463 lines
12 KiB
Go
463 lines
12 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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"errors"
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"io"
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"sync"
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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/metadata"
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"google.golang.org/grpc/transport"
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)
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// StreamHandler defines the handler called by gRPC server to complete the
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// execution of a streaming RPC.
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type StreamHandler func(srv interface{}, stream ServerStream) error
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// StreamDesc represents a streaming RPC service's method specification.
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type StreamDesc struct {
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StreamName string
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Handler StreamHandler
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// At least one of these is true.
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ServerStreams bool
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ClientStreams bool
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}
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// Stream defines the common interface a client or server stream has to satisfy.
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type Stream interface {
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// Context returns the context for this stream.
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Context() context.Context
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// SendMsg blocks until it sends m, the stream is done or the stream
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// breaks.
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// On error, it aborts the stream and returns an RPC status on client
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// side. On server side, it simply returns the error to the caller.
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// SendMsg is called by generated code. Also Users can call SendMsg
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// directly when it is really needed in their use cases.
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SendMsg(m interface{}) error
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// RecvMsg blocks until it receives a message or the stream is
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// done. On client side, it returns io.EOF when the stream is done. On
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// any other error, it aborts the stream and returns an RPC status. On
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// server side, it simply returns the error to the caller.
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RecvMsg(m interface{}) error
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}
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// ClientStream defines the interface a client stream has to satisfy.
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type ClientStream interface {
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// Header returns the header metadata received from the server if there
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// is any. It blocks if the metadata is not ready to read.
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Header() (metadata.MD, error)
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// Trailer returns the trailer metadata from the server. It must be called
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// after stream.Recv() returns non-nil error (including io.EOF) for
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// bi-directional streaming and server streaming or stream.CloseAndRecv()
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// returns for client streaming in order to receive trailer metadata if
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// present. Otherwise, it could returns an empty MD even though trailer
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// is present.
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Trailer() metadata.MD
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// CloseSend closes the send direction of the stream. It closes the stream
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// when non-nil error is met.
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CloseSend() error
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Stream
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}
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// NewClientStream creates a new Stream for the client side. This is called
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// by generated code.
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func NewClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error) {
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var (
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t transport.ClientTransport
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s *transport.Stream
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err error
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put func()
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)
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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 nil, toRPCErr(err)
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}
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}
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callHdr := &transport.CallHdr{
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Host: cc.authority,
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Method: method,
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Flush: desc.ServerStreams && desc.ClientStreams,
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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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cs := &clientStream{
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opts: opts,
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c: c,
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desc: desc,
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codec: cc.dopts.codec,
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cp: cc.dopts.cp,
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dc: cc.dopts.dc,
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tracing: EnableTracing,
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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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cs.cbuf = new(bytes.Buffer)
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}
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if cs.tracing {
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cs.trInfo.tr = trace.New("grpc.Sent."+methodFamily(method), method)
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cs.trInfo.firstLine.client = true
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if deadline, ok := ctx.Deadline(); ok {
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cs.trInfo.firstLine.deadline = deadline.Sub(time.Now())
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}
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cs.trInfo.tr.LazyLog(&cs.trInfo.firstLine, false)
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ctx = trace.NewContext(ctx, cs.trInfo.tr)
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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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for {
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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 nil, err
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}
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if err == errConnClosing {
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if c.failFast {
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return nil, Errorf(codes.Unavailable, "%v", errConnClosing)
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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 nil, Errorf(codes.Internal, "%v", err)
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}
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s, err = t.NewStream(ctx, callHdr)
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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 {
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if c.failFast {
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cs.finish(err)
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return nil, toRPCErr(err)
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}
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continue
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}
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return nil, toRPCErr(err)
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}
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break
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}
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cs.put = put
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cs.t = t
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cs.s = s
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cs.p = &parser{r: s}
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// Listen on ctx.Done() to detect cancellation when there is no pending
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// I/O operations on this stream.
