wiki.techinc.nl/includes/cache/dependency/CacheDependency.php

<?php
/**
 * Data caching with dependencies.
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 * @ingroup Cache
 */

/**
 * @ingroup Cache
 */
abstract class CacheDependency {
	/**
	 * Returns true if the dependency is expired, false otherwise
	 */
	abstract public function isExpired();

	/**
	 * Hook to perform any expensive pre-serialize loading of dependency values.
	 */
	public function loadDependencyValues() {
	}
}