// 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.
func recvResponse(dopts dialOptions, t transport.ClientTransport, c *callInfo, stream *transport.Stream, reply interface{}) error {
// Try to acquire header metadata from the server if there is any.
var err error
defer func() {
if err != nil {
if _, ok := err.(transport.ConnectionError); !ok {
t.CloseStream(stream, err)
}
}
}()
c.headerMD, err = stream.Header()
if err != nil {
return err
}
p := &parser{r: stream}
for {
if err = recv(p, dopts.codec, stream, dopts.dc, reply, math.MaxInt32); err != nil {
if err == io.EOF {
break
}
return err
}
}
c.trailerMD = stream.Trailer()
return nil
}
func (s *Server) handleStream(t transport.ServerTransport, stream *transport.Stream) {
sm := stream.Method()
if sm != "" && sm[0] == '/' {
sm = sm[1:]
}
pos := strings.LastIndex(sm, "/")
if pos == -1 {
if err := t.WriteStatus(stream, codes.InvalidArgument, fmt.Sprintf("malformed method name: %q", stream.Method())); err != nil {
log.Printf("grpc: Server.handleStream failed to write status: %v", err)
}
return
}
service := sm[:pos]
method := sm[pos+1:]
srv, ok := s.m[service]
if !ok {
if err := t.WriteStatus(stream, codes.Unimplemented, fmt.Sprintf("unknown service %v", service)); err != nil {
log.Printf("grpc: Server.handleStream failed to write status: %v", err)
}
return
}
// Unary RPC or Streaming RPC?
if md, ok := srv.md[method]; ok {
s.processUnaryRPC(t, stream, srv, md)
return
}
if sd, ok := srv.sd[method]; ok {
s.processStreamingRPC(t, stream, srv, sd)
return
}
if err := t.WriteStatus(stream, codes.Unimplemented, fmt.Sprintf("unknown method %v", method)); err != nil {
log.Printf("grpc: Server.handleStream failed to write status: %v", err)
}
}
func recv(p *parser, c Codec, s *transport.Stream, dc Decompressor, m interface{}) error {
// 1. 获取1帧请求数据
pf, d, err := p.recvMsg()
if err != nil {
return err
}
// 2. 压缩算法在 Stream中都已经通信过?
if err := checkRecvPayload(pf, s.RecvCompress(), dc); err != nil {
return err
}
// 3. 解压缩数据
if pf == compressionMade {
d, err = dc.Do(bytes.NewReader(d))
if err != nil {
return transport.StreamErrorf(codes.Internal, "grpc: failed to decompress the received message %v", err)
}
}
// 4. 反序列化(可以使用protobuf, 也可以使用thrift等等)
if err := c.Unmarshal(d, m); err != nil {
return transport.StreamErrorf(codes.Internal, "grpc: failed to unmarshal the received message %v", err)
}
return nil
}
func (s *Server) processStreamingRPC(t transport.ServerTransport, stream *transport.Stream, srv *service, sd *StreamDesc) (err error) {
ss := &serverStream{
t: t,
s: stream,
p: &parser{s: stream},
codec: s.opts.codec,
tracing: EnableTracing,
}
if ss.tracing {
ss.traceInfo.tr = trace.New("grpc.Recv."+methodFamily(stream.Method()), stream.Method())
ss.traceInfo.firstLine.client = false
ss.traceInfo.tr.LazyLog(&ss.traceInfo.firstLine, false)
defer func() {
ss.mu.Lock()
if err != nil && err != io.EOF {
ss.traceInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
ss.traceInfo.tr.SetError()
}
ss.traceInfo.tr.Finish()
ss.traceInfo.tr = nil
ss.mu.Unlock()
}()
}
if appErr := sd.Handler(srv.server, ss); appErr != nil {
if err, ok := appErr.(rpcError); ok {
ss.statusCode = err.code
ss.statusDesc = err.desc
} else {
ss.statusCode = convertCode(appErr)
ss.statusDesc = appErr.Error()
}
}
return t.WriteStatus(ss.s, ss.statusCode, ss.statusDesc)
}
func (s *Server) sendResponse(t transport.ServerTransport, stream *transport.Stream, msg interface{}, cp Compressor, opts *transport.Options) error {
var (
cbuf *bytes.Buffer
outPayload *stats.OutPayload
)
if cp != nil {
cbuf = new(bytes.Buffer)
}
if stats.On() {
outPayload = &stats.OutPayload{}
}
p, err := encode(s.opts.codec, msg, cp, cbuf, outPayload)
if err != nil {
// This typically indicates a fatal issue (e.g., memory
// corruption or hardware faults) the application program
// cannot handle.
//
// TODO(zhaoq): There exist other options also such as only closing the
// faulty stream locally and remotely (Other streams can keep going). Find
// the optimal option.
grpclog.Fatalf("grpc: Server failed to encode response %v", err)
}
err = t.Write(stream, p, opts)
if err == nil && outPayload != nil {
outPayload.SentTime = time.Now()
stats.HandleRPC(stream.Context(), outPayload)
}
return err
}
func recv(p *parser, c Codec, s *transport.Stream, dc Decompressor, m interface{}, maxMsgSize int, inPayload *stats.InPayload) error {
pf, d, err := p.recvMsg(maxMsgSize)
if err != nil {
return err
}
if inPayload != nil {
inPayload.WireLength = len(d)
}
if err := checkRecvPayload(pf, s.RecvCompress(), dc); err != nil {
return err
}
if pf == compressionMade {
d, err = dc.Do(bytes.NewReader(d))
if err != nil {
return Errorf(codes.Internal, "grpc: failed to decompress the received message %v", err)
}
}
if len(d) > maxMsgSize {
// TODO: Revisit the error code. Currently keep it consistent with java
// implementation.
