s.sendCompress) + } +} + +func (ht *serverHandlerTransport) Write(s *Stream, data []byte, opts *Options) error { + return ht.do(func() { + ht.writeCommonHeaders(s) + ht.rw.Write(data) + if !opts.Delay { + ht.rw.(http.Flusher).Flush() + } + }) +} + +func (ht *serverHandlerTransport) WriteHeader(s *Stream, md metadata.MD) error { + return ht.do(func() { + ht.writeCommonHeaders(s) + h := ht.rw.Header() + for k, vv := range md { + // Clients don't tolerate reading restricted headers after some non restricted ones were sent. + if isReservedHeader(k) { + continue + } + for _, v := range vv { + h.Add(k, v) + } + } + ht.rw.WriteHeader(200) + ht.rw.(http.Flusher).Flush() + }) +} + +func (ht *serverHandlerTransport) HandleStreams(startStream func(*Stream)) { + // With this transport type there will be exactly 1 stream: this HTTP request. + + var ctx context.Context + var cancel context.CancelFunc + if ht.timeoutSet { + ctx, cancel = context.WithTimeout(context.Background(), ht.timeout) + } else { + ctx, cancel = context.WithCancel(context.Background()) + } + + // requestOver is closed when either the request's context is done + // or the status has been written via WriteStatus. + requestOver := make(chan struct{}) + + // clientGone receives a single value if peer is gone, either + // because the underlying connection is dead or because the + // peer sends an http2 RST_STREAM. + clientGone := ht.rw.(http.CloseNotifier).CloseNotify() + go func() { + select { + case <-requestOver: + return + case <-ht.closedCh: + case <-clientGone: + } + cancel() + }() + + req := ht.req + + s := &Stream{ + id: 0, // irrelevant + windowHandler: func(int) {}, // nothing + cancel: cancel, + buf: newRecvBuffer(), + st: ht, + method: req.URL.Path, + recvCompress: req.Header.Get("grpc-encoding"), + } + pr := &peer.Peer{ + Addr: ht.RemoteAddr(), + } + if req.TLS != nil { + pr.AuthInfo = credentials.TLSInfo{*req.TLS} + } + ctx = metadata.NewContext(ctx, ht.headerMD) + ctx = peer.NewContext(ctx, pr) + s.ctx = newContextWithStream(ctx, s) + s.dec = &recvBufferReader{ctx: s.ctx, recv: s.buf} + + // readerDone is closed when the Body.Read-ing goroutine exits. + readerDone := make(chan struct{}) + go func() { + defer close(readerDone) + + // TODO: minimize garbage, optimize recvBuffer code/ownership + const readSize = 8196 + for buf := make([]byte, readSize); ; { + n, err := req.Body.Read(buf) + if n > 0 { + s.buf.put(&recvMsg{data: buf[:n:n]}) + buf = buf[n:] + } + if err != nil { + s.buf.put(&recvMsg{err: mapRecvMsgError(err)}) + return + } + if len(buf) == 0 { + buf = make([]byte, readSize) + } + } + }() + + // startStream is provided by the *grpc.Server's serveStreams. + // It starts a goroutine serving s and exits immediately. + // The goroutine that is started is the one that then calls + // into ht, calling WriteHeader, Write, WriteStatus, Close, etc. + startStream(s) + + ht.runStream() + close(requestOver) + + // Wait for reading goroutine to finish. + req.Body.Close() + <-readerDone +} + +func (ht *serverHandlerTransport) runStream() { + for { + select { + case fn, ok := <-ht.writes: + if !ok { + return + } + fn() + case <-ht.closedCh: + return + } + } +} + +// mapRecvMsgError returns the non-nil err into the appropriate +// error value as expected by callers of *grpc.parser.recvMsg. +// In particular, in can only be: +// * io.EOF +// * io.ErrUnexpectedEOF +// * of type transport.ConnectionError +// * of type transport.StreamError +func mapRecvMsgError(err error) error { + if err == io.EOF || err == io.ErrUnexpectedEOF { + return err + } + if se, ok := err.(http2.StreamError); ok { + if code, ok := http2ErrConvTab[se.Code]; ok { + return StreamError{ + Code: code, + Desc: se.Error(), + } + } + } + return ConnectionError{Desc: err.Error()} +} 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) + } +} diff --git a/vendor/google.golang.org/grpc/transport/http2_server.go b/vendor/google.golang.org/grpc/transport/http2_server.go new file mode 100644 index 0000000..1c4d585 --- /dev/null +++ b/vendor/google.golang.org/grpc/transport/http2_server.go @@ -0,0 +1,743 @@ +/* + * + * 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" + "errors" + "io" + "math" + "net" + "strconv" + "sync" + + "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" +) + +// ErrIllegalHeaderWrite indicates that setting header is illegal because of +// the stream's state. +var ErrIllegalHeaderWrite = errors.New("transport: the stream is done or WriteHeader was already called") + +// http2Server implements the ServerTransport interface with HTTP2. +type http2Server struct { + conn net.Conn + maxStreamID uint32 // max stream ID ever seen + authInfo credentials.AuthInfo // auth info about the connection + // writableChan synchronizes write access to the transport. + // A writer acquires the write lock by receiving a value on writableChan + // and releases it by sending on writableChan. + writableChan chan int + // shutdownChan is closed when Close is called. + // Blocking operations should select on shutdownChan to avoid + // blocking forever after Close. + shutdownChan chan struct{} + framer *framer + hBuf *bytes.Buffer // the buffer for HPACK encoding + hEnc *hpack.Encoder // HPACK encoder + + // The max number of concurrent streams. + maxStreams uint32 + // 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 + + mu sync.Mutex // guard the following + state transportState + activeStreams map[uint32]*Stream + // the per-stream outbound flow control window size set by the peer. + streamSendQuota uint32 +} + +// newHTTP2Server constructs a ServerTransport based