com.alibaba.rocketmq.common.queue.RoundQueue Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.rocketmq.common.queue;
import java.util.LinkedList;
import java.util.Queue;
/**
* not thread safe
*
* @auther lansheng.zj
*/
public class RoundQueue {
private Queue queue;
private int capacity;
public RoundQueue(int capacity) {
this.capacity = capacity;
queue = new LinkedList();
}
public boolean put(E e) {
boolean ok = false;
if (!queue.contains(e)) {
if (queue.size() >= capacity) {
queue.poll();
}
queue.add(e);
ok = true;
}
return ok;
}
}