chore: bump deps

vendor/google.golang.org/grpc/internal/transport/client_stream.go

@@ -59,7 +59,7 @@ func (s *ClientStream) Read(n int) (mem.BufferSlice, error) {
 	return b, err
 }
 
-// Close closes the stream and popagates err to any readers.
+// Close closes the stream and propagates err to any readers.
 func (s *ClientStream) Close(err error) {
 	var (
 		rst     bool

vendor/google.golang.org/grpc/internal/transport/controlbuf.go

@@ -40,6 +40,13 @@ var updateHeaderTblSize = func(e *hpack.Encoder, v uint32) {
 	e.SetMaxDynamicTableSizeLimit(v)
 }
 
+// itemNodePool is used to reduce heap allocations.
+var itemNodePool = sync.Pool{
+	New: func() any {
+		return &itemNode{}
+	},
+}
+
 type itemNode struct {
 	it   any
 	next *itemNode
@@ -51,7 +58,9 @@ type itemList struct {
 }
 
 func (il *itemList) enqueue(i any) {
-	n := &itemNode{it: i}
+	n := itemNodePool.Get().(*itemNode)
+	n.next = nil
+	n.it = i
 	if il.tail == nil {
 		il.head, il.tail = n, n
 		return
@@ -71,7 +80,9 @@ func (il *itemList) dequeue() any {
 		return nil
 	}
 	i := il.head.it
+	temp := il.head
 	il.head = il.head.next
+	itemNodePool.Put(temp)
 	if il.head == nil {
 		il.tail = nil
 	}
@@ -146,10 +157,11 @@ type earlyAbortStream struct {
 func (*earlyAbortStream) isTransportResponseFrame() bool { return false }
 
 type dataFrame struct {
-	streamID  uint32
-	endStream bool
-	h         []byte
-	reader    mem.Reader
+	streamID   uint32
+	endStream  bool
+	h          []byte
+	data       mem.BufferSlice
+	processing bool
 	// onEachWrite is called every time
 	// a part of data is written out.
 	onEachWrite func()
@@ -234,6 +246,7 @@ type outStream struct {
 	itl              *itemList
 	bytesOutStanding int
 	wq               *writeQuota
+	reader           mem.Reader
 
 	next *outStream
 	prev *outStream
@@ -461,7 +474,9 @@ func (c *controlBuffer) finish() {
 				v.onOrphaned(ErrConnClosing)
 			}
 		case *dataFrame:
-			_ = v.reader.Close()
+			if !v.processing {
+				v.data.Free()
+			}
 		}
 	}
 
@@ -650,10 +665,11 @@ func (l *loopyWriter) incomingSettingsHandler(s *incomingSettings) error {
 
 func (l *loopyWriter) registerStreamHandler(h *registerStream) {
 	str := &outStream{
-		id:    h.streamID,
-		state: empty,
-		itl:   &itemList{},
-		wq:    h.wq,
+		id:     h.streamID,
+		state:  empty,
+		itl:    &itemList{},
+		wq:     h.wq,
+		reader: mem.BufferSlice{}.Reader(),
 	}
 	l.estdStreams[h.streamID] = str
 }
@@ -685,10 +701,11 @@ func (l *loopyWriter) headerHandler(h *headerFrame) error {
 	}
 	// Case 2: Client wants to originate stream.
 	str := &outStream{
-		id:    h.streamID,
-		state: empty,
-		itl:   &itemList{},
-		wq:    h.wq,
+		id:     h.streamID,
+		state:  empty,
+		itl:    &itemList{},
+		wq:     h.wq,
+		reader: mem.BufferSlice{}.Reader(),
 	}
 	return l.originateStream(str, h)
 }
@@ -790,10 +807,13 @@ func (l *loopyWriter) cleanupStreamHandler(c *cleanupStream) error {
 		// a RST_STREAM before stream initialization thus the stream might
 		// not be established yet.
 		delete(l.estdStreams, c.streamID)
+		str.reader.Close()
 		str.deleteSelf()
 		for head := str.itl.dequeueAll(); head != nil; head = head.next {
 			if df, ok := head.it.(*dataFrame); ok {
-				_ = df.reader.Close()
+				if !df.processing {
+					df.data.Free()
+				}
 			}
 		}
 	}
@@ -928,7 +948,13 @@ func (l *loopyWriter) processData() (bool, error) {
 	if str == nil {
 		return true, nil
 	}
+	reader := str.reader
 	dataItem := str.itl.peek().(*dataFrame) // Peek at the first data item this stream.
+	if !dataItem.processing {
+		dataItem.processing = true
+		str.reader.Reset(dataItem.data)
+		dataItem.data.Free()
+	}
 	// A data item is represented by a dataFrame, since it later translates into
 	// multiple HTTP2 data frames.
 	// Every dataFrame has two buffers; h that keeps grpc-message header and data
@@ -936,13 +962,13 @@ func (l *loopyWriter) processData() (bool, error) {
 	// from data is copied to h to make as big as the maximum possible HTTP2 frame
 	// size.
 
