/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Jun 2, 2010
*/
package com.bigdata.quorum;
import java.util.UUID;
/**
* An interface for informational quorum events. These events are intended for
* clients interested in quorum state changes. Services that are HA aware use a
* more intimate API to handle the state changes.
*
* @see QuorumListener
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public interface QuorumEvent {
/**
* The type of event and never <code>null</code>.
*/
QuorumEventEnum getEventType();
/**
* The lastValid token at the time of the event.
*/
long lastValidToken();
/**
* The current quorum token at the time the event was generated.
*/
long token();
/**
* The service identifier associated with the event, if any. For example,
* when a service joins or leaves the quorum, this will be the {@link UUID}
* of that service.
*/
UUID getServiceId();
/**
* The lastCommitTime for which a vote was cast.
*
* @return The lastCommitTime for which the vote was cast.
*
* @throws UnsupportedOperationException
* unless {@link #getEventType()} returns
* {@link QuorumEventEnum#CAST_VOTE}
*/
long lastCommitTime();
}