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go func() {
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select {
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case <-t.Error():
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// Incur transport error, simply exit.
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case <-s.Context().Done():
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err := s.Context().Err()
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cs.finish(err)
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cs.closeTransportStream(transport.ContextErr(err))
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}
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}()
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return cs, nil
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}
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// clientStream implements a client side Stream.
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type clientStream struct {
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opts []CallOption
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c callInfo
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t transport.ClientTransport
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s *transport.Stream
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p *parser
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desc *StreamDesc
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codec Codec
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cp Compressor
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cbuf *bytes.Buffer
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dc Decompressor
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tracing bool // set to EnableTracing when the clientStream is created.
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mu sync.Mutex
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put func()
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closed bool
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// trInfo.tr is set when the clientStream is created (if EnableTracing is true),
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// and is set to nil when the clientStream's finish method is called.
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trInfo traceInfo
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}
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func (cs *clientStream) Context() context.Context {
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return cs.s.Context()
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}
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func (cs *clientStream) Header() (metadata.MD, error) {
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m, err := cs.s.Header()
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if err != nil {
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if _, ok := err.(transport.ConnectionError); !ok {
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cs.closeTransportStream(err)
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}
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}
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return m, err
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}
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func (cs *clientStream) Trailer() metadata.MD {
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return cs.s.Trailer()
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}
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func (cs *clientStream) SendMsg(m interface{}) (err error) {
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if cs.tracing {
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cs.mu.Lock()
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if cs.trInfo.tr != nil {
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cs.trInfo.tr.LazyLog(&payload{sent: true, msg: m}, true)
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}
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cs.mu.Unlock()
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}
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defer func() {
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if err != nil {
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cs.finish(err)
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}
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if err == nil || err == io.EOF {
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return
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}
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if _, ok := err.(transport.ConnectionError); !ok {
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cs.closeTransportStream(err)
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}
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err = toRPCErr(err)
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}()
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out, err := encode(cs.codec, m, cs.cp, cs.cbuf)
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defer func() {
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if cs.cbuf != nil {
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cs.cbuf.Reset()
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}
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}()
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if err != nil {
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return transport.StreamErrorf(codes.Internal, "grpc: %v", err)
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}
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return cs.t.Write(cs.s, out, &transport.Options{Last: false})
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}
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func (cs *clientStream) RecvMsg(m interface{}) (err error) {
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err = recv(cs.p, cs.codec, cs.s, cs.dc, m)
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defer func() {
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// err != nil indicates the termination of the stream.
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if err != nil {
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cs.finish(err)
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}
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}()
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if err == nil {
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if cs.tracing {
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cs.mu.Lock()
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if cs.trInfo.tr != nil {
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cs.trInfo.tr.LazyLog(&payload{sent: false, msg: m}, true)
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}
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cs.mu.Unlock()
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}
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if !cs.desc.ClientStreams || cs.desc.ServerStreams {
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return
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}
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// Special handling for client streaming rpc.
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err = recv(cs.p, cs.codec, cs.s, cs.dc, m)
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cs.closeTransportStream(err)
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if err == nil {
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return toRPCErr(errors.New("grpc: client streaming protocol violation: get <nil>, want <EOF>"))
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}
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if err == io.EOF {
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if cs.s.StatusCode() == codes.OK {
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cs.finish(err)
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return nil
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}
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return Errorf(cs.s.StatusCode(), "%s", cs.s.StatusDesc())
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}
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return toRPCErr(err)
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}
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if _, ok := err.(transport.ConnectionError); !ok {
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cs.closeTransportStream(err)
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}
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if err == io.EOF {
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if cs.s.StatusCode() == codes.OK {
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// Returns io.EOF to indicate the end of the stream.