-	if len(dataItem.h) == 0 && dataItem.reader.Remaining() == 0 { // Empty data frame
+	if len(dataItem.h) == 0 && reader.Remaining() == 0 { // Empty data frame
 		// Client sends out empty data frame with endStream = true
 		if err := l.framer.fr.WriteData(dataItem.streamID, dataItem.endStream, nil); err != nil {
 			return false, err
 		}
 		str.itl.dequeue() // remove the empty data item from stream
-		_ = dataItem.reader.Close()
+		_ = reader.Close()
 		if str.itl.isEmpty() {
 			str.state = empty
 		} else if trailer, ok := str.itl.peek().(*headerFrame); ok { // the next item is trailers.
@@ -971,8 +997,8 @@ func (l *loopyWriter) processData() (bool, error) {
 	}
 	// Compute how much of the header and data we can send within quota and max frame length
 	hSize := min(maxSize, len(dataItem.h))
-	dSize := min(maxSize-hSize, dataItem.reader.Remaining())
-	remainingBytes := len(dataItem.h) + dataItem.reader.Remaining() - hSize - dSize
+	dSize := min(maxSize-hSize, reader.Remaining())
+	remainingBytes := len(dataItem.h) + reader.Remaining() - hSize - dSize
 	size := hSize + dSize
 
 	var buf *[]byte
@@ -993,7 +1019,7 @@ func (l *loopyWriter) processData() (bool, error) {
 		defer pool.Put(buf)
 
 		copy((*buf)[:hSize], dataItem.h)
-		_, _ = dataItem.reader.Read((*buf)[hSize:])
+		_, _ = reader.Read((*buf)[hSize:])
 	}
 
 	// Now that outgoing flow controls are checked we can replenish str's write quota
@@ -1014,7 +1040,7 @@ func (l *loopyWriter) processData() (bool, error) {
 	dataItem.h = dataItem.h[hSize:]
 
 	if remainingBytes == 0 { // All the data from that message was written out.
-		_ = dataItem.reader.Close()
+		_ = reader.Close()
 		str.itl.dequeue()
 	}
 	if str.itl.isEmpty() {

