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transport.go
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transport.go
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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Transport code.
package http2
import (
"bufio"
"bytes"
"crypto/tls"
"errors"
"fmt"
"io"
"io/ioutil"
"log"
"net"
"net/http"
"strconv"
"strings"
"sync"
"golang.org/x/net/http2/hpack"
)
const (
// transportDefaultConnFlow is how many connection-level flow control
// tokens we give the server at start-up, past the default 64k.
transportDefaultConnFlow = 1 << 30
// transportDefaultStreamFlow is how many stream-level flow
// control tokens we announce to the peer, and how many bytes
// we buffer per stream.
transportDefaultStreamFlow = 4 << 20
// transportDefaultStreamMinRefresh is the minimum number of bytes we'll send
// a stream-level WINDOW_UPDATE for at a time.
transportDefaultStreamMinRefresh = 4 << 10
)
// Transport is an HTTP/2 Transport.
//
// A Transport internally caches connections to servers. It is safe
// for concurrent use by multiple goroutines.
type Transport struct {
// DialTLS specifies an optional dial function for creating
// TLS connections for requests.
//
// If DialTLS is nil, tls.Dial is used.
//
// If the returned net.Conn has a ConnectionState method like tls.Conn,
// it will be used to set http.Response.TLS.
DialTLS func(network, addr string, cfg *tls.Config) (net.Conn, error)
// TLSClientConfig specifies the TLS configuration to use with
// tls.Client. If nil, the default configuration is used.
TLSClientConfig *tls.Config
// ConnPool optionally specifies an alternate connection pool to use.
// If nil, the default is used.
ConnPool ClientConnPool
connPoolOnce sync.Once
connPoolOrDef ClientConnPool // non-nil version of ConnPool
}
var errTransportVersion = errors.New("http2: ConfigureTransport is only supported starting at Go 1.6")
// ConfigureTransport configures a net/http HTTP/1 Transport to use HTTP/2.
// It requires Go 1.6 or later and returns an error if the net/http package is too old
// or if t1 has already been HTTP/2-enabled.
func ConfigureTransport(t1 *http.Transport) error {
return configureTransport(t1) // in configure_transport.go (go1.6) or go15.go
}
func (t *Transport) connPool() ClientConnPool {
t.connPoolOnce.Do(t.initConnPool)
return t.connPoolOrDef
}
func (t *Transport) initConnPool() {
if t.ConnPool != nil {
t.connPoolOrDef = t.ConnPool
} else {
t.connPoolOrDef = &clientConnPool{t: t}
}
}
// ClientConn is the state of a single HTTP/2 client connection to an
// HTTP/2 server.
type ClientConn struct {
t *Transport
tconn net.Conn // usually *tls.Conn, except specialized impls
tlsState *tls.ConnectionState // nil only for specialized impls
// readLoop goroutine fields:
readerDone chan struct{} // closed on error
readerErr error // set before readerDone is closed
mu sync.Mutex // guards following
cond *sync.Cond // hold mu; broadcast on flow/closed changes
flow flow // our conn-level flow control quota (cs.flow is per stream)
inflow flow // peer's conn-level flow control
closed bool
goAway *GoAwayFrame // if non-nil, the GoAwayFrame we received
streams map[uint32]*clientStream // client-initiated
nextStreamID uint32
bw *bufio.Writer
br *bufio.Reader
fr *Framer
// Settings from peer:
maxFrameSize uint32
maxConcurrentStreams uint32
initialWindowSize uint32
hbuf bytes.Buffer // HPACK encoder writes into this
henc *hpack.Encoder
freeBuf [][]byte
wmu sync.Mutex // held while writing; acquire AFTER wmu if holding both
werr error // first write error that has occurred
}
// clientStream is the state for a single HTTP/2 stream. One of these
// is created for each Transport.RoundTrip call.
type clientStream struct {
cc *ClientConn
ID uint32
resc chan resAndError
bufPipe pipe // buffered pipe with the flow-controlled response payload
flow flow // guarded by cc.mu
inflow flow // guarded by cc.mu
peerReset chan struct{} // closed on peer reset
resetErr error // populated before peerReset is closed
}
// checkReset reports any error sent in a RST_STREAM frame by the
// server.
