VOL-1967 move api-server to separate repository
Current with voltha-go acf0adaf2d91ae72b55192cc8a939e0485918d16
Change-Id: I000ea6be0789e20c922bd671562b58a7120892ae
diff --git a/vendor/google.golang.org/grpc/balancer_conn_wrappers.go b/vendor/google.golang.org/grpc/balancer_conn_wrappers.go
new file mode 100644
index 0000000..7233ade
--- /dev/null
+++ b/vendor/google.golang.org/grpc/balancer_conn_wrappers.go
@@ -0,0 +1,328 @@
+/*
+ *
+ * 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 (
+ "fmt"
+ "sync"
+
+ "google.golang.org/grpc/balancer"
+ "google.golang.org/grpc/connectivity"
+ "google.golang.org/grpc/grpclog"
+ "google.golang.org/grpc/resolver"
+)
+
+// scStateUpdate contains the subConn and the new state it changed to.
+type scStateUpdate struct {
+ sc balancer.SubConn
+ state connectivity.State
+}
+
+// scStateUpdateBuffer is an unbounded channel for scStateChangeTuple.
+// TODO make a general purpose buffer that uses interface{}.
+type scStateUpdateBuffer struct {
+ c chan *scStateUpdate
+ mu sync.Mutex
+ backlog []*scStateUpdate
+}
+
+func newSCStateUpdateBuffer() *scStateUpdateBuffer {
+ return &scStateUpdateBuffer{
+ c: make(chan *scStateUpdate, 1),
+ }
+}
+
+func (b *scStateUpdateBuffer) put(t *scStateUpdate) {
+ b.mu.Lock()
+ defer b.mu.Unlock()
+ if len(b.backlog) == 0 {
+ select {
+ case b.c <- t:
+ return
+ default:
+ }
+ }
+ b.backlog = append(b.backlog, t)
+}
+
+func (b *scStateUpdateBuffer) load() {
+ b.mu.Lock()
+ defer b.mu.Unlock()
+ if len(b.backlog) > 0 {
+ select {
+ case b.c <- b.backlog[0]:
+ b.backlog[0] = nil
+ b.backlog = b.backlog[1:]
+ default:
+ }
+ }
+}
+
+// get returns the channel that the scStateUpdate will be sent to.
+//
+// Upon receiving, the caller should call load to send another
+// scStateChangeTuple onto the channel if there is any.
+func (b *scStateUpdateBuffer) get() <-chan *scStateUpdate {
+ return b.c
+}
+
+// resolverUpdate contains the new resolved addresses or error if there's
+// any.
+type resolverUpdate struct {
+ addrs []resolver.Address
+ err error
+}
+
+// ccBalancerWrapper is a wrapper on top of cc for balancers.
+// It implements balancer.ClientConn interface.
+type ccBalancerWrapper struct {
+ cc *ClientConn
+ balancer balancer.Balancer
+ stateChangeQueue *scStateUpdateBuffer
+ resolverUpdateCh chan *resolverUpdate
+ done chan struct{}
+
+ mu sync.Mutex
+ subConns map[*acBalancerWrapper]struct{}
+}
+
+func newCCBalancerWrapper(cc *ClientConn, b balancer.Builder, bopts balancer.BuildOptions) *ccBalancerWrapper {
+ ccb := &ccBalancerWrapper{
+ cc: cc,
+ stateChangeQueue: newSCStateUpdateBuffer(),
+ resolverUpdateCh: make(chan *resolverUpdate, 1),
+ done: make(chan struct{}),
+ subConns: make(map[*acBalancerWrapper]struct{}),
+ }
+ go ccb.watcher()
+ ccb.balancer = b.Build(ccb, bopts)
+ return ccb
+}
+
+// watcher balancer functions sequentially, so the balancer can be implemented
+// lock-free.
+func (ccb *ccBalancerWrapper) watcher() {
+ for {
+ select {
+ case t := <-ccb.stateChangeQueue.get():
+ ccb.stateChangeQueue.load()
+ select {
+ case <-ccb.done:
+ ccb.balancer.Close()
+ return
+ default:
+ }
+ ccb.balancer.HandleSubConnStateChange(t.sc, t.state)
+ case t := <-ccb.resolverUpdateCh:
+ select {
+ case <-ccb.done:
+ ccb.balancer.Close()
+ return
+ default:
+ }
+ ccb.balancer.HandleResolvedAddrs(t.addrs, t.err)
+ case <-ccb.done:
+ }
+
+ select {
+ case <-ccb.done:
+ ccb.balancer.Close()
+ ccb.mu.Lock()
+ scs := ccb.subConns
+ ccb.subConns = nil
+ ccb.mu.Unlock()
+ for acbw := range scs {
+ ccb.cc.removeAddrConn(acbw.getAddrConn(), errConnDrain)
+ }
+ return
+ default:
+ }
+ }
+}
+
+func (ccb *ccBalancerWrapper) close() {
+ close(ccb.done)
+}
+
+func (ccb *ccBalancerWrapper) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State) {
+ // When updating addresses for a SubConn, if the address in use is not in
+ // the new addresses, the old ac will be tearDown() and a new ac will be
+ // created. tearDown() generates a state change with Shutdown state, we
+ // don't want the balancer to receive this state change. So before
+ // tearDown() on the old ac, ac.acbw (acWrapper) will be set to nil, and
+ // this function will be called with (nil, Shutdown). We don't need to call
+ // balancer method in this case.
