// wait blocks until it can receive from ctx.Done, closing, or proceed.
// If it receives from ctx.Done, it returns 0, the StreamError for ctx.Err.
// If it receives from closing, it returns 0, ErrConnClosing.
// If it receives from proceed, it returns the received integer, nil.
func wait(ctx context.Context, closing <-chan struct{}, proceed <-chan int) (int, error) {
select {
case <-ctx.Done():
return 0, ContextErr(ctx.Err())
case <-closing:
return 0, ErrConnClosing
case i := <-proceed:
return i, nil
}
}
func (mn *multiNode) step(ctx context.Context, m multiMessage) error {
ch := mn.recvc
if m.msg.Type == pb.MsgProp {
ch = mn.propc
}
select {
case ch <- m:
return nil
case <-ctx.Done():
return ctx.Err()
case <-mn.done:
return ErrStopped
}
}
func (c *httpClusterClient) AutoSync(ctx context.Context, interval time.Duration) error {
ticker := time.NewTicker(interval)
defer ticker.Stop()
for {
err := c.Sync(ctx)
if err != nil {
return err
}
select {
case <-ctx.Done():
return ctx.Err()
case <-ticker.C:
}
}
}
func contextClient(ctx context.Context) (*http.Client, error) {
for _, fn := range contextClientFuncs {
c, err := fn(ctx)
if err != nil {
return nil, err
}
if c != nil {
return c, nil
}
}
if hc, ok := ctx.Value(HTTPClient).(*http.Client); ok {
return hc, nil
}
return http.DefaultClient, nil
}
func handleKeyWatch(ctx context.Context, w http.ResponseWriter, wa store.Watcher, stream bool, rt etcdserver.RaftTimer) {
defer wa.Remove()
ech := wa.EventChan()
var nch <-chan bool
if x, ok := w.(http.CloseNotifier); ok {
nch = x.CloseNotify()
}
w.Header().Set("Content-Type", "application/json")
w.Header().Set("X-Etcd-Index", fmt.Sprint(wa.StartIndex()))
w.Header().Set("X-Raft-Index", fmt.Sprint(rt.Index()))
w.Header().Set("X-Raft-Term", fmt.Sprint(rt.Term()))
w.WriteHeader(http.StatusOK)
// Ensure headers are flushed early, in case of long polling
w.(http.Flusher).Flush()
for {
select {
case <-nch:
// Client closed connection. Nothing to do.
return
case <-ctx.Done():
// Timed out. net/http will close the connection for us, so nothing to do.
return
case ev, ok := <-ech:
if !ok {
// If the channel is closed this may be an indication of
// that notifications are much more than we are able to
// send to the client in time. Then we simply end streaming.
return
}
ev = trimEventPrefix(ev, etcdserver.StoreKeysPrefix)
if err := json.NewEncoder(w).Encode(ev); err != nil {
// Should never be reached
plog.Warningf("error writing event (%v)", err)
return
}
if !stream {
return
}
w.(http.Flusher).Flush()
}
}
}
func (s *EtcdServer) V3DemoDo(ctx context.Context, r pb.InternalRaftRequest) (proto.Message, error) {
r.ID = s.reqIDGen.Next()
data, err := r.Marshal()
if err != nil {
return &pb.EmptyResponse{}, err
}
ch := s.w.Register(r.ID)
s.r.Propose(ctx, data)
select {
case x := <-ch:
result := x.(*applyResult)
return result.resp, result.err
case <-ctx.Done():
s.w.Trigger(r.ID, nil) // GC wait
return &pb.EmptyResponse{}, ctx.Err()
case <-s.done:
return &pb.EmptyResponse{}, ErrStopped
}
}
// FromContext returns the MD in ctx if it exists.
func FromContext(ctx context.Context) (md MD, ok bool) {
md, ok = ctx.Value(mdKey{}).(MD)
return
}
func (c *simpleHTTPClient) Do(ctx context.Context, act httpAction) (*http.Response, []byte, error) {
req := act.HTTPRequest(c.endpoint)
if err := printcURL(req); err != nil {
return nil, nil, err
}
hctx, hcancel := context.WithCancel(ctx)
if c.headerTimeout > 0 {
hctx, hcancel = context.WithTimeout(ctx, c.headerTimeout)
}
defer hcancel()
reqcancel := requestCanceler(c.transport, req)
rtchan := make(chan roundTripResponse, 1)
go func() {
resp, err := c.transport.RoundTrip(req)
rtchan <- roundTripResponse{resp: resp, err: err}
close(rtchan)
}()
var resp *http.Response
var err error
select {
case rtresp := <-rtchan:
resp, err = rtresp.resp, rtresp.err
case <-hctx.Done():
// cancel and wait for request to actually exit before continuing
reqcancel()
rtresp := <-rtchan
resp = rtresp.resp
switch {
case ctx.Err() != nil:
err = ctx.Err()
case hctx.Err() != nil:
err = fmt.Errorf("client: endpoint %s exceeded header timeout", c.endpoint.String())
default:
panic("failed to get error from context")
}
}
// always check for resp nil-ness to deal with possible
// race conditions between channels above
defer func() {
if resp != nil {
resp.Body.Close()
}
}()
if err != nil {
return nil, nil, err
}
var body []byte
done := make(chan struct{})
go func() {
body, err = ioutil.ReadAll(resp.Body)
done <- struct{}{}
}()
select {
case <-ctx.Done():
resp.Body.Close()
<-done
return nil, nil, ctx.Err()
case <-done:
}
return resp, body, err
}
// StreamFromContext returns the stream saved in ctx.
func StreamFromContext(ctx context.Context) (s *Stream, ok bool) {
s, ok = ctx.Value(streamKey).(*Stream)
return
}
// cc returns the internal *cloudContext (cc) state for a context.Context.
// It panics if the user did it wrong.
func cc(ctx context.Context) *cloudContext {
if c, ok := ctx.Value(contextKey{}).(*cloudContext); ok {
return c
}
panic("invalid context.Context type; it should be created with cloud.NewContext")
}
// 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)
}
}
authData := make(map[string]string)
for _, c := range t.authCreds {
data, err := c.GetRequestMetadata(ctx)
if err != nil {
return nil, StreamErrorf(codes.InvalidArgument, "transport: %v", err)
}
for k, v := range data {
authData[k] = v
}
}
if _, err := wait(ctx, t.shutdownChan, t.writableChan); err != nil {
return nil, err
}
t.mu.Lock()
if t.state != reachable {
t.mu.Unlock()
return nil, ErrConnClosing
}
if uint32(len(t.activeStreams)) >= t.maxStreams {
t.mu.Unlock()
t.writableChan <- 0
return nil, StreamErrorf(codes.Unavailable, "transport: failed to create new stream because the limit has been reached.")
}
s := t.newStream(ctx, callHdr)
t.activeStreams[s.id] = s
t.mu.Unlock()
// 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: "te", Value: "trailers"})
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 {
t.hEnc.WriteField(hpack.HeaderField{Name: k, Value: v})
}
}
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
}
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(hasMD && endHeaders, p)
first = false
} else {
// Sends Continuation frames for the leftover headers.
err = t.framer.writeContinuation(hasMD && endHeaders, 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
}