on HTTP2. ConnectionError is +// returned if something goes wrong. +func newHTTP2Server(conn net.Conn, maxStreams uint32, authInfo credentials.AuthInfo) (_ ServerTransport, err error) { + framer := newFramer(conn) + // Send initial settings as connection preface to client. + var settings []http2.Setting + // TODO(zhaoq): Have a better way to signal "no limit" because 0 is + // permitted in the HTTP2 spec. + if maxStreams == 0 { + maxStreams = math.MaxUint32 + } else { + settings = append(settings, http2.Setting{http2.SettingMaxConcurrentStreams, maxStreams}) + } + if initialWindowSize != defaultWindowSize { + settings = append(settings, http2.Setting{http2.SettingInitialWindowSize, uint32(initialWindowSize)}) + } + if err := framer.writeSettings(true, settings...); err != nil { + return nil, ConnectionErrorf("transport: %v", err) + } + // Adjust the connection flow control window if needed. + if delta := uint32(initialConnWindowSize - defaultWindowSize); delta > 0 { + if err := framer.writeWindowUpdate(true, 0, delta); err != nil { + return nil, ConnectionErrorf("transport: %v", err) + } + } + var buf bytes.Buffer + t := &http2Server{ + conn: conn, + authInfo: authInfo, + framer: framer, + hBuf: &buf, + hEnc: hpack.NewEncoder(&buf), + maxStreams: maxStreams, + controlBuf: newRecvBuffer(), + fc: &inFlow{limit: initialConnWindowSize}, + sendQuotaPool: newQuotaPool(defaultWindowSize), + state: reachable, + writableChan: make(chan int, 1), + shutdownChan: make(chan struct{}), + activeStreams: make(map[uint32]*Stream), + streamSendQuota: defaultWindowSize, + } + go t.controller() + t.writableChan <- 0 + return t, nil +} + +// operateHeader takes action on the decoded headers. +func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(*Stream)) { + buf := newRecvBuffer() + s := &Stream{ + id: frame.Header().StreamID, + st: t, + buf: buf, + fc: &inFlow{limit: initialWindowSize}, + } + + var state decodeState + for _, hf := range frame.Fields { + state.processHeaderField(hf) + } + if err := state.err; err != nil { + if se, ok := err.(StreamError); ok { + t.controlBuf.put(&resetStream{s.id, statusCodeConvTab[se.Code]}) + } + return + } + + if frame.StreamEnded() { + // s is just created by the caller. No lock needed. + s.state = streamReadDone + } + s.recvCompress = state.encoding + if state.timeoutSet { + s.ctx, s.cancel = context.WithTimeout(context.TODO(), state.timeout) + } else { + s.ctx, s.cancel = context.WithCancel(context.TODO()) + } + pr := &peer.Peer{ + Addr: t.conn.RemoteAddr(), + } + // Attach Auth info if there is any. + if t.authInfo != nil { + pr.AuthInfo = t.authInfo + } + s.ctx = peer.NewContext(s.ctx, pr) + // Cache the current stream to the context so that the server application + // can find out. Required when the server wants to send some metadata + // back to the client (unary call only). + s.ctx = newContextWithStream(s.ctx, s) + // Attach the received metadata to the context. + if len(state.mdata) > 0 { + s.ctx = metadata.NewContext(s.ctx, state.mdata) + } + + s.dec = &recvBufferReader{ + ctx: s.ctx, + recv: s.buf, + } + s.recvCompress = state.encoding + s.method = state.method + t.mu.Lock() + if t.state != reachable { + t.mu.Unlock() + return + } + if uint32(len(t.activeStreams)) >= t.maxStreams { + t.mu.Unlock() + t.controlBuf.put(&resetStream{s.id, http2.ErrCodeRefusedStream}) + return + } + s.sendQuotaPool = newQuotaPool(int(t.streamSendQuota)) + t.activeStreams[s.id] = s + t.mu.Unlock() + s.windowHandler = func(n int) { + t.updateWindow(s, uint32(n)) + } + handle(s) +} + +// HandleStreams receives incoming streams using the given handler. This is +// typically run in a separate goroutine. +func (t *http2Server) HandleStreams(handle func(*Stream)) { + // Check the validity of client preface. + preface := make([]byte, len(clientPreface)) + if _, err := io.ReadFull(t.conn, preface); err != nil { + grpclog.Printf("transport: http2Server.HandleStreams failed to receive the preface from client: %v", err) + t.Close() + return + } + if !bytes.Equal(preface, clientPreface) { + grpclog.Printf("transport: http2Server.HandleStreams received bogus greeting from client: %q", preface) + t.Close() + return + } + + frame, err := t.framer.readFrame() + if err != nil { + grpclog.Printf("transport: http2Server.HandleStreams failed to read frame: %v", err) + t.Close() + return + } + sf, ok := frame.(*http2.SettingsFrame) + if !ok { + grpclog.Printf("transport: http2Server.HandleStreams saw invalid preface type %T from client", frame) + t.Close() + return + } + t.handleSettings(sf) + + for { + frame, err := t.framer.readFrame() + if err != nil { + if se, ok := err.(http2.StreamError); ok { + t.mu.Lock() + s := t.activeStreams[se.StreamID] + t.mu.Unlock() + if s != nil { + t.closeStream(s) + } + t.controlBuf.put(&resetStream{se.StreamID, se.Code}) + continue + } + t.Close() + return + } + switch frame := frame.