func (ht *serverHandlerTransport) HandleStreams(startStream func(*Stream)) {
// With this transport type there will be exactly 1 stream: this HTTP request.
var ctx context.Context
var cancel context.CancelFunc
if ht.timeoutSet {
ctx, cancel = context.WithTimeout(context.Background(), ht.timeout)
} else {
ctx, cancel = context.WithCancel(context.Background())
}
// requestOver is closed when either the request's context is done
// or the status has been written via WriteStatus.
requestOver := make(chan struct{})
// clientGone receives a single value if peer is gone, either
// because the underlying connection is dead or because the
// peer sends an http2 RST_STREAM.
clientGone := ht.rw.(http.CloseNotifier).CloseNotify()
go func() {
select {
case <-requestOver:
return
case <-ht.closedCh:
case <-clientGone:
}
cancel()
}()
req := ht.req
s := &Stream{
id: 0, // irrelevant
windowHandler: func(int) {}, // nothing
cancel: cancel,
buf: newRecvBuffer(),
st: ht,
method: req.URL.Path,
recvCompress: req.Header.Get("grpc-encoding"),
}
pr := &peer.Peer{
Addr: ht.RemoteAddr(),
}
if req.TLS != nil {
pr.AuthInfo = credentials.TLSInfo{*req.TLS}
}
ctx = metadata.NewContext(ctx, ht.headerMD)
ctx = peer.NewContext(ctx, pr)
s.ctx = newContextWithStream(ctx, s)
s.dec = &recvBufferReader{ctx: s.ctx, recv: s.buf}
// readerDone is closed when the Body.Read-ing goroutine exits.
readerDone := make(chan struct{})
go func() {
defer close(readerDone)
for {
buf := make([]byte, 1024) // TODO: minimize garbage, optimize recvBuffer code/ownership
n, err := req.Body.Read(buf)
if n > 0 {
s.buf.put(&recvMsg{data: buf[:n]})
}
if err != nil {
s.buf.put(&recvMsg{err: mapRecvMsgError(err)})
return
}
}
}()
// startStream is provided by the *grpc.Server's serveStreams.
// It starts a goroutine serving s and exits immediately.
// The goroutine that is started is the one that then calls
// into ht, calling WriteHeader, Write, WriteStatus, Close, etc.
startStream(s)
ht.runStream()
close(requestOver)
// Wait for reading goroutine to finish.
req.Body.Close()
<-readerDone
}
// operateHeader takes action on the decoded headers. It returns the current
// stream if there are remaining headers on the wire (in the following
// Continuation frame).
func (t *http2Server) operateHeaders(hDec *hpackDecoder, s *Stream, frame headerFrame, endStream bool, handle func(*Stream)) (pendingStream *Stream) {
defer func() {
if pendingStream == nil {
hDec.state = decodeState{}
}
}()
endHeaders, err := hDec.decodeServerHTTP2Headers(frame)
if s == nil {
// s has been closed.
return nil
}
if err != nil {
grpclog.Printf("transport: http2Server.operateHeader found %v", err)
if se, ok := err.(StreamError); ok {
t.controlBuf.put(&resetStream{s.id, statusCodeConvTab[se.Code]})
}
return nil
}
if endStream {
// s is just created by the caller. No lock needed.
s.state = streamReadDone
}
if !endHeaders {
return s
}
s.recvCompress = hDec.state.encoding
if hDec.state.timeoutSet {
s.ctx, s.cancel = context.WithTimeout(context.TODO(), hDec.state.timeout)
} else {
s.ctx, s.cancel = context.WithCancel(context.TODO())
}
pr := &peer.Peer{
Addr: t.conn.RemoteAddr(),
}
// Attach Auth info if there is any.
if t.authInfo != nil {
pr.AuthInfo = t.authInfo
}
s.ctx = peer.NewContext(s.ctx, pr)
// Cache the current stream to the context so that the server application
// can find out. Required when the server wants to send some metadata
// back to the client (unary call only).
s.ctx = newContextWithStream(s.ctx, s)
// Attach the received metadata to the context.
