--- /dev/null
+/*
+ *
+ * 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 (
+ "bytes"
+ "io"
+ "time"
+
+ "golang.org/x/net/context"
+ "golang.org/x/net/trace"
+ "google.golang.org/grpc/balancer"
+ "google.golang.org/grpc/codes"
+ "google.golang.org/grpc/peer"
+ "google.golang.org/grpc/stats"
+ "google.golang.org/grpc/status"
+ "google.golang.org/grpc/transport"
+)
+
+// recvResponse receives and parses an RPC response.
+// On error, it returns the error and indicates whether the call should be retried.
+//
+// TODO(zhaoq): Check whether the received message sequence is valid.
+// TODO ctx is used for stats collection and processing. It is the context passed from the application.
+func recvResponse(ctx context.Context, dopts dialOptions, t transport.ClientTransport, c *callInfo, stream *transport.Stream, reply interface{}) (err error) {
+ // Try to acquire header metadata from the server if there is any.
+ defer func() {
+ if err != nil {
+ if _, ok := err.(transport.ConnectionError); !ok {
+ t.CloseStream(stream, err)
+ }
+ }
+ }()
+ c.headerMD, err = stream.Header()
+ if err != nil {
+ return
+ }
+ p := &parser{r: stream}
+ var inPayload *stats.InPayload
+ if dopts.copts.StatsHandler != nil {
+ inPayload = &stats.InPayload{
+ Client: true,
+ }
+ }
+ for {
+ if c.maxReceiveMessageSize == nil {
+ return Errorf(codes.Internal, "callInfo maxReceiveMessageSize field uninitialized(nil)")
+ }
+ if err = recv(p, dopts.codec, stream, dopts.dc, reply, *c.maxReceiveMessageSize, inPayload); err != nil {
+ if err == io.EOF {
+ break
+ }
+ return
+ }
+ }
+ if inPayload != nil && err == io.EOF && stream.Status().Code() == codes.OK {
+ // TODO in the current implementation, inTrailer may be handled before inPayload in some cases.
+ // Fix the order if necessary.
+ dopts.copts.StatsHandler.HandleRPC(ctx, inPayload)
+ }
+ c.trailerMD = stream.Trailer()
+ return nil
+}
+
+// sendRequest writes out various information of an RPC such as Context and Message.
+func sendRequest(ctx context.Context, dopts dialOptions, compressor Compressor, c *callInfo, callHdr *transport.CallHdr, stream *transport.Stream, t transport.ClientTransport, args interface{}, opts *transport.Options) (err error) {
+ defer func() {
+ if err != nil {
+ // If err is connection error, t will be closed, no need to close stream here.
+ if _, ok := err.(transport.ConnectionError); !ok {
+ t.CloseStream(stream, err)
+ }
+ }
+ }()
+ var (
+ cbuf *bytes.Buffer
+ outPayload *stats.OutPayload
+ )
+ if compressor != nil {
+ cbuf = new(bytes.Buffer)
+ }
+ if dopts.copts.StatsHandler != nil {
+ outPayload = &stats.OutPayload{
+ Client: true,
+ }
+ }
+ hdr, data, err := encode(dopts.codec, args, compressor, cbuf, outPayload)
+ if err != nil {
+ return err
+ }
+ if c.maxSendMessageSize == nil {
+ return Errorf(codes.Internal, "callInfo maxSendMessageSize field uninitialized(nil)")
+ }
+ if len(data) > *c.maxSendMessageSize {
+ return Errorf(codes.ResourceExhausted, "grpc: trying to send message larger than max (%d vs. %d)", len(data), *c.maxSendMessageSize)
+ }
+ err = t.Write(stream, hdr, data, opts)
+ if err == nil && outPayload != nil {
+ outPayload.SentTime = time.Now()
+ dopts.copts.StatsHandler.HandleRPC(ctx, outPayload)
+ }
+ // t.NewStream(...) could lead to an early rejection of the RPC (e.g., the service/method
+ // does not exist.) so that t.Write could get io.EOF from wait(...). Leave the following
+ // recvResponse to get the final status.
+ if err != nil && err != io.EOF {
+ return err
+ }
+ // Sent successfully.
+ return nil
+}
+
+// Invoke sends the RPC request on the wire and returns after response is
+// received. This is typically called by generated code.
+func (cc *ClientConn) Invoke(ctx context.Context, method string, args, reply interface{}, opts ...CallOption) error {
+ if cc.dopts.unaryInt != nil {
+ return cc.dopts.unaryInt(ctx, method, args, reply, cc, invoke, opts...)
+ }
+ return invoke(ctx, method, args, reply, cc, opts...)
+}
+
+// Invoke sends the RPC request on the wire and returns after response is
+// received. This is typically called by generated code.
+//
+// DEPRECATED: Use ClientConn.Invoke instead.
+func Invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) error {
+ return cc.Invoke(ctx, method, args, reply, opts...)
+}
+
+func invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) (e error) {
+ c := defaultCallInfo()
+ mc := cc.GetMethodConfig(method)
+ if mc.WaitForReady != nil {
+ c.failFast = !*mc.WaitForReady
+ }
+
+ if mc.Timeout != nil && *mc.Timeout >= 0 {
+ var cancel context.CancelFunc
+ ctx, cancel = context.WithTimeout(ctx, *mc.Timeout)
+ defer cancel()
+ }
+
+ opts = append(cc.dopts.callOptions, opts...)