(type) { + case *http2.MetaHeadersFrame: + id := frame.Header().StreamID + if id%2 != 1 || id <= t.maxStreamID { + // illegal gRPC stream id. + grpclog.Println("transport: http2Server.HandleStreams received an illegal stream id: ", id) + t.Close() + break + } + t.maxStreamID = id + t.operateHeaders(frame, handle) + 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.WindowUpdateFrame: + t.handleWindowUpdate(frame) + case *http2.GoAwayFrame: + break + default: + grpclog.Printf("transport: http2Server.HandleStreams found unhandled frame type %v.", frame) + } + } +} + +func (t *http2Server) getStream(f http2.Frame) (*Stream, bool) { + t.mu.Lock() + defer t.mu.Unlock() + if t.activeStreams == nil { + // The transport is closing. + return nil, false + } + s, ok := t.activeStreams[f.Header().StreamID] + if !ok { + // The stream is already done. + return nil, false + } + return s, true +} + +// 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 *http2Server) 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 *http2Server) handleData(f *http2.DataFrame) { + size := len(f.Data()) + if err := t.fc.onData(uint32(size)); err != nil { + grpclog.Printf("transport: http2Server %v", err) + t.Close() + 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.mu.Unlock() + t.closeStream(s) + 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}) + } + if f.Header().Flags.Has(http2.FlagDataEndStream) { + // Received the end of stream from the client. + s.mu.Lock() + if s.state != streamDone { + if s.state == streamWriteDone { + s.state = streamDone + } else { + s.state = streamReadDone + } + } + s.mu.Unlock() + s.write(recvMsg{err: io.EOF}) + } +} + +func (t *http2Server) handleRSTStream(f *http2.RSTStreamFrame) { + s, ok := t.getStream(f) + if !ok { + return + } + t.closeStream(s) +} + +func (t *http2Server) 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 *http2Server) handlePing(f *http2.PingFrame) { + pingAck := &ping{ack: true} + copy(pingAck.data[:], f.Data[:]) + t.controlBuf.put(pingAck) +} + +func (t *http2Server) 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)) + } +} + +func (t *http2Server) writeHeaders(s *Stream, b *bytes.Buffer, endStream bool) error { + first := true + endHeaders := false + var err error + // Sends the headers in a single batch. + for !endHeaders { + size := t.hBuf.Len() + if size > http2MaxFrameLen { + size = http2MaxFrameLen + } else { + endHeaders = true + } + if first { + p := http2.HeadersFrameParam{ + StreamID: s.id, + BlockFragment: b.Next(size), + EndStream: endStream, + EndHeaders: endHeaders, + } + err = t.framer.writeHeaders(endHeaders, p) + first = false + } else { + err = t.framer.writeContinuation(endHeaders, s.id, endHeaders, b.Next(size)) + } + if err != nil { + t.Close() + return ConnectionErrorf("transport: %v", err) + } + } + return nil +} + +// WriteHeader sends the header metedata md back to the client. +func (t *http2Server) WriteHeader(s *Stream, md metadata.MD) error { + s.mu.Lock() + if s.headerOk || s.state == streamDone { + s.mu.Unlock() + return ErrIllegalHeaderWrite + } + s.headerOk = true + s.mu.Unlock() + if _, err := wait(s.ctx, t.shutdownChan, t.writableChan); err != nil { + return err + } + t.hBuf.Reset() + t.hEnc.WriteField(hpack.HeaderField{Name: ":status", Value: "200"}) + t.hEnc.WriteField(hpack.HeaderField{Name: "content-type", Value: "application/grpc"}) + if s.sendCompress != "" { + t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-encoding", Value: s.sendCompress}) + } + for k, v := range md { + if isReservedHeader(k) { + // Clients don't tolerate reading restricted headers after some non restricted ones were sent. + continue + } + for _, entry := range v { + t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: entry}) + } + } + if err := t.writeHeaders(s, t.hBuf, false); err != nil { + return err + } + t.writableChan <- 0 + return nil +} + +// WriteStatus sends stream status to the client and terminates the stream. +// There is no further I/O operations being able to perform on this stream. +// TODO(zhaoq): Now it indicates the end of entire stream. Revisit if early +// OK is adopted. +func (t *http2Server) WriteStatus(s *Stream, statusCode codes.Code, statusDesc string) error { + var headersSent bool + s.mu.Lock() + if s.state == streamDone { + s.mu.Unlock() + return nil + } + if s.headerOk { + headersSent = true + } + s.mu.Unlock() + if _, err := wait(s.ctx, t.shutdownChan, t.writableChan); err != nil { + return err + } + t.hBuf.Reset() + if !headersSent { + t.hEnc.WriteField(hpack.HeaderField{Name: ":status", Value: "200"}) + t.hEnc.WriteField(hpack.HeaderField{Name: "content-type", Value: "application/grpc"}) + } + t.hEnc.WriteField( + hpack.HeaderField{ + Name: "grpc-status", + Value: strconv.Itoa(int(statusCode)), + }) + t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-message", Value: statusDesc}) + // Attach the trailer metadata. + for k, v := range s.trailer { + // Clients don't tolerate reading restricted headers after some non restricted ones were sent. + if isReservedHeader(k) { + continue + } + for _, entry := range v { + t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: entry}) + } + } + if err := t.writeHeaders(s, t.hBuf, true); err != nil { + t.Close() + return err + } + t.closeStream(s) + t.writableChan <- 0 + return nil +} + +// Write converts the data into HTTP2 data frame and sends it out. Non-nil error +// is returns if it fails (e.g., framing error, transport error). +func (t *http2Server) Write(s *Stream, data []byte, opts *Options) error { + // TODO(zhaoq): Support multi-writers for a single stream. + var writeHeaderFrame bool + s.mu.Lock() + if s.state == streamDone { + s.mu.Unlock() + return StreamErrorf(codes.Unknown, "the stream has been done") + } + if !s.headerOk { + writeHeaderFrame = true + s.headerOk = true + } + s.mu.Unlock() + if writeHeaderFrame { + if _, err := wait(s.ctx, t.shutdownChan, t.writableChan); err != nil { + return err + } + t.hBuf.Reset() + t.hEnc.WriteField(hpack.HeaderField{Name: ":status", Value: "200"}) + t.hEnc.WriteField(hpack.HeaderField{Name: "content-type", Value: "application/grpc"}) + if s.sendCompress != "" { + t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-encoding", Value: s.sendCompress}) + } + p := http2.HeadersFrameParam{ + StreamID: s.id, + BlockFragment: t.hBuf.Bytes(), + EndHeaders: true, + } + if err := t.framer.writeHeaders(false, p); err != nil { + t.Close() + return ConnectionErrorf("transport: %v", err) + } + t.writableChan <- 0 + } + r := bytes.NewBuffer(data) + for { + if r.Len() == 0 { + return nil + } + 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) + } + 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(ps) + } + 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(ps) + if t.framer.adjustNumWriters(-1) == 0 { + t.controlBuf.put(&flushIO{}) + } + t.writableChan <- 0 + return ContextErr(s.ctx.Err()) + default: + } + var forceFlush bool + if r.Len() == 0 && t.framer.adjustNumWriters(0) == 1 && !opts.Last { + forceFlush = true + } + if err := t.framer.writeData(forceFlush, s.id, false, p); err != nil { + t.Close() + return ConnectionErrorf("transport: %v", err) + } + if t.framer.adjustNumWriters(-1) == 0 { + t.framer.flushWrite() + } + t.writableChan <- 0 + } + +} + +func (t *http2Server) applySettings(ss []http2.Setting) { + for _, s := range ss { + if s.ID == http2.SettingInitialWindowSize { + t.mu.Lock() + defer t.mu.Unlock() + for _, stream := range t.activeStreams { + stream.sendQuotaPool.reset(int(s.Val - t.streamSendQuota)) + } + t.streamSendQuota = s.Val + } + + } +} + +// 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 *http2Server) 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: http2Server.controller got unexpected item type %v\n", i) + } + t.writableChan <- 0 + continue + case <-t.shutdownChan: + return + } + case <-t.shutdownChan: + return + } + } +} + +// Close starts shutting down the http2Server transport. +// TODO(zhaoq): Now the destruction is not blocked on any pending streams. This +// could cause some resource issue. Revisit this later. +func (t *http2Server) Close() (err error) { + t.mu.Lock() + if t.state == closing { + t.mu.Unlock() + return errors.New("transport: Close() was already called") + } + t.state = closing + streams := t.activeStreams + t.activeStreams = nil + t.mu.Unlock() + close(t.shutdownChan) + err = t.conn.Close() + // Cancel all active streams. + for _, s := range streams { + s.cancel() + } + return +} + +// closeStream clears the footprint of a stream when the stream is not needed +// any more. +func (t *http2Server) closeStream(s *Stream) { + t.mu.Lock() + delete(t.activeStreams, s.id) + t.mu.Unlock() + // In case stream sending and receiving are invoked in separate + // goroutines (e.g., bi-directional streaming), cancel needs to be + // called to interrupt the potential blocking on other goroutines. + s.cancel() + s.mu.Lock() + if q := s.fc.resetPendingData(); q > 0 { + if w := t.fc.onRead(q); w > 0 { + t.controlBuf.put(&windowUpdate{0, w}) + } + } + if s.state == streamDone { + s.mu.Unlock() + return + } + s.state = streamDone + s.mu.Unlock() +} + +func (t *http2Server) RemoteAddr() net.Addr { + return t.conn.RemoteAddr() +} diff --git a/vendor/google.golang.org/grpc/transport/http_util.go b/vendor/google.golang.org/grpc/transport/http_util.go new file mode 100644 index 0000000..a4b1b07 --- /dev/null +++ b/vendor/google.golang.org/grpc/transport/http_util.go @@ -0,0 +1,422 @@ +/* + * + * 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 ( + "bufio" + "fmt" + "io" + "net" + "strconv" + "strings" + "sync/atomic" + "time" + + "golang.org/x/net/http2" + "golang.org/x/net/http2/hpack" + "google.golang.org/grpc/codes" + "google.golang.org/grpc/grpclog" + "google.golang.org/grpc/metadata" +) + +const ( + // The primary user agent + primaryUA = "grpc-go/0.11" + // http2MaxFrameLen specifies the max length of a HTTP2 frame. + http2MaxFrameLen = 16384 // 16KB frame + // http://http2.github.io/http2-spec/#SettingValues + http2InitHeaderTableSize = 4096 + // http2IOBufSize specifies the buffer size for sending frames. + http2IOBufSize = 32 * 1024 +) + +var ( + clientPreface = []byte(http2.ClientPreface) + http2ErrConvTab = map[http2.ErrCode]codes.Code{ + http2.ErrCodeNo: codes.Internal, + http2.ErrCodeProtocol: codes.Internal, + http2.ErrCodeInternal: codes.Internal, + http2.ErrCodeFlowControl: codes.ResourceExhausted, + http2.ErrCodeSettingsTimeout: codes.Internal, + http2.ErrCodeStreamClosed: codes.Internal, + http2.ErrCodeFrameSize: codes.Internal, + http2.ErrCodeRefusedStream: codes.Unavailable, + http2.ErrCodeCancel: codes.Canceled, + http2.ErrCodeCompression: codes.Internal, + http2.ErrCodeConnect: codes.Internal, + http2.ErrCodeEnhanceYourCalm: codes.ResourceExhausted, + http2.ErrCodeInadequateSecurity: codes.PermissionDenied, + http2.ErrCodeHTTP11Required: codes.FailedPrecondition, + } + statusCodeConvTab = map[codes.Code]http2.ErrCode{ + codes.Internal: http2.ErrCodeInternal, + codes.Canceled: http2.ErrCodeCancel, + codes.Unavailable: http2.ErrCodeRefusedStream, + codes.ResourceExhausted: http2.ErrCodeEnhanceYourCalm, + codes.PermissionDenied: http2.ErrCodeInadequateSecurity, + } +) + +// Records the states during HPACK decoding. Must be reset once the +// decoding of the entire headers are finished. +type decodeState struct { + err error // first error encountered decoding + + encoding string + // statusCode caches the stream status received from the trailer + // the server sent. Client side only. + statusCode codes.Code + statusDesc string + // Server side only fields. + timeoutSet bool + timeout time.Duration + method string + // key-value metadata map from the peer. + mdata map[string][]string +} + +// isReservedHeader checks whether hdr belongs to HTTP2 headers +// reserved by gRPC protocol. Any other headers are classified as