io.etcd.jetcd.Election Maven / Gradle / Ivy
/*
* Copyright 2016-2021 The jetcd 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 io.etcd.jetcd;
import java.util.concurrent.CompletableFuture;
import io.etcd.jetcd.election.CampaignResponse;
import io.etcd.jetcd.election.LeaderKey;
import io.etcd.jetcd.election.LeaderResponse;
import io.etcd.jetcd.election.ProclaimResponse;
import io.etcd.jetcd.election.ResignResponse;
import io.etcd.jetcd.support.CloseableClient;
/**
* Interface of leader election client talking to etcd.
*/
public interface Election extends CloseableClient {
/**
* Campaign waits to acquire leadership in an election, returning a leader key
* representing the leadership if successful. The leader key can then be used
* to issue new values on the election, transactionally guard API requests on
* leadership still being held, and resign from the election.
*
* @param electionName election name
* @param leaseId lease identifier
* @param proposal proposal
* @return the response
*/
CompletableFuture campaign(ByteSequence electionName, long leaseId, ByteSequence proposal);
/**
* Proclaim updates the leader's posted value with a new value. Only active
* leader can change the value.
*
* @param leaderKey leader key
* @param proposal new proposal
* @return the response
*/
CompletableFuture proclaim(LeaderKey leaderKey, ByteSequence proposal);
/**
* Returns the current election proclamation, if any.
*
* @param electionName election name
* @return the response
*/
CompletableFuture leader(ByteSequence electionName);
/**
* Listens to election proclamations in-order as made by the election's
* elected leaders.
*
* @param electionName election name
* @param listener listener
*/
void observe(ByteSequence electionName, Listener listener);
/**
* Resign releases election leadership so other campaigners may acquire
* leadership on the election.
*
* @param leaderKey leader key
* @return the response
*/
CompletableFuture resign(LeaderKey leaderKey);
/**
* Interface of leadership notification listener.
*/
interface Listener {
/**
* Invoked on new leader elected.
*
* @param response the response.
*/
void onNext(LeaderResponse response);
/**
* Invoked on errors.
*
* @param throwable the error.
*/
void onError(Throwable throwable);
/**
* Invoked on completion.
*/
void onCompleted();
}
}