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Diffstat (limited to 'vendor/google.golang.org/grpc/stream.go')
| -rw-r--r-- | vendor/google.golang.org/grpc/stream.go | 1551 |
1 files changed, 1551 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/stream.go b/vendor/google.golang.org/grpc/stream.go new file mode 100644 index 000000000..5fd856a38 --- /dev/null +++ b/vendor/google.golang.org/grpc/stream.go @@ -0,0 +1,1551 @@ +/* + * + * Copyright 2014 gRPC authors. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + */ + +package grpc + +import ( + "context" + "errors" + "io" + "math" + "strconv" + "sync" + "time" + + "golang.org/x/net/trace" + "google.golang.org/grpc/balancer" + "google.golang.org/grpc/codes" + "google.golang.org/grpc/encoding" + "google.golang.org/grpc/internal/balancerload" + "google.golang.org/grpc/internal/binarylog" + "google.golang.org/grpc/internal/channelz" + "google.golang.org/grpc/internal/grpcrand" + "google.golang.org/grpc/internal/grpcutil" + "google.golang.org/grpc/internal/transport" + "google.golang.org/grpc/metadata" + "google.golang.org/grpc/peer" + "google.golang.org/grpc/stats" + "google.golang.org/grpc/status" +) + +// StreamHandler defines the handler called by gRPC server to complete the +// execution of a streaming RPC. If a StreamHandler returns an error, it +// should be produced by the status package, or else gRPC will use +// codes.Unknown as the status code and err.Error() as the status message +// of the RPC. +type StreamHandler func(srv interface{}, stream ServerStream) error + +// StreamDesc represents a streaming RPC service's method specification. +type StreamDesc struct { + StreamName string + Handler StreamHandler + + // At least one of these is true. + ServerStreams bool + ClientStreams bool +} + +// Stream defines the common interface a client or server stream has to satisfy. +// +// Deprecated: See ClientStream and ServerStream documentation instead. +type Stream interface { + // Deprecated: See ClientStream and ServerStream documentation instead. + Context() context.Context + // Deprecated: See ClientStream and ServerStream documentation instead. + SendMsg(m interface{}) error + // Deprecated: See ClientStream and ServerStream documentation instead. + RecvMsg(m interface{}) error +} + +// ClientStream defines the client-side behavior of a streaming RPC. +// +// All errors returned from ClientStream methods are compatible with the +// status package. +type ClientStream interface { + // Header returns the header metadata received from the server if there + // is any. It blocks if the metadata is not ready to read. + Header() (metadata.MD, error) + // Trailer returns the trailer metadata from the server, if there is any. + // It must only be called after stream.CloseAndRecv has returned, or + // stream.Recv has returned a non-nil error (including io.EOF). + Trailer() metadata.MD + // CloseSend closes the send direction of the stream. It closes the stream + // when non-nil error is met. It is also not safe to call CloseSend + // concurrently with SendMsg. + CloseSend() error + // Context returns the context for this stream. + // + // It should not be called until after Header or RecvMsg has returned. Once + // called, subsequent client-side retries are disabled. + Context() context.Context + // SendMsg is generally called by generated code. On error, SendMsg aborts + // the stream. If the error was generated by the client, the status is + // returned directly; otherwise, io.EOF is returned and the status of + // the stream may be discovered using RecvMsg. + // + // SendMsg blocks until: + // - There is sufficient flow control to schedule m with the transport, or + // - The stream is done, or + // - The stream breaks. + // + // SendMsg does not wait until the message is received by the server. An + // untimely stream closure may result in lost messages. To ensure delivery, + // users should ensure the RPC completed successfully using RecvMsg. + // + // It is safe to have a goroutine calling SendMsg and another goroutine + // calling RecvMsg on the same stream at the same time, but it is not safe + // to call SendMsg on the same stream in different goroutines. It is also + // not safe to call CloseSend concurrently with SendMsg. + SendMsg(m interface{}) error + // RecvMsg blocks until it receives a message into m or the stream is + // done. It returns io.EOF when the stream completes successfully. On + // any other error, the stream is aborted and the error contains the RPC + // status. + // + // It is safe to have a goroutine calling SendMsg and another goroutine + // calling RecvMsg on the same stream at the same time, but it is not + // safe to call RecvMsg on the same stream in different goroutines. + RecvMsg(m interface{}) error +} + +// NewStream creates a new Stream for the client side. This is typically +// called by generated code. ctx is used for the lifetime of the stream. +// +// To ensure resources are not leaked due to the stream returned, one of the following +// actions must be performed: +// +// 1. Call Close on the ClientConn. +// 2. Cancel the context provided. +// 3. Call RecvMsg until a non-nil error is returned. A protobuf-generated +// client-streaming RPC, for instance, might use the helper function +// CloseAndRecv (note that CloseSend does not Recv, therefore is not +// guaranteed to release all resources). +// 4. Receive a non-nil, non-io.EOF error from Header or SendMsg. +// +// If none of the above happen, a goroutine and a context will be leaked, and grpc +// will not call the optionally-configured stats handler with a stats.End message. +func (cc *ClientConn) NewStream(ctx context.Context, desc *StreamDesc, method string, opts ...CallOption) (ClientStream, error) { + // allow interceptor to see