func (cs *clientStream) checkReset() error {
select {
case <-cs.peerReset:
return cs.resetErr
default:
return nil
}
}
type stickyErrWriter struct {
w io.Writer
err *error
}
func (sew stickyErrWriter) Write(p []byte) (n int, err error) {
if *sew.err != nil {
return 0, *sew.err
}
n, err = sew.w.Write(p)
*sew.err = err
return
}
var ErrNoCachedConn = errors.New("http2: no cached connection was available")
// RoundTripOpt are options for the Transport.RoundTripOpt method.
type RoundTripOpt struct {
// OnlyCachedConn controls whether RoundTripOpt may
// create a new TCP connection. If set true and
// no cached connection is available, RoundTripOpt
// will return ErrNoCachedConn.
OnlyCachedConn bool
}
func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
return t.RoundTripOpt(req, RoundTripOpt{})
}
// authorityAddr returns a given authority (a host/IP, or host:port / ip:port)
// and returns a host:port. The port 443 is added if needed.
func authorityAddr(authority string) (addr string) {
if _, _, err := net.SplitHostPort(authority); err == nil {
return authority
}
return net.JoinHostPort(authority, "443")
}
// RoundTripOpt is like RoundTrip, but takes options.
func (t *Transport) RoundTripOpt(req *http.Request, opt RoundTripOpt) (*http.Response, error) {
if req.URL.Scheme != "https" {
return nil, errors.New("http2: unsupported scheme")
}
addr := authorityAddr(req.URL.Host)
for {
cc, err := t.connPool().GetClientConn(req, addr)
if err != nil {
return nil, err
}
res, err := cc.RoundTrip(req)
if shouldRetryRequest(req, err) {
continue
}
if err != nil {
return nil, err
}
return res, nil
}
}
// CloseIdleConnections closes any connections which were previously
// connected from previous requests but are now sitting idle.
// It does not interrupt any connections currently in use.
func (t *Transport) CloseIdleConnections() {
if cp, ok := t.connPool().(*clientConnPool); ok {
cp.closeIdleConnections()
}
}
var (
errClientConnClosed = errors.New("http2: client conn is closed")
errClientConnUnusable = errors.New("http2: client conn not usable")
)
func shouldRetryRequest(req *http.Request, err error) bool {
// TODO: retry GET requests (no bodies) more aggressively, if shutdown
// before response.
return err == errClientConnUnusable
}
func (t *Transport) dialClientConn(addr string) (*ClientConn, error) {
host, _, err := net.SplitHostPort(addr)
if err != nil {
return nil, err
}
tconn, err := t.dialTLS()("tcp", addr, t.newTLSConfig(host))
if err != nil {
return nil, err
}
return t.NewClientConn(tconn)
}
func (t *Transport) newTLSConfig(host string) *tls.Config {
cfg := new(tls.Config)
if t.TLSClientConfig != nil {
*cfg = *t.TLSClientConfig
}
cfg.NextProtos = []string{NextProtoTLS} // TODO: don't override if already in list
cfg.ServerName = host
return cfg
}
func (t *Transport) dialTLS() func(string, string, *tls.Config) (net.Conn, error) {
if t.DialTLS != nil {
return t.DialTLS
}
return t.dialTLSDefault
}
func (t *Transport) dialTLSDefault(network, addr string, cfg *tls.Config) (net.Conn, error) {
cn, err := tls.Dial(network, addr, cfg)
if err != nil {
return nil, err
}
if err := cn.Handshake(); err != nil {
return nil, err
}
if !cfg.InsecureSkipVerify {
if err := cn.VerifyHostname(cfg.ServerName); err != nil {
return nil, err
}
}
state := cn.ConnectionState()
if p := state.NegotiatedProtocol; p != NextProtoTLS {
return nil, fmt.Errorf("http2: unexpected ALPN protocol %q; want %q", p, NextProtoTLS)
}
if !state.NegotiatedProtocolIsMutual {
return nil, errors.New("http2: could not negotiate protocol mutually")
}
return cn, nil
}
func (t *Transport) NewClientConn(c net.Conn) (*ClientConn, error) {
if _, err := c.Write(clientPreface); err != nil {
return nil, err
}
cc := &ClientConn{
t: t,
tconn: c,
readerDone: make(chan struct{}),
nextStreamID: 1,
maxFrameSize: 16 << 10, // spec default
initialWindowSize: 65535, // spec default
maxConcurrentStreams: 1000, // "infinite", per spec. 1000 seems good enough.