vendor/google.golang.org/grpc/internal/transport/http2_client.go

@@ -176,7 +176,7 @@ func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error
 		return fn(ctx, address)
 	}
 	if !ok {
-		networkType, address = parseDialTarget(address)
+		networkType, address = ParseDialTarget(address)
 	}
 	if opts, present := proxyattributes.Get(addr); present {
 		return proxyDial(ctx, addr, grpcUA, opts)
@@ -309,11 +309,9 @@ func NewHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 			scheme = "https"
 		}
 	}
-	dynamicWindow := true
 	icwz := int32(initialWindowSize)
 	if opts.InitialConnWindowSize >= defaultWindowSize {
 		icwz = opts.InitialConnWindowSize
-		dynamicWindow = false
 	}
 	writeBufSize := opts.WriteBufferSize
 	readBufSize := opts.ReadBufferSize
@@ -381,9 +379,8 @@ func NewHTTP2Client(connectCtx, ctx context.Context, addr resolver.Address, opts
 	t.controlBuf = newControlBuffer(t.ctxDone)
 	if opts.InitialWindowSize >= defaultWindowSize {
 		t.initialWindowSize = opts.InitialWindowSize
-		dynamicWindow = false
 	}
-	if dynamicWindow {
+	if !opts.StaticWindowSize {
 		t.bdpEst = &bdpEstimator{
 			bdp:               initialWindowSize,
 			updateFlowControl: t.updateFlowControl,
@@ -545,7 +542,7 @@ func (t *http2Client) createHeaderFields(ctx context.Context, callHdr *CallHdr)
 		Method:   callHdr.Method,
 		AuthInfo: t.authInfo,
 	}
-	ctxWithRequestInfo := icredentials.NewRequestInfoContext(ctx, ri)
+	ctxWithRequestInfo := credentials.NewContextWithRequestInfo(ctx, ri)
 	authData, err := t.getTrAuthData(ctxWithRequestInfo, aud)
 	if err != nil {
 		return nil, err
@@ -592,6 +589,9 @@ func (t *http2Client) createHeaderFields(ctx context.Context, callHdr *CallHdr)
 		// Send out timeout regardless its value. The server can detect timeout context by itself.
 		// TODO(mmukhi): Perhaps this field should be updated when actually writing out to the wire.
 		timeout := time.Until(dl)
+		if timeout <= 0 {
+			return nil, status.Error(codes.DeadlineExceeded, context.DeadlineExceeded.Error())
+		}
 		headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-timeout", Value: grpcutil.EncodeDuration(timeout)})
 	}
 	for k, v := range authData {
@@ -749,6 +749,25 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (*ClientS
 		callHdr = &newCallHdr
 	}
 
+	// The authority specified via the `CallAuthority` CallOption takes the
+	// highest precedence when determining the `:authority` header. It overrides
+	// any value present in the Host field of CallHdr. Before applying this
+	// override, the authority string is validated. If the credentials do not
+	// implement the AuthorityValidator interface, or if validation fails, the
+	// RPC is failed with a status code of `UNAVAILABLE`.
+	if callHdr.Authority != "" {
+		auth, ok := t.authInfo.(credentials.AuthorityValidator)
+		if !ok {
+			return nil, &NewStreamError{Err: status.Errorf(codes.Unavailable, "credentials type %q does not implement the AuthorityValidator interface, but authority override specified with CallAuthority call option", t.authInfo.AuthType())}
+		}
+		if err := auth.ValidateAuthority(callHdr.Authority); err != nil {
+			return nil, &NewStreamError{Err: status.Errorf(codes.Unavailable, "failed to validate authority %q : %v", callHdr.Authority, err)}
+		}
+		newCallHdr := *callHdr
+		newCallHdr.Host = callHdr.Authority
+		callHdr = &newCallHdr
+	}
+
 	headerFields, err := t.createHeaderFields(ctx, callHdr)
 	if err != nil {
 		return nil, &NewStreamError{Err: err, AllowTransparentRetry: false}
@@ -1069,32 +1088,29 @@ func (t *http2Client) GracefulClose() {
 // Write formats the data into HTTP2 data frame(s) and sends it out. The caller
 // should proceed only if Write returns nil.
 func (t *http2Client) write(s *ClientStream, hdr []byte, data mem.BufferSlice, opts *WriteOptions) error {
-	reader := data.Reader()
-
 	if opts.Last {
 		// If it's the last message, update stream state.
 		if !s.compareAndSwapState(streamActive, streamWriteDone) {
-			_ = reader.Close()
 			return errStreamDone
 		}
 	} else if s.getState() != streamActive {
-		_ = reader.Close()
 		return errStreamDone
 	}
 	df := &dataFrame{
 		streamID:  s.id,
 		endStream: opts.Last,
 		h:         hdr,
-		reader:    reader,
+		data:      data,
 	}
-	if hdr != nil || df.reader.Remaining() != 0 { // If it's not an empty data frame, check quota.
-		if err := s.wq.get(int32(len(hdr) + df.reader.Remaining())); err != nil {
-			_ = reader.Close()
+	dataLen := data.Len()
+	if hdr != nil || dataLen != 0 { // If it's not an empty data frame, check quota.
+		if err := s.wq.get(int32(len(hdr) + dataLen)); err != nil {
 			return err
 		}
 	}
+	data.Ref()
 	if err := t.controlBuf.put(df); err != nil {
-		_ = reader.Close()
+		data.Free()
 		return err
 	}
 	t.incrMsgSent()
@@ -1242,7 +1258,8 @@ func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) {
 			statusCode = codes.DeadlineExceeded
 		}
 	}
-	t.closeStream(s, io.EOF, false, http2.ErrCodeNo, status.Newf(statusCode, "stream terminated by RST_STREAM with error code: %v", f.ErrCode), nil, false)
+	st := status.Newf(statusCode, "stream terminated by RST_STREAM with error code: %v", f.ErrCode)
+	t.closeStream(s, st.Err(), false, http2.ErrCodeNo, st, nil, false)
 }
 