the +// user-specified metadata. +func isReservedHeader(hdr string) bool { + if hdr != "" && hdr[0] == ':' { + return true + } + switch hdr { + case "content-type", + "grpc-message-type", + "grpc-encoding", + "grpc-message", + "grpc-status", + "grpc-timeout", + "te": + return true + default: + return false + } +} + +// isWhitelistedPseudoHeader checks whether hdr belongs to HTTP2 pseudoheaders +// that should be propagated into metadata visible to users. +func isWhitelistedPseudoHeader(hdr string) bool { + switch hdr { + case ":authority": + return true + default: + return false + } +} + +func (d *decodeState) setErr(err error) { + if d.err == nil { + d.err = err + } +} + +func (d *decodeState) processHeaderField(f hpack.HeaderField) { + switch f.Name { + case "content-type": + if !strings.Contains(f.Value, "application/grpc") { + d.setErr(StreamErrorf(codes.FailedPrecondition, "transport: received the unexpected content-type %q", f.Value)) + return + } + case "grpc-encoding": + d.encoding = f.Value + case "grpc-status": + code, err := strconv.Atoi(f.Value) + if err != nil { + d.setErr(StreamErrorf(codes.Internal, "transport: malformed grpc-status: %v", err)) + return + } + d.statusCode = codes.Code(code) + case "grpc-message": + d.statusDesc = f.Value + case "grpc-timeout": + d.timeoutSet = true + var err error + d.timeout, err = timeoutDecode(f.Value) + if err != nil { + d.setErr(StreamErrorf(codes.Internal, "transport: malformed time-out: %v", err)) + return + } + case ":path": + d.method = f.Value + default: + if !isReservedHeader(f.Name) || isWhitelistedPseudoHeader(f.Name) { + if f.Name == "user-agent" { + i := strings.LastIndex(f.Value, " ") + if i == -1 { + // There is no application user agent string being set. + return + } + // Extract the application user agent string. + f.Value = f.Value[:i] + } + if d.mdata == nil { + d.mdata = make(map[string][]string) + } + k, v, err := metadata.DecodeKeyValue(f.Name, f.Value) + if err != nil { + grpclog.Printf("Failed to decode (%q, %q): %v", f.Name, f.Value, err) + return + } + d.mdata[k] = append(d.mdata[k], v) + } + } +} + +type timeoutUnit uint8 + +const ( + hour timeoutUnit = 'H' + minute timeoutUnit = 'M' + second timeoutUnit = 'S' + millisecond timeoutUnit = 'm' + microsecond timeoutUnit = 'u' + nanosecond timeoutUnit = 'n' +) + +func timeoutUnitToDuration(u timeoutUnit) (d time.Duration, ok bool) { + switch u { + case hour: + return time.Hour, true + case minute: + return time.Minute, true + case second: + return time.Second, true + case millisecond: + return time.Millisecond, true + case microsecond: + return time.Microsecond, true + case nanosecond: + return time.Nanosecond, true + default: + } + return +} + +const maxTimeoutValue int64 = 100000000 - 1 + +// div does integer division and round-up the result. Note that this is +// equivalent to (d+r-1)/r but has less chance to overflow. +func div(d, r time.Duration) int64 { + if m := d % r; m > 0 { + return int64(d/r + 1) + } + return int64(d / r) +} + +// TODO(zhaoq): It is the simplistic and not bandwidth efficient. Improve it. +func timeoutEncode(t time.Duration) string { + if d := div(t, time.Nanosecond); d <= maxTimeoutValue { + return strconv.FormatInt(d, 10) + "n" + } + if d := div(t, time.Microsecond); d <= maxTimeoutValue { + return strconv.FormatInt(d, 10) + "u" + } + if d := div(t, time.Millisecond); d <= maxTimeoutValue { + return strconv.FormatInt(d, 10) + "m" + } + if d := div(t, time.Second); d <= maxTimeoutValue { + return strconv.FormatInt(d, 10) + "S" + } + if d := div(t, time.Minute); d <= maxTimeoutValue { + return strconv.FormatInt(d, 10) + "M" + } + // Note that maxTimeoutValue * time.Hour > MaxInt64. + return strconv.FormatInt(div(t, time.Hour), 10) + "H" +} + +func timeoutDecode(s string) (time.Duration, error) { + size := len(s) + if size < 2 { + return 0, fmt.Errorf("transport: timeout string is too short: %q", s) + } + unit := timeoutUnit(s[size-1]) + d, ok := timeoutUnitToDuration(unit) + if !ok { + return 0, fmt.Errorf("transport: timeout unit is not recognized: %q", s) + } + t, err := strconv.ParseInt(s[:size-1], 10, 64) + if err != nil { + return 0, err + } + return d * time.Duration(t), nil +} + +type framer struct { + numWriters int32 + reader io.Reader + writer *bufio.Writer + fr *http2.Framer +} + +func newFramer(conn net.Conn) *framer { + f := &framer{ + reader: bufio.NewReaderSize(conn, http2IOBufSize), + writer: bufio.NewWriterSize(conn, http2IOBufSize), + } + f.fr = http2.NewFramer(f.writer, f.reader) + f.fr.ReadMetaHeaders = hpack.NewDecoder(http2InitHeaderTableSize, nil) + return f +} + +func (f *framer) adjustNumWriters(i int32) int32 { + return atomic.AddInt32(&f.numWriters, i) +} + +// The following writeXXX functions can only be called when the caller gets +// unblocked from writableChan channel (i.e., owns the privilege to write). + +func (f *framer) writeContinuation(forceFlush bool, streamID uint32, endHeaders bool, headerBlockFragment []byte) error { + if err := f.fr.WriteContinuation(streamID, endHeaders, headerBlockFragment); err != nil { + return err + } + if forceFlush { + return f.writer.Flush() + } + return nil +} + +func (f *framer) writeData(forceFlush bool, streamID uint32, endStream bool, data []byte) error { + if err := f.fr.WriteData(streamID, endStream, data); err != nil { + return err + } + if forceFlush { + return f.writer.Flush() + } + return nil +} + +func (f *framer) writeGoAway(forceFlush bool, maxStreamID uint32, code http2.ErrCode, debugData []byte) error { + if err := f.fr.WriteGoAway(maxStreamID, code, debugData); err != nil { + return err + } + if forceFlush { + return f.writer.Flush() + } + return nil +} + +func (f *framer) writeHeaders(forceFlush bool, p http2.HeadersFrameParam) error { + if err := f.fr.WriteHeaders(p); err != nil { + return err + } + if forceFlush { + return f.writer.Flush() + } + return nil +} + +func (f *framer) writePing(forceFlush, ack bool, data [8]byte) error { + if err := f.fr.WritePing(ack, data); err != nil { + return err + } + if forceFlush { + return f.writer.Flush() + } + return nil +} + +func (f *framer) writePriority(forceFlush bool, streamID uint32, p http2.PriorityParam) error { + if err := f.fr.WritePriority(streamID, p); err != nil { + return err + } + if forceFlush { + return f.writer.Flush() + } + return nil +} + +func (f *framer) writePushPromise(forceFlush bool, p http2.PushPromiseParam) error { + if err := f.fr.WritePushPromise(p); err != nil { + return err + } + if forceFlush { + return f.writer.Flush() + } + return nil +} + +func (f *framer) writeRSTStream(forceFlush bool, streamID uint32, code http2.ErrCode) error { + if err := f.fr.WriteRSTStream(streamID, code); err != nil { + return err + } + if forceFlush { + return f.writer.Flush() + } + return nil +} + +func (f *framer) writeSettings(forceFlush bool, settings ...http2.Setting) error { + if err := f.fr.WriteSettings(settings...); err != nil { + return err + } + if forceFlush { + return f.writer.Flush() + } + return nil +} + +func (f *framer) writeSettingsAck(forceFlush bool) error { + if err := f.fr.WriteSettingsAck(); err != nil { + return err + } + if forceFlush { + return f.writer.Flush() + } + return nil +} + +func (f *framer) writeWindowUpdate(forceFlush bool, streamID, incr uint32) error { + if err := f.fr.WriteWindowUpdate(streamID, incr); err != nil { + return err + } + if forceFlush { + return f.writer.Flush() + } + return nil +} + +func (f *framer) flushWrite() error { + return f.writer.Flush() +} + +func (f *framer) readFrame() (http2.Frame, error) { + return f.fr.ReadFrame() +} + +func (f *framer) errorDetail() error { + return f.fr.ErrorDetail() +} diff --git a/vendor/google.golang.org/grpc/transport/transport.go b/vendor/google.golang.org/grpc/transport/transport.go new file mode 100644 index 0000000..1c9af54 --- /dev/null +++ b/vendor/google.golang.org/grpc/transport/transport.go @@ -0,0 +1,513 @@ +/* + * + * 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 defines and implements message oriented communication channel +to complete various transactions (e.g., an RPC). +*/ +package transport // import "google.golang.org/grpc/transport" + +import ( + "bytes" + "errors" + "fmt" + "io" + "net" + "sync" + "time" + + "golang.org/x/net/context" + "golang.org/x/net/trace" + "google.golang.org/grpc/codes" + "google.golang.org/grpc/credentials" + "google.golang.org/grpc/metadata" +) + +// recvMsg represents the received msg from the transport. All transport +// protocol specific info has been removed. +type recvMsg struct { + data []byte + // nil: received some data + // io.EOF: stream is completed. data is nil. + // other non-nil error: transport failure. data is nil. + err error +} + +func (*recvMsg) item() {} + +// All items in an out of a recvBuffer should be the same type. +type item interface { + item() +} + +// recvBuffer is an unbounded channel of item. +type recvBuffer struct { + c chan item + mu sync.Mutex + backlog []item +} + +func newRecvBuffer() *recvBuffer { + b := &recvBuffer{ + c: make(chan item, 1), + } + return b +} + +func (b *recvBuffer) put(r item) { + b.mu.Lock() + defer b.mu.Unlock() + if len(b.backlog) == 0 { + select { + case b.c <- r: + return + default: + } + } + b.backlog = append(b.backlog, r) +} + +func (b *recvBuffer) load() { + b.mu.Lock() + defer b.mu.Unlock() + if len(b.backlog) > 0 { + select { + case b.c <- b.backlog[0]: + b.backlog = b.backlog[1:] + default: + } + } +} + +// get returns the channel that receives an item in the buffer. +// +// Upon receipt of an item, the caller should call load to send another +// item onto the channel if there is any. +func (b *recvBuffer) get() <-chan item { + return b.c +} + +// recvBufferReader implements io.Reader interface to read the data from +// recvBuffer. +type recvBufferReader struct { + ctx context.Context + recv *recvBuffer + last *bytes.Reader // Stores the remaining data in the previous calls. + err error +} + +// Read reads the next len(p) bytes from last. If last is drained, it tries to +// read additional data from recv. It blocks if there no additional data available +// in recv. If Read returns any non-nil error, it will continue to return that error. +func (r *recvBufferReader) Read(p []byte) (n int, err error) { + if r.err != nil { + return 0, r.err + } + defer func() { r.err = err }() + if r.last != nil && r.last.Len() > 0 { + // Read remaining data left in last call. + return r.last.Read(p) + } + select { + case <-r.ctx.Done(): + return 0, ContextErr(r.ctx.Err()) + case i := <-r.recv.get(): + r.recv.load() + m := i.