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-rw-r--r--vendor/google.golang.org/grpc/balancer/base/balancer.go208
-rw-r--r--vendor/google.golang.org/grpc/balancer/base/base.go52
2 files changed, 260 insertions, 0 deletions
diff --git a/vendor/google.golang.org/grpc/balancer/base/balancer.go b/vendor/google.golang.org/grpc/balancer/base/balancer.go
new file mode 100644
index 000000000..23d13511b
--- /dev/null
+++ b/vendor/google.golang.org/grpc/balancer/base/balancer.go
@@ -0,0 +1,208 @@
+/*
+ *
+ * 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 base
+
+import (
+ "golang.org/x/net/context"
+ "google.golang.org/grpc/balancer"
+ "google.golang.org/grpc/connectivity"
+ "google.golang.org/grpc/grpclog"
+ "google.golang.org/grpc/resolver"
+)
+
+type baseBuilder struct {
+ name string
+ pickerBuilder PickerBuilder
+}
+
+func (bb *baseBuilder) Build(cc balancer.ClientConn, opt balancer.BuildOptions) balancer.Balancer {
+ return &baseBalancer{
+ cc: cc,
+ pickerBuilder: bb.pickerBuilder,
+
+ subConns: make(map[resolver.Address]balancer.SubConn),
+ scStates: make(map[balancer.SubConn]connectivity.State),
+ csEvltr: &connectivityStateEvaluator{},
+ // Initialize picker to a picker that always return
+ // ErrNoSubConnAvailable, because when state of a SubConn changes, we
+ // may call UpdateBalancerState with this picker.
+ picker: NewErrPicker(balancer.ErrNoSubConnAvailable),
+ }
+}
+
+func (bb *baseBuilder) Name() string {
+ return bb.name
+}
+
+type baseBalancer struct {
+ cc balancer.ClientConn
+ pickerBuilder PickerBuilder
+
+ csEvltr *connectivityStateEvaluator
+ state connectivity.State
+
+ subConns map[resolver.Address]balancer.SubConn
+ scStates map[balancer.SubConn]connectivity.State
+ picker balancer.Picker
+}
+
+func (b *baseBalancer) HandleResolvedAddrs(addrs []resolver.Address, err error) {
+ if err != nil {
+ grpclog.Infof("base.baseBalancer: HandleResolvedAddrs called with error %v", err)
+ return
+ }
+ grpclog.Infoln("base.baseBalancer: got new resolved addresses: ", addrs)
+ // addrsSet is the set converted from addrs, it's used for quick lookup of an address.
+ addrsSet := make(map[resolver.Address]struct{})
+ for _, a := range addrs {
+ addrsSet[a] = struct{}{}
+ if _, ok := b.subConns[a]; !ok {
+ // a is a new address (not existing in b.subConns).
+ sc, err := b.cc.NewSubConn([]resolver.Address{a}, balancer.NewSubConnOptions{})
+ if err != nil {
+ grpclog.Warningf("base.baseBalancer: failed to create new SubConn: %v", err)
+ continue
+ }
+ b.subConns[a] = sc
+ b.scStates[sc] = connectivity.Idle
+ sc.Connect()
+ }
+ }
+ for a, sc := range b.subConns {
+ // a was removed by resolver.
+ if _, ok := addrsSet[a]; !ok {
+ b.cc.RemoveSubConn(sc)
+ delete(b.subConns, a)
+ // Keep the state of this sc in b.scStates until sc's state becomes Shutdown.
+ // The entry will be deleted in HandleSubConnStateChange.
+ }
+ }
+}
+
+// regeneratePicker takes a snapshot of the balancer, and generates a picker
+// from it. The picker is
+// - errPicker with ErrTransientFailure if the balancer is in TransientFailure,
+// - built by the pickerBuilder with all READY SubConns otherwise.
+func (b *baseBalancer) regeneratePicker() {
+ if b.state == connectivity.TransientFailure {
+ b.picker = NewErrPicker(balancer.ErrTransientFailure)
+ return
+ }
+ readySCs := make(map[resolver.Address]balancer.SubConn)
+
+ // Filter out all ready SCs from full subConn map.
+ for addr, sc := range b.subConns {
+ if st, ok := b.scStates[sc]; ok && st == connectivity.Ready {
+ readySCs[addr] = sc
+ }
+ }
+ b.picker = b.pickerBuilder.Build(readySCs)
+}
+
+func (b *baseBalancer) HandleSubConnStateChange(sc balancer.SubConn, s connectivity.State) {
+ grpclog.Infof("base.baseBalancer: handle SubConn state change: %p, %v", sc, s)
+ oldS, ok := b.scStates[sc]
+ if !ok {
+ grpclog.Infof("base.baseBalancer: got state changes for an unknown SubConn: %p, %v", sc, s)
+ return
+ }
+ b.scStates[sc] = s
+ switch s {
+ case connectivity.Idle:
+ sc.Connect()
+ case connectivity.Shutdown:
+ // When an address was removed by resolver, b called RemoveSubConn but
+ // kept the sc's state in scStates. Remove state for this sc here.
