/*
* Copyright 2004 - 2008 Christian Sprajc, Dennis Waldherr. All rights reserved.
*
* This file is part of PowerFolder.
*
* PowerFolder 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.
*
* PowerFolder 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 PowerFolder. If not, see <http://www.gnu.org/licenses/>.
*
* $Id$
*/
package de.dal33t.powerfolder.util.delta;

import java.util.zip.Checksum;

/**
 * Interface for checksum algorithms which supports "rolling".
 * 
 * @author Dennis "Dante" Waldherr
 * @version $Revision: $ 
 * */
public interface RollingChecksum extends Checksum {
	/**
	 * Returns the size of frame used to "roll" over the data. 
	 * @return the framesize
	 */
	int getFrameSize();
	
	/**
	 * Updates the checksum.
	 * @param data the data to add to the checksum
	 */
	void update(byte[] data);
}