(*recvMsg) + if m.err != nil { + return 0, m.err + } + r.last = bytes.NewReader(m.data) + return r.last.Read(p) + } +} + +type streamState uint8 + +const ( + streamActive streamState = iota + streamWriteDone // EndStream sent + streamReadDone // EndStream received + streamDone // sendDone and recvDone or RSTStreamFrame is sent or received. +) + +// Stream represents an RPC in the transport layer. +type Stream struct { + id uint32 + // nil for client side Stream. + st ServerTransport + // ctx is the associated context of the stream. + ctx context.Context + cancel context.CancelFunc + // method records the associated RPC method of the stream. + method string + recvCompress string + sendCompress string + buf *recvBuffer + dec io.Reader + fc *inFlow + recvQuota uint32 + // The accumulated inbound quota pending for window update. + updateQuota uint32 + // The handler to control the window update procedure for both this + // particular stream and the associated transport. + windowHandler func(int) + + sendQuotaPool *quotaPool + // Close headerChan to indicate the end of reception of header metadata. + headerChan chan struct{} + // header caches the received header metadata. + header metadata.MD + // The key-value map of trailer metadata. + trailer metadata.MD + + mu sync.RWMutex // guard the following + // headerOK becomes true from the first header is about to send. + headerOk bool + state streamState + // true iff headerChan is closed. Used to avoid closing headerChan + // multiple times. + headerDone bool + // the status received from the server. + statusCode codes.Code + statusDesc string +} + +// RecvCompress returns the compression algorithm applied to the inbound +// message. It is empty string if there is no compression applied. +func (s *Stream) RecvCompress() string { + return s.recvCompress +} + +// SetSendCompress sets the compression algorithm to the stream. +func (s *Stream) SetSendCompress(str string) { + s.sendCompress = str +} + +// Header acquires the key-value pairs of header metadata once it +// is available. It blocks until i) the metadata is ready or ii) there is no +// header metadata or iii) the stream is cancelled/expired. +func (s *Stream) Header() (metadata.MD, error) { + select { + case <-s.ctx.Done(): + return nil, ContextErr(s.ctx.Err()) + case <-s.headerChan: + return s.header.Copy(), nil + } +} + +// Trailer returns the cached trailer metedata. Note that if it is not called +// after the entire stream is done, it could return an empty MD. Client +// side only. +func (s *Stream) Trailer() metadata.MD { + s.mu.RLock() + defer s.mu.RUnlock() + return s.trailer.Copy() +} + +// ServerTransport returns the underlying ServerTransport for the stream. +// The client side stream always returns nil. +func (s *Stream) ServerTransport() ServerTransport { + return s.st +} + +// Context returns the context of the stream. +func (s *Stream) Context() context.Context { + return s.ctx +} + +// TraceContext recreates the context of s with a trace.Trace. +func (s *Stream) TraceContext(tr trace.Trace) { + s.ctx = trace.NewContext(s.ctx, tr) +} + +// Method returns the method for the stream. +func (s *Stream) Method() string { + return s.method +} + +// StatusCode returns statusCode received from the server. +func (s *Stream) StatusCode() codes.Code { + return s.statusCode +} + +// StatusDesc returns statusDesc received from the server. +func (s *Stream) StatusDesc() string { + return s.statusDesc +} + +// ErrIllegalTrailerSet indicates that the trailer has already been set or it +// is too late to do so. +var ErrIllegalTrailerSet = errors.New("transport: trailer has been set") + +// SetTrailer sets the trailer metadata which will be sent with the RPC status +// by the server. This can only be called at most once. Server side only. +func (s *Stream) SetTrailer(md metadata.MD) error { + s.mu.Lock() + defer s.mu.Unlock() + if s.trailer != nil { + return ErrIllegalTrailerSet + } + s.trailer = md.Copy() + return nil +} + +func (s *Stream) write(m recvMsg) { + s.buf.put(&m) +} + +// Read reads all the data available for this Stream from the transport and +// passes them into the decoder, which converts them into a gRPC message stream. +// The error is io.EOF when the stream is done or another non-nil error if +// the stream broke. +func (s *Stream) Read(p []byte) (n int, err error) { + n, err = s.dec.Read(p) + if err != nil { + return + } + s.windowHandler(n) + return +} + +// The key to save transport.Stream in the context. +type streamKey struct{} + +// newContextWithStream creates a new context from ctx and attaches stream +// to it. +func newContextWithStream(ctx context.Context, stream *Stream) context.Context { + return context.WithValue(ctx, streamKey{}, stream) +} + +// StreamFromContext returns the stream saved in ctx. +func StreamFromContext(ctx context.Context) (s *Stream, ok bool) { + s, ok = ctx.Value(streamKey{}).(*Stream) + return +} + +// state of transport +type transportState int + +const ( + reachable transportState = iota + unreachable + closing + draining +) + +// NewServerTransport creates a ServerTransport with conn or non-nil error +// if it fails. +func NewServerTransport(protocol string, conn net.Conn, maxStreams uint32, authInfo credentials.AuthInfo) (ServerTransport, error) { + return newHTTP2Server(conn, maxStreams, authInfo) +} + +// ConnectOptions covers all relevant options for dialing a server. +type ConnectOptions struct { + // UserAgent is the application user agent. + UserAgent string + // Dialer specifies how to dial a network address. + Dialer func(string, time.Duration) (net.Conn, error) + // AuthOptions stores the credentials required to setup a client connection and/or issue RPCs. + AuthOptions []credentials.Credentials + // Timeout specifies the timeout for dialing a client connection. + Timeout time.Duration +} + +// NewClientTransport establishes the transport with the required ConnectOptions +// and returns it to the caller. +func NewClientTransport(target string, opts *ConnectOptions) (ClientTransport, error) { + return newHTTP2Client(target, opts) +} + +// Options provides additional hints and information for message +// transmission. +type Options