72 lines
2.3 KiB
Go
72 lines
2.3 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 base defines a balancer base that can be used to build balancers with
|
|
// different picking algorithms.
|
|
//
|
|
// The base balancer creates a new SubConn for each resolved address. The
|
|
// provided picker will only be notified about READY SubConns.
|
|
//
|
|
// This package is the base of round_robin balancer, its purpose is to be used
|
|
// to build round_robin like balancers with complex picking algorithms.
|
|
// Balancers with more complicated logic should try to implement a balancer
|
|
// builder from scratch.
|
|
//
|
|
// All APIs in this package are experimental.
|
|
package base
|
|
|
|
import (
|
|
"google.golang.org/grpc/balancer"
|
|
"google.golang.org/grpc/resolver"
|
|
)
|
|
|
|
// PickerBuilder creates balancer.Picker.
|
|
type PickerBuilder interface {
|
|
// Build returns a picker that will be used by gRPC to pick a SubConn.
|
|
Build(info PickerBuildInfo) balancer.Picker
|
|
}
|
|
|
|
// PickerBuildInfo contains information needed by the picker builder to
|
|
// construct a picker.
|
|
type PickerBuildInfo struct {
|
|
// ReadySCs is a map from all ready SubConns to the Addresses used to
|
|
// create them.
|
|
ReadySCs map[balancer.SubConn]SubConnInfo
|
|
}
|
|
|
|
// SubConnInfo contains information about a SubConn created by the base
|
|
// balancer.
|
|
type SubConnInfo struct {
|
|
Address resolver.Address // the address used to create this SubConn
|
|
}
|
|
|
|
// Config contains the config info about the base balancer builder.
|
|
type Config struct {
|
|
// HealthCheck indicates whether health checking should be enabled for this specific balancer.
|
|
HealthCheck bool
|
|
}
|
|
|
|
// NewBalancerBuilder returns a base balancer builder configured by the provided config.
|
|
func NewBalancerBuilder(name string, pb PickerBuilder, config Config) balancer.Builder {
|
|
return &baseBuilder{
|
|
name: name,
|
|
pickerBuilder: pb,
|
|
config: config,
|
|
}
|
|
}
|