peridot/vendor/google.golang.org/grpc/resolver/manual/manual.go
Mustafa Gezen ad0f7a5305
Major upgrades
Upgrade to Go 1.20.5, Hydra v2 SDK, rules-go v0.44.2 (with proper resolves), protobuf v25.3 and mass upgrade of Go dependencies.
2024-03-17 08:06:08 +01:00

127 lines
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Go

/*
*
* 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 manual defines a resolver that can be used to manually send resolved
// addresses to ClientConn.
package manual
import (
"sync"
"google.golang.org/grpc/resolver"
)
// NewBuilderWithScheme creates a new manual resolver builder with the given
// scheme. Every instance of the manual resolver may only ever be used with a
// single grpc.ClientConn. Otherwise, bad things will happen.
func NewBuilderWithScheme(scheme string) *Resolver {
return &Resolver{
BuildCallback: func(resolver.Target, resolver.ClientConn, resolver.BuildOptions) {},
UpdateStateCallback: func(error) {},
ResolveNowCallback: func(resolver.ResolveNowOptions) {},
CloseCallback: func() {},
scheme: scheme,
}
}
// Resolver is also a resolver builder.
// It's build() function always returns itself.
type Resolver struct {
// BuildCallback is called when the Build method is called. Must not be
// nil. Must not be changed after the resolver may be built.
BuildCallback func(resolver.Target, resolver.ClientConn, resolver.BuildOptions)
// UpdateStateCallback is called when the UpdateState method is called on
// the resolver. The value passed as argument to this callback is the value
// returned by the resolver.ClientConn. Must not be nil. Must not be
// changed after the resolver may be built.
UpdateStateCallback func(err error)
// ResolveNowCallback is called when the ResolveNow method is called on the
// resolver. Must not be nil. Must not be changed after the resolver may
// be built.
ResolveNowCallback func(resolver.ResolveNowOptions)
// CloseCallback is called when the Close method is called. Must not be
// nil. Must not be changed after the resolver may be built.
CloseCallback func()
scheme string
// Fields actually belong to the resolver.
// Guards access to below fields.
mu sync.Mutex
CC resolver.ClientConn
// Storing the most recent state update makes this resolver resilient to
// restarts, which is possible with channel idleness.
lastSeenState *resolver.State
}
// InitialState adds initial state to the resolver so that UpdateState doesn't
// need to be explicitly called after Dial.
func (r *Resolver) InitialState(s resolver.State) {
r.lastSeenState = &s
}
// Build returns itself for Resolver, because it's both a builder and a resolver.
func (r *Resolver) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (resolver.Resolver, error) {
r.BuildCallback(target, cc, opts)
r.mu.Lock()
defer r.mu.Unlock()
r.CC = cc
if r.lastSeenState != nil {
err := r.CC.UpdateState(*r.lastSeenState)
go r.UpdateStateCallback(err)
}
return r, nil
}
// Scheme returns the manual resolver's scheme.
func (r *Resolver) Scheme() string {
return r.scheme
}
// ResolveNow is a noop for Resolver.
func (r *Resolver) ResolveNow(o resolver.ResolveNowOptions) {
r.ResolveNowCallback(o)
}
// Close is a noop for Resolver.
func (r *Resolver) Close() {
r.CloseCallback()
}
// UpdateState calls CC.UpdateState.
func (r *Resolver) UpdateState(s resolver.State) {
r.mu.Lock()
defer r.mu.Unlock()
var err error
if r.CC == nil {
panic("cannot update state as grpc.Dial with resolver has not been called")
}
err = r.CC.UpdateState(s)
r.lastSeenState = &s
r.UpdateStateCallback(err)
}
// ReportError calls CC.ReportError.
func (r *Resolver) ReportError(err error) {
r.mu.Lock()
defer r.mu.Unlock()
if r.CC == nil {
panic("cannot report error as grpc.Dial with resolver has not been called")
}
r.CC.ReportError(err)
}