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return
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}
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return Errorf(cs.s.StatusCode(), "%s", cs.s.StatusDesc())
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}
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return toRPCErr(err)
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}
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func (cs *clientStream) CloseSend() (err error) {
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err = cs.t.Write(cs.s, nil, &transport.Options{Last: true})
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defer func() {
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if err != nil {
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cs.finish(err)
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}
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}()
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if err == nil || err == io.EOF {
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return
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}
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if _, ok := err.(transport.ConnectionError); !ok {
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cs.closeTransportStream(err)
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}
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err = toRPCErr(err)
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return
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}
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func (cs *clientStream) closeTransportStream(err error) {
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cs.mu.Lock()
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if cs.closed {
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cs.mu.Unlock()
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return
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}
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cs.closed = true
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cs.mu.Unlock()
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cs.t.CloseStream(cs.s, err)
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}
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func (cs *clientStream) finish(err error) {
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cs.mu.Lock()
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defer cs.mu.Unlock()
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for _, o := range cs.opts {
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o.after(&cs.c)
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}
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if cs.put != nil {
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cs.put()
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cs.put = nil
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}
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if !cs.tracing {
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return
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}
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if cs.trInfo.tr != nil {
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if err == nil || err == io.EOF {
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cs.trInfo.tr.LazyPrintf("RPC: [OK]")
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} else {
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cs.trInfo.tr.LazyPrintf("RPC: [%v]", err)
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cs.trInfo.tr.SetError()
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}
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cs.trInfo.tr.Finish()
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cs.trInfo.tr = nil
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}
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}
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// ServerStream defines the interface a server stream has to satisfy.
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type ServerStream interface {
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// SendHeader sends the header metadata. It should not be called
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// after SendProto. It fails if called multiple times or if
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// called after SendProto.
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SendHeader(metadata.MD) error
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// SetTrailer sets the trailer metadata which will be sent with the
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// RPC status.
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SetTrailer(metadata.MD)
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Stream
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}
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// serverStream implements a server side Stream.
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type serverStream struct {
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t transport.ServerTransport
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s *transport.Stream
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p *parser
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codec Codec
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cp Compressor
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dc Decompressor
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cbuf *bytes.Buffer
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statusCode codes.Code
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statusDesc string
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trInfo *traceInfo
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mu sync.Mutex // protects trInfo.tr after the service handler runs.
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}
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func (ss *serverStream) Context() context.Context {
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return ss.s.Context()
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}
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func (ss *serverStream) SendHeader(md metadata.MD) error {
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return ss.t.WriteHeader(ss.s, md)
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}
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func (ss *serverStream) SetTrailer(md metadata.MD) {
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if md.Len() == 0 {
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return
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}
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ss.s.SetTrailer(md)
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return
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}
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func (ss *serverStream) SendMsg(m interface{}) (err error) {
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defer func() {
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if ss.trInfo != nil {
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ss.mu.Lock()
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if ss.trInfo.tr != nil {
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if err == nil {
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ss.trInfo.tr.LazyLog(&payload{sent: true, msg: m}, true)
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} else {
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ss.trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
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ss.trInfo.tr.SetError()
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}
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}
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ss.mu.Unlock()
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}
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}()
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out, err := encode(ss.codec, m, ss.cp, ss.cbuf)
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defer func() {
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if ss.cbuf != nil {
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ss.cbuf.Reset()
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}
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}()
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if err != nil {
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err = transport.StreamErrorf(codes.Internal, "grpc: %v", err)
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return err
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}
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return ss.t.Write(ss.s, out, &transport.Options{Last: false})
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}
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func (ss *serverStream) RecvMsg(m interface{}) (err error) {
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defer func() {
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if ss.trInfo != nil {
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ss.mu.Lock()
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if ss.trInfo.tr != nil {
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if err == nil {
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ss.trInfo.tr.LazyLog(&payload{sent: false, msg: m}, true)
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} else if err != io.EOF {
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ss.trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
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ss.trInfo.tr.SetError()
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}
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}
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ss.mu.Unlock()
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}
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}()
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return recv(ss.p, ss.codec, ss.s, ss.dc, m)
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}
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