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 err := t.WriteStatus(stream, codes.InvalidArgument, fmt.Sprintf("malformed method name: %q", stream.Method())); err != nil {
grpclog.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 {
grpclog.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, trInfo)
return
}
if sd, ok := srv.sd[method]; ok {
s.processStreamingRPC(t, stream, srv, sd, trInfo)
return
}
if err := t.WriteStatus(stream, codes.Unimplemented, fmt.Sprintf("unknown method %v", method)); err != nil {
grpclog.Printf("grpc: Server.handleStream failed to write status: %v", err)
}
}
// 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(codec Codec, 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{s: stream}
for {
if err = recv(p, codec, reply); err != nil {
if err == io.EOF {
break
}
return err
}
}
c.trailerMD = stream.Trailer()
return nil
}
// 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())
}
}
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{s: stream}
for {
pf, req, err := p.recvMsg()
if err == io.EOF {
// The entire stream is done (for unary RPC only).
return err
}
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
}
switch pf {
case compressionNone:
statusCode := codes.OK
statusDesc := ""
df := func(v interface{}) error {
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)
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, compressionNone, 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)
default:
panic(fmt.Sprintf("payload format to be supported: %d", pf))
}
}
}