return Errorf(codes.Internal, "grpc: received a message of %d bytes exceeding %d limit", len(d), maxMsgSize)
}
if err := c.Unmarshal(d, m); err != nil {
return Errorf(codes.Internal, "grpc: failed to unmarshal the received message %v", err)
}
if inPayload != nil {
inPayload.RecvTime = time.Now()
inPayload.Payload = m
// TODO truncate large payload.
inPayload.Data = d
inPayload.Length = len(d)
}
return nil
}
func recv(p *parser, s *transport.Stream, dg DecompressorGenerator, m interface{}) error {
codecType, compressType, d, err := p.recvMsg()
if err != nil {
return err
}
//decompress
var dc Decompressor
if compressType == COMPRESS_TYPE_GZIP && dg != nil {
dc = dg()
}
if err := checkRecvPayload(codecType, compressType, s.RecvCompress(), dc); err != nil {
return err
}
if compressType == COMPRESS_TYPE_GZIP {
d, err = dc.Do(bytes.NewReader(d))
if err != nil {
return transport.StreamErrorf(codes.Internal, "grpc: failed to decompress the received message %v", err)
}
}
//unmarshal
c, err := GetCodec(codecType)
if err != nil {
return err
}
if err := c.Unmarshal(d, m); err != nil {
return transport.StreamErrorf(codes.Internal, "grpc: failed to unmarshal the received message %v", err)
}
return nil
}
// 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.
func recvResponse(dopts dialOptions, t transport.ClientTransport, c *callInfo, stream *transport.Stream, reply interface{}) error {
// Try to acquire header metadata from the server if there is any.
// 如何接受请求呢?
// 1. 和处理的Http请求类似, 首先是: 处理Header
var err error
c.headerMD, err = stream.Header()
if err != nil {
return err
}
// 2. 然后处理stream
p := &parser{r: stream}
for {
// stream --> (parser) --> msg --> decompress --> unmarshal --> reply
// Iter 1: 读取到Reply
// Iter 2: 读取失败，碰到EOF
if err = recv(p, dopts.codec, stream, dopts.dc, reply); err != nil {
// 似乎需要等待stream的EOF
if err == io.EOF {
break
}
return err
}
}
// 3. 获取Trailer?
c.trailerMD = stream.Trailer()
return nil
}
func (s *Server) processStreamingRPC(t transport.ServerTransport, stream *transport.Stream, srv *service, sd *StreamDesc, trInfo *traceInfo) (err error) {
var cp Compressor
if s.opts.cg != nil {
cp = s.opts.cg()
stream.SetSendCompress(cp.Type())
}
ss := &serverStream{
t: t,
s: stream,
p: &parser{s: stream},
codec: s.opts.codec,
cp: cp,
dg: s.opts.dg,
trInfo: trInfo,
}
if cp != nil {
ss.cbuf = new(bytes.Buffer)
}
if trInfo != nil {
trInfo.tr.LazyLog(&trInfo.firstLine, false)
defer func() {
ss.mu.Lock()
if err != nil && err != io.EOF {
ss.trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
ss.trInfo.tr.SetError()
}
ss.trInfo.tr.Finish()
ss.trInfo.tr = nil
ss.mu.Unlock()
}()
}
if appErr := sd.Handler(srv.server, ss); appErr != nil {
if err, ok := appErr.(rpcError); ok {
ss.statusCode = err.code
ss.statusDesc = err.desc
} else if err, ok := appErr.(transport.StreamError); ok {
ss.statusCode = err.Code
ss.statusDesc = err.Desc
} else {
ss.statusCode = convertCode(appErr)
ss.statusDesc = appErr.Error()
}
}
if trInfo != nil {
ss.mu.Lock()
if ss.statusCode != codes.OK {
ss.trInfo.tr.LazyLog(stringer(ss.statusDesc), true)
ss.trInfo.tr.SetError()
} else {
ss.trInfo.tr.LazyLog(stringer("OK"), false)
}
ss.mu.Unlock()
}
return t.WriteStatus(ss.s, ss.statusCode, ss.statusDesc)
}
func (s *Server) processUnaryRPC(t transport.ServerTransport, stream *transport.Stream, srv *service, md *MethodDesc) {
p := &parser{s: stream}
for {
pf, req, err := p.recvMsg()
if err == io.EOF {
// The entire stream is done (for unary RPC only).
return
}
if err != nil {
switch err := err.(type) {
case transport.ConnectionError:
// Nothing to do here.
case transport.StreamError:
if err := t.WriteStatus(stream, err.Code, err.Desc); err != nil {
log.Printf("grpc: Server.processUnaryRPC failed to write status: %v", err)
}
default:
panic(fmt.Sprintf("grpc: Unexpected error (%T) from recvMsg: %v", err, err))
}
return
}
switch pf {
case compressionNone:
reply, appErr := md.Handler(srv.server, stream.Context(), req)
if appErr != nil {
if err := t.WriteStatus(stream, convertCode(appErr), appErr.Error()); err != nil {
log.Printf("grpc: Server.processUnaryRPC failed to write status: %v", err)
}
return
}
opts := &transport.Options{
Last: true,
Delay: false,
}
statusCode := codes.OK
statusDesc := ""
if err := s.sendProto(t, stream, reply, compressionNone, opts); err != nil {
if _, ok := err.(transport.ConnectionError); ok {
return
}
if e, ok := err.(transport.StreamError); ok {
statusCode = e.Code
statusDesc = e.Desc
} else {
statusCode = codes.Unknown
statusDesc = err.Error()
}
}
if err := t.WriteStatus(stream, statusCode, statusDesc); err != nil {
log.Printf("grpc: Server.processUnaryRPC failed to write status: %v", err)
}
default:
panic(fmt.Sprintf("payload format to be supported: %d", pf))
}
}
}
func (g *grpcServer) processStream(t transport.ServerTransport, stream *transport.Stream, service *service, mtype *methodType, codec grpc.Codec, ct string, ctx context.Context) (err error) {
opts := g.opts
r := &rpcRequest{
service: opts.Name,
contentType: ct,
method: stream.Method(),
stream: true,
}
ss := &rpcStream{
request: r,
t: t,
s: stream,
p: &parser{r: stream},
codec: codec,
maxMsgSize: defaultMaxMsgSize,
}
function := mtype.method.Func
var returnValues []reflect.Value
// Invoke the method, providing a new value for the reply.