struct { + // Last indicates whether this write is the last piece for + // this stream. + Last bool + + // Delay is a hint to the transport implementation for whether + // the data could be buffered for a batching write. The + // Transport implementation may ignore the hint. + Delay bool +} + +// CallHdr carries the information of a particular RPC. +type CallHdr struct { + // Host specifies the peer's host. + Host string + + // Method specifies the operation to perform. + Method string + + // RecvCompress specifies the compression algorithm applied on + // inbound messages. + RecvCompress string + + // SendCompress specifies the compression algorithm applied on + // outbound message. + SendCompress string + + // Flush indicates whether a new stream command should be sent + // to the peer without waiting for the first data. This is + // only a hint. The transport may modify the flush decision + // for performance purposes. + Flush bool +} + +// ClientTransport is the common interface for all gRPC client-side transport +// implementations. +type ClientTransport interface { + // Close tears down this transport. Once it returns, the transport + // should not be accessed any more. The caller must make sure this + // is called only once. + Close() error + + // GracefulClose starts to tear down the transport. It stops accepting + // new RPCs and wait the completion of the pending RPCs. + GracefulClose() error + + // Write sends the data for the given stream. A nil stream indicates + // the write is to be performed on the transport as a whole. + Write(s *Stream, data []byte, opts *Options) error + + // NewStream creates a Stream for an RPC. + NewStream(ctx context.Context, callHdr *CallHdr) (*Stream, error) + + // CloseStream clears the footprint of a stream when the stream is + // not needed any more. The err indicates the error incurred when + // CloseStream is called. Must be called when a stream is finished + // unless the associated transport is closing. + CloseStream(stream *Stream, err error) + + // Error returns a channel that is closed when some I/O error + // happens. Typically the caller should have a goroutine to monitor + // this in order to take action (e.g., close the current transport + // and create a new one) in error case. It should not return nil + // once the transport is initiated. + Error() <-chan struct{} +} + +// ServerTransport is the common interface for all gRPC server-side transport +// implementations. +// +// Methods may be called concurrently from multiple goroutines, but +// Write methods for a given Stream will be called serially. +type ServerTransport interface { + // HandleStreams receives incoming streams using the given handler. + HandleStreams(func(*Stream)) + + // WriteHeader sends the header metadata for the given stream. + // WriteHeader may not be called on all streams. + WriteHeader(s *Stream, md metadata.MD) error + + // Write sends the data for the given stream. + // Write may not be called on all streams. + Write(s *Stream, data []byte, opts *Options) error + + // WriteStatus sends the status of a stream to the client. + // WriteStatus is the final call made on a stream and always + // occurs. + WriteStatus(s *Stream, statusCode codes.Code, statusDesc string) error + + // Close tears down the transport. Once it is called, the transport + // should not be accessed any more. All the pending streams and their + // handlers will be terminated asynchronously. + Close() error + + // RemoteAddr returns the remote network address. + RemoteAddr() net.Addr +} + +// StreamErrorf creates an StreamError with the specified error code and description. +func StreamErrorf(c codes.Code, format string, a ...interface{}) StreamError { + return StreamError{ + Code: c, + Desc: fmt.Sprintf(format, a...), + } +} + +// ConnectionErrorf creates an ConnectionError with the specified error description. +func ConnectionErrorf(format string, a ...interface{}) ConnectionError { + return ConnectionError{ + Desc: fmt.Sprintf(format, a...), + } +} + +// ConnectionError is an error that results in the termination of the +// entire connection and the retry of all the active streams. +type ConnectionError struct { + Desc string +} + +func (e ConnectionError) Error() string { + return fmt.Sprintf("connection error: desc = %q", e.Desc) +} + +// Define some common ConnectionErrors. +var ErrConnClosing = ConnectionError{Desc: "transport is closing"} + +// StreamError is an error that only affects one stream within a connection. +type StreamError struct { + Code codes.Code + Desc string +} + +func (e StreamError) Error() string { + return fmt.Sprintf("stream error: code = %d desc = %q", e.Code, e.Desc) +} + +// ContextErr converts the error from context package into a StreamError. +func ContextErr(err error) StreamError { + switch err { + case context.DeadlineExceeded: + return StreamErrorf(codes.DeadlineExceeded, "%v", err) + case context.Canceled: + return StreamErrorf(codes.Canceled, "%v", err) + } + panic(fmt.Sprintf("Unexpected error from context packet: %v", err)) +} + +// wait blocks until it can receive from ctx.Done, closing, or proceed. +// If it receives from ctx.Done, it returns 0, the StreamError for ctx.Err. +// If it receives from closing, it returns 0, ErrConnClosing. +// If it receives from proceed, it returns the received integer, nil. +func wait(ctx context.Context, closing <-chan struct{}, proceed <-chan int) (int, error) { + select { + case <-ctx.Done(): + return 0, ContextErr(ctx.Err()) + case <-closing: + return 0, ErrConnClosing + case i := <-proceed: + return i, nil + } +} |