 func (t *http2Client) handleSettings(f *http2.SettingsFrame, isFirst bool) {
@@ -1390,8 +1407,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) error {
 // the caller.
 func (t *http2Client) setGoAwayReason(f *http2.GoAwayFrame) {
 	t.goAwayReason = GoAwayNoReason
-	switch f.ErrCode {
-	case http2.ErrCodeEnhanceYourCalm:
+	if f.ErrCode == http2.ErrCodeEnhanceYourCalm {
 		if string(f.DebugData()) == "too_many_pings" {
 			t.goAwayReason = GoAwayTooManyPings
 		}

vendor/google.golang.org/grpc/internal/transport/http2_server.go

@@ -35,9 +35,11 @@ import (
 
 	"golang.org/x/net/http2"
 	"golang.org/x/net/http2/hpack"
+	"google.golang.org/grpc/internal"
 	"google.golang.org/grpc/internal/grpclog"
 	"google.golang.org/grpc/internal/grpcutil"
 	"google.golang.org/grpc/internal/pretty"
+	istatus "google.golang.org/grpc/internal/status"
 	"google.golang.org/grpc/internal/syscall"
 	"google.golang.org/grpc/mem"
 	"google.golang.org/protobuf/proto"
@@ -130,6 +132,10 @@ type http2Server struct {
 	maxStreamID uint32 // max stream ID ever seen
 
 	logger *grpclog.PrefixLogger
+	// setResetPingStrikes is stored as a closure instead of making this a
+	// method on http2Server to avoid a heap allocation when converting a method
+	// to a closure for passing to frames objects.
+	setResetPingStrikes func()
 }
 
 // NewServerTransport creates a http2 transport with conn and configuration
@@ -174,16 +180,13 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 			Val: config.MaxStreams,
 		})
 	}
-	dynamicWindow := true
 	iwz := int32(initialWindowSize)
 	if config.InitialWindowSize >= defaultWindowSize {
 		iwz = config.InitialWindowSize
-		dynamicWindow = false
 	}
 	icwz := int32(initialWindowSize)
 	if config.InitialConnWindowSize >= defaultWindowSize {
 		icwz = config.InitialConnWindowSize
-		dynamicWindow = false
 	}
 	if iwz != defaultWindowSize {
 		isettings = append(isettings, http2.Setting{
@@ -264,6 +267,9 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 		initialWindowSize: iwz,
 		bufferPool:        config.BufferPool,
 	}
+	t.setResetPingStrikes = func() {
+		atomic.StoreUint32(&t.resetPingStrikes, 1)
+	}
 	var czSecurity credentials.ChannelzSecurityValue
 	if au, ok := authInfo.(credentials.ChannelzSecurityInfo); ok {
 		czSecurity = au.GetSecurityValue()
@@ -283,7 +289,7 @@ func NewServerTransport(conn net.Conn, config *ServerConfig) (_ ServerTransport,
 	t.logger = prefixLoggerForServerTransport(t)
 