fn := func(ctx context.Context, req server.Request, stream interface{}) error {
returnValues = function.Call([]reflect.Value{service.rcvr, mtype.prepareContext(ctx), reflect.ValueOf(stream)})
if err := returnValues[0].Interface(); err != nil {
return err.(error)
}
return nil
}
for i := len(opts.HdlrWrappers); i > 0; i-- {
fn = opts.HdlrWrappers[i-1](fn)
}
appErr := fn(ctx, r, ss)
if appErr != nil {
if err, ok := appErr.(*rpcError); ok {
ss.statusCode = err.code
ss.statusDesc = err.desc
} else if err, ok := appErr.(transport.StreamError); ok {
ss.statusCode = err.Code
ss.statusDesc = err.Desc
} else {
ss.statusCode = convertCode(appErr)
ss.statusDesc = appErr.Error()
}
}
return t.WriteStatus(ss.s, ss.statusCode, ss.statusDesc)
}
func (s *Server) processStreamingRPC(t transport.ServerTransport, stream *transport.Stream, srv *service, sd *StreamDesc) (err error) {
ss := &serverStream{
t: t,
s: stream,
p: &parser{s: stream},
codec: s.opts.codec,
tracing: EnableTracing,
}
if ss.tracing {
ss.traceInfo.tr = stream.Trace()
ss.traceInfo.firstLine.client = false
ss.traceInfo.firstLine.remoteAddr = t.RemoteAddr()
if dl, ok := stream.Context().Deadline(); ok {
ss.traceInfo.firstLine.deadline = dl.Sub(time.Now())
}
ss.traceInfo.tr.LazyLog(&ss.traceInfo.firstLine, false)
defer func() {
ss.mu.Lock()
if err != nil && err != io.EOF {
ss.traceInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
ss.traceInfo.tr.SetError()
}
ss.traceInfo.tr.Finish()
ss.traceInfo.tr = nil
ss.mu.Unlock()
}()
}
if appErr := sd.Handler(srv.server, ss); appErr != nil {
if err, ok := appErr.(rpcError); ok {
ss.statusCode = err.code
ss.statusDesc = err.desc
} else {
ss.statusCode = convertCode(appErr)
ss.statusDesc = appErr.Error()
}
}
if ss.tracing {
ss.mu.Lock()
if ss.statusCode != codes.OK {
ss.traceInfo.tr.LazyLog(stringer(ss.statusDesc), true)
ss.traceInfo.tr.SetError()
} else {
ss.traceInfo.tr.LazyLog(stringer("OK"), false)
}
ss.mu.Unlock()
}
return t.WriteStatus(ss.s, ss.statusCode, ss.statusDesc)
}
func (s *Proxy) handleStream(frontTrans transport.ServerTransport, frontStream *transport.Stream) {
sm := frontStream.Method()
if sm != "" && sm[0] == '/' {
sm = sm[1:]
}
pos := strings.LastIndex(sm, "/")
if pos == -1 {
if err := frontTrans.WriteStatus(frontStream, codes.InvalidArgument, fmt.Sprintf("malformed method name: %q", frontStream.Method())); err != nil {
s.logger.Printf("proxy: Proxy.handleStream failed to write status: %v", err)
}
return
}
ProxyStream(s.director, s.logger, frontTrans, frontStream)
}
// traceInfo returns a traceInfo and associates it with stream, if tracing is enabled.
// If tracing is not enabled, it returns nil.
func (s *Server) traceInfo(st transport.ServerTransport, stream *transport.Stream) (trInfo *traceInfo) {
tr, ok := trace.FromContext(stream.Context())
if !ok {
return nil
}
trInfo = &traceInfo{
tr: tr,
}
trInfo.firstLine.client = false
trInfo.firstLine.remoteAddr = st.RemoteAddr()
if dl, ok := stream.Context().Deadline(); ok {
trInfo.firstLine.deadline = dl.Sub(time.Now())
}
return trInfo
}
func recv(p *parser, c Codec, s *transport.Stream, dc Decompressor, m interface{}) error {
pf, d, err := p.recvMsg()
if err != nil {
return err
}
if err := checkRecvPayload(pf, s.RecvCompress(), dc); err != nil {
return err
}
if pf == compressionMade {
d, err = dc.Do(bytes.NewReader(d))
if err != nil {
return transport.StreamErrorf(codes.Internal, "grpc: failed to decompress the received message %v", err)
}
}
if err := c.Unmarshal(d, m); err != nil {
return transport.StreamErrorf(codes.Internal, "grpc: failed to unmarshal the received message %v", err)
}
return nil
}
// 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.
func recvResponse(dopts dialOptions, t transport.ClientTransport, c *callInfo, stream *transport.Stream, reply interface{}) error {
// Try to acquire header metadata from the server if there is any.
var err error
c.headerMD, err = stream.Header()
if err != nil {
return err
}
p := &parser{r: stream}
for {
if err = recv(p, dopts.codec, stream, dopts.dc, reply); err != nil {
if err == io.EOF {
break
}
return err
}
}
c.trailerMD = stream.Trailer()
return nil
}
// recv 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.
func recv(t transport.ClientTransport, c *callInfo, stream *transport.Stream, reply proto.Message) error {
// Try to acquire header metadata from the server if there is any.
var err error
c.headerMD, err = stream.Header()
if err != nil {
return err
}
p := &parser{s: stream}
for {
if err = recvProto(p, reply); err != nil {
if err == io.EOF {
break
}
return err
}
}
c.trailerMD = stream.Trailer()
return nil
}
// ProxyStream performs a forward of a gRPC frontend stream to a backend.
