1/* 2 * 3 * Copyright 2017 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19// Package manual defines a resolver that can be used to manually send resolved 20// addresses to ClientConn. 21package manual 22 23import ( 24 "google.golang.org/grpc/resolver" 25) 26 27// NewBuilderWithScheme creates a new test resolver builder with the given scheme. 28func NewBuilderWithScheme(scheme string) *Resolver { 29 return &Resolver{ 30 BuildCallback: func(resolver.Target, resolver.ClientConn, resolver.BuildOptions) {}, 31 ResolveNowCallback: func(resolver.ResolveNowOptions) {}, 32 CloseCallback: func() {}, 33 scheme: scheme, 34 } 35} 36 37// Resolver is also a resolver builder. 38// It's build() function always returns itself. 39type Resolver struct { 40 // BuildCallback is called when the Build method is called. Must not be 41 // nil. Must not be changed after the resolver may be built. 42 BuildCallback func(resolver.Target, resolver.ClientConn, resolver.BuildOptions) 43 // ResolveNowCallback is called when the ResolveNow method is called on the 44 // resolver. Must not be nil. Must not be changed after the resolver may 45 // be built. 46 ResolveNowCallback func(resolver.ResolveNowOptions) 47 // CloseCallback is called when the Close method is called. Must not be 48 // nil. Must not be changed after the resolver may be built. 49 CloseCallback func() 50 scheme string 51 52 // Fields actually belong to the resolver. 53 CC resolver.ClientConn 54 bootstrapState *resolver.State 55} 56 57// InitialState adds initial state to the resolver so that UpdateState doesn't 58// need to be explicitly called after Dial. 59func (r *Resolver) InitialState(s resolver.State) { 60 r.bootstrapState = &s 61} 62 63// Build returns itself for Resolver, because it's both a builder and a resolver. 64func (r *Resolver) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) { 65 r.BuildCallback(target, cc, opts) 66 r.CC = cc 67 if r.bootstrapState != nil { 68 r.UpdateState(*r.bootstrapState) 69 } 70 return r, nil 71} 72 73// Scheme returns the test scheme. 74func (r *Resolver) Scheme() string { 75 return r.scheme 76} 77 78// ResolveNow is a noop for Resolver. 79func (r *Resolver) ResolveNow(o resolver.ResolveNowOptions) { 80 r.ResolveNowCallback(o) 81} 82 83// Close is a noop for Resolver. 84func (r *Resolver) Close() { 85 r.CloseCallback() 86} 87 88// UpdateState calls CC.UpdateState. 89func (r *Resolver) UpdateState(s resolver.State) { 90 r.CC.UpdateState(s) 91} 92 93// ReportError calls CC.ReportError. 94func (r *Resolver) ReportError(err error) { 95 r.CC.ReportError(err) 96} 97