streams: make(map[uint32]*clientStream),
}
cc.cond = sync.NewCond(&cc.mu)
cc.flow.add(int32(initialWindowSize))
// TODO: adjust this writer size to account for frame size +
// MTU + crypto/tls record padding.
cc.bw = bufio.NewWriter(stickyErrWriter{c, &cc.werr})
cc.br = bufio.NewReader(c)
cc.fr = NewFramer(cc.bw, cc.br)
cc.henc = hpack.NewEncoder(&cc.hbuf)
type connectionStater interface {
ConnectionState() tls.ConnectionState
}
if cs, ok := c.(connectionStater); ok {
state := cs.ConnectionState()
cc.tlsState = &state
}
cc.fr.WriteSettings(
Setting{ID: SettingEnablePush, Val: 0},
Setting{ID: SettingInitialWindowSize, Val: transportDefaultStreamFlow},
)
cc.fr.WriteWindowUpdate(0, transportDefaultConnFlow)
cc.inflow.add(transportDefaultConnFlow + initialWindowSize)
cc.bw.Flush()
if cc.werr != nil {
return nil, cc.werr
}
// Read the obligatory SETTINGS frame
f, err := cc.fr.ReadFrame()
if err != nil {
return nil, err
}
sf, ok := f.(*SettingsFrame)
if !ok {
return nil, fmt.Errorf("expected settings frame, got: %T", f)
}
cc.fr.WriteSettingsAck()
cc.bw.Flush()
sf.ForeachSetting(func(s Setting) error {
switch s.ID {
case SettingMaxFrameSize:
cc.maxFrameSize = s.Val
case SettingMaxConcurrentStreams:
cc.maxConcurrentStreams = s.Val
case SettingInitialWindowSize:
cc.initialWindowSize = s.Val
default:
// TODO(bradfitz): handle more
t.vlogf("Unhandled Setting: %v", s)
}
return nil
})
go cc.readLoop()
return cc, nil
}
func (cc *ClientConn) setGoAway(f *GoAwayFrame) {
cc.mu.Lock()
defer cc.mu.Unlock()
cc.goAway = f
}
func (cc *ClientConn) CanTakeNewRequest() bool {
cc.mu.Lock()
defer cc.mu.Unlock()
return cc.canTakeNewRequestLocked()
}
func (cc *ClientConn) canTakeNewRequestLocked() bool {
return cc.goAway == nil &&
int64(len(cc.streams)+1) < int64(cc.maxConcurrentStreams) &&
cc.nextStreamID < 2147483647
}
func (cc *ClientConn) closeIfIdle() {
cc.mu.Lock()
if len(cc.streams) > 0 {
cc.mu.Unlock()
return
}
cc.closed = true
// TODO: do clients send GOAWAY too? maybe? Just Close:
cc.mu.Unlock()
cc.tconn.Close()
}
const maxAllocFrameSize = 512 << 10
// frameBuffer returns a scratch buffer suitable for writing DATA frames.
// They're capped at the min of the peer's max frame size or 512KB
// (kinda arbitrarily), but definitely capped so we don't allocate 4GB
// bufers.
func (cc *ClientConn) frameScratchBuffer() []byte {
cc.mu.Lock()
size := cc.maxFrameSize
if size > maxAllocFrameSize {
size = maxAllocFrameSize
}
for i, buf := range cc.freeBuf {
if len(buf) >= int(size) {
cc.freeBuf[i] = nil
cc.mu.Unlock()
return buf[:size]
}
}
cc.mu.Unlock()
return make([]byte, size)
}
func (cc *ClientConn) putFrameScratchBuffer(buf []byte) {
cc.mu.Lock()
defer cc.mu.Unlock()
const maxBufs = 4 // arbitrary; 4 concurrent requests per conn? investigate.
if len(cc.freeBuf) < maxBufs {
cc.freeBuf = append(cc.freeBuf, buf)
return
}
for i, old := range cc.freeBuf {
if old == nil {
cc.freeBuf[i] = buf
return
}
}
// forget about it.
