com.alibaba.nacos.common.utils.ConcurrentHashSet Maven / Gradle / Ivy
/*
* Copyright 1999-2018 Alibaba Group Holding Ltd.
*
* 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.alibaba.nacos.common.utils;
import java.util.AbstractSet;
import java.util.Iterator;
import java.util.concurrent.ConcurrentHashMap;
/**
* Concurrent Hash Set implement by {@link ConcurrentHashMap}.
*
* @author liaochuntao
*/
public class ConcurrentHashSet extends AbstractSet {
private ConcurrentHashMap map;
public ConcurrentHashSet() {
super();
map = new ConcurrentHashMap<>();
}
@Override
public int size() {
return map.size();
}
@Override
public boolean contains(Object o) {
return map.containsKey(o);
}
@Override
public Iterator iterator() {
return map.keySet().iterator();
}
@Override
public boolean add(E o) {
return map.putIfAbsent(o, Boolean.TRUE) == null;
}
@Override
public boolean remove(Object o) {
return map.remove(o) != null;
}
@Override
public void clear() {
map.clear();
}
}