all applicable call options, which means those + // configured as defaults from dial option as well as per-call options + opts = combine(cc.dopts.callOptions, opts) + + if cc.dopts.streamInt != nil { + return cc.dopts.streamInt(ctx, desc, cc, method, newClientStream, opts...) + } + return newClientStream(ctx, desc, cc, method, opts...) +} + +// NewClientStream is a wrapper for ClientConn.NewStream. +func NewClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error) { + return cc.NewStream(ctx, desc, method, opts...) +} + +func newClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (_ ClientStream, err error) { + if channelz.IsOn() { + cc.incrCallsStarted() + defer func() { + if err != nil { + cc.incrCallsFailed() + } + }() + } + c := defaultCallInfo() + // Provide an opportunity for the first RPC to see the first service config + // provided by the resolver. + if err := cc.waitForResolvedAddrs(ctx); err != nil { + return nil, err + } + mc := cc.GetMethodConfig(method) + if mc.WaitForReady != nil { + c.failFast = !*mc.WaitForReady + } + + // Possible context leak: + // The cancel function for the child context we create will only be called + // when RecvMsg returns a non-nil error, if the ClientConn is closed, or if + // an error is generated by SendMsg. + // https://github.com/grpc/grpc-go/issues/1818. + var cancel context.CancelFunc + if mc.Timeout != nil && *mc.Timeout >= 0 { + ctx, cancel = context.WithTimeout(ctx, *mc.Timeout) + } else { + ctx, cancel = context.WithCancel(ctx) + } + defer func() { + if err != nil { + cancel() + } + }() + + for _, o := range opts { + if err := o.before(c); err != nil { + return nil, toRPCErr(err) + } + } + c.maxSendMessageSize = getMaxSize(mc.MaxReqSize, c.maxSendMessageSize, defaultClientMaxSendMessageSize) + c.maxReceiveMessageSize = getMaxSize(mc.MaxRespSize, c.maxReceiveMessageSize, defaultClientMaxReceiveMessageSize) + if err := setCallInfoCodec(c); err != nil { + return nil, err + } + + callHdr := &transport.CallHdr{ + Host: cc.authority, + Method: method, + ContentSubtype: c.contentSubtype, + } + + // Set our outgoing compression according to the UseCompressor CallOption, if + // set. In that case, also find the compressor from the encoding package. + // Otherwise, use the compressor configured by the WithCompressor DialOption, + // if set. + var cp Compressor + var comp encoding.Compressor + if ct := c.compressorType; ct != "" { + callHdr.SendCompress = ct + if ct != encoding.Identity { + comp = encoding.GetCompressor(ct) + if comp == nil { + return nil, status.Errorf(codes.Internal, "grpc: Compressor is not installed for requested grpc-encoding %q", ct) + } + } + } else if cc.dopts.cp != nil { + callHdr.SendCompress = cc.dopts.cp.Type() + cp = cc.dopts.cp + } + if c.creds != nil { + callHdr.Creds = c.creds + } + var trInfo *traceInfo + if EnableTracing { + trInfo = &traceInfo{ + tr: trace.New("grpc.Sent."+methodFamily(method), method), + firstLine: firstLine{ + client: true, + }, + } + if deadline, ok := ctx.Deadline(); ok { + trInfo.firstLine.deadline = time.Until(deadline) + } + trInfo.tr.LazyLog(&trInfo.firstLine, false) + ctx = trace.NewContext(ctx, trInfo.tr) + } + ctx = newContextWithRPCInfo(ctx, c.failFast, c.codec, cp, comp) + sh := cc.dopts.copts.StatsHandler + var beginTime time.Time + if sh != nil { + ctx = sh.TagRPC(ctx, &stats.RPCTagInfo{FullMethodName: method, FailFast: c.failFast}) + beginTime = time.Now() + begin := &stats.Begin{ + Client: true, + BeginTime: beginTime, + FailFast: c.failFast, + } + sh.HandleRPC(ctx, begin) + } + + cs := &clientStream{ + callHdr: callHdr, + ctx: ctx, + methodConfig: &mc, + opts: opts, + callInfo: c, + cc: cc, + desc: desc, + codec: c.codec, + cp: cp, + comp: comp, + cancel: cancel, + beginTime: beginTime, + firstAttempt: true, + } + if !cc.dopts.disableRetry { + cs.retryThrottler = cc.retryThrottler.Load().(*retryThrottler) + } + cs.binlog = binarylog.GetMethodLogger(method) + + // Only this initial attempt has stats/tracing. + // TODO(dfawley): move to newAttempt when per-attempt stats are implemented. + if err := cs.newAttemptLocked(sh, trInfo); err != nil { + cs.finish(err) + return nil, err + } + + op := func(a *csAttempt) error { return a.newStream() } + if err := cs.withRetry(op, func() { cs.bufferForRetryLocked(0, op) }); err != nil { + cs.finish(err) + return nil, err + } + + if cs.binlog != nil { + md, _ := metadata.FromOutgoingContext(ctx) + logEntry := &binarylog.ClientHeader{ + OnClientSide: true, + Header: md, + MethodName: method, + Authority: cs.cc.authority, + } + if deadline, ok := ctx.Deadline(); ok { + logEntry.Timeout = time.Until(deadline) + if logEntry.Timeout < 0 { + logEntry.Timeout = 0 + } + } + cs.binlog.Log(logEntry) + } + + if desc != unaryStreamDesc { + // Listen on cc and stream contexts to cleanup when the user closes the + // ClientConn or cancels the stream context. In all other cases, an error + // should already be injected into the recv buffer by the transport, which + // the client will eventually receive, and then we will cancel the stream's + // context in clientStream.finish. + go func() { + select { + case <-cc.ctx.Done(): + cs.finish(ErrClientConnClosing) + case <-ctx.Done(): + cs.finish(toRPCErr(ctx.Err())) + } + }() + } + return cs, nil +} + +// newAttemptLocked creates a new attempt with a transport. +// If it succeeds, then it replaces clientStream's attempt with this new attempt. +func (cs *clientStream) newAttemptLocked(sh stats.Handler, trInfo *traceInfo) (retErr error) { + newAttempt := &csAttempt{ + cs: cs, + dc: cs.cc.dopts.dc, + statsHandler: sh, + trInfo: trInfo, + } + defer func() { + if retErr != nil { + // This attempt is not set in the clientStream, so it's finish won't + // be called. Call it here for stats and trace in case