/*
* $Id$
*
* Copyright (c) 2007-2008 by Joel Uckelman
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License (LGPL) as published by the Free Software Foundation.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, copies are available
* at http://www.opensource.org.
*/
package VASSAL.tools.opcache;
import java.util.List;
/**
* An operation with a cachecabe result.
*
* @author Joel Uckelman
* @since 3.1.0
*/
public interface Op<V> {
/**
* Runs the <code>Op</code>. This method should be called only by the
* caching framework.
*
* @return the result of running this <code>Op</code>
*/
public V eval() throws Exception;
/**
* Returns a list of <code>Op</code>s on which this <code>Op</code> depends.
*
* @return the <code>Op</code>s on which this <code>Op</code> depends
*/
public List<Op<?>> getSources();
/**
* Returns the current cache key for this <code>Op</code>.
*
* @return the current cache key for this <code>Op</code>
*/
public OpCache.Key<V> newKey();
/**
* Invalidates the current cache key for this <code>Op</code>.
*/
public void update();
}