func ProxyStream(director StreamDirector, logger grpclog.Logger, frontTrans transport.ServerTransport, frontStream *transport.Stream) {
backendTrans, backendStream, err := backendTransportStream(director, frontStream.Context())
if err != nil {
frontTrans.WriteStatus(frontStream, grpc.Code(err), grpc.ErrorDesc(err))
logger.Printf("proxy: Proxy.handleStream %v failed to allocate backend: %v", frontStream.Method(), err)
return
}
defer backendTrans.CloseStream(backendStream, nil)
// data coming from client call to backend
ingressPathChan := forwardDataFrames(frontStream, backendStream, backendTrans)
// custom header handling *must* be after some data is processed by the backend, otherwise there's a deadlock
headerMd, err := backendStream.Header()
if err == nil && len(headerMd) > 0 {
frontTrans.WriteHeader(frontStream, headerMd)
}
// data coming from backend back to client call
egressPathChan := forwardDataFrames(backendStream, frontStream, frontTrans)
// wait for both data streams to complete.
egressErr := <-egressPathChan
ingressErr := <-ingressPathChan
if egressErr != io.EOF || ingressErr != io.EOF {
logger.Printf("proxy: Proxy.handleStream %v failure during transfer ingres: %v egress: %v", frontStream.Method(), ingressErr, egressErr)
frontTrans.WriteStatus(frontStream, codes.Unavailable, fmt.Sprintf("problem in transfer ingress: %v egress: %v", ingressErr, egressErr))
return
}
// handle trailing metadata
trailingMd := backendStream.Trailer()
if len(trailingMd) > 0 {
frontStream.SetTrailer(trailingMd)
}
frontTrans.WriteStatus(frontStream, backendStream.StatusCode(), backendStream.StatusDesc())
}
// traceInfo returns a traceInfo and associates it with stream, if tracing is enabled.
// If tracing is not enabled, it returns nil.
func (s *Server) traceInfo(st transport.ServerTransport, stream *transport.Stream) (trInfo *traceInfo) {
if !EnableTracing {
return nil
}
trInfo = &traceInfo{
tr: trace.New("grpc.Recv."+methodFamily(stream.Method()), stream.Method()),
}
trInfo.firstLine.client = false
trInfo.firstLine.remoteAddr = st.RemoteAddr()
stream.TraceContext(trInfo.tr)
if dl, ok := stream.Context().Deadline(); ok {
trInfo.firstLine.deadline = dl.Sub(time.Now())
}
return trInfo
}
// forwardDataFrames moves data from one gRPC transport `Stream` to another in async fashion.
// It returns an error channel. `nil` on it signifies everything was fine, anything else is a serious problem.
func forwardDataFrames(srcStream *transport.Stream, dstStream *transport.Stream, dstTransport transportWriter) chan error {
ret := make(chan error, 1)
go func() {
data := make([]byte, 4096)
opt := &transport.Options{}
for {
n, err := srcStream.Read(data)
if err != nil { // including io.EOF
// Send nil to terminate the stream.
opt.Last = true
dstTransport.Write(dstStream, nil, opt)
ret <- err
break
}
if err := dstTransport.Write(dstStream, data[:n], opt); err != nil {
ret <- err
break
}
}
close(ret)
}()
return ret
}
// 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 stats.On() {
inPayload = &stats.InPayload{
Client: true,
}
}
for {
if err = recv(p, dopts.codec, stream, dopts.dc, reply, math.MaxInt32, inPayload); err != nil {
if err == io.EOF {
break
}
return
}
}
if inPayload != nil && err == io.EOF && stream.StatusCode() == codes.OK {
// TODO in the current implementation, inTrailer may be handled before inPayload in some cases.
// Fix the order if necessary.
stats.Handle(ctx, inPayload)
}
c.trailerMD = stream.Trailer()
return nil
}
// Invoke sends the RPC request on the wire and returns after response is received.
// Invoke is called by generated code. Also users can call Invoke directly when it
// is really needed in their use cases.
func Invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) (err error) {
c := defaultCallInfo
for _, o := range opts {
if err := o.before(&c); err != nil {
return toRPCErr(err)
}
}
defer func() {
for _, o := range opts {
o.after(&c)
}
}()
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 err != nil {
c.traceInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
c.traceInfo.tr.SetError()
}
}()
}
topts := &transport.Options{
Last: true,
Delay: false,
}
for {
var (
err error
t transport.ClientTransport
stream *transport.Stream
// Record the put handler from Balancer.Get(...). It is called once the
// RPC has completed or failed.
put func()
)
// 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()
}
gopts := BalancerGetOptions{
BlockingWait: !c.failFast,
}
t, put, err = cc.getTransport(ctx, gopts)
if err != nil {
// TODO(zhaoq): Probably revisit the error handling.
