github.com/hxx258456/ccgo@v0.0.5-0.20230213014102-48b35f46f66f/grpc/balancer/base/base.go (about)

     1  /*
     2   *
     3   * Copyright 2017 gRPC authors.
     4   *
     5   * Licensed under the Apache License, Version 2.0 (the "License");
     6   * you may not use this file except in compliance with the License.
     7   * You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   */
    18  
    19  // Package base defines a balancer base that can be used to build balancers with
    20  // different picking algorithms.
    21  //
    22  // The base balancer creates a new SubConn for each resolved address. The
    23  // provided picker will only be notified about READY SubConns.
    24  //
    25  // This package is the base of round_robin balancer, its purpose is to be used
    26  // to build round_robin like balancers with complex picking algorithms.
    27  // Balancers with more complicated logic should try to implement a balancer
    28  // builder from scratch.
    29  //
    30  // All APIs in this package are experimental.
    31  package base
    32  
    33  import (
    34  	"github.com/hxx258456/ccgo/grpc/balancer"
    35  	"github.com/hxx258456/ccgo/grpc/resolver"
    36  )
    37  
    38  // PickerBuilder creates balancer.Picker.
    39  type PickerBuilder interface {
    40  	// Build returns a picker that will be used by gRPC to pick a SubConn.
    41  	Build(info PickerBuildInfo) balancer.Picker
    42  }
    43  
    44  // PickerBuildInfo contains information needed by the picker builder to
    45  // construct a picker.
    46  type PickerBuildInfo struct {
    47  	// ReadySCs is a map from all ready SubConns to the Addresses used to
    48  	// create them.
    49  	ReadySCs map[balancer.SubConn]SubConnInfo
    50  }
    51  
    52  // SubConnInfo contains information about a SubConn created by the base
    53  // balancer.
    54  type SubConnInfo struct {
    55  	Address resolver.Address // the address used to create this SubConn
    56  }
    57  
    58  // Config contains the config info about the base balancer builder.
    59  type Config struct {
    60  	// HealthCheck indicates whether health checking should be enabled for this specific balancer.
    61  	HealthCheck bool
    62  }
    63  
    64  // NewBalancerBuilder returns a base balancer builder configured by the provided config.
    65  func NewBalancerBuilder(name string, pb PickerBuilder, config Config) balancer.Builder {
    66  	return &baseBuilder{
    67  		name:          name,
    68  		pickerBuilder: pb,
    69  		config:        config,
    70  	}
    71  }