blob: cd11ac52b0cc7df156b368f2d00b6a6d4c1ddbe1 [file] [log] [blame]
/*
* 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.
*/
package component
// LeaderCallbacks defines callbacks for events from LeaderElector
// It is guaranteed that each methods will be executed from the same goroutine, so only one method can be run at once.
type LeaderCallbacks struct {
OnStartedLeading func()
OnStoppedLeading func()
}
type LeaderElector interface {
AddCallbacks(LeaderCallbacks)
// IsLeader should be used for diagnostic reasons (metrics/API info), because there may not be any leader elector for a short period of time.
// Use Callbacks to write logic to execute when Leader is elected.
IsLeader() bool
// Start blocks until the channel is closed or an error occurs.
Start(stop <-chan struct{})
}