initial add - go fmt on grpc
Change-Id: Ib0afadd2fe5571d1456a091f94f5644458f7d3f4
diff --git a/vendor/google.golang.org/grpc/internal/transport/flowcontrol.go b/vendor/google.golang.org/grpc/internal/transport/flowcontrol.go
new file mode 100644
index 0000000..f262edd
--- /dev/null
+++ b/vendor/google.golang.org/grpc/internal/transport/flowcontrol.go
@@ -0,0 +1,217 @@
+/*
+ *
+ * Copyright 2014 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 transport
+
+import (
+ "fmt"
+ "math"
+ "sync"
+ "sync/atomic"
+)
+
+// writeQuota is a soft limit on the amount of data a stream can
+// schedule before some of it is written out.
+type writeQuota struct {
+ quota int32
+ // get waits on read from when quota goes less than or equal to zero.
+ // replenish writes on it when quota goes positive again.
+ ch chan struct{}
+ // done is triggered in error case.
+ done <-chan struct{}
+ // replenish is called by loopyWriter to give quota back to.
+ // It is implemented as a field so that it can be updated
+ // by tests.
+ replenish func(n int)
+}
+
+func newWriteQuota(sz int32, done <-chan struct{}) *writeQuota {
+ w := &writeQuota{
+ quota: sz,
+ ch: make(chan struct{}, 1),
+ done: done,
+ }
+ w.replenish = w.realReplenish
+ return w
+}
+
+func (w *writeQuota) get(sz int32) error {
+ for {
+ if atomic.LoadInt32(&w.quota) > 0 {
+ atomic.AddInt32(&w.quota, -sz)
+ return nil
+ }
+ select {
+ case <-w.ch:
+ continue
+ case <-w.done:
+ return errStreamDone
+ }
+ }
+}
+
+func (w *writeQuota) realReplenish(n int) {
+ sz := int32(n)
+ a := atomic.AddInt32(&w.quota, sz)
+ b := a - sz
+ if b <= 0 && a > 0 {
+ select {
+ case w.ch <- struct{}{}:
+ default:
+ }
+ }
+}
+
+type trInFlow struct {
+ limit uint32
+ unacked uint32
+ effectiveWindowSize uint32
+}
+
+func (f *trInFlow) newLimit(n uint32) uint32 {
+ d := n - f.limit
+ f.limit = n
+ f.updateEffectiveWindowSize()
+ return d
+}
+
+func (f *trInFlow) onData(n uint32) uint32 {
+ f.unacked += n
+ if f.unacked >= f.limit/4 {
+ w := f.unacked
+ f.unacked = 0
+ f.updateEffectiveWindowSize()
+ return w
+ }
+ f.updateEffectiveWindowSize()
+ return 0
+}
+
+func (f *trInFlow) reset() uint32 {
+ w := f.unacked
+ f.unacked = 0
+ f.updateEffectiveWindowSize()
+ return w
+}
+
+func (f *trInFlow) updateEffectiveWindowSize() {
+ atomic.StoreUint32(&f.effectiveWindowSize, f.limit-f.unacked)
+}
+
+func (f *trInFlow) getSize() uint32 {
+ return atomic.LoadUint32(&f.effectiveWindowSize)
+}
+
+// TODO(mmukhi): Simplify this code.
+// inFlow deals with inbound flow control
+type inFlow struct {
+ mu sync.Mutex
+ // The inbound flow control limit for pending data.
+ limit uint32
+ // pendingData is the overall data which have been received but not been
+ // consumed by applications.
+ pendingData uint32
+ // The amount of data the application has consumed but grpc has not sent
+ // window update for them. Used to reduce window update frequency.
+ pendingUpdate uint32
+ // delta is the extra window update given by receiver when an application
+ // is reading data bigger in size than the inFlow limit.
+ delta uint32
+}
+
+// newLimit updates the inflow window to a new value n.
+// It assumes that n is always greater than the old limit.
+func (f *inFlow) newLimit(n uint32) uint32 {
+ f.mu.Lock()
+ d := n - f.limit
+ f.limit = n
+ f.mu.Unlock()
+ return d
+}
+
+func (f *inFlow) maybeAdjust(n uint32) uint32 {
+ if n > uint32(math.MaxInt32) {
+ n = uint32(math.MaxInt32)
+ }
+ f.mu.Lock()
+ defer f.mu.Unlock()
+ // estSenderQuota is the receiver's view of the maximum number of bytes the sender
+ // can send without a window update.
+ estSenderQuota := int32(f.limit - (f.pendingData + f.pendingUpdate))
+ // estUntransmittedData is the maximum number of bytes the sends might not have put
+ // on the wire yet. A value of 0 or less means that we have already received all or
+ // more bytes than the application is requesting to read.
+ estUntransmittedData := int32(n - f.pendingData) // Casting into int32 since it could be negative.
+ // This implies that unless we send a window update, the sender won't be able to send all the bytes
+ // for this message. Therefore we must send an update over the limit since there's an active read
+ // request from the application.
+ if estUntransmittedData > estSenderQuota {
+ // Sender's window shouldn't go more than 2^31 - 1 as specified in the HTTP spec.
+ if f.limit+n > maxWindowSize {
+ f.delta = maxWindowSize - f.limit
+ } else {
+ // Send a window update for the whole message and not just the difference between
+ // estUntransmittedData and estSenderQuota. This will be helpful in case the message
+ // is padded; We will fallback on the current available window(at least a 1/4th of the limit).
+ f.delta = n
+ }
+ return f.delta
+ }
+ return 0
+}
+
+// onData is invoked when some data frame is received. It updates pendingData.
+func (f *inFlow) onData(n uint32) error {
+ f.mu.Lock()
+ f.pendingData += n
+ if f.pendingData+f.pendingUpdate > f.limit+f.delta {
+ limit := f.limit
+ rcvd := f.pendingData + f.pendingUpdate
+ f.mu.Unlock()
+ return fmt.Errorf("received %d-bytes data exceeding the limit %d bytes", rcvd, limit)
+ }
+ f.mu.Unlock()
+ return nil
+}
+
+// onRead is invoked when the application reads the data. It returns the window size
+// to be sent to the peer.
+func (f *inFlow) onRead(n uint32) uint32 {
+ f.mu.Lock()
+ if f.pendingData == 0 {
+ f.mu.Unlock()
+ return 0
+ }
+ f.pendingData -= n
+ if n > f.delta {
+ n -= f.delta
+ f.delta = 0
+ } else {
+ f.delta -= n
+ n = 0
+ }
+ f.pendingUpdate += n
+ if f.pendingUpdate >= f.limit/4 {
+ wu := f.pendingUpdate
+ f.pendingUpdate = 0
+ f.mu.Unlock()
+ return wu
+ }
+ f.mu.Unlock()
+ return 0
+}