}
func (cc *ClientConn) RoundTrip(req *http.Request) (*http.Response, error) {
cc.mu.Lock()
if cc.closed || !cc.canTakeNewRequestLocked() {
cc.mu.Unlock()
return nil, errClientConnUnusable
}
cs := cc.newStream()
hasBody := req.Body != nil
// we send: HEADERS{1}, CONTINUATION{0,} + DATA{0,}
hdrs := cc.encodeHeaders(req)
first := true // first frame written (HEADERS is first, then CONTINUATION)
cc.wmu.Lock()
frameSize := int(cc.maxFrameSize)
for len(hdrs) > 0 && cc.werr == nil {
chunk := hdrs
if len(chunk) > frameSize {
chunk = chunk[:frameSize]
}
hdrs = hdrs[len(chunk):]
endHeaders := len(hdrs) == 0
if first {
cc.fr.WriteHeaders(HeadersFrameParam{
StreamID: cs.ID,
BlockFragment: chunk,
EndStream: !hasBody,
EndHeaders: endHeaders,
})
first = false
} else {
cc.fr.WriteContinuation(cs.ID, endHeaders, chunk)
}
}
cc.bw.Flush()
werr := cc.werr
cc.wmu.Unlock()
cc.mu.Unlock()
if werr != nil {
return nil, werr
}
var bodyCopyErrc chan error
var gotResHeaders chan struct{} // closed on resheaders
if hasBody {
bodyCopyErrc = make(chan error, 1)
gotResHeaders = make(chan struct{})
go func() {
bodyCopyErrc <- cs.writeRequestBody(req.Body, gotResHeaders)
}()
}
for {
select {
case re := <-cs.resc:
if gotResHeaders != nil {
close(gotResHeaders)
}
if re.err != nil {
return nil, re.err
}
res := re.res
res.Request = req
res.TLS = cc.tlsState
return res, nil
case err := <-bodyCopyErrc:
if err != nil {
return nil, err
}
}
}
}
var errServerResponseBeforeRequestBody = errors.New("http2: server sent response while still writing request body")
func (cs *clientStream) writeRequestBody(body io.Reader, gotResHeaders <-chan struct{}) error {
cc := cs.cc
sentEnd := false // whether we sent the final DATA frame w/ END_STREAM
buf := cc.frameScratchBuffer()
defer cc.putFrameScratchBuffer(buf)
for !sentEnd {
var sawEOF bool
n, err := io.ReadFull(body, buf)
if err == io.ErrUnexpectedEOF {
sawEOF = true
err = nil
} else if err == io.EOF {
break
} else if err != nil {
return err
}
toWrite := buf[:n]
for len(toWrite) > 0 && err == nil {
var allowed int32
allowed, err = cs.awaitFlowControl(int32(len(toWrite)))
if err != nil {
return err
}
cc.wmu.Lock()
select {
case <-gotResHeaders:
err = errServerResponseBeforeRequestBody
case <-cs.peerReset:
err = cs.resetErr
default:
data := toWrite[:allowed]
toWrite = toWrite[allowed:]
sentEnd = sawEOF && len(toWrite) == 0
err = cc.fr.WriteData(cs.ID, sentEnd, data)
}
cc.wmu.Unlock()
}
if err != nil {
return err
}
}
var err error
cc.wmu.Lock()
if !sentEnd {
err = cc.fr.WriteData(cs.ID, true, nil)
}
if ferr := cc.bw.Flush(); ferr != nil && err == nil {
err = ferr
}
cc.wmu.Unlock()
return err
}
// awaitFlowControl waits for [1, min(maxBytes, cc.cs.maxFrameSize)] flow
// control tokens from the server.