+ delete(b.scStates, sc)
+ }
+
+ oldAggrState := b.state
+ b.state = b.csEvltr.recordTransition(oldS, s)
+
+ // Regenerate picker when one of the following happens:
+ // - this sc became ready from not-ready
+ // - this sc became not-ready from ready
+ // - the aggregated state of balancer became TransientFailure from non-TransientFailure
+ // - the aggregated state of balancer became non-TransientFailure from TransientFailure
+ if (s == connectivity.Ready) != (oldS == connectivity.Ready) ||
+ (b.state == connectivity.TransientFailure) != (oldAggrState == connectivity.TransientFailure) {
+ b.regeneratePicker()
+ }
+
+ b.cc.UpdateBalancerState(b.state, b.picker)
+}
+
+// Close is a nop because base balancer doesn't have internal state to clean up,
+// and it doesn't need to call RemoveSubConn for the SubConns.
+func (b *baseBalancer) Close() {
+}
+
+// NewErrPicker returns a picker that always returns err on Pick().
+func NewErrPicker(err error) balancer.Picker {
+ return &errPicker{err: err}
+}
+
+type errPicker struct {
+ err error // Pick() always returns this err.
+}
+
+func (p *errPicker) Pick(ctx context.Context, opts balancer.PickOptions) (balancer.SubConn, func(balancer.DoneInfo), error) {
+ return nil, nil, p.err
+}
+
+// connectivityStateEvaluator gets updated by addrConns when their
+// states transition, based on which it evaluates the state of
+// ClientConn.
+type connectivityStateEvaluator struct {
+ numReady uint64 // Number of addrConns in ready state.
+ numConnecting uint64 // Number of addrConns in connecting state.
+ numTransientFailure uint64 // Number of addrConns in transientFailure.
+}
+
+// recordTransition records state change happening in every subConn and based on
+// that it evaluates what aggregated state should be.
+// It can only transition between Ready, Connecting and TransientFailure. Other states,
+// Idle and Shutdown are transitioned into by ClientConn; in the beginning of the connection
+// before any subConn is created ClientConn is in idle state. In the end when ClientConn
+// closes it is in Shutdown state.
+//
+// recordTransition should only be called synchronously from the same goroutine.
+func (cse *connectivityStateEvaluator) recordTransition(oldState, newState connectivity.State) connectivity.State {
+ // Update counters.
+ for idx, state := range []connectivity.State{oldState, newState} {
+ updateVal := 2*uint64(idx) - 1 // -1 for oldState and +1 for new.
+ switch state {
+ case connectivity.Ready:
+ cse.numReady += updateVal
+ case connectivity.Connecting:
+ cse.numConnecting += updateVal
+ case connectivity.TransientFailure:
+ cse.numTransientFailure += updateVal
+ }
+ }
+
+ // Evaluate.
+ if cse.numReady > 0 {
+ return connectivity.Ready
+ }
+ if cse.numConnecting > 0 {
+ return connectivity.Connecting
+ }
+ return connectivity.TransientFailure
+}
diff --git a/vendor/google.golang.org/grpc/balancer/base/base.go b/vendor/google.golang.org/grpc/balancer/base/base.go
new file mode 100644
index 000000000..012ace2f2
--- /dev/null
+++ b/vendor/google.golang.org/grpc/balancer/base/base.go
@@ -0,0 +1,52 @@
+/*
+ *
+ * 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 base defines a balancer base that can be used to build balancers with
+// different picking algorithms.
+//
+// The base balancer creates a new SubConn for each resolved address. The
+// provided picker will only be notified about READY SubConns.
+//
+// This package is the base of round_robin balancer, its purpose is to be used
+// to build round_robin like balancers with complex picking algorithms.
+// Balancers with more complicated logic should try to implement a balancer
+// builder from scratch.
+//
+// All APIs in this package are experimental.
+package base
+
+import (
+ "google.golang.org/grpc/balancer"
+ "google.golang.org/grpc/resolver"
+)
+
+// PickerBuilder creates balancer.Picker.
+type PickerBuilder interface {
+ // Build takes a slice of ready SubConns, and returns a picker that will be
+ // used by gRPC to pick a SubConn.
+ Build(readySCs map[resolver.Address]balancer.SubConn) balancer.Picker
+}
+
+// NewBalancerBuilder returns a balancer builder. The balancers
+// built by this builder will use the picker builder to build pickers.
+func NewBalancerBuilder(name string, pb PickerBuilder) balancer.Builder {
+ return &baseBuilder{
+ name: name,
+ pickerBuilder: pb,
+ }
+}