package org.apache.lucene.util.cache;
/**
* 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.
*/
import java.util.LinkedHashMap;
import java.util.Map;
/**
* Simple LRU cache implementation that uses a LinkedHashMap.
* This cache is not synchronized, use {@link Cache#synchronizedCache(Cache)}
* if needed.
*
*/
public class SimpleLRUCache<K,V> extends SimpleMapCache<K,V> {
private final static float LOADFACTOR = 0.75f;
/**
* Creates a last-recently-used cache with the specified size.
*/
public SimpleLRUCache(final int cacheSize) {
super(new LinkedHashMap<K,V>((int) Math.ceil(cacheSize / LOADFACTOR) + 1, LOADFACTOR, true) {
@Override
protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
return size() > cacheSize;
}
});
}
}