if len(hDec.state.mdata) > 0 {
s.ctx = metadata.NewContext(s.ctx, hDec.state.mdata)
}
s.dec = &recvBufferReader{
ctx: s.ctx,
recv: s.buf,
}
s.recvCompress = hDec.state.encoding
s.method = hDec.state.method
t.mu.Lock()
if t.state != reachable {
t.mu.Unlock()
return nil
}
if uint32(len(t.activeStreams)) >= t.maxStreams {
t.mu.Unlock()
t.controlBuf.put(&resetStream{s.id, http2.ErrCodeRefusedStream})
return nil
}
s.sendQuotaPool = newQuotaPool(int(t.streamSendQuota))
t.activeStreams[s.id] = s
t.mu.Unlock()
s.windowHandler = func(n int) {
t.updateWindow(s, uint32(n))
}
handle(s)
return nil
}
// NewStream creates a stream and register it into the transport as "active"
// streams.
func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Stream, err error) {
// Record the timeout value on the context.
var timeout time.Duration
if dl, ok := ctx.Deadline(); ok {
timeout = dl.Sub(time.Now())
if timeout <= 0 {
return nil, ContextErr(context.DeadlineExceeded)
}
}
pr := &peer.Peer{
Addr: t.conn.RemoteAddr(),
}
// Attach Auth info if there is any.
if t.authInfo != nil {
pr.AuthInfo = t.authInfo
}
ctx = peer.NewContext(ctx, pr)
authData := make(map[string]string)
for _, c := range t.authCreds {
// Construct URI required to get auth request metadata.
var port string
if pos := strings.LastIndex(t.target, ":"); pos != -1 {
// Omit port if it is the default one.
if t.target[pos+1:] != "443" {
port = ":" + t.target[pos+1:]
}
}
pos := strings.LastIndex(callHdr.Method, "/")
if pos == -1 {
return nil, StreamErrorf(codes.InvalidArgument, "transport: malformed method name: %q", callHdr.Method)
}
audience := "https://" + callHdr.Host + port + callHdr.Method[:pos]
data, err := c.GetRequestMetadata(ctx, audience)
if err != nil {
return nil, StreamErrorf(codes.InvalidArgument, "transport: %v", err)
}
for k, v := range data {
authData[k] = v
}
}
t.mu.Lock()
if t.state != reachable {
t.mu.Unlock()
return nil, ErrConnClosing
}
checkStreamsQuota := t.streamsQuota != nil
t.mu.Unlock()
if checkStreamsQuota {
sq, err := wait(ctx, t.shutdownChan, t.streamsQuota.acquire())
if err != nil {
return nil, err
}
// Returns the quota balance back.
if sq > 1 {
t.streamsQuota.add(sq - 1)
}
}
if _, err := wait(ctx, t.shutdownChan, t.writableChan); err != nil {
// t.streamsQuota will be updated when t.CloseStream is invoked.
return nil, err
}
t.mu.Lock()
if t.state != reachable {
t.mu.Unlock()
return nil, ErrConnClosing
}
s := t.newStream(ctx, callHdr)
t.activeStreams[s.id] = s
// This stream is not counted when applySetings(...) initialize t.streamsQuota.
// Reset t.streamsQuota to the right value.
var reset bool
if !checkStreamsQuota && t.streamsQuota != nil {
reset = true
}
t.mu.Unlock()
if reset {
t.streamsQuota.reset(-1)
}
// HPACK encodes various headers. Note that once WriteField(...) is
// called, the corresponding headers/continuation frame has to be sent
// because hpack.Encoder is stateful.
