org.apache.kafka.common.cache.LRUCache 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 org.apache.kafka.common.cache;
import java.util.LinkedHashMap;
import java.util.Map;
/**
* A cache implementing a least recently used policy.
*/
public class LRUCache implements Cache {
private final LinkedHashMap cache;
public LRUCache(final int maxSize) {
cache = new LinkedHashMap(16, .75f, true) {
private static final long serialVersionUID = 1L;
@Override
protected boolean removeEldestEntry(Map.Entry eldest) {
return this.size() > maxSize; // require this. prefix to make lgtm.com happy
}
};
}
@Override
public V get(K key) {
return cache.get(key);
}
@Override
public void put(K key, V value) {
cache.put(key, value);
}
@Override
public boolean remove(K key) {
return cache.remove(key) != null;
}
@Override
public long size() {
return cache.size();
}
}