 	t.controlBuf = newControlBuffer(t.done)
-	if dynamicWindow {
+	if !config.StaticWindowSize {
 		t.bdpEst = &bdpEstimator{
 			bdp:               initialWindowSize,
 			updateFlowControl: t.updateFlowControl,
@@ -594,10 +600,41 @@ func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeade
 			return nil
 		}
 	}
+
+	if s.ctx.Err() != nil {
+		t.mu.Unlock()
+		// Early abort in case the timeout was zero or so low it already fired.
+		t.controlBuf.put(&earlyAbortStream{
+			httpStatus:     http.StatusOK,
+			streamID:       s.id,
+			contentSubtype: s.contentSubtype,
+			status:         status.New(codes.DeadlineExceeded, context.DeadlineExceeded.Error()),
+			rst:            !frame.StreamEnded(),
+		})
+		return nil
+	}
+
 	t.activeStreams[streamID] = s
 	if len(t.activeStreams) == 1 {
 		t.idle = time.Time{}
 	}
+
+	// Start a timer to close the stream on reaching the deadline.
+	if timeoutSet {
+		// We need to wait for s.cancel to be updated before calling
+		// t.closeStream to avoid data races.
+		cancelUpdated := make(chan struct{})
+		timer := internal.TimeAfterFunc(timeout, func() {
+			<-cancelUpdated
+			t.closeStream(s, true, http2.ErrCodeCancel, false)
+		})
+		oldCancel := s.cancel
+		s.cancel = func() {
+			oldCancel()
+			timer.Stop()
+		}
+		close(cancelUpdated)
+	}
 	t.mu.Unlock()
 	if channelz.IsOn() {
 		t.channelz.SocketMetrics.StreamsStarted.Add(1)
@@ -998,10 +1035,6 @@ func (t *http2Server) writeHeader(s *ServerStream, md metadata.MD) error {
 	return nil
 }
 
-func (t *http2Server) setResetPingStrikes() {
-	atomic.StoreUint32(&t.resetPingStrikes, 1)
-}
-
 func (t *http2Server) writeHeaderLocked(s *ServerStream) error {
 	// TODO(mmukhi): Benchmark if the performance gets better if count the metadata and other header fields
 	// first and create a slice of that exact size.
@@ -1038,7 +1071,7 @@ func (t *http2Server) writeHeaderLocked(s *ServerStream) error {
 	return nil
 }
 
-// WriteStatus sends stream status to the client and terminates the stream.
+// writeStatus sends stream status to the client and terminates the stream.
 // There is no further I/O operations being able to perform on this stream.
 // TODO(zhaoq): Now it indicates the end of entire stream. Revisit if early
 // OK is adopted.
@@ -1066,7 +1099,7 @@ func (t *http2Server) writeStatus(s *ServerStream, st *status.Status) error {
 	headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-status", Value: strconv.Itoa(int(st.Code()))})
 	headerFields = append(headerFields, hpack.HeaderField{Name: "grpc-message", Value: encodeGrpcMessage(st.Message())})
 
-	if p := st.Proto(); p != nil && len(p.Details) > 0 {
+	if p := istatus.RawStatusProto(st); len(p.GetDetails()) > 0 {
 		// Do not use the user's grpc-status-details-bin (if present) if we are
 		// even attempting to set our own.
 		delete(s.trailer, grpcStatusDetailsBinHeader)
@@ -1114,17 +1147,13 @@ func (t *http2Server) writeStatus(s *ServerStream, st *status.Status) error {
 // Write converts the data into HTTP2 data frame and sends it out. Non-nil error
 // is returns if it fails (e.g., framing error, transport error).
 func (t *http2Server) write(s *ServerStream, hdr []byte, data mem.BufferSlice, _ *WriteOptions) error {
-	reader := data.Reader()
-
 	if !s.isHeaderSent() { // Headers haven't been written yet.
 		if err := t.writeHeader(s, nil); err != nil {
-			_ = reader.Close()
 			return err
 		}
 	} else {
 		// Writing headers checks for this condition.
 		if s.getState() == streamDone {
-			_ = reader.Close()
 			return t.streamContextErr(s)
 		}
 	}
@@ -1132,15 +1161,16 @@ func (t *http2Server) write(s *ServerStream, hdr []byte, data mem.BufferSlice, _
 	df := &dataFrame{
 		streamID:    s.id,
 		h:           hdr,
-		reader:      reader,
+		data:        data,
 		onEachWrite: t.setResetPingStrikes,
 	}
-	if err := s.wq.get(int32(len(hdr) + df.reader.Remaining())); err != nil {
-		_ = reader.Close()
+	dataLen := data.Len()
+	if err := s.wq.get(int32(len(hdr) + dataLen)); err != nil {
 		return t.streamContextErr(s)
 	}
+	data.Ref()
 	if err := t.controlBuf.put(df); err != nil {
-		_ = reader.Close()
+		data.Free()
 		return err
 	}
 	t.incrMsgSent()
@@ -1274,7 +1304,6 @@ func (t *http2Server) Close(err error) {
 
