// NewClientStream creates a new Stream for the client side. This is called
// by generated code.
func NewClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error) {
var (
t transport.ClientTransport
err error
)
t, err = cc.dopts.picker.Pick(ctx)
if err != nil {
return nil, toRPCErr(err)
}
// TODO(zhaoq): CallOption is omitted. Add support when it is needed.
callHdr := &transport.CallHdr{
Host: cc.authority,
Method: method,
Flush: desc.ServerStreams && desc.ClientStreams,
}
if cc.dopts.cp != nil {
callHdr.SendCompress = cc.dopts.cp.Type()
}
cs := &clientStream{
desc: desc,
codec: cc.dopts.codec,
cp: cc.dopts.cp,
dc: cc.dopts.dc,
tracing: EnableTracing,
}
if cc.dopts.cp != nil {
callHdr.SendCompress = cc.dopts.cp.Type()
cs.cbuf = new(bytes.Buffer)
}
if cs.tracing {
cs.trInfo.tr = trace.New("grpc.Sent."+methodFamily(method), method)
cs.trInfo.firstLine.client = true
if deadline, ok := ctx.Deadline(); ok {
cs.trInfo.firstLine.deadline = deadline.Sub(time.Now())
}
cs.trInfo.tr.LazyLog(&cs.trInfo.firstLine, false)
ctx = trace.NewContext(ctx, cs.trInfo.tr)
}
s, err := t.NewStream(ctx, callHdr)
if err != nil {
cs.finish(err)
return nil, toRPCErr(err)
}
cs.t = t
cs.s = s
cs.p = &parser{s: s}
// Listen on ctx.Done() to detect cancellation when there is no pending
// I/O operations on this stream.
go func() {
select {
case <-t.Error():
// Incur transport error, simply exit.
case <-s.Context().Done():
err := s.Context().Err()
cs.finish(err)
cs.closeTransportStream(transport.ContextErr(err))
}
}()
return cs, nil
}
// sendRequest writes out various information of an RPC such as Context and Message.
func sendRequest(ctx context.Context, codec Codec, compressor Compressor, callHdr *transport.CallHdr, t transport.ClientTransport, args interface{}, opts *transport.Options) (_ *transport.Stream, err error) {
stream, err := t.NewStream(ctx, callHdr)
if err != nil {
return nil, err
}
defer func() {
if err != nil {
if _, ok := err.(transport.ConnectionError); !ok {
t.CloseStream(stream, err)
}
}
}()
var cbuf *bytes.Buffer
if compressor != nil {
cbuf = new(bytes.Buffer)
}
outBuf, err := encode(codec, args, compressor, cbuf)
if err != nil {
return nil, transport.StreamErrorf(codes.Internal, "grpc: %v", err)
}
err = t.Write(stream, outBuf, opts)
if err != nil {
return nil, err
}
// Sent successfully.
return stream, nil
}
func (cc *Conn) resetTransport(closeTransport bool) error {
var retries int
start := time.Now()
for {
cc.mu.Lock()
cc.printf("connecting")
if cc.state == Shutdown {
// cc.Close() has been invoked.
cc.mu.Unlock()
return ErrClientConnClosing
}
cc.state = Connecting
cc.stateCV.Broadcast()
cc.mu.Unlock()
if closeTransport {
cc.transport.Close()
}
// Adjust timeout for the current try.
copts := cc.dopts.copts
if copts.Timeout < 0 {
cc.Close()
return ErrClientConnTimeout
}
if copts.Timeout > 0 {
copts.Timeout -= time.Since(start)
if copts.Timeout <= 0 {
cc.Close()
return ErrClientConnTimeout
}
}
sleepTime := backoff(retries)
timeout := sleepTime
if timeout < minConnectTimeout {
timeout = minConnectTimeout
}
if copts.Timeout == 0 || copts.Timeout > timeout {
copts.Timeout = timeout
}
connectTime := time.Now()
addr, err := cc.dopts.picker.PickAddr()
var newTransport transport.ClientTransport
if err == nil {
newTransport, err = transport.NewClientTransport(addr, &copts)
}
if err != nil {
cc.mu.Lock()
if cc.state == Shutdown {
// cc.Close() has been invoked.
cc.mu.Unlock()
return ErrClientConnClosing
}
cc.errorf("transient failure: %v", err)
cc.state = TransientFailure
cc.stateCV.Broadcast()
if cc.ready != nil {
close(cc.ready)
cc.ready = nil
}
cc.mu.Unlock()
sleepTime -= time.Since(connectTime)
if sleepTime < 0 {
sleepTime = 0
}
// Fail early before falling into sleep.
if cc.dopts.copts.Timeout > 0 && cc.dopts.copts.Timeout < sleepTime+time.Since(start) {
cc.mu.Lock()
cc.errorf("connection timeout")
cc.mu.Unlock()
cc.Close()
return ErrClientConnTimeout
}
closeTransport = false
time.Sleep(sleepTime)
retries++
grpclog.Printf("grpc: Conn.resetTransport failed to create client transport: %v; Reconnecting to %q", err, cc.target)
continue
}
cc.mu.Lock()
cc.printf("ready")
if cc.state == Shutdown {
// cc.Close() has been invoked.
cc.mu.Unlock()
newTransport.Close()
return ErrClientConnClosing
}
cc.state = Ready
cc.stateCV.Broadcast()
cc.transport = newTransport
if cc.ready != nil {
close(cc.ready)
cc.ready = nil
}
cc.mu.Unlock()
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,
}
if cc.dopts.cp != nil {
callHdr.SendCompress = cc.dopts.cp.Type()
}
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, cc.dopts.cp, 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, 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())
}
}