234 lines
7.1 KiB
Go
234 lines
7.1 KiB
Go
/*
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*
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* Copyright 2014, Google Inc.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following disclaimer
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* in the documentation and/or other materials provided with the
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* distribution.
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* * Neither the name of Google Inc. nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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package grpc
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import (
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"bytes"
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"io"
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"math"
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"time"
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"golang.org/x/net/context"
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"golang.org/x/net/trace"
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"google.golang.org/grpc/codes"
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"google.golang.org/grpc/transport"
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)
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// recvResponse receives and parses an RPC response.
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// On error, it returns the error and indicates whether the call should be retried.
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//
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// TODO(zhaoq): Check whether the received message sequence is valid.
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func recvResponse(dopts dialOptions, t transport.ClientTransport, c *callInfo, stream *transport.Stream, reply interface{}) error {
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// Try to acquire header metadata from the server if there is any.
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var err error
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defer func() {
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if err != nil {
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if _, ok := err.(transport.ConnectionError); !ok {
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t.CloseStream(stream, err)
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}
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}
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}()
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c.headerMD, err = stream.Header()
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if err != nil {
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return err
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}
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p := &parser{r: stream}
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for {
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if err = recv(p, dopts.codec, stream, dopts.dc, reply, math.MaxInt32); err != nil {
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if err == io.EOF {
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break
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}
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return err
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}
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}
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c.trailerMD = stream.Trailer()
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return nil
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}
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// sendRequest writes out various information of an RPC such as Context and Message.
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func sendRequest(ctx context.Context, codec Codec, compressor Compressor, callHdr *transport.CallHdr, t transport.ClientTransport, args interface{}, opts *transport.Options) (_ *transport.Stream, err error) {
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stream, err := t.NewStream(ctx, callHdr)
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if err != nil {
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return nil, err
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}
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defer func() {
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if err != nil {
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// If err is connection error, t will be closed, no need to close stream here.
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if _, ok := err.(transport.ConnectionError); !ok {
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t.CloseStream(stream, err)
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}
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}
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}()
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var cbuf *bytes.Buffer
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if compressor != nil {
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cbuf = new(bytes.Buffer)
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}
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outBuf, err := encode(codec, args, compressor, cbuf)
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if err != nil {
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return nil, Errorf(codes.Internal, "grpc: %v", err)
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}
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err = t.Write(stream, outBuf, opts)
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// t.NewStream(...) could lead to an early rejection of the RPC (e.g., the service/method
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// does not exist.) so that t.Write could get io.EOF from wait(...). Leave the following
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// recvResponse to get the final status.
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if err != nil && err != io.EOF {
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return nil, err
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}
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// Sent successfully.
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return stream, nil
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}
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// Invoke sends the RPC request on the wire and returns after response is received.
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// Invoke is called by generated code. Also users can call Invoke directly when it
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// is really needed in their use cases.
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func Invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) error {
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if cc.dopts.unaryInt != nil {
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return cc.dopts.unaryInt(ctx, method, args, reply, cc, invoke, opts...)
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}
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return invoke(ctx, method, args, reply, cc, opts...)
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}
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func invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) (err error) {
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c := defaultCallInfo
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for _, o := range opts {
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if err := o.before(&c); err != nil {
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return toRPCErr(err)
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}
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}
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defer func() {
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for _, o := range opts {
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o.after(&c)
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}
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}()
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if EnableTracing {
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c.traceInfo.tr = trace.New("grpc.Sent."+methodFamily(method), method)
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defer c.traceInfo.tr.Finish()
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c.traceInfo.firstLine.client = true
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if deadline, ok := ctx.Deadline(); ok {
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c.traceInfo.firstLine.deadline = deadline.Sub(time.Now())
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}
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c.traceInfo.tr.LazyLog(&c.traceInfo.firstLine, false)
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// TODO(dsymonds): Arrange for c.traceInfo.firstLine.remoteAddr to be set.
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defer func() {
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if err != nil {
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c.traceInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
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c.traceInfo.tr.SetError()
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}
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}()
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}
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topts := &transport.Options{
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Last: true,
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Delay: false,
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}
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for {
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var (
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err error
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t transport.ClientTransport
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stream *transport.Stream
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// Record the put handler from Balancer.Get(...). It is called once the
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// RPC has completed or failed.
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put func()
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)
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// TODO(zhaoq): Need a formal spec of fail-fast.
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callHdr := &transport.CallHdr{
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Host: cc.authority,
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Method: method,
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}
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if cc.dopts.cp != nil {
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callHdr.SendCompress = cc.dopts.cp.Type()
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}
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gopts := BalancerGetOptions{
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BlockingWait: !c.failFast,
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}
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t, put, err = cc.getTransport(ctx, gopts)
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if err != nil {
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// TODO(zhaoq): Probably revisit the error handling.
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if _, ok := err.(*rpcError); ok {
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return err
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}
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if err == errConnClosing || err == errConnUnavailable {
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if c.failFast {
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return Errorf(codes.Unavailable, "%v", err)
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}
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continue
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}
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// All the other errors are treated as Internal errors.
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return Errorf(codes.Internal, "%v", err)
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}
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if c.traceInfo.tr != nil {
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c.traceInfo.tr.LazyLog(&payload{sent: true, msg: args}, true)
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}
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stream, err = sendRequest(ctx, cc.dopts.codec, cc.dopts.cp, callHdr, t, args, topts)
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if err != nil {
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if put != nil {
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put()
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put = nil
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}
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// Retry a non-failfast RPC when
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// i) there is a connection error; or
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// ii) the server started to drain before this RPC was initiated.
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if _, ok := err.(transport.ConnectionError); ok || err == transport.ErrStreamDrain {
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if c.failFast {
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return toRPCErr(err)
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}
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continue
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}
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return toRPCErr(err)
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}
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err = recvResponse(cc.dopts, t, &c, stream, reply)
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if err != nil {
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if put != nil {
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put()
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put = nil
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}
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if _, ok := err.(transport.ConnectionError); ok || err == transport.ErrStreamDrain {
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if c.failFast {
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return toRPCErr(err)
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}
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continue
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}
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return toRPCErr(err)
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}
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if c.traceInfo.tr != nil {
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c.traceInfo.tr.LazyLog(&payload{sent: false, msg: reply}, true)
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}
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t.CloseStream(stream, nil)
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if put != nil {
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put()
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put = nil
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}
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return Errorf(stream.StatusCode(), "%s", stream.StatusDesc())
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}
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}
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