// It returns either the non-zero number of tokens taken or an error
// if the stream is dead.
func (cs *clientStream) awaitFlowControl(maxBytes int32) (taken int32, err error) {
cc := cs.cc
cc.mu.Lock()
defer cc.mu.Unlock()
for {
if cc.closed {
return 0, errClientConnClosed
}
if err := cs.checkReset(); err != nil {
return 0, err
}
if a := cs.flow.available(); a > 0 {
take := a
if take > maxBytes {
take = maxBytes
}
if take > int32(cc.maxFrameSize) {
take = int32(cc.maxFrameSize)
}
cs.flow.take(take)
return take, nil
}
cc.cond.Wait()
}
}
// requires cc.mu be held.
func (cc *ClientConn) encodeHeaders(req *http.Request) []byte {
cc.hbuf.Reset()
// TODO(bradfitz): figure out :authority-vs-Host stuff between http2 and Go
host := req.Host
if host == "" {
host = req.URL.Host
}
// 8.1.2.3 Request Pseudo-Header Fields
// The :path pseudo-header field includes the path and query parts of the
// target URI (the path-absolute production and optionally a '?' character
// followed by the query production (see Sections 3.3 and 3.4 of
// [RFC3986]).
cc.writeHeader(":authority", host) // probably not right for all sites
cc.writeHeader(":method", req.Method)
cc.writeHeader(":path", req.URL.RequestURI())
cc.writeHeader(":scheme", "https")
for k, vv := range req.Header {
lowKey := strings.ToLower(k)
if lowKey == "host" {
continue
}
for _, v := range vv {
cc.writeHeader(lowKey, v)
}
}
return cc.hbuf.Bytes()
}
func (cc *ClientConn) writeHeader(name, value string) {
cc.henc.WriteField(hpack.HeaderField{Name: name, Value: value})
}
type resAndError struct {
res *http.Response
err error
}
// requires cc.mu be held.
func (cc *ClientConn) newStream() *clientStream {
cs := &clientStream{
cc: cc,
ID: cc.nextStreamID,
resc: make(chan resAndError, 1),
peerReset: make(chan struct{}),
}
cs.flow.add(int32(cc.initialWindowSize))
cs.flow.setConnFlow(&cc.flow)
cs.inflow.add(transportDefaultStreamFlow)
cs.inflow.setConnFlow(&cc.inflow)
cc.nextStreamID += 2
cc.streams[cs.ID] = cs
return cs
}
func (cc *ClientConn) streamByID(id uint32, andRemove bool) *clientStream {
cc.mu.Lock()
defer cc.mu.Unlock()
cs := cc.streams[id]
if andRemove {
delete(cc.streams, id)
}
return cs
}
// clientConnReadLoop is the state owned by the clientConn's frame-reading readLoop.
type clientConnReadLoop struct {
cc *ClientConn
activeRes map[uint32]*clientStream // keyed by streamID
// continueStreamID is the stream ID we're waiting for
// continuation frames for.
continueStreamID uint32
hdec *hpack.Decoder
// Fields reset on each HEADERS:
nextRes *http.Response
sawRegHeader bool // saw non-pseudo header
reqMalformed error // non-nil once known to be malformed
}
// readLoop runs in its own goroutine and reads and dispatches frames.
func (cc *ClientConn) readLoop() {
rl := &clientConnReadLoop{
cc: cc,
activeRes: make(map[uint32]*clientStream),
}
// TODO: figure out henc size
rl.hdec = hpack.NewDecoder(initialHeaderTableSize, rl.onNewHeaderField)
defer rl.cleanup()
cc.readerErr = rl.run()
if ce, ok := cc.readerErr.(ConnectionError); ok {
cc.wmu.Lock()
cc.fr.WriteGoAway(0, ErrCode(ce), nil)
cc.wmu.Unlock()
}
}
func (rl *clientConnReadLoop) cleanup() {
cc := rl.cc
defer cc.tconn.Close()
defer cc.t.connPool().MarkDead(cc)
defer close(cc.readerDone)
// Close any response bodies if the server closes prematurely.
