/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2000 - 2008, Red Hat Middleware LLC, and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.jboss.cache.commands;

import org.jboss.cache.optimistic.DataVersion;

/**
 * Just like a {@link org.jboss.cache.commands.DataCommand}, except that these are versioned and reversible too.  Versioning
 * is currently used by optimistic locking, and in future will be used by MVCC as well.
 *
 * @author Mircea.Markus@jboss.com
 * @author Manik Surtani (<a href="mailto:manik AT jboss DOT org">manik AT jboss DOT org</a>)
 * @since 2.2.0
 */
public interface VersionedDataCommand extends WriteCommand
{
   /**
    * @return the DataVersion pertaining to this command.
    */
   DataVersion getDataVersion();

   /**
    * Sets the DataVersion pertaining to this command.
    *
    * @param dataVersion to set
    */
   void setDataVersion(DataVersion dataVersion);

   /**
    * Has data version set? (i.e. not null)
    *
    * @return true if getDataVersion() would not return null; false otherwise.
    */
   boolean isVersioned();
}