001package org.apache.commons.jcs.utils.struct; 002 003/* 004 * Licensed to the Apache Software Foundation (ASF) under one 005 * or more contributor license agreements. See the NOTICE file 006 * distributed with this work for additional information 007 * regarding copyright ownership. The ASF licenses this file 008 * to you under the Apache License, Version 2.0 (the 009 * "License"); you may not use this file except in compliance 010 * with the License. You may obtain a copy of the License at 011 * 012 * http://www.apache.org/licenses/LICENSE-2.0 013 * 014 * Unless required by applicable law or agreed to in writing, 015 * software distributed under the License is distributed on an 016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 017 * KIND, either express or implied. See the License for the 018 * specific language governing permissions and limitations 019 * under the License. 020 */ 021 022import java.util.concurrent.atomic.AtomicInteger; 023 024/** 025 * 026 * @author Wiktor Niesiobędzki 027 * 028 * Simple LRUMap implementation that keeps the number of the objects below or equal maxObjects 029 * 030 * @param <K> 031 * @param <V> 032 */ 033public class LRUMap<K, V> extends AbstractLRUMap<K, V> 034{ 035 036 /** if the max is less than 0, there is no limit! */ 037 int maxObjects = -1; 038 AtomicInteger counter = new AtomicInteger(0); 039 040 public LRUMap() 041 { 042 super(); 043 } 044 045 /** 046 * 047 * @param maxObjects 048 * maximum number to keep in the map 049 */ 050 public LRUMap(int maxObjects) 051 { 052 super(); 053 this.maxObjects = maxObjects; 054 } 055 056 @Override 057 public boolean shouldRemove() 058 { 059 return maxObjects > 0 && this.size() > maxObjects; 060 } 061 062 public Object getMaxCounter() 063 { 064 return maxObjects; 065 } 066}