they are not + // nil. + newAttempt.finish(retErr) + } + }() + + if err := cs.ctx.Err(); err != nil { + return toRPCErr(err) + } + + ctx := cs.ctx + if cs.cc.parsedTarget.Scheme == "xds" { + // Add extra metadata (metadata that will be added by transport) to context + // so the balancer can see them. + ctx = grpcutil.WithExtraMetadata(cs.ctx, metadata.Pairs( + "content-type", grpcutil.ContentType(cs.callHdr.ContentSubtype), + )) + } + t, done, err := cs.cc.getTransport(ctx, cs.callInfo.failFast, cs.callHdr.Method) + if err != nil { + return err + } + if trInfo != nil { + trInfo.firstLine.SetRemoteAddr(t.RemoteAddr()) + } + newAttempt.t = t + newAttempt.done = done + cs.attempt = newAttempt + return nil +} + +func (a *csAttempt) newStream() error { + cs := a.cs + cs.callHdr.PreviousAttempts = cs.numRetries + s, err := a.t.NewStream(cs.ctx, cs.callHdr) + if err != nil { + if _, ok := err.(transport.PerformedIOError); ok { + // Return without converting to an RPC error so retry code can + // inspect. + return err + } + return toRPCErr(err) + } + cs.attempt.s = s + cs.attempt.p = &parser{r: s} + return nil +} + +// clientStream implements a client side Stream. +type clientStream struct { + callHdr *transport.CallHdr + opts []CallOption + callInfo *callInfo + cc *ClientConn + desc *StreamDesc + + codec baseCodec + cp Compressor + comp encoding.Compressor + + cancel context.CancelFunc // cancels all attempts + + sentLast bool // sent an end stream + beginTime time.Time + + methodConfig *MethodConfig + + ctx context.Context // the application's context, wrapped by stats/tracing + + retryThrottler *retryThrottler // The throttler active when the RPC began. + + binlog *binarylog.MethodLogger // Binary logger, can be nil. + // serverHeaderBinlogged is a boolean for whether server header has been + // logged. Server header will be logged when the first time one of those + // happens: stream.Header(), stream.Recv(). + // + // It's only read and used by Recv() and Header(), so it doesn't need to be + // synchronized. + serverHeaderBinlogged bool + + mu sync.Mutex + firstAttempt bool // if true, transparent retry is valid + numRetries int // exclusive of transparent retry attempt(s) + numRetriesSincePushback int // retries since pushback; to reset backoff + finished bool // TODO: replace with atomic cmpxchg or sync.Once? + // attempt is the active client stream attempt. + // The only place where it is written is the newAttemptLocked method and this method never writes nil. + // So, attempt can be nil only inside newClientStream function when clientStream is first created. + // One of the first things done after clientStream's creation, is to call newAttemptLocked which either + // assigns a non nil value to the attempt or returns an error. If an error is returned from newAttemptLocked, + // then newClientStream calls finish on the clientStream and returns. So, finish method is the only + // place where we need to check if the attempt is nil. + attempt *csAttempt + // TODO(hedging): hedging will have multiple attempts simultaneously. + committed bool // active attempt committed for retry? + buffer []func(a *csAttempt) error // operations to replay on retry + bufferSize int // current size of buffer +} + +// csAttempt implements a single transport stream attempt within a +// clientStream. +type csAttempt struct { + cs *clientStream + t transport.ClientTransport + s *transport.Stream + p *parser + done func(balancer.DoneInfo) + + finished bool + dc Decompressor + decomp encoding.Compressor + decompSet bool + + mu sync.Mutex // guards trInfo.tr + // trInfo may be nil (if EnableTracing is false). + // trInfo.tr is set when created (if EnableTracing is true), + // and cleared when the finish method is called. + trInfo *traceInfo + + statsHandler stats.Handler +} + +func (cs *clientStream) commitAttemptLocked() { + cs.committed = true + cs.buffer = nil +} + +func (cs *clientStream) commitAttempt() { + cs.mu.Lock() + cs.commitAttemptLocked() + cs.mu.Unlock() +} + +// shouldRetry returns nil if the RPC should be retried; otherwise it returns +// the error that should be returned by the operation. +func (cs *clientStream) shouldRetry(err error) error { + unprocessed := false + if cs.attempt.s == nil { + pioErr, ok := err.(transport.PerformedIOError) + if ok { + // Unwrap error. + err = toRPCErr(pioErr.Err) + } else { + unprocessed = true + } + if !ok && !cs.callInfo.failFast { + // In the event of a non-IO operation error from NewStream, we + // never attempted to write anything to the wire, so we can retry + // indefinitely for non-fail-fast RPCs. + return nil + } + } + if cs.finished || cs.committed { + // RPC is finished or committed; cannot retry. + return err + } + // Wait for the trailers. + if cs.attempt.s != nil { + <-cs.attempt.s.Done() + unprocessed = cs.attempt.s.Unprocessed() + } + if cs.firstAttempt && unprocessed { + // First attempt, stream unprocessed: transparently retry. + return nil + } + if cs.cc.dopts.disableRetry { + return err + } + + pushback := 0 + hasPushback := false + if cs.attempt.s != nil { + if !cs.attempt.s.TrailersOnly() { + return err + } + + // TODO(retry): Move down if the spec changes to not check server pushback + // before considering this a failure for throttling. + sps := cs.attempt.s.Trailer()["grpc-retry-pushback-ms"] + if len(sps) == 1 { + var e error + if pushback, e = strconv.Atoi(sps[0]); e != nil || pushback < 0 { + channelz.Infof(logger, cs.cc.channelzID, "Server retry pushback specified to abort (%q).", sps[0]) + cs.retryThrottler.throttle() // This counts as a failure for throttling. + return err + } + hasPushback = true + } else if len(sps) > 1 { + channelz.Warningf(logger, cs.cc.channelzID, "Server retry pushback specified multiple values (%q); not