if _, ok := err.(*rpcError); ok {
return err
}
if err == errConnClosing {
if c.failFast {
return Errorf(codes.Unavailable, "%v", errConnClosing)
}
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 = sendRequest(ctx, cc.dopts.codec, cc.dopts.cp, callHdr, t, args, topts)
if err != nil {
if put != nil {
put()
put = nil
}
if _, ok := err.(transport.ConnectionError); ok {
if c.failFast {
return toRPCErr(err)
}
continue
}
return toRPCErr(err)
}
// Receive the response
err = recvResponse(cc.dopts, t, &c, stream, reply)
if err != nil {
if put != nil {
put()
put = nil
}
if _, ok := err.(transport.ConnectionError); ok {
if c.failFast {
return toRPCErr(err)
}
continue
}
t.CloseStream(stream, err)
return toRPCErr(err)
}
if c.traceInfo.tr != nil {
c.traceInfo.tr.LazyLog(&payload{sent: false, msg: reply}, true)
}
t.CloseStream(stream, nil)
if put != nil {
put()
put = nil
}
return Errorf(stream.StatusCode(), "%s", stream.StatusDesc())
}
}
func (s *Server) processStreamingRPC(t transport.ServerTransport, stream *transport.Stream, srv *service, sd *StreamDesc, trInfo *traceInfo) (err error) {
if s.opts.cp != nil {
stream.SetSendCompress(s.opts.cp.Type())
}
ss := &serverStream{
t: t,
s: stream,
p: &parser{r: stream},
codec: s.opts.codec,
cp: s.opts.cp,
dc: s.opts.dc,
maxMsgSize: s.opts.maxMsgSize,
trInfo: trInfo,
}
if ss.cp != nil {
ss.cbuf = new(bytes.Buffer)
}
if trInfo != nil {
trInfo.tr.LazyLog(&trInfo.firstLine, false)
defer func() {
ss.mu.Lock()
if err != nil && err != io.EOF {
ss.trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
ss.trInfo.tr.SetError()
}
ss.trInfo.tr.Finish()
ss.trInfo.tr = nil
ss.mu.Unlock()
}()
}
var appErr error
if s.opts.streamInt == nil {
appErr = sd.Handler(srv.server, ss)
} else {
info := &StreamServerInfo{
FullMethod: stream.Method(),
IsClientStream: sd.ClientStreams,
IsServerStream: sd.ServerStreams,
}
appErr = s.opts.streamInt(srv.server, ss, info, sd.Handler)
}
if appErr != nil {
if err, ok := appErr.(*rpcError); ok {
ss.statusCode = err.code
ss.statusDesc = err.desc
} else if err, ok := appErr.(transport.StreamError); ok {
ss.statusCode = err.Code
ss.statusDesc = err.Desc
} else {
ss.statusCode = convertCode(appErr)
ss.statusDesc = appErr.Error()
}
}
if trInfo != nil {
ss.mu.Lock()
if ss.statusCode != codes.OK {
ss.trInfo.tr.LazyLog(stringer(ss.statusDesc), true)
ss.trInfo.tr.SetError()
} else {
ss.trInfo.tr.LazyLog(stringer("OK"), false)
}
ss.mu.Unlock()
}
return t.WriteStatus(ss.s, ss.statusCode, ss.statusDesc)
}
func (s *Server) processUnaryRPC(t transport.ServerTransport, stream *transport.Stream, srv *service, md *MethodDesc, trInfo *traceInfo) (err error) {
if trInfo != nil {
defer trInfo.tr.Finish()
trInfo.firstLine.client = false
trInfo.tr.LazyLog(&trInfo.firstLine, false)
defer func() {
if err != nil && err != io.EOF {
trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
trInfo.tr.SetError()
}
}()
}
if s.opts.cp != nil {
// NOTE: this needs to be ahead of all handling, https://github.com/grpc/grpc-go/issues/686.
stream.SetSendCompress(s.opts.cp.Type())
}
p := &parser{r: stream}
for {
pf, req, err := p.recvMsg(s.opts.maxMsgSize)
if err == io.EOF {
// The entire stream is done (for unary RPC only).
return err
}
if err == io.ErrUnexpectedEOF {
err = Errorf(codes.Internal, io.ErrUnexpectedEOF.Error())
}
if err != nil {
switch err := err.(type) {
case *rpcError:
if err := t.WriteStatus(stream, err.code, err.desc); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
case transport.ConnectionError:
// Nothing to do here.
case transport.StreamError:
if err := t.WriteStatus(stream, err.Code, err.Desc); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
default:
panic(fmt.Sprintf("grpc: Unexpected error (%T) from recvMsg: %v", err, err))
}
return err
}
if err := checkRecvPayload(pf, stream.RecvCompress(), s.opts.dc); err != nil {
switch err := err.(type) {
case *rpcError:
if err := t.WriteStatus(stream, err.code, err.desc); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
default:
if err := t.WriteStatus(stream, codes.Internal, err.Error()); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
}
return err
}
statusCode := codes.OK
statusDesc := ""
df := func(v interface{}) error {
if pf == compressionMade {
var err error
req, err = s.opts.dc.Do(bytes.NewReader(req))
if err != nil {
if err := t.WriteStatus(stream, codes.Internal, err.Error()); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
return err
}
}
if len(req) > s.opts.maxMsgSize {
// TODO: Revisit the error code. Currently keep it consistent with
// java implementation.
statusCode = codes.Internal
statusDesc = fmt.Sprintf("grpc: server received a message of %d bytes exceeding %d limit", len(req), s.opts.maxMsgSize)
}
if err := s.opts.codec.Unmarshal(req, v); err != nil {
return err
}
if trInfo != nil {
trInfo.tr.LazyLog(&payload{sent: false, msg: v}, true)
}
return nil
}
reply, appErr := md.Handler(srv.server, stream.Context(), df, s.opts.unaryInt)
if appErr != nil {
if err, ok := appErr.(*rpcError); ok {
statusCode = err.code
statusDesc = err.desc
} else {
statusCode = convertCode(appErr)
statusDesc = appErr.Error()
}
if trInfo != nil && statusCode != codes.OK {
trInfo.tr.LazyLog(stringer(statusDesc), true)
trInfo.tr.SetError()
}
if err := t.WriteStatus(stream, statusCode, statusDesc); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status: %v", err)
return err
}
return nil
}
if trInfo != nil {
trInfo.tr.LazyLog(stringer("OK"), false)
}
opts := &transport.Options{
Last: true,
Delay: false,
}
if err := s.sendResponse(t, stream, reply, s.opts.cp, opts); err != nil {
switch err := err.(type) {
case transport.ConnectionError:
// Nothing to do here.
case transport.StreamError:
statusCode = err.Code
statusDesc = err.Desc
default:
statusCode = codes.Unknown
statusDesc = err.Error()
}
return err
}
if trInfo != nil {
trInfo.tr.LazyLog(&payload{sent: true, msg: reply}, true)
}
return t.WriteStatus(stream, statusCode, statusDesc)
}
}
// Invoke is called by the generated code. It sends the RPC request on the
// wire and returns after response is received.
func Invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) (err error) {
var c callInfo
for _, o := range opts {
if err := o.before(&c); err != nil {
return toRPCErr(err)
}
}
defer func() {
for _, o := range opts {
o.after(&c)
}
}()
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 err != nil {
c.traceInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
c.traceInfo.tr.SetError()
}
}()
}
topts := &transport.Options{
Last: true,
Delay: false,
}
var (
lastErr error // record the error that happened
)
for {
var (
err error
t transport.ClientTransport
stream *transport.Stream
)
// TODO(zhaoq): Need a formal spec of retry strategy for non-failfast rpcs.
if lastErr != nil && c.failFast {
return toRPCErr(lastErr)
}
callHdr := &transport.CallHdr{
Host: cc.authority,
Method: method,
}
t, err = cc.dopts.picker.Pick(ctx)
if err != nil {
if lastErr != nil {
// This was a retry; return the error from the last attempt.
return toRPCErr(lastErr)
}
return toRPCErr(err)
}
if c.traceInfo.tr != nil {
c.traceInfo.tr.LazyLog(&payload{sent: true, msg: args}, true)
}
stream, err = sendRequest(ctx, cc.dopts.codec, callHdr, t, args, topts)
if err != nil {
if _, ok := err.(transport.ConnectionError); ok {
lastErr = err
continue
}
if lastErr != nil {
return toRPCErr(lastErr)
}
return toRPCErr(err)
}
// Receive the response
lastErr = recvResponse(cc.dopts.codec, t, &c, stream, reply)
if _, ok := lastErr.(transport.ConnectionError); ok {
continue
}
if c.traceInfo.tr != nil {
c.traceInfo.tr.LazyLog(&payload{sent: false, msg: reply}, true)
}
t.CloseStream(stream, lastErr)
if lastErr != nil {
return toRPCErr(lastErr)
}
return Errorf(stream.StatusCode(), stream.StatusDesc())
}
}
//
// service存在, MethodDesc也存在
//
func (s *Server) processUnaryRPC(t transport.ServerTransport, stream *transport.Stream, srv *service, md *MethodDesc, trInfo *traceInfo) (err error) {
if trInfo != nil {
defer trInfo.tr.Finish()
trInfo.firstLine.client = false
trInfo.tr.LazyLog(&trInfo.firstLine, false)
defer func() {
if err != nil && err != io.EOF {
trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
trInfo.tr.SetError()
}
}()
}
p := &parser{r: stream}
for {
// PayloadFormat, Request Data, Err
pf, req, err := p.recvMsg()
if err == io.EOF {
// The entire stream is done (for unary RPC only).
return err
}
if err == io.ErrUnexpectedEOF {
err = transport.StreamError{Code: codes.Internal, Desc: "io.ErrUnexpectedEOF"}
}
if err != nil {
switch err := err.(type) {
case transport.ConnectionError:
// Nothing to do here.
// 连接断开了，则直接返回
case transport.StreamError:
if err := t.WriteStatus(stream, err.Code, err.Desc); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
default:
panic(fmt.Sprintf("grpc: Unexpected error (%T) from recvMsg: %v", err, err))
}
return err
}
if err := checkRecvPayload(pf, stream.RecvCompress(), s.opts.dc); err != nil {
switch err := err.(type) {
case transport.StreamError:
if err := t.WriteStatus(stream, err.Code, err.Desc); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
default:
if err := t.WriteStatus(stream, codes.Internal, err.Error()); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
}
return err
}
// 处理正常的Method Invocation
statusCode := codes.OK
statusDesc := ""
// Decode Input
df := func(v interface{}) error {
if pf == compressionMade {
// 如果数据有压缩，则通过opts中配置的Compressor/Decompressor进行处理
var err error
req, err = s.opts.dc.Do(bytes.NewReader(req))
if err != nil {
if err := t.WriteStatus(stream, codes.Internal, err.Error()); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
return err
}
}
// 将req中的数据反序列化到: v 中，例如:
// in := new(HelloRequest)
// if err := dec(in); err != nil {
// return nil, err
// }
if err := s.opts.codec.Unmarshal(req, v); err != nil {
return err
}
// 打印trace info
if trInfo != nil {
trInfo.tr.LazyLog(&payload{sent: false, msg: v}, true)
}
return nil
}
// 参考: func _Greeter_SayHello_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error) (interface{}, error) {
//var _Greeter_serviceDesc = grpc.ServiceDesc{
// ServiceName: "helloworld.Greeter",
// HandlerType: (*GreeterServer)(nil),
// Methods: []grpc.MethodDesc{
// {
// // 方法的描述
// MethodName: "SayHello",
// Handler: _Greeter_SayHello_Handler,
// },
// },
//
// // Streams如何处理呢?
// Streams: []grpc.StreamDesc{},
//}
// Handler是直接可调用的函数
// 其中: df 接受输入参数的类型，进行数据的反序列化
//
reply, appErr := md.Handler(srv.server, stream.Context(), df)
// 如果处理应用返回来的Error
if appErr != nil {
if err, ok := appErr.(rpcError); ok {
statusCode = err.code
statusDesc = err.desc
} else {
statusCode = convertCode(appErr)
statusDesc = appErr.Error()
}
if trInfo != nil && statusCode != codes.OK {
trInfo.tr.LazyLog(stringer(statusDesc), true)
trInfo.tr.SetError()
}
if err := t.WriteStatus(stream, statusCode, statusDesc); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status: %v", err)
return err
}
return nil
}
// 处理完毕之后，正常返回数据
if trInfo != nil {
trInfo.tr.LazyLog(stringer("OK"), false)
}
opts := &transport.Options{
Last: true,
Delay: false,
}
if s.opts.cp != nil {
stream.SetSendCompress(s.opts.cp.Type())
}
// 返回数据
if err := s.sendResponse(t, stream, reply, s.opts.cp, opts); err != nil {
switch err := err.(type) {
case transport.ConnectionError:
// Nothing to do here.
