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/**

Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016.  All rights reserved.

Contact:
     SYSTAP, LLC DBA Blazegraph
     2501 Calvert ST NW #106
     Washington, DC 20008
     [email protected]

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 Feb 16, 2007
 */

package com.bigdata.journal;

import java.io.IOException;

import com.bigdata.service.IService;

/**
 * A service for unique timestamps.
 * 
 * @author Bryan Thompson
 * @version $Id$
 */
public interface ITimestampService extends IService {

    /**
     * Return the next unique timestamp. Timestamps must be strictly increasing.
     * 
     * Note: This method MUST return strictly increasing values, even when it is
     * invoked by concurrent threads. While other implementations are possible
     * and may be more efficient, one way to insure thread safety is to
     * synchronize on some object such that the implementaiton exhibits a FIFO
     * behavior.
     * 
     * @throws IOException
     *             if there is an RMI problem.
     * 
     * @see TimestampServiceUtil#nextTimestamp(ITimestampService)
     */
    public long nextTimestamp() throws IOException;

}