retrying.", sps) + cs.retryThrottler.throttle() // This counts as a failure for throttling. + return err + } + } + + var code codes.Code + if cs.attempt.s != nil { + code = cs.attempt.s.Status().Code() + } else { + code = status.Convert(err).Code() + } + + rp := cs.methodConfig.retryPolicy + if rp == nil || !rp.retryableStatusCodes[code] { + return err + } + + // Note: the ordering here is important; we count this as a failure + // only if the code matched a retryable code. + if cs.retryThrottler.throttle() { + return err + } + if cs.numRetries+1 >= rp.maxAttempts { + return err + } + + var dur time.Duration + if hasPushback { + dur = time.Millisecond * time.Duration(pushback) + cs.numRetriesSincePushback = 0 + } else { + fact := math.Pow(rp.backoffMultiplier, float64(cs.numRetriesSincePushback)) + cur := float64(rp.initialBackoff) * fact + if max := float64(rp.maxBackoff); cur > max { + cur = max + } + dur = time.Duration(grpcrand.Int63n(int64(cur))) + cs.numRetriesSincePushback++ + } + + // TODO(dfawley): we could eagerly fail here if dur puts us past the + // deadline, but unsure if it is worth doing. + t := time.NewTimer(dur) + select { + case <-t.C: + cs.numRetries++ + return nil + case <-cs.ctx.Done(): + t.Stop() + return status.FromContextError(cs.ctx.Err()).Err() + } +} + +// Returns nil if a retry was performed and succeeded; error otherwise. +func (cs *clientStream) retryLocked(lastErr error) error { + for { + cs.attempt.finish(lastErr) + if err := cs.shouldRetry(lastErr); err != nil { + cs.commitAttemptLocked() + return err + } + cs.firstAttempt = false + if err := cs.newAttemptLocked(nil, nil); err != nil { + return err + } + if lastErr = cs.replayBufferLocked(); lastErr == nil { + return nil + } + } +} + +func (cs *clientStream) Context() context.Context { + cs.commitAttempt() + // No need to lock before using attempt, since we know it is committed and + // cannot change. + return cs.attempt.s.Context() +} + +func (cs *clientStream) withRetry(op func(a *csAttempt) error, onSuccess func()) error { + cs.mu.Lock() + for { + if cs.committed { + cs.mu.Unlock() + return op(cs.attempt) + } + a := cs.attempt + cs.mu.Unlock() + err := op(a) + cs.mu.Lock() + if a != cs.attempt { + // We started another attempt already. + continue + } + if err == io.EOF { + <-a.s.Done() + } + if err == nil || (err == io.EOF && a.s.Status().Code() == codes.OK) { + onSuccess() + cs.mu.Unlock() + return err + } + if err := cs.retryLocked(err); err != nil { + cs.mu.Unlock() + return err + } + } +} + +func (cs *clientStream) Header() (metadata.MD, error) { + var m metadata.MD + err := cs.withRetry(func(a *csAttempt) error { + var err error + m, err = a.s.Header() + return toRPCErr(err) + }, cs.commitAttemptLocked) + if err != nil { + cs.finish(err) + return nil, err + } + if cs.binlog != nil && !cs.serverHeaderBinlogged { + // Only log if binary log is on and header has not been logged. + logEntry := &binarylog.ServerHeader{ + OnClientSide: true, + Header: m, + PeerAddr: nil, + } + if peer, ok := peer.FromContext(cs.Context()); ok { + logEntry.PeerAddr = peer.Addr + } + cs.binlog.Log(logEntry) + cs.serverHeaderBinlogged = true + } + return m, err +} + +func (cs *clientStream) Trailer() metadata.MD { + // On RPC failure, we never need to retry, because usage requires that + // RecvMsg() returned a non-nil error before calling this function is valid. + // We would have retried earlier if necessary. + // + // Commit the attempt anyway, just in case users are not following those + // directions -- it will prevent races and should not meaningfully impact + // performance. + cs.commitAttempt() + if cs.attempt.s == nil { + return nil + } + return cs.attempt.s.Trailer() +} + +func (cs *clientStream) replayBufferLocked() error { + a := cs.attempt + for _, f := range cs.buffer { + if err := f(a); err != nil { + return err + } + } + return nil +} + +func (cs *clientStream) bufferForRetryLocked(sz int, op func(a *csAttempt) error) { + // Note: we still will buffer if retry is disabled (for transparent retries). + if cs.committed { + return + } + cs.bufferSize += sz + if cs.bufferSize > cs.callInfo.maxRetryRPCBufferSize { + cs.commitAttemptLocked() + return + } + cs.buffer = append(cs.buffer, op) +} + +func (cs *clientStream) SendMsg(m interface{}) (err error) { + defer func() { + if err != nil && err != io.EOF { + // Call finish on the client stream for errors generated by this SendMsg + // call, as these indicate problems created by this client. (Transport + // errors are converted to an io.EOF error in csAttempt.sendMsg; the real + // error will be returned from RecvMsg eventually in that case, or be + // retried.) + cs.finish(err) + } + }() + if cs.sentLast { + return status.Errorf(codes.Internal, "SendMsg called after CloseSend") + } + if !cs.desc.ClientStreams { + cs.sentLast = true + } + + // load hdr, payload, data + hdr, payload, data, err := prepareMsg(m, cs.codec, cs.cp, cs.comp) + if err != nil { + return err + } + + // TODO(dfawley): should we be checking len(data) instead? + if len(payload) > *cs.callInfo.maxSendMessageSize { + return status.Errorf(codes.ResourceExhausted, "trying to send message larger than max (%d vs. %d)", len(payload), *cs.callInfo.maxSendMessageSize) + } + msgBytes := data // Store the pointer before setting to nil. For binary logging. + op := func(a *csAttempt) error { + err := a.sendMsg(m, hdr, payload, data) + // nil out the message and uncomp when replaying; they are only needed for + // stats which is disabled for subsequent attempts. + m, data = nil, nil + return err + } + err = cs.withRetry(op, func() { cs.bufferForRetryLocked(len(hdr)+len(payload), op) }) + if cs.binlog != nil && err == nil { + cs.binlog.Log(&binarylog.ClientMessage{ + OnClientSide: true, + Message: msgBytes, + }) + } + return +} + +func (cs *clientStream) RecvMsg(m interface{}) error { + if cs.binlog != nil && !cs.serverHeaderBinlogged { + // Call Header() to binary log header if it's not already logged. + cs.Header() + } + var recvInfo *payloadInfo + if cs.binlog != nil { + recvInfo = &payloadInfo{} + } + err := cs.withRetry(func(a *csAttempt) error { + return a.recvMsg(m, recvInfo) + }, cs.commitAttemptLocked) + if cs.binlog != nil && err == nil { + cs.binlog.Log(&binarylog.ServerMessage{ + OnClientSide: true, + Message: recvInfo.uncompressedBytes, + }) + } + if err != nil || !cs.desc.ServerStreams { + // err != nil or non-server-streaming indicates end of stream. + cs.finish(err) + + if cs.binlog != nil { + // finish will not log Trailer. Log Trailer here. + logEntry := &binarylog.ServerTrailer{ + OnClientSide: true, + Trailer: cs.Trailer(), + Err: err, + } + if logEntry.Err == io.EOF { + logEntry.Err = nil + } + if peer, ok := peer.FromContext(cs.Context()); ok { + logEntry.PeerAddr = peer.Addr + } + cs.binlog.Log(logEntry) + } + } + return err +} + +func (cs *clientStream) CloseSend() error { + if cs.sentLast { + // TODO: return an error and finish the stream instead, due to API misuse? + return nil + } + cs.sentLast = true + op := func(a *csAttempt) error { + a.t.Write(a.s, nil, nil, &transport.Options{Last: true}) + // Always return nil; io.EOF is the only error that might make sense + // instead, but there is no need to signal the client to call RecvMsg + // as the only use left for the stream after CloseSend is to call + // RecvMsg. This also matches historical behavior. + return nil + } + cs.withRetry(op, func() { cs.bufferForRetryLocked(0, op) }) + if cs.binlog != nil { + cs.binlog.Log(&binarylog.ClientHalfClose{ + OnClientSide: true, + }) + } + // We never returned an error here for reasons. + return nil +} + +func (cs *clientStream) finish(err error) { + if err == io.EOF { + // Ending a stream with EOF indicates a success. + err = nil + } + cs.mu.Lock() + if cs.finished { + cs.mu.Unlock() + return + } + cs.finished = true + cs.commitAttemptLocked() + if cs.attempt != nil { + cs.attempt.finish(err) + // after functions all rely upon having a stream. + if cs.attempt.s != nil { + for _, o := range cs.opts { + o.after(cs.callInfo, cs.attempt) + } + } + } + cs.mu.Unlock() + // For binary logging. only log cancel in finish (could be caused by RPC ctx + // canceled or ClientConn closed). Trailer will be logged in RecvMsg. + // + // Only one of cancel or trailer needs to be logged. In the cases where + // users don't call RecvMsg, users must have already canceled the RPC. + if cs.binlog != nil && status.Code(err) == codes.Canceled { + cs.binlog.Log(&binarylog.Cancel{ + OnClientSide: true, + }) + } + if err == nil { + cs.retryThrottler.successfulRPC() + } + if channelz.IsOn() { + if err != nil { + cs.cc.incrCallsFailed() + } else { + cs.cc.incrCallsSucceeded() + } + } + cs.cancel() +} + +func (a *csAttempt) sendMsg(m interface{}, hdr, payld, data []byte) error { + cs := a.cs + if a.trInfo != nil { + a.mu.Lock() + if a.trInfo.tr != nil { + a.trInfo.tr.LazyLog(&payload{sent: true, msg: m}, true) + } + a.mu.Unlock() + } + if err := a.t.Write(a.s, hdr, payld, &transport.Options{Last: !cs.desc.ClientStreams}); err != nil { + if !cs.desc.ClientStreams { + // For non-client-streaming RPCs, we return nil instead of EOF on error + // because the generated code requires it. finish is not called; RecvMsg() + // will call it with the stream's status independently. + return nil + } + return io.EOF + } + if a.statsHandler != nil { + a.statsHandler.HandleRPC(cs.ctx, outPayload(true, m, data, payld, time.Now())) + } + if channelz.IsOn() { + a.t.IncrMsgSent() + } + return nil +} + +func (a *csAttempt) recvMsg(m interface{}, payInfo *payloadInfo) (err error) { + cs := a.cs + if a.statsHandler != nil && payInfo == nil { + payInfo = &payloadInfo{} + } + + if !a.decompSet { + // Block until we receive headers containing received message encoding. + if ct := a.s.RecvCompress(); ct != "" && ct != encoding.Identity { + if a.dc == nil || a.dc.Type() != ct { + // No configured decompressor, or it does not match the incoming + // message encoding; attempt to find a registered compressor that does. + a.dc = nil + a.decomp = encoding.GetCompressor(ct) + } + } else { + // No compression is used; disable our decompressor. + a.dc = nil + } + // Only initialize this state once per stream. + a.decompSet = true + } + err = recv(a.p, cs.codec, a.s, a.dc, m, *cs.callInfo.maxReceiveMessageSize, payInfo, a.decomp) + if err != nil { + if err == io.EOF { + if statusErr := a.s.Status().Err(); statusErr != nil { + return statusErr + } + return io.EOF // indicates successful end of stream. + } + return toRPCErr(err) + } + if a.trInfo != nil { + a.mu.Lock() + if a.trInfo.tr != nil { + a.trInfo.tr.LazyLog(&payload{sent: false, msg: m}, true) + } + a.mu.Unlock() + } + if a.statsHandler != nil { + a.statsHandler.HandleRPC(cs.ctx, &stats.InPayload{ + Client: true, + RecvTime: time.Now(), + Payload: m, + // TODO truncate large payload. + Data: payInfo.uncompressedBytes, + WireLength: payInfo.wireLength + headerLen, + Length: len(payInfo.uncompressedBytes), + }) + } + if channelz.IsOn() { + a.t.IncrMsgRecv() + } + if cs.desc.ServerStreams { + // Subsequent messages should be received by subsequent RecvMsg calls. + return nil + } + // Special handling for non-server-stream rpcs. + // This recv expects EOF or errors, so we don't collect inPayload. + err = recv(a.p, cs.codec, a.s, a.dc, m, *cs.callInfo.maxReceiveMessageSize, nil, a.decomp) + if err == nil { + return toRPCErr(errors.New("grpc: client streaming protocol violation: get <nil>, want <EOF>")) + } + if err == io.EOF { + return a.s.Status().Err() // non-server streaming Recv returns