case transport.StreamError:
statusCode = err.Code
statusDesc = err.Desc
default:
statusCode = codes.Unknown
statusDesc = err.Error()
}
return err
}
if trInfo != nil {
trInfo.tr.LazyLog(&payload{sent: true, msg: reply}, true)
}
return t.WriteStatus(stream, statusCode, statusDesc)
}
}
func newClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (_ ClientStream, err error) {
var (
t transport.ClientTransport
s *transport.Stream
put func()
)
c := defaultCallInfo
for _, o := range opts {
if err := o.before(&c); err != nil {
return nil, toRPCErr(err)
}
}
callHdr := &transport.CallHdr{
Host: cc.authority,
Method: method,
Flush: desc.ServerStreams && desc.ClientStreams,
}
if cc.dopts.cp != nil {
callHdr.SendCompress = cc.dopts.cp.Type()
}
var trInfo traceInfo
if EnableTracing {
trInfo.tr = trace.New("grpc.Sent."+methodFamily(method), method)
trInfo.firstLine.client = true
if deadline, ok := ctx.Deadline(); ok {
trInfo.firstLine.deadline = deadline.Sub(time.Now())
}
trInfo.tr.LazyLog(&trInfo.firstLine, false)
ctx = trace.NewContext(ctx, trInfo.tr)
defer func() {
if err != nil {
// Need to call tr.finish() if error is returned.
// Because tr will not be returned to caller.
trInfo.tr.LazyPrintf("RPC: [%v]", err)
trInfo.tr.SetError()
trInfo.tr.Finish()
}
}()
}
if stats.On() {
ctx = stats.TagRPC(ctx, &stats.RPCTagInfo{FullMethodName: method})
begin := &stats.Begin{
Client: true,
BeginTime: time.Now(),
FailFast: c.failFast,
}
stats.HandleRPC(ctx, begin)
}
defer func() {
if err != nil && stats.On() {
// Only handle end stats if err != nil.
end := &stats.End{
Client: true,
Error: err,
}
stats.HandleRPC(ctx, end)
}
}()
gopts := BalancerGetOptions{
BlockingWait: !c.failFast,
}
for {
t, put, err = cc.getTransport(ctx, gopts)
if err != nil {
// TODO(zhaoq): Probably revisit the error handling.
if _, ok := err.(*rpcError); ok {
return nil, err
}
if err == errConnClosing || err == errConnUnavailable {
if c.failFast {
return nil, Errorf(codes.Unavailable, "%v", err)
}
continue
}
// All the other errors are treated as Internal errors.
return nil, Errorf(codes.Internal, "%v", err)
}
s, err = t.NewStream(ctx, callHdr)
if err != nil {
if put != nil {
put()
put = nil
}
if _, ok := err.(transport.ConnectionError); ok || err == transport.ErrStreamDrain {
if c.failFast {
return nil, toRPCErr(err)
}
continue
}
return nil, toRPCErr(err)
}
break
}
cs := &clientStream{
opts: opts,
c: c,
desc: desc,
codec: cc.dopts.codec,
cp: cc.dopts.cp,
dc: cc.dopts.dc,
put: put,
t: t,
s: s,
p: &parser{r: s},
tracing: EnableTracing,
trInfo: trInfo,
statsCtx: ctx,
}
if cc.dopts.cp != nil {
cs.cbuf = new(bytes.Buffer)
}
// Listen on ctx.Done() to detect cancellation and s.Done() to detect normal termination
// when there is no pending I/O operations on this stream.
go func() {
select {
case <-t.Error():
// Incur transport error, simply exit.
case <-s.Done():
// TODO: The trace of the RPC is terminated here when there is no pending
// I/O, which is probably not the optimal solution.
if s.StatusCode() == codes.OK {
cs.finish(nil)
} else {
cs.finish(Errorf(s.StatusCode(), "%s", s.StatusDesc()))
}
cs.closeTransportStream(nil)
case <-s.GoAway():
cs.finish(errConnDrain)
cs.closeTransportStream(errConnDrain)
case <-s.Context().Done():
err := s.Context().Err()
cs.finish(err)
cs.closeTransportStream(transport.ContextErr(err))
}
}()
return cs, nil
}
func (s *Server) processUnaryRPC(t transport.ServerTransport, stream *transport.Stream, srv *service, md *MethodDesc, trInfo *traceInfo) (err error) {
if trInfo != nil {
defer trInfo.tr.Finish()
trInfo.firstLine.client = false
trInfo.tr.LazyLog(&trInfo.firstLine, false)
defer func() {
if err != nil && err != io.EOF {
trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
trInfo.tr.SetError()
}
}()
}
p := &parser{r: stream}
for {
pf, req, err := p.recvMsg()
if err == io.EOF {
// The entire stream is done (for unary RPC only).
return err
}
if err == io.ErrUnexpectedEOF {
err = transport.StreamError{Code: codes.Internal, Desc: "io.ErrUnexpectedEOF"}
}
if err != nil {
switch err := err.(type) {
case transport.ConnectionError:
// Nothing to do here.
