/**
*Copyright [2009-2010] [dennis zhuang(killme2008@gmail.com)]
*Licensed under the Apache License, Version 2.0 (the "License");
*you may not use this file except in compliance with the License.
*You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
*Unless required by applicable law or agreed to in writing,
*software distributed under the License is distributed on an "AS IS" BASIS,
*WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
*either express or implied. See the License for the specific language governing permissions and limitations under the License
*/
/**
*Copyright [2009-2010] [dennis zhuang(killme2008@gmail.com)]
*Licensed under the Apache License, Version 2.0 (the "License");
*you may not use this file except in compliance with the License.
*You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
*Unless required by applicable law or agreed to in writing,
*software distributed under the License is distributed on an "AS IS" BASIS,
*WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
*either express or implied. See the License for the specific language governing permissions and limitations under the License
*/
package com.google.code.hs4j.network.util;
import java.util.Collection;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
/**
* A {@link ConcurrentHashMap}-backed {@link Set}.
*
* @author The Apache MINA Project (dev@mina.apache.org)
* @version $Rev: 597692 $, $Date: 2007-11-23 08:56:32 -0700 (Fri, 23 Nov 2007) $
*/
public class ConcurrentHashSet<E> extends MapBackedSet<E> {
private static final long serialVersionUID = 8518578988740277828L;
public ConcurrentHashSet() {
super(new ConcurrentHashMap<E, Boolean>());
}
public ConcurrentHashSet(Collection<E> c) {
super(new ConcurrentHashMap<E, Boolean>(), c);
}
@Override
public boolean add(E o) {
Boolean answer = ((ConcurrentMap<E, Boolean>) map).putIfAbsent(o,
Boolean.TRUE);
return answer == null;
}
}