cubefs

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/*
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 *
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 * Copyright 2017 gRPC authors.
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 *
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 * Licensed under the Apache License, Version 2.0 (the "License");
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 * you may not use this file except in compliance with the License.
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 * You may obtain a copy of the License at
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 *
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 *     http://www.apache.org/licenses/LICENSE-2.0
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 *
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 * Unless required by applicable law or agreed to in writing, software
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 * distributed under the License is distributed on an "AS IS" BASIS,
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 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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 * See the License for the specific language governing permissions and
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 * limitations under the License.
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 *
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 */
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// Package base defines a balancer base that can be used to build balancers with
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// different picking algorithms.
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//
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// The base balancer creates a new SubConn for each resolved address. The
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// provided picker will only be notified about READY SubConns.
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//
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// This package is the base of round_robin balancer, its purpose is to be used
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// to build round_robin like balancers with complex picking algorithms.
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// Balancers with more complicated logic should try to implement a balancer
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// builder from scratch.
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//
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// All APIs in this package are experimental.
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package base
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import (
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	"google.golang.org/grpc/balancer"
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	"google.golang.org/grpc/resolver"
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)
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// PickerBuilder creates balancer.Picker.
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type PickerBuilder interface {
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	// Build returns a picker that will be used by gRPC to pick a SubConn.
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	Build(info PickerBuildInfo) balancer.Picker
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}
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// PickerBuildInfo contains information needed by the picker builder to
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// construct a picker.
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type PickerBuildInfo struct {
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	// ReadySCs is a map from all ready SubConns to the Addresses used to
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	// create them.
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	ReadySCs map[balancer.SubConn]SubConnInfo
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}
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// SubConnInfo contains information about a SubConn created by the base
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// balancer.
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type SubConnInfo struct {
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	Address resolver.Address // the address used to create this SubConn
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}
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// Config contains the config info about the base balancer builder.
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type Config struct {
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	// HealthCheck indicates whether health checking should be enabled for this specific balancer.
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	HealthCheck bool
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}
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// NewBalancerBuilder returns a base balancer builder configured by the provided config.
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func NewBalancerBuilder(name string, pb PickerBuilder, config Config) balancer.Builder {
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	return &baseBuilder{
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		name:          name,
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		pickerBuilder: pb,
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		config:        config,
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	}
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}
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