case transport.StreamError:
if err := t.WriteStatus(stream, err.Code, err.Desc); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
default:
panic(fmt.Sprintf("grpc: Unexpected error (%T) from recvMsg: %v", err, err))
}
return err
}
if err := checkRecvPayload(pf, stream.RecvCompress(), s.opts.dc); err != nil {
switch err := err.(type) {
case transport.StreamError:
if err := t.WriteStatus(stream, err.Code, err.Desc); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
default:
if err := t.WriteStatus(stream, codes.Internal, err.Error()); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
}
return err
}
statusCode := codes.OK
statusDesc := ""
df := func(v interface{}) error {
if pf == compressionMade {
var err error
req, err = s.opts.dc.Do(bytes.NewReader(req))
if err != nil {
if err := t.WriteStatus(stream, codes.Internal, err.Error()); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status %v", err)
}
return err
}
}
if err := s.opts.codec.Unmarshal(req, v); err != nil {
return err
}
if trInfo != nil {
trInfo.tr.LazyLog(&payload{sent: false, msg: v}, true)
}
return nil
}
reply, appErr := md.Handler(srv.server, stream.Context(), df, s.opts.unaryInt)
if appErr != nil {
if err, ok := appErr.(rpcError); ok {
statusCode = err.code
statusDesc = err.desc
} else {
statusCode = convertCode(appErr)
statusDesc = appErr.Error()
}
if trInfo != nil && statusCode != codes.OK {
trInfo.tr.LazyLog(stringer(statusDesc), true)
trInfo.tr.SetError()
}
if err := t.WriteStatus(stream, statusCode, statusDesc); err != nil {
grpclog.Printf("grpc: Server.processUnaryRPC failed to write status: %v", err)
return err
}
return nil
}
if trInfo != nil {
trInfo.tr.LazyLog(stringer("OK"), false)
}
opts := &transport.Options{
Last: true,
Delay: false,
}
if s.opts.cp != nil {
stream.SetSendCompress(s.opts.cp.Type())
}
if err := s.sendResponse(t, stream, reply, s.opts.cp, opts); err != nil {
switch err := err.(type) {
case transport.ConnectionError:
// Nothing to do here.
case transport.StreamError:
statusCode = err.Code
statusDesc = err.Desc
default:
statusCode = codes.Unknown
statusDesc = err.Error()
}
return err
}
if trInfo != nil {
trInfo.tr.LazyLog(&payload{sent: true, msg: reply}, true)
}
return t.WriteStatus(stream, statusCode, statusDesc)
}
}
func (s *Server) handleStream(t transport.ServerTransport, stream *transport.Stream, trInfo *traceInfo) {
sm := stream.Method()
if sm != "" && sm[0] == '/' {
sm = sm[1:]
}
pos := strings.LastIndex(sm, "/")
if pos == -1 {
if trInfo != nil {
trInfo.tr.LazyLog(&fmtStringer{"Malformed method name %q", []interface{}{sm}}, true)
trInfo.tr.SetError()
}
if err := t.WriteStatus(stream, codes.InvalidArgument, fmt.Sprintf("malformed method name: %q", stream.Method())); err != nil {
if trInfo != nil {
trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
trInfo.tr.SetError()
}
grpclog.Printf("grpc: Server.handleStream failed to write status: %v", err)
}
if trInfo != nil {
trInfo.tr.Finish()
}
return
}
service := sm[:pos]
method := sm[pos+1:]
srv, ok := s.m[service]
if !ok {
if trInfo != nil {
trInfo.tr.LazyLog(&fmtStringer{"Unknown service %v", []interface{}{service}}, true)
trInfo.tr.SetError()
}
if err := t.WriteStatus(stream, codes.Unimplemented, fmt.Sprintf("unknown service %v", service)); err != nil {
if trInfo != nil {
trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
trInfo.tr.SetError()
}
grpclog.Printf("grpc: Server.handleStream failed to write status: %v", err)
}
if trInfo != nil {
trInfo.tr.Finish()
}
return
}
// Unary RPC or Streaming RPC?
if md, ok := srv.md[method]; ok {
s.processUnaryRPC(t, stream, srv, md, trInfo)
return
}
if sd, ok := srv.sd[method]; ok {
s.processStreamingRPC(t, stream, srv, sd, trInfo)
return
}
if trInfo != nil {
trInfo.tr.LazyLog(&fmtStringer{"Unknown method %v", []interface{}{method}}, true)
trInfo.tr.SetError()
}
if err := t.WriteStatus(stream, codes.Unimplemented, fmt.Sprintf("unknown method %v", method)); err != nil {
if trInfo != nil {
trInfo.tr.LazyLog(&fmtStringer{"%v", []interface{}{err}}, true)
trInfo.tr.SetError()
}
grpclog.Printf("grpc: Server.handleStream failed to write status: %v", err)
}
if trInfo != nil {
trInfo.tr.Finish()
}
}
// Invoke is called by the generated code. It sends the RPC request on the
// wire and returns after response is received.
func Invoke(ctx context.Context, method string, args, reply proto.Message, cc *ClientConn, opts ...CallOption) error {
var c callInfo
for _, o := range opts {
if err := o.before(&c); err != nil {
return toRPCErr(err)
}
}
defer func() {
for _, o := range opts {
o.after(&c)
}
}()
host, _, err := net.SplitHostPort(cc.target)
if err != nil {
return toRPCErr(err)
}
callHdr := &transport.CallHdr{
Host: host,
Method: method,
}
topts := &transport.Options{
Last: true,
Delay: false,
}
ts := 0
var lastErr error // record the error that happened
for {
var (
err error
t transport.ClientTransport
stream *transport.Stream
)
// TODO(zhaoq): Need a formal spec of retry strategy for non-failfast rpcs.
if lastErr != nil && c.failFast {
return lastErr
}
t, ts, err = cc.wait(ctx, ts)
if err != nil {
if lastErr != nil {
// This was a retry; return the error from the last attempt.
return lastErr
}
return err
}
stream, err = sendRPC(ctx, callHdr, t, args, topts)
if err != nil {
if _, ok := err.(transport.ConnectionError); ok {
lastErr = err
continue
}
if lastErr != nil {
return toRPCErr(lastErr)
}
return toRPCErr(err)
}
// Receive the response
lastErr = recv(t, &c, stream, reply)
if _, ok := lastErr.(transport.ConnectionError); ok {
continue
}
t.CloseStream(stream, lastErr)
if lastErr != nil {
return toRPCErr(lastErr)
}
return Errorf(stream.StatusCode(), stream.StatusDesc())
}
}