| /* |
| * |
| * Copyright 2020 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 stub implements a balancer for testing purposes. |
| package stub |
| |
| import "google.golang.org/grpc/balancer" |
| |
| // BalancerFuncs contains all balancer.Balancer functions with a preceding |
| // *BalancerData parameter for passing additional instance information. Any |
| // nil functions will never be called. |
| type BalancerFuncs struct { |
| // Init is called after ClientConn and BuildOptions are set in |
| // BalancerData. It may be used to initialize BalancerData.Data. |
| Init func(*BalancerData) |
| |
| UpdateClientConnState func(*BalancerData, balancer.ClientConnState) error |
| ResolverError func(*BalancerData, error) |
| UpdateSubConnState func(*BalancerData, balancer.SubConn, balancer.SubConnState) |
| Close func(*BalancerData) |
| } |
| |
| // BalancerData contains data relevant to a stub balancer. |
| type BalancerData struct { |
| // ClientConn is set by the builder. |
| ClientConn balancer.ClientConn |
| // BuildOptions is set by the builder. |
| BuildOptions balancer.BuildOptions |
| // Data may be used to store arbitrary user data. |
| Data interface{} |
| } |
| |
| type bal struct { |
| bf BalancerFuncs |
| bd *BalancerData |
| } |
| |
| func (b *bal) UpdateClientConnState(c balancer.ClientConnState) error { |
| if b.bf.UpdateClientConnState != nil { |
| return b.bf.UpdateClientConnState(b.bd, c) |
| } |
| return nil |
| } |
| |
| func (b *bal) ResolverError(e error) { |
| if b.bf.ResolverError != nil { |
| b.bf.ResolverError(b.bd, e) |
| } |
| } |
| |
| func (b *bal) UpdateSubConnState(sc balancer.SubConn, scs balancer.SubConnState) { |
| if b.bf.UpdateSubConnState != nil { |
| b.bf.UpdateSubConnState(b.bd, sc, scs) |
| } |
| } |
| |
| func (b *bal) Close() { |
| if b.bf.Close != nil { |
| b.bf.Close(b.bd) |
| } |
| } |
| |
| type bb struct { |
| name string |
| bf BalancerFuncs |
| } |
| |
| func (bb bb) Build(cc balancer.ClientConn, opts balancer.BuildOptions) balancer.Balancer { |
| b := &bal{bf: bb.bf, bd: &BalancerData{ClientConn: cc, BuildOptions: opts}} |
| if b.bf.Init != nil { |
| b.bf.Init(b.bd) |
| } |
| return b |
| } |
| |
| func (bb bb) Name() string { return bb.name } |
| |
| // Register registers a stub balancer builder which will call the provided |
| // functions. The name used should be unique. |
| func Register(name string, bf BalancerFuncs) { |
| balancer.Register(bb{name: name, bf: bf}) |
| } |