/*
* Copyright (C) 2009 eXo Platform SAS.
*
* 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.exoplatform.services.cache.concurrent;
import java.util.ArrayList;
/**
* The queue needed by the concurrent FIFO cache.
*
* @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
* @version $Revision$
*/
public interface Queue<I extends Item>
{
/**
* Returns the queue size
* @return the size
*/
public int size();
/**
* Attempt to remove an item from the queue.
*
* @param item the item to remove
* @return true if the item was removed by this thread
*/
public boolean remove(I item);
/**
* Add the item to the head of the list.
*
* @param item the item to add
*/
public void add(I item);
/**
* Attempt to trim the queue. Trim will occur if no other thread is already performing a trim
* and the queue size is greater than the provided size.
*
* @param size the wanted size
* @return the list of evicted items
*/
public ArrayList<I> trim(int size);
}