81 lines
2.2 KiB
Go
81 lines
2.2 KiB
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 roundrobin defines a roundrobin balancer. Roundrobin balancer is
|
|
// installed as one of the default balancers in gRPC, users don't need to
|
|
// explicitly install this balancer.
|
|
package random
|
|
|
|
import (
|
|
"google.golang.org/grpc/balancer"
|
|
"google.golang.org/grpc/balancer/base"
|
|
"google.golang.org/grpc/grpclog"
|
|
"log"
|
|
"math/rand"
|
|
)
|
|
|
|
// Name is the name of round_robin balancer.
|
|
const Name = "my_random_robin"
|
|
|
|
var logger = grpclog.Component("myrandomrobin")
|
|
|
|
// newBuilder creates a new roundrobin balancer builder.
|
|
func newBuilder() balancer.Builder {
|
|
return base.NewBalancerBuilder(Name, &randomPickerBuilder{}, base.Config{HealthCheck: true})
|
|
}
|
|
|
|
func init() {
|
|
balancer.Register(newBuilder())
|
|
}
|
|
|
|
type randomPickerBuilder struct{}
|
|
|
|
type subConnInfo struct {
|
|
conn balancer.SubConn
|
|
connInfo base.SubConnInfo
|
|
}
|
|
|
|
func (r *randomPickerBuilder) Build(info base.PickerBuildInfo) balancer.Picker {
|
|
logger.Infof("myrandomrobin Picker: Build called with info: %v", info)
|
|
log.Printf("myrandomrobin Picker: Build called with info: %v", info)
|
|
if len(info.ReadySCs) == 0 {
|
|
return base.NewErrPicker(balancer.ErrNoSubConnAvailable)
|
|
}
|
|
scs := make([]*subConnInfo, 0, len(info.ReadySCs))
|
|
|
|
for sc, scInfo := range info.ReadySCs {
|
|
scs = append(scs, &subConnInfo{
|
|
conn: sc,
|
|
connInfo: scInfo,
|
|
})
|
|
}
|
|
return &randomPicker{
|
|
subConns: scs,
|
|
}
|
|
}
|
|
|
|
type randomPicker struct {
|
|
subConns []*subConnInfo
|
|
}
|
|
|
|
func (p *randomPicker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
|
|
sc := p.subConns[rand.Intn(len(p.subConns))]
|
|
log.Printf("randomPicker Pick: SubConn: %s", sc.connInfo.Address.String())
|
|
return balancer.PickResult{SubConn: sc.conn}, nil
|
|
}
|