 // deleteStream deletes the stream s from transport's active streams.
 func (t *http2Server) deleteStream(s *ServerStream, eosReceived bool) {
-
 	t.mu.Lock()
 	if _, ok := t.activeStreams[s.id]; ok {
 		delete(t.activeStreams, s.id)
@@ -1324,7 +1353,10 @@ func (t *http2Server) closeStream(s *ServerStream, rst bool, rstCode http2.ErrCo
 	// called to interrupt the potential blocking on other goroutines.
 	s.cancel()
 
-	s.swapState(streamDone)
+	oldState := s.swapState(streamDone)
+	if oldState == streamDone {
+		return
+	}
 	t.deleteStream(s, eosReceived)
 
 	t.controlBuf.put(&cleanupStream{

vendor/google.golang.org/grpc/internal/transport/http_util.go

@@ -196,11 +196,11 @@ func decodeTimeout(s string) (time.Duration, error) {
 	if !ok {
 		return 0, fmt.Errorf("transport: timeout unit is not recognized: %q", s)
 	}
-	t, err := strconv.ParseInt(s[:size-1], 10, 64)
+	t, err := strconv.ParseUint(s[:size-1], 10, 64)
 	if err != nil {
 		return 0, err
 	}
-	const maxHours = math.MaxInt64 / int64(time.Hour)
+	const maxHours = math.MaxInt64 / uint64(time.Hour)
 	if d == time.Hour && t > maxHours {
 		// This timeout would overflow math.MaxInt64; clamp it.
 		return time.Duration(math.MaxInt64), nil
@@ -439,8 +439,8 @@ func getWriteBufferPool(size int) *sync.Pool {
 	return pool
 }
 
-// parseDialTarget returns the network and address to pass to dialer.
-func parseDialTarget(target string) (string, string) {
+// ParseDialTarget returns the network and address to pass to dialer.
+func ParseDialTarget(target string) (string, string) {
 	net := "tcp"
 	m1 := strings.Index(target, ":")
 	m2 := strings.Index(target, ":/")

vendor/google.golang.org/grpc/internal/transport/server_stream.go

@@ -35,8 +35,10 @@ type ServerStream struct {
 	*Stream // Embed for common stream functionality.
 
 	st      internalServerTransport
-	ctxDone <-chan struct{}    // closed at the end of stream.  Cache of ctx.Done() (for performance)
-	cancel  context.CancelFunc // invoked at the end of stream to cancel ctx.
+	ctxDone <-chan struct{} // closed at the end of stream.  Cache of ctx.Done() (for performance)
+	// cancel is invoked at the end of stream to cancel ctx. It also stops the
+	// timer for monitoring the rpc deadline if configured.
+	cancel func()
 
 	// Holds compressor names passed in grpc-accept-encoding metadata from the
 	// client.

vendor/google.golang.org/grpc/internal/transport/transport.go

@@ -466,6 +466,7 @@ type ServerConfig struct {
 	MaxHeaderListSize     *uint32
 	HeaderTableSize       *uint32
 	BufferPool            mem.BufferPool
+	StaticWindowSize      bool
 }
 
 // ConnectOptions covers all relevant options for communicating with the server.
@@ -504,6 +505,8 @@ type ConnectOptions struct {
 	MaxHeaderListSize *uint32
 	// The mem.BufferPool to use when reading/writing to the wire.
 	BufferPool mem.BufferPool
+	// StaticWindowSize controls whether dynamic window sizing is enabled.
+	StaticWindowSize bool
 }
 
 // WriteOptions provides additional hints and information for message
@@ -540,6 +543,11 @@ type CallHdr struct {
 	PreviousAttempts int // value of grpc-previous-rpc-attempts header to set
 
 	DoneFunc func() // called when the stream is finished
+
+	// Authority is used to explicitly override the `:authority` header. If set,
+	// this value takes precedence over the Host field and will be used as the
+	// value for the `:authority` header.
+	Authority string
 }
 
 // ClientTransport is the common interface for all gRPC client-side transport