// TODO: also do this if we've written the headers but not
// gotten a response yet.
err := cc.readerErr
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
cc.mu.Lock()
for _, cs := range rl.activeRes {
cs.bufPipe.CloseWithError(err)
}
for _, cs := range cc.streams {
select {
case cs.resc <- resAndError{err: err}:
default:
}
}
cc.closed = true
cc.cond.Broadcast()
cc.mu.Unlock()
}
func (rl *clientConnReadLoop) run() error {
cc := rl.cc
for {
f, err := cc.fr.ReadFrame()
if se, ok := err.(StreamError); ok {
// TODO: deal with stream errors from the framer.
return se
} else if err != nil {
return err
}
cc.vlogf("Transport received %v: %#v", f.Header(), f)
streamID := f.Header().StreamID
_, isContinue := f.(*ContinuationFrame)
if isContinue {
if streamID != rl.continueStreamID {
cc.logf("Protocol violation: got CONTINUATION with id %d; want %d", streamID, rl.continueStreamID)
return ConnectionError(ErrCodeProtocol)
}
} else if rl.continueStreamID != 0 {
// Continue frames need to be adjacent in the stream
// and we were in the middle of headers.
cc.logf("Protocol violation: got %T for stream %d, want CONTINUATION for %d", f, streamID, rl.continueStreamID)
return ConnectionError(ErrCodeProtocol)
}
switch f := f.(type) {
case *HeadersFrame:
err = rl.processHeaders(f)
case *ContinuationFrame:
err = rl.processContinuation(f)
case *DataFrame:
err = rl.processData(f)
case *GoAwayFrame:
err = rl.processGoAway(f)
case *RSTStreamFrame:
err = rl.processResetStream(f)
case *SettingsFrame:
err = rl.processSettings(f)
case *PushPromiseFrame:
err = rl.processPushPromise(f)
case *WindowUpdateFrame:
err = rl.processWindowUpdate(f)
case *PingFrame:
err = rl.processPing(f)
default:
cc.logf("Transport: unhandled response frame type %T", f)
}
if err != nil {
return err
}
}
}
func (rl *clientConnReadLoop) processHeaders(f *HeadersFrame) error {
rl.sawRegHeader = false
rl.reqMalformed = nil
rl.nextRes = &http.Response{
Proto: "HTTP/2.0",
ProtoMajor: 2,
Header: make(http.Header),
}
return rl.processHeaderBlockFragment(f.HeaderBlockFragment(), f.StreamID, f.HeadersEnded(), f.StreamEnded())
}
func (rl *clientConnReadLoop) processContinuation(f *ContinuationFrame) error {
return rl.processHeaderBlockFragment(f.HeaderBlockFragment(), f.StreamID, f.HeadersEnded(), f.StreamEnded())
}
func (rl *clientConnReadLoop) processHeaderBlockFragment(frag []byte, streamID uint32, headersEnded, streamEnded bool) error {
cc := rl.cc
cs := cc.streamByID(streamID, streamEnded)
if cs == nil {
// We could return a ConnectionError(ErrCodeProtocol)
// here, except that in the case of us canceling
// client requests, we may also delete from the
// streams map, in which case we forgot that we sent
// this request. So, just ignore any responses for
// now. They might've been in-flight before the
// server got our RST_STREAM.
return nil
}
_, err := rl.hdec.Write(frag)
if err != nil {
return err
}
if !headersEnded {
rl.continueStreamID = cs.ID
return nil
}
// HEADERS (or CONTINUATION) are now over.
rl.continueStreamID = 0
if rl.reqMalformed != nil {
cs.resc <- resAndError{err: rl.reqMalformed}
rl.cc.writeStreamReset(cs.ID, ErrCodeProtocol, rl.reqMalformed)
return nil
}
res := rl.nextRes
if streamEnded {
res.Body = noBody
} else {
buf := new(bytes.Buffer) // TODO(bradfitz): recycle this garbage
cs.bufPipe = pipe{b: buf}
res.Body = transportResponseBody{cs}
}
rl.activeRes[cs.ID] = cs
cs.resc <- resAndError{res: res}
rl.nextRes = nil // unused now; will be reset next HEADERS frame
return nil
}
// transportResponseBody is the concrete type of Transport.RoundTrip's
// Response.Body. It is an io.ReadCloser. On Read, it reads from cs.body.
