diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/balancer/base/balancer.go')
| -rw-r--r-- | vendor/google.golang.org/grpc/balancer/base/balancer.go | 208 |
1 files changed, 0 insertions, 208 deletions
diff --git a/vendor/google.golang.org/grpc/balancer/base/balancer.go b/vendor/google.golang.org/grpc/balancer/base/balancer.go deleted file mode 100644 index 23d1351..0000000 --- a/vendor/google.golang.org/grpc/balancer/base/balancer.go +++ /dev/null @@ -1,208 +0,0 @@ -/* - * - * 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 -} |