+ for _, o := range opts {
+ if err := o.before(c); err != nil {
+ return toRPCErr(err)
+ }
+ }
+ defer func() {
+ for _, o := range opts {
+ o.after(c)
+ }
+ }()
+
+ c.maxSendMessageSize = getMaxSize(mc.MaxReqSize, c.maxSendMessageSize, defaultClientMaxSendMessageSize)
+ c.maxReceiveMessageSize = getMaxSize(mc.MaxRespSize, c.maxReceiveMessageSize, defaultClientMaxReceiveMessageSize)
+
+ if EnableTracing {
+ c.traceInfo.tr = trace.New("grpc.Sent."+methodFamily(method), method)
+ defer c.traceInfo.tr.Finish()
+ c.traceInfo.firstLine.client = true
+ if deadline, ok := ctx.Deadline(); ok {
+ c.traceInfo.firstLine.deadline = deadline.Sub(time.Now())
+ }
+ c.traceInfo.tr.LazyLog(&c.traceInfo.firstLine, false)
+ // TODO(dsymonds): Arrange for c.traceInfo.firstLine.remoteAddr to be set.
+ defer func() {
+ if e != nil {
+ c.traceInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{e}}, true)
+ c.traceInfo.tr.SetError()
+ }
+ }()
+ }
+ ctx = newContextWithRPCInfo(ctx, c.failFast)
+ sh := cc.dopts.copts.StatsHandler
+ if sh != nil {
+ ctx = sh.TagRPC(ctx, &stats.RPCTagInfo{FullMethodName: method, FailFast: c.failFast})
+ begin := &stats.Begin{
+ Client: true,
+ BeginTime: time.Now(),
+ FailFast: c.failFast,
+ }
+ sh.HandleRPC(ctx, begin)
+ defer func() {
+ end := &stats.End{
+ Client: true,
+ EndTime: time.Now(),
+ Error: e,
+ }
+ sh.HandleRPC(ctx, end)
+ }()
+ }
+ topts := &transport.Options{
+ Last: true,
+ Delay: false,
+ }
+ for {
+ var (
+ err error
+ t transport.ClientTransport
+ stream *transport.Stream
+ // Record the done handler from Balancer.Get(...). It is called once the
+ // RPC has completed or failed.
+ done func(balancer.DoneInfo)
+ )
+ // TODO(zhaoq): Need a formal spec of fail-fast.
+ callHdr := &transport.CallHdr{
+ Host: cc.authority,
+ Method: method,
+ }
+ if cc.dopts.cp != nil {
+ callHdr.SendCompress = cc.dopts.cp.Type()
+ }
+ if c.creds != nil {
+ callHdr.Creds = c.creds
+ }
+
+ t, done, err = cc.getTransport(ctx, c.failFast)
+ if err != nil {
+ // TODO(zhaoq): Probably revisit the error handling.
+ if _, ok := status.FromError(err); ok {
+ return err
+ }
+ if err == errConnClosing || err == errConnUnavailable {
+ if c.failFast {
+ return Errorf(codes.Unavailable, "%v", err)
+ }
+ continue
+ }
+ // All the other errors are treated as Internal errors.
+ return Errorf(codes.Internal, "%v", err)
+ }
+ if c.traceInfo.tr != nil {
+ c.traceInfo.tr.LazyLog(&payload{sent: true, msg: args}, true)
+ }
+ stream, err = t.NewStream(ctx, callHdr)
+ if err != nil {
+ if done != nil {
+ if _, ok := err.(transport.ConnectionError); ok {
+ // If error is connection error, transport was sending data on wire,
+ // and we are not sure if anything has been sent on wire.
+ // If error is not connection error, we are sure nothing has been sent.
+ updateRPCInfoInContext(ctx, rpcInfo{bytesSent: true, bytesReceived: false})
+ }
+ done(balancer.DoneInfo{Err: err})
+ }
+ if _, ok := err.(transport.ConnectionError); (ok || err == transport.ErrStreamDrain) && !c.failFast {
+ continue
+ }
+ return toRPCErr(err)
+ }
+ if peer, ok := peer.FromContext(stream.Context()); ok {
+ c.peer = peer
+ }
+ err = sendRequest(ctx, cc.dopts, cc.dopts.cp, c, callHdr, stream, t, args, topts)
+ if err != nil {
+ if done != nil {
+ updateRPCInfoInContext(ctx, rpcInfo{
+ bytesSent: stream.BytesSent(),
+ bytesReceived: stream.BytesReceived(),
+ })
+ done(balancer.DoneInfo{Err: err})
+ }
+ // Retry a non-failfast RPC when
+ // i) there is a connection error; or
+ // ii) the server started to drain before this RPC was initiated.
+ if _, ok := err.(transport.ConnectionError); (ok || err == transport.ErrStreamDrain) && !c.failFast {
+ continue
+ }
+ return toRPCErr(err)
+ }
+ err = recvResponse(ctx, cc.dopts, t, c, stream, reply)
+ if err != nil {
+ if done != nil {
+ updateRPCInfoInContext(ctx, rpcInfo{
+ bytesSent: stream.BytesSent(),
+ bytesReceived: stream.BytesReceived(),
+ })
+ done(balancer.DoneInfo{Err: err})
+ }
+ if _, ok := err.(transport.ConnectionError); (ok || err == transport.ErrStreamDrain) && !c.failFast {
+ continue
+ }
+ return toRPCErr(err)
+ }
+ if c.traceInfo.tr != nil {
+ c.traceInfo.tr.LazyLog(&payload{sent: false, msg: reply}, true)
+ }
+ t.CloseStream(stream, nil)
+ if done != nil {
+ updateRPCInfoInContext(ctx, rpcInfo{
+ bytesSent: stream.BytesSent(),
+ bytesReceived: stream.BytesReceived(),
+ })
+ done(balancer.DoneInfo{Err: err})
+ }
+ return stream.Status().Err()
+ }
+}
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