Struct clientStream

stream.go:574–627

clientStream implements a client side Stream.

// clientStream implements a client side Stream.
type clientStream struct {
	callHdr  *transport.CallHdr
	opts     []CallOption
	callInfo *callInfo
	cc       *ClientConn
	desc     *StreamDesc

	codec        baseCodec
	compressorV0 Compressor
	compressorV1 encoding.Compressor

	cancel context.CancelFunc // cancels all attempts

	sentLast bool // sent an end stream

	receivedFirstMsg bool // set after the first message is received

	methodConfig *MethodConfig

	ctx context.Context // the application's context, wrapped by stats/tracing

	retryThrottler *retryThrottler // The throttler active when the RPC began.

	binlogs []binarylog.MethodLogger
	// serverHeaderBinlogged is a boolean for whether server header has been
	// logged. Server header will be logged when the first time one of those
	// happens: stream.Header(), stream.Recv().
	//
	// It's only read and used by Recv() and Header(), so it doesn't need to be
	// synchronized.
	serverHeaderBinlogged bool

	mu                      sync.Mutex
	firstAttempt            bool // if true, transparent retry is valid
	numRetries              int  // exclusive of transparent retry attempt(s)
	numRetriesSincePushback int  // retries since pushback; to reset backoff
	finished                bool // TODO: replace with atomic cmpxchg or sync.Once?
	// attempt is the active client stream attempt.
	// The only place where it is written is the newAttemptLocked method and this method never writes nil.
	// So, attempt can be nil only inside newClientStream function when clientStream is first created.
	// One of the first things done after clientStream's creation, is to call newAttemptLocked which either
	// assigns a non nil value to the attempt or returns an error. If an error is returned from newAttemptLocked,
	// then newClientStream calls finish on the clientStream and returns. So, finish method is the only
	// place where we need to check if the attempt is nil.
	attempt *csAttempt
	// TODO(hedging): hedging will have multiple attempts simultaneously.
	committed        bool // active attempt committed for retry?
	onCommit         func()
	replayBuffer     []replayOp // operations to replay on retry
	replayBufferSize int        // current size of replayBuffer
	// nameResolutionDelay indicates if there was a delay in the name resolution.
	// This field is only valid on client side, it's always false on server side.
	nameResolutionDelay bool
}

type replayOp struct {
	op      func(a *csAttempt) error