nil on success + } + return toRPCErr(err) +} + +func (a *csAttempt) finish(err error) { + a.mu.Lock() + if a.finished { + a.mu.Unlock() + return + } + a.finished = true + if err == io.EOF { + // Ending a stream with EOF indicates a success. + err = nil + } + var tr metadata.MD + if a.s != nil { + a.t.CloseStream(a.s, err) + tr = a.s.Trailer() + } + + if a.done != nil { + br := false + if a.s != nil { + br = a.s.BytesReceived() + } + a.done(balancer.DoneInfo{ + Err: err, + Trailer: tr, + BytesSent: a.s != nil, + BytesReceived: br, + ServerLoad: balancerload.Parse(tr), + }) + } + if a.statsHandler != nil { + end := &stats.End{ + Client: true, + BeginTime: a.cs.beginTime, + EndTime: time.Now(), + Trailer: tr, + Error: err, + } + a.statsHandler.HandleRPC(a.cs.ctx, end) + } + if a.trInfo != nil && a.trInfo.tr != nil { + if err == nil { + a.trInfo.tr.LazyPrintf("RPC: [OK]") + } else { + a.trInfo.tr.LazyPrintf("RPC: [%v]", err) + a.trInfo.tr.SetError() + } + a.trInfo.tr.Finish() + a.trInfo.tr = nil + } + a.mu.Unlock() +} + +// newClientStream creates a ClientStream with the specified transport, on the +// given addrConn. +// +// It's expected that the given transport is either the same one in addrConn, or +// is already closed. To avoid race, transport is specified separately, instead +// of using ac.transpot. +// +// Main difference between this and ClientConn.NewStream: +// - no retry +// - no service config (or wait for service config) +// - no tracing or stats +func newNonRetryClientStream(ctx context.Context, desc *StreamDesc, method string, t transport.ClientTransport, ac *addrConn, opts ...CallOption) (_ ClientStream, err error) { + if t == nil { + // TODO: return RPC error here? + return nil, errors.New("transport provided is nil") + } + // defaultCallInfo contains unnecessary info(i.e. failfast, maxRetryRPCBufferSize), so we just initialize an empty struct. + c := &callInfo{} + + // Possible context leak: + // The cancel function for the child context we create will only be called + // when RecvMsg returns a non-nil error, if the ClientConn is closed, or if + // an error is generated by SendMsg. + // https://github.com/grpc/grpc-go/issues/1818. + ctx, cancel := context.WithCancel(ctx) + defer func() { + if err != nil { + cancel() + } + }() + + for _, o := range opts { + if err := o.before(c); err != nil { + return nil, toRPCErr(err) + } + } + c.maxReceiveMessageSize = getMaxSize(nil, c.maxReceiveMessageSize, defaultClientMaxReceiveMessageSize) + c.maxSendMessageSize = getMaxSize(nil, c.maxSendMessageSize, defaultServerMaxSendMessageSize) + if err := setCallInfoCodec(c); err != nil { + return nil, err + } + + callHdr := &transport.CallHdr{ + Host: ac.cc.authority, + Method: method, + ContentSubtype: c.contentSubtype, + } + + // Set our outgoing compression according to the UseCompressor CallOption, if + // set. In that case, also find the compressor from the encoding package. + // Otherwise, use the compressor configured by the WithCompressor DialOption, + // if set. + var cp Compressor + var comp encoding.Compressor + if ct := c.compressorType; ct != "" { + callHdr.SendCompress = ct + if ct != encoding.Identity { + comp = encoding.GetCompressor(ct) + if comp == nil { + return nil, status.Errorf(codes.Internal, "grpc: Compressor is not installed for requested grpc-encoding %q", ct) + } + } + } else if ac.cc.dopts.cp != nil { + callHdr.SendCompress = ac.cc.dopts.cp.Type() + cp = ac.cc.dopts.cp + } + if c.creds != nil { + callHdr.Creds = c.creds + } + + // Use a special addrConnStream to avoid retry. + as := &addrConnStream{ + callHdr: callHdr, + ac: ac, + ctx: ctx, + cancel: cancel, + opts: opts, + callInfo: c, + desc: desc, + codec: c.codec, + cp: cp, + comp: comp, + t: t, + } + + s, err := as.t.NewStream(as.ctx, as.callHdr) + if err != nil { + err = toRPCErr(err) + return nil, err + } + as.s = s + as.p = &parser{r: s} + ac.incrCallsStarted() + if desc != unaryStreamDesc { + // Listen on cc and stream contexts to cleanup when the user closes the + // ClientConn or cancels the stream context. In all other cases, an error + // should already be injected into the recv buffer by the transport, which + // the client will eventually receive, and then we will cancel the stream's + // context in clientStream.finish. + go func() { + select { + case <-ac.ctx.Done(): + as.finish(status.Error(codes.Canceled, "grpc: the SubConn is closing")) + case <-ctx.Done(): + as.finish(toRPCErr(ctx.Err())) + } + }() + } + return as, nil +} + +type addrConnStream struct { + s *transport.Stream + ac *addrConn + callHdr *transport.CallHdr + cancel context.CancelFunc + opts []CallOption + callInfo *callInfo + t transport.ClientTransport + ctx context.Context + sentLast bool + desc *StreamDesc + codec baseCodec + cp Compressor + comp encoding.Compressor + decompSet bool + dc Decompressor + decomp encoding.Compressor + p *parser + mu sync.Mutex + finished bool +} + +func (as *addrConnStream) Header() (metadata.MD, error) { + m, err := as.s.Header() + if err != nil { + as.finish(toRPCErr(err)) + } + return m, err +} + +func (as *addrConnStream) Trailer() metadata.MD { + return as.s.Trailer() +} + +func (as *addrConnStream) CloseSend() error { + if as.sentLast { + // TODO: return an error and finish the stream instead, due to API misuse? + return nil + } + as.sentLast = true + + as.t.Write(as.s, nil, nil, &transport.Options{Last: true}) + // Always return nil; io.EOF is the only error that might make sense + // instead, but there is no need to signal the client to call RecvMsg + // as the only use left for the stream after CloseSend is to call + // RecvMsg. This also matches historical behavior. + return nil +} + +func (as *addrConnStream) Context() context.Context { + return as.s.Context() +} + +func (as *addrConnStream) SendMsg(m interface{}) (err error) { + defer func() { + if err != nil && err != io.EOF { + // Call finish on the client stream for errors generated by this SendMsg + // call, as these indicate problems created by this client. (Transport + // errors are converted to an io.EOF error in csAttempt.sendMsg; the real + // error will be returned from RecvMsg eventually in that case, or be + // retried.) + as.finish(err) + } + }() + if as.sentLast { + return status.Errorf(codes.Internal, "SendMsg called after CloseSend") + } + if !as.desc.ClientStreams { + as.sentLast = true + } + + // load hdr, payload, data + hdr, payld, _, err := prepareMsg(m, as.codec, as.cp, as.comp) + if err != nil { + return err + } + + // TODO(dfawley): should we be checking len(data) instead? + if len(payld) > *as.callInfo.maxSendMessageSize { + return status.Errorf(codes.ResourceExhausted, "trying to send message larger than max (%d vs. %d)", len(payld), *as.callInfo.maxSendMessageSize) + } + + if err := as.t.Write(as.s, hdr, payld, &transport.Options{Last: !as.desc.ClientStreams}); err != nil { + if !as.desc.ClientStreams { + // For non-client-streaming RPCs, we return nil instead of EOF on error + // because the generated code requires it. finish is not called; RecvMsg() + // will call it with the stream's status independently. + return nil + } + return io.EOF + } + + if channelz.IsOn() { + as.t.IncrMsgSent() + } + return nil +} + +func (as *addrConnStream) RecvMsg(m interface{}) (err error) { + defer func() { + if err != nil || !as.desc.ServerStreams { + // err != nil or non-server-streaming indicates end of stream. + as.finish(err) + } + }() + + if !as.decompSet { + // Block until we receive headers containing received message encoding. + if ct := as.s.RecvCompress(); ct != "" && ct != encoding.Identity { + if as.dc == nil || as.dc.Type() != ct { + // No configured decompressor, or it does not match the incoming + // message encoding; attempt to find a registered compressor that does. + as.dc = nil + as.decomp = encoding.GetCompressor(ct) + } + } else { + // No compression is used; disable our decompressor. + as.dc = nil + } + // Only initialize this state once per stream. + as.decompSet = true + } + err = recv(as.p, as.codec, as.s, as.dc, m, *as.callInfo.maxReceiveMessageSize, nil, as.decomp) + if err != nil { + if err == io.EOF { + if statusErr := as.s.Status().Err(); statusErr != nil { + return statusErr + } + return io.EOF // indicates successful end of stream. + } + return toRPCErr(err) + } + + if channelz.IsOn() { + as.t.IncrMsgRecv() + } + if as.desc.ServerStreams { + // Subsequent messages should be received by subsequent RecvMsg calls. + return nil + } + + // Special handling for non-server-stream rpcs. + // This recv expects EOF or errors, so we don't collect inPayload. + err = recv(as.p, as.codec, as.s, as.dc, m, *as.callInfo.maxReceiveMessageSize, nil, as.decomp) + if err == nil { + return toRPCErr(errors.New("grpc: client streaming protocol violation: get <nil>, want <EOF>")) + } + if err == io.EOF { + return as.s.Status().Err() // non-server streaming Recv returns nil on success + } + return toRPCErr(err) +} + +func (as *addrConnStream) finish(err error) { + as.mu.Lock() + if as.finished { + as.mu.Unlock() + return + } + as.finished = true + if err == io.EOF { + // Ending a stream with EOF indicates a success. + err = nil + } + if as.s != nil { + as.t.CloseStream(as.s, err) + } + + if err != nil { + as.ac.incrCallsFailed() + } else { + as.ac.incrCallsSucceeded() + } + as.cancel() + as.mu.Unlock() +} + +// ServerStream defines the server-side behavior of a streaming RPC. +// +// All errors returned from ServerStream methods are compatible with the +// status package. +type ServerStream interface { + // SetHeader sets the header metadata. It may be called multiple times. + // When call multiple times, all the provided metadata will be merged. + // All the metadata will be sent out when one of the following happens: + // - ServerStream.SendHeader() is called; + // - The first response is sent out; + // - An RPC status is sent out (error or success). + SetHeader(metadata.MD) error + // SendHeader sends the header metadata. + // The provided md and headers set by SetHeader() will be sent. + // It fails if called multiple times. + SendHeader(metadata.MD) error + // SetTrailer sets the trailer metadata which will be sent with the RPC status. + // When called more than once, all the provided metadata will be merged. + SetTrailer(metadata.MD) + // Context returns the context for this stream. + Context() context.Context + // SendMsg sends a message. On error, SendMsg aborts the stream and the + // error is returned directly. + // + // SendMsg blocks until: + // - There is sufficient flow control to schedule m with the transport, or + // - The stream is done, or + // - The stream breaks. + // + // SendMsg does not wait until the message is received by the client. An + // untimely stream closure may result in lost messages. + // + // It is safe to have a goroutine calling SendMsg and another goroutine + // calling RecvMsg on the same stream at the same time, but it is not safe + // to call SendMsg on the same stream in different goroutines. + SendMsg(m interface{}) error + // RecvMsg blocks until it receives a message into m or the stream is + // done. It returns io.EOF when the client has performed a CloseSend. On + // any non-EOF error, the stream is aborted and the error contains the + // RPC status. + // + // It is safe to have a goroutine calling SendMsg and another goroutine + // calling RecvMsg on the same stream at the same time, but it is not + // safe to call RecvMsg on the same stream in different goroutines. + RecvMsg(m interface{}) error +} + +// serverStream implements a server side