// On Close it sends RST_STREAM if EOF wasn't already seen.
type transportResponseBody struct {
cs *clientStream
}
func (b transportResponseBody) Read(p []byte) (n int, err error) {
n, err = b.cs.bufPipe.Read(p)
if n == 0 {
return
}
cs := b.cs
cc := cs.cc
cc.mu.Lock()
defer cc.mu.Unlock()
var connAdd, streamAdd int32
// Check the conn-level first, before the stream-level.
if v := cc.inflow.available(); v < transportDefaultConnFlow/2 {
connAdd = transportDefaultConnFlow - v
cc.inflow.add(connAdd)
}
if err == nil { // No need to refresh if the stream is over or failed.
if v := cs.inflow.available(); v < transportDefaultStreamFlow-transportDefaultStreamMinRefresh {
streamAdd = transportDefaultStreamFlow - v
cs.inflow.add(streamAdd)
}
}
if connAdd != 0 || streamAdd != 0 {
cc.wmu.Lock()
defer cc.wmu.Unlock()
if connAdd != 0 {
cc.fr.WriteWindowUpdate(0, mustUint31(connAdd))
}
if streamAdd != 0 {
cc.fr.WriteWindowUpdate(cs.ID, mustUint31(streamAdd))
}
cc.bw.Flush()
}
return
}
func (b transportResponseBody) Close() error {
if b.cs.bufPipe.Err() != io.EOF {
// TODO: write test for this
b.cs.cc.writeStreamReset(b.cs.ID, ErrCodeCancel, nil)
}
return nil
}
func (rl *clientConnReadLoop) processData(f *DataFrame) error {
cc := rl.cc
cs := cc.streamByID(f.StreamID, f.StreamEnded())
if cs == nil {
return nil
}
data := f.Data()
if VerboseLogs {
rl.cc.logf("DATA: %q", data)
}
// Check connection-level flow control.
cc.mu.Lock()
if cs.inflow.available() >= int32(len(data)) {
cs.inflow.take(int32(len(data)))
} else {
cc.mu.Unlock()
return ConnectionError(ErrCodeFlowControl)
}
cc.mu.Unlock()
if _, err := cs.bufPipe.Write(data); err != nil {
return err
}
if f.StreamEnded() {
cs.bufPipe.CloseWithError(io.EOF)
delete(rl.activeRes, cs.ID)
}
return nil
}
func (rl *clientConnReadLoop) processGoAway(f *GoAwayFrame) error {
cc := rl.cc
cc.t.connPool().MarkDead(cc)
if f.ErrCode != 0 {
// TODO: deal with GOAWAY more. particularly the error code
cc.vlogf("transport got GOAWAY with error code = %v", f.ErrCode)
}
cc.setGoAway(f)
return nil
}
func (rl *clientConnReadLoop) processSettings(f *SettingsFrame) error {
cc := rl.cc
cc.mu.Lock()
defer cc.mu.Unlock()
return f.ForeachSetting(func(s Setting) error {
switch s.ID {
case SettingMaxFrameSize:
cc.maxFrameSize = s.Val
case SettingMaxConcurrentStreams:
cc.maxConcurrentStreams = s.Val
case SettingInitialWindowSize:
// TODO: error if this is too large.
// TODO: adjust flow control of still-open
// frames by the difference of the old initial
// window size and this one.
cc.initialWindowSize = s.Val
default:
// TODO(bradfitz): handle more settings?
cc.vlogf("Unhandled Setting: %v", s)
}
return nil
})
}
func (rl *clientConnReadLoop) processWindowUpdate(f *WindowUpdateFrame) error {
cc := rl.cc
cs := cc.streamByID(f.StreamID, false)
if f.StreamID != 0 && cs == nil {
return nil
}
cc.mu.Lock()
defer cc.mu.Unlock()
fl := &cc.flow
if cs != nil {
fl = &cs.flow
}
if !fl.add(int32(f.Increment)) {
return ConnectionError(ErrCodeFlowControl)
}
cc.cond.Broadcast()
return nil
}
func (rl *clientConnReadLoop) processResetStream(f *RSTStreamFrame) error {
cs := rl.cc.streamByID(f.StreamID, true)
if cs == nil {
// TODO: return error if server tries to RST_STEAM an idle stream
return nil
}
select {
case <-cs.peerReset:
// Already reset.
// This is the only goroutine
// which closes this, so there
// isn't a race.
default:
err := StreamError{cs.ID, f.ErrCode}
cs.resetErr = err
close(cs.peerReset)
cs.bufPipe.CloseWithError(err)
}