/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt 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.messaging.util;
import java.util.AbstractSet;
import java.util.Iterator;
import java.util.Map;
import EDU.oswego.cs.dl.util.concurrent.ConcurrentHashMap;
/**
*
* A ConcurrentHashSet.
*
* Offers same concurrency as ConcurrentHashMap but for a Set
*
* @author <a href="tim.fox@jboss.com">Tim Fox</a>
* @version $Revision: 1237 $
*
* $Id: ConcurrentHashSet.java 1237 2006-08-30 18:36:36Z timfox $
*/
public class ConcurrentHashSet extends AbstractSet
{
private Map theMap;
private static Object dummy = new Object();
public ConcurrentHashSet()
{
theMap = new ConcurrentHashMap();
}
public int size()
{
return theMap.size();
}
public Iterator iterator()
{
return theMap.keySet().iterator();
}
public boolean isEmpty()
{
return theMap.isEmpty();
}
public boolean add(Object o)
{
return theMap.put(o, dummy) == dummy;
}
public boolean contains(Object o)
{
return theMap.containsKey(o);
}
public void clear()
{
theMap.clear();
}
public boolean remove(Object o)
{
return theMap.remove(o) == dummy;
}
}