Stream. +type serverStream struct { + ctx context.Context + t transport.ServerTransport + s *transport.Stream + p *parser + codec baseCodec + + cp Compressor + dc Decompressor + comp encoding.Compressor + decomp encoding.Compressor + + maxReceiveMessageSize int + maxSendMessageSize int + trInfo *traceInfo + + statsHandler stats.Handler + + binlog *binarylog.MethodLogger + // serverHeaderBinlogged indicates whether server header has been logged. It + // will happen when one of the following two happens: stream.SendHeader(), + // stream.Send(). + // + // It's only checked in send and sendHeader, doesn't need to be + // synchronized. + serverHeaderBinlogged bool + + mu sync.Mutex // protects trInfo.tr after the service handler runs. +} + +func (ss *serverStream) Context() context.Context { + return ss.ctx +} + +func (ss *serverStream) SetHeader(md metadata.MD) error { + if md.Len() == 0 { + return nil + } + return ss.s.SetHeader(md) +} + +func (ss *serverStream) SendHeader(md metadata.MD) error { + err := ss.t.WriteHeader(ss.s, md) + if ss.binlog != nil && !ss.serverHeaderBinlogged { + h, _ := ss.s.Header() + ss.binlog.Log(&binarylog.ServerHeader{ + Header: h, + }) + ss.serverHeaderBinlogged = true + } + return err +} + +func (ss *serverStream) SetTrailer(md metadata.MD) { + if md.Len() == 0 { + return + } + ss.s.SetTrailer(md) +} + +func (ss *serverStream) SendMsg(m interface{}) (err error) { + defer func() { + if ss.trInfo != nil { + ss.mu.Lock() + if ss.trInfo.tr != nil { + if err == nil { + ss.trInfo.tr.LazyLog(&payload{sent: true, msg: m}, true) + } else { + ss.trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true) + ss.trInfo.tr.SetError() + } + } + ss.mu.Unlock() + } + if err != nil && err != io.EOF { + st, _ := status.FromError(toRPCErr(err)) + ss.t.WriteStatus(ss.s, st) + // Non-user specified status was sent out. This should be an error + // case (as a server side Cancel maybe). + // + // This is not handled specifically now. User will return a final + // status from the service handler, we will log that error instead. + // This behavior is similar to an interceptor. + } + if channelz.IsOn() && err == nil { + ss.t.IncrMsgSent() + } + }() + + // load hdr, payload, data + hdr, payload, data, err := prepareMsg(m, ss.codec, ss.cp, ss.comp) + if err != nil { + return err + } + + // TODO(dfawley): should we be checking len(data) instead? + if len(payload) > ss.maxSendMessageSize { + return status.Errorf(codes.ResourceExhausted, "trying to send message larger than max (%d vs. %d)", len(payload), ss.maxSendMessageSize) + } + if err := ss.t.Write(ss.s, hdr, payload, &transport.Options{Last: false}); err != nil { + return toRPCErr(err) + } + if ss.binlog != nil { + if !ss.serverHeaderBinlogged { + h, _ := ss.s.Header() + ss.binlog.Log(&binarylog.ServerHeader{ + Header: h, + }) + ss.serverHeaderBinlogged = true + } + ss.binlog.Log(&binarylog.ServerMessage{ + Message: data, + }) + } + if ss.statsHandler != nil { + ss.statsHandler.HandleRPC(ss.s.Context(), outPayload(false, m, data, payload, time.Now())) + } + return nil +} + +func (ss *serverStream) RecvMsg(m interface{}) (err error) { + defer func() { + if ss.trInfo != nil { + ss.mu.Lock() + if ss.trInfo.tr != nil { + if err == nil { + ss.trInfo.tr.LazyLog(&payload{sent: false, msg: m}, true) + } else if err != io.EOF { + ss.trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true) + ss.trInfo.tr.SetError() + } + } + ss.mu.Unlock() + } + if err != nil && err != io.EOF { + st, _ := status.FromError(toRPCErr(err)) + ss.t.WriteStatus(ss.s, st) + // Non-user specified status was sent out. This should be an error + // case (as a server side Cancel maybe). + // + // This is not handled specifically now. User will return a final + // status from the service handler, we will log that error instead. + // This behavior is similar to an interceptor. + } + if channelz.IsOn() && err == nil { + ss.t.IncrMsgRecv() + } + }() + var payInfo *payloadInfo + if ss.statsHandler != nil || ss.binlog != nil { + payInfo = &payloadInfo{} + } + if err := recv(ss.p, ss.codec, ss.s, ss.dc, m, ss.maxReceiveMessageSize, payInfo, ss.decomp); err != nil { + if err == io.EOF { + if ss.binlog != nil { + ss.binlog.Log(&binarylog.ClientHalfClose{}) + } + return err + } + if err == io.ErrUnexpectedEOF { + err = status.Errorf(codes.Internal, io.ErrUnexpectedEOF.Error()) + } + return toRPCErr(err) + } + if ss.statsHandler != nil { + ss.statsHandler.HandleRPC(ss.s.Context(), &stats.InPayload{ + RecvTime: time.Now(), + Payload: m, + // TODO truncate large payload. + Data: payInfo.uncompressedBytes, + WireLength: payInfo.wireLength + headerLen, + Length: len(payInfo.uncompressedBytes), + }) + } + if ss.binlog != nil { + ss.binlog.Log(&binarylog.ClientMessage{ + Message: payInfo.uncompressedBytes, + }) + } + return nil +} + +// MethodFromServerStream returns the method string for the input stream. +// The returned string is in the format of "/service/method". +func MethodFromServerStream(stream ServerStream) (string, bool) { + return Method(stream.Context()) +} + +// prepareMsg returns the hdr, payload and data +// using the compressors passed or using the +// passed preparedmsg +func prepareMsg(m interface{}, codec baseCodec, cp Compressor, comp encoding.Compressor) (hdr, payload, data []byte, err error) { + if preparedMsg, ok := m.(*PreparedMsg); ok { + return preparedMsg.hdr, preparedMsg.payload, preparedMsg.encodedData, nil + } + // The input interface is not a prepared msg. + // Marshal and Compress the data at this point + data, err = encode(codec, m) + if err != nil { + return nil, nil, nil, err + } + compData, err := compress(data, cp, comp) + if err != nil { + return nil, nil, nil, err + } + hdr, payload = msgHeader(data, compData) + return hdr, payload, data, nil +} |