update

mygrpc/mybalancer/random/random.go

@@ -0,0 +1,80 @@
+/*
+ *
+ * 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
+}