github.com/cloudwego/kitex@v0.9.0/pkg/loadbalance/loadbalancer.go (about)

     1  /*
     2   * Copyright 2021 CloudWeGo Authors
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  package loadbalance
    18  
    19  import (
    20  	"context"
    21  
    22  	"github.com/cloudwego/kitex/pkg/discovery"
    23  )
    24  
    25  // Picker picks an instance for next RPC call.
    26  type Picker interface {
    27  	Next(ctx context.Context, request interface{}) discovery.Instance
    28  }
    29  
    30  // Loadbalancer generates pickers for the given service discovery result.
    31  type Loadbalancer interface {
    32  	GetPicker(discovery.Result) Picker
    33  	Name() string // unique key
    34  }
    35  
    36  // Rebalancer is a kind of Loadbalancer that performs rebalancing when the result of service discovery changes.
    37  type Rebalancer interface {
    38  	Rebalance(discovery.Change)
    39  	Delete(discovery.Change)
    40  }