+ if sc == nil {
+ return
+ }
+ ccb.stateChangeQueue.put(&scStateUpdate{
+ sc: sc,
+ state: s,
+ })
+}
+
+func (ccb *ccBalancerWrapper) handleResolvedAddrs(addrs []resolver.Address, err error) {
+ if ccb.cc.curBalancerName != grpclbName {
+ var containsGRPCLB bool
+ for _, a := range addrs {
+ if a.Type == resolver.GRPCLB {
+ containsGRPCLB = true
+ break
+ }
+ }
+ if containsGRPCLB {
+ // The current balancer is not grpclb, but addresses contain grpclb
+ // address. This means we failed to switch to grpclb, most likely
+ // because grpclb is not registered. Filter out all grpclb addresses
+ // from addrs before sending to balancer.
+ tempAddrs := make([]resolver.Address, 0, len(addrs))
+ for _, a := range addrs {
+ if a.Type != resolver.GRPCLB {
+ tempAddrs = append(tempAddrs, a)
+ }
+ }
+ addrs = tempAddrs
+ }
+ }
+ select {
+ case <-ccb.resolverUpdateCh:
+ default:
+ }
+ ccb.resolverUpdateCh <- &resolverUpdate{
+ addrs: addrs,
+ err: err,
+ }
+}
+
+func (ccb *ccBalancerWrapper) NewSubConn(addrs []resolver.Address, opts balancer.NewSubConnOptions) (balancer.SubConn, error) {
+ if len(addrs) <= 0 {
+ return nil, fmt.Errorf("grpc: cannot create SubConn with empty address list")
+ }
+ ccb.mu.Lock()
+ defer ccb.mu.Unlock()
+ if ccb.subConns == nil {
+ return nil, fmt.Errorf("grpc: ClientConn balancer wrapper was closed")
+ }
+ ac, err := ccb.cc.newAddrConn(addrs, opts)
+ if err != nil {
+ return nil, err
+ }
+ acbw := &acBalancerWrapper{ac: ac}
+ acbw.ac.mu.Lock()
+ ac.acbw = acbw
+ acbw.ac.mu.Unlock()
+ ccb.subConns[acbw] = struct{}{}
+ return acbw, nil
+}
+
+func (ccb *ccBalancerWrapper) RemoveSubConn(sc balancer.SubConn) {
+ acbw, ok := sc.(*acBalancerWrapper)
+ if !ok {
+ return
+ }
+ ccb.mu.Lock()
+ defer ccb.mu.Unlock()
+ if ccb.subConns == nil {
+ return
+ }
+ delete(ccb.subConns, acbw)
+ ccb.cc.removeAddrConn(acbw.getAddrConn(), errConnDrain)
+}
+
+func (ccb *ccBalancerWrapper) UpdateBalancerState(s connectivity.State, p balancer.Picker) {
+ ccb.mu.Lock()
+ defer ccb.mu.Unlock()
+ if ccb.subConns == nil {
+ return
+ }
+ // Update picker before updating state. Even though the ordering here does
+ // not matter, it can lead to multiple calls of Pick in the common start-up
+ // case where we wait for ready and then perform an RPC. If the picker is
+ // updated later, we could call the "connecting" picker when the state is
+ // updated, and then call the "ready" picker after the picker gets updated.
+ ccb.cc.blockingpicker.updatePicker(p)
+ ccb.cc.csMgr.updateState(s)
+}
+
+func (ccb *ccBalancerWrapper) ResolveNow(o resolver.ResolveNowOption) {
+ ccb.cc.resolveNow(o)
+}
+
+func (ccb *ccBalancerWrapper) Target() string {
+ return ccb.cc.target
+}
+
+// acBalancerWrapper is a wrapper on top of ac for balancers.
+// It implements balancer.SubConn interface.
+type acBalancerWrapper struct {
+ mu sync.Mutex
+ ac *addrConn
+}
+
+func (acbw *acBalancerWrapper) UpdateAddresses(addrs []resolver.Address) {
+ acbw.mu.Lock()
+ defer acbw.mu.Unlock()
+ if len(addrs) <= 0 {
+ acbw.ac.tearDown(errConnDrain)
+ return
+ }
+ if !acbw.ac.tryUpdateAddrs(addrs) {
+ cc := acbw.ac.cc
+ opts := acbw.ac.scopts
+ acbw.ac.mu.Lock()
+ // Set old ac.acbw to nil so the Shutdown state update will be ignored
+ // by balancer.
+ //
+ // TODO(bar) the state transition could be wrong when tearDown() old ac
+ // and creating new ac, fix the transition.
+ acbw.ac.acbw = nil
+ acbw.ac.mu.Unlock()
+ acState := acbw.ac.getState()
+ acbw.ac.tearDown(errConnDrain)
+
+ if acState == connectivity.Shutdown {
+ return
+ }
+
+ ac, err := cc.newAddrConn(addrs, opts)
+ if err != nil {
+ grpclog.Warningf("acBalancerWrapper: UpdateAddresses: failed to newAddrConn: %v", err)
+ return
+ }
+ acbw.ac = ac
+ ac.mu.Lock()
+ ac.acbw = acbw
+ ac.mu.Unlock()
+ if acState != connectivity.Idle {
+ ac.connect()
+ }
+ }
+}
+
+func (acbw *acBalancerWrapper) Connect() {
+ acbw.mu.Lock()
+ defer acbw.mu.Unlock()
+ acbw.ac.connect()
+}
+
+func (acbw *acBalancerWrapper) getAddrConn() *addrConn {
+ acbw.mu.Lock()
+ defer acbw.mu.Unlock()
+ return acbw.ac
+}