xds/utils/balancergroup/balancerstateaggregator.go

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

/*
 *
 * Copyright 2021 gRPC authors.
 *
 */

package balancergroup

import (
	"google.golang.org/grpc/balancer"
)

// BalancerStateAggregator aggregates sub-picker and connectivity states into a
// state.
//
// It takes care of merging sub-picker into one picker. The picking config is
// passed directly from the the parent to the aggregator implementation (instead
// via balancer group).
type BalancerStateAggregator interface {
	// UpdateState updates the state of the id.
	//
	// It's up to the implementation whether this will trigger an update to the
	// parent ClientConn.
	UpdateState(id string, state balancer.State)
}