[VOL-4289] Proto changes for gRPC migration
Change-Id: I317a0a865ccf78d0c37aa229c50d293a3f66c8bb
diff --git a/vendor/google.golang.org/grpc/picker_wrapper.go b/vendor/google.golang.org/grpc/picker_wrapper.go
new file mode 100644
index 0000000..0878ada
--- /dev/null
+++ b/vendor/google.golang.org/grpc/picker_wrapper.go
@@ -0,0 +1,177 @@
+/*
+ *
+ * Copyright 2017 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpc
+
+import (
+ "context"
+ "io"
+ "sync"
+
+ "google.golang.org/grpc/balancer"
+ "google.golang.org/grpc/codes"
+ "google.golang.org/grpc/internal/channelz"
+ "google.golang.org/grpc/internal/transport"
+ "google.golang.org/grpc/status"
+)
+
+// pickerWrapper is a wrapper of balancer.Picker. It blocks on certain pick
+// actions and unblock when there's a picker update.
+type pickerWrapper struct {
+ mu sync.Mutex
+ done bool
+ blockingCh chan struct{}
+ picker balancer.Picker
+}
+
+func newPickerWrapper() *pickerWrapper {
+ return &pickerWrapper{blockingCh: make(chan struct{})}
+}
+
+// updatePicker is called by UpdateBalancerState. It unblocks all blocked pick.
+func (pw *pickerWrapper) updatePicker(p balancer.Picker) {
+ pw.mu.Lock()
+ if pw.done {
+ pw.mu.Unlock()
+ return
+ }
+ pw.picker = p
+ // pw.blockingCh should never be nil.
+ close(pw.blockingCh)
+ pw.blockingCh = make(chan struct{})
+ pw.mu.Unlock()
+}
+
+func doneChannelzWrapper(acw *acBalancerWrapper, done func(balancer.DoneInfo)) func(balancer.DoneInfo) {
+ acw.mu.Lock()
+ ac := acw.ac
+ acw.mu.Unlock()
+ ac.incrCallsStarted()
+ return func(b balancer.DoneInfo) {
+ if b.Err != nil && b.Err != io.EOF {
+ ac.incrCallsFailed()
+ } else {
+ ac.incrCallsSucceeded()
+ }
+ if done != nil {
+ done(b)
+ }
+ }
+}
+
+// pick returns the transport that will be used for the RPC.
+// It may block in the following cases:
+// - there's no picker
+// - the current picker returns ErrNoSubConnAvailable
+// - the current picker returns other errors and failfast is false.
+// - the subConn returned by the current picker is not READY
+// When one of these situations happens, pick blocks until the picker gets updated.
+func (pw *pickerWrapper) pick(ctx context.Context, failfast bool, info balancer.PickInfo) (transport.ClientTransport, func(balancer.DoneInfo), error) {
+ var ch chan struct{}
+
+ var lastPickErr error
+ for {
+ pw.mu.Lock()
+ if pw.done {
+ pw.mu.Unlock()
+ return nil, nil, ErrClientConnClosing
+ }
+
+ if pw.picker == nil {
+ ch = pw.blockingCh
+ }
+ if ch == pw.blockingCh {
+ // This could happen when either:
+ // - pw.picker is nil (the previous if condition), or
+ // - has called pick on the current picker.
+ pw.mu.Unlock()
+ select {
+ case <-ctx.Done():
+ var errStr string
+ if lastPickErr != nil {
+ errStr = "latest balancer error: " + lastPickErr.Error()
+ } else {
+ errStr = ctx.Err().Error()
+ }
+ switch ctx.Err() {
+ case context.DeadlineExceeded:
+ return nil, nil, status.Error(codes.DeadlineExceeded, errStr)
+ case context.Canceled:
+ return nil, nil, status.Error(codes.Canceled, errStr)
+ }
+ case <-ch:
+ }
+ continue
+ }
+
+ ch = pw.blockingCh
+ p := pw.picker
+ pw.mu.Unlock()
+
+ pickResult, err := p.Pick(info)
+
+ if err != nil {
+ if err == balancer.ErrNoSubConnAvailable {
+ continue
+ }
+ if _, ok := status.FromError(err); ok {
+ // Status error: end the RPC unconditionally with this status.
+ return nil, nil, err
+ }
+ // For all other errors, wait for ready RPCs should block and other
+ // RPCs should fail with unavailable.
+ if !failfast {
+ lastPickErr = err
+ continue
+ }
+ return nil, nil, status.Error(codes.Unavailable, err.Error())
+ }
+
+ acw, ok := pickResult.SubConn.(*acBalancerWrapper)
+ if !ok {
+ logger.Error("subconn returned from pick is not *acBalancerWrapper")
+ continue
+ }
+ if t := acw.getAddrConn().getReadyTransport(); t != nil {
+ if channelz.IsOn() {
+ return t, doneChannelzWrapper(acw, pickResult.Done), nil
+ }
+ return t, pickResult.Done, nil
+ }
+ if pickResult.Done != nil {
+ // Calling done with nil error, no bytes sent and no bytes received.
+ // DoneInfo with default value works.
+ pickResult.Done(balancer.DoneInfo{})
+ }
+ logger.Infof("blockingPicker: the picked transport is not ready, loop back to repick")
+ // If ok == false, ac.state is not READY.
+ // A valid picker always returns READY subConn. This means the state of ac
+ // just changed, and picker will be updated shortly.
+ // continue back to the beginning of the for loop to repick.
+ }
+}
+
+func (pw *pickerWrapper) close() {
+ pw.mu.Lock()
+ defer pw.mu.Unlock()
+ if pw.done {
+ return
+ }
+ pw.done = true
+ close(pw.blockingCh)
+}