/* * Copyright 2014-2015 Open Networking Laboratory * * 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 org.onosproject.cluster; import java.util.Objects; import java.util.List; import java.util.Optional; import org.joda.time.DateTime; import com.google.common.base.MoreObjects; import com.google.common.collect.ImmutableList; /** * Abstract leadership concept. The information carried by this construct * include the topic of contention, the {@link NodeId}s of Nodes that could * become leader for the topic, the epoch when the term for a given leader * began, and the system time when the term began. Note: *
* Comparing epochs is only appropriate for leadership events for the same * topic. The system guarantees that for any given topic the epoch for a new * term is higher (not necessarily by 1) than the epoch for any previous * term. * * @return leadership epoch */ public long epoch() { return epoch; } /** * The system time when the term started. *
* The elected time is initially set on the node coordinating * the leader election using its local system time. Due to possible * clock skew, relying on this value for determining event ordering * is discouraged. Epoch is more appropriate for determining * event ordering. * * @return elected time. */ public long electedTime() { return electedTime; } @Override public int hashCode() { return Objects.hash(topic, leader, candidates, epoch, electedTime); } @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (obj instanceof Leadership) { final Leadership other = (Leadership) obj; return Objects.equals(this.topic, other.topic) && Objects.equals(this.leader, other.leader) && Objects.equals(this.candidates, other.candidates) && Objects.equals(this.epoch, other.epoch) && Objects.equals(this.electedTime, other.electedTime); } return false; } @Override public String toString() { return MoreObjects.toStringHelper(this.getClass()) .add("topic", topic) .add("leader", leader) .add("candidates", candidates) .add("epoch", epoch) .add("electedTime", new DateTime(electedTime)) .toString(); } }