t.hBuf.Reset()
t.hEnc.WriteField(hpack.HeaderField{Name: ":method", Value: "POST"})
t.hEnc.WriteField(hpack.HeaderField{Name: ":scheme", Value: t.scheme})
t.hEnc.WriteField(hpack.HeaderField{Name: ":path", Value: callHdr.Method})
t.hEnc.WriteField(hpack.HeaderField{Name: ":authority", Value: callHdr.Host})
t.hEnc.WriteField(hpack.HeaderField{Name: "content-type", Value: "application/grpc"})
t.hEnc.WriteField(hpack.HeaderField{Name: "user-agent", Value: t.userAgent})
t.hEnc.WriteField(hpack.HeaderField{Name: "te", Value: "trailers"})
if callHdr.SendCompress != "" {
t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-encoding", Value: callHdr.SendCompress})
}
if timeout > 0 {
t.hEnc.WriteField(hpack.HeaderField{Name: "grpc-timeout", Value: timeoutEncode(timeout)})
}
for k, v := range authData {
t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: v})
}
var (
hasMD bool
endHeaders bool
)
if md, ok := metadata.FromContext(ctx); ok {
hasMD = true
for k, v := range md {
for _, entry := range v {
t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: entry})
}
}
}
first := true
// Sends the headers in a single batch even when they span multiple frames.
for !endHeaders {
size := t.hBuf.Len()
if size > http2MaxFrameLen {
size = http2MaxFrameLen
} else {
endHeaders = true
}
var flush bool
if endHeaders && (hasMD || callHdr.Flush) {
flush = true
}
if first {
// Sends a HeadersFrame to server to start a new stream.
p := http2.HeadersFrameParam{
StreamID: s.id,
BlockFragment: t.hBuf.Next(size),
EndStream: false,
EndHeaders: endHeaders,
}
// Do a force flush for the buffered frames iff it is the last headers frame
// and there is header metadata to be sent. Otherwise, there is flushing until
// the corresponding data frame is written.
err = t.framer.writeHeaders(flush, p)
first = false
} else {
// Sends Continuation frames for the leftover headers.
err = t.framer.writeContinuation(flush, s.id, endHeaders, t.hBuf.Next(size))
}
if err != nil {
t.notifyError(err)
return nil, ConnectionErrorf("transport: %v", err)
}
}
t.writableChan <- 0
return s, nil
}
// operateHeader takes action on the decoded headers.
func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(*Stream)) {
buf := newRecvBuffer()
fc := &inFlow{
limit: initialWindowSize,
conn: t.fc,
}
s := &Stream{
id: frame.Header().StreamID,
st: t,
buf: buf,
fc: fc,
}
var state decodeState
for _, hf := range frame.Fields {
state.processHeaderField(hf)
}
if err := state.err; err != nil {
if se, ok := err.(StreamError); ok {
t.controlBuf.put(&resetStream{s.id, statusCodeConvTab[se.Code]})
}
return
}
if frame.StreamEnded() {
// s is just created by the caller. No lock needed.
s.state = streamReadDone
}
s.recvCompress = state.encoding
if state.timeoutSet {
s.ctx, s.cancel = context.WithTimeout(context.TODO(), state.timeout)
} else {
s.ctx, s.cancel = context.WithCancel(context.TODO())
}
pr := &peer.Peer{
Addr: t.conn.RemoteAddr(),
}
// Attach Auth info if there is any.
if t.authInfo != nil {
pr.AuthInfo = t.authInfo
}
s.ctx = peer.NewContext(s.ctx, pr)
// Cache the current stream to the context so that the server application
// can find out. Required when the server wants to send some metadata
// back to the client (unary call only).
s.ctx = newContextWithStream(s.ctx, s)
// Attach the received metadata to the context.
if len(state.mdata) > 0 {
s.ctx = metadata.NewContext(s.ctx, state.mdata)
}
s.dec = &recvBufferReader{
ctx: s.ctx,
recv: s.buf,
}
s.recvCompress = state.encoding
s.method = state.method
t.mu.Lock()
if t.state != reachable {
t.mu.Unlock()
return
}
if uint32(len(t.activeStreams)) >= t.maxStreams {
t.mu.Unlock()
t.controlBuf.put(&resetStream{s.id, http2.ErrCodeRefusedStream})
return
}
s.sendQuotaPool = newQuotaPool(int(t.streamSendQuota))
t.activeStreams[s.id] = s
t.mu.Unlock()
s.windowHandler = func(n int) {
t.updateWindow(s, uint32(n))
}
handle(s)
}