storm-client/src/jvm/org/apache/storm/trident/util/LRUMap.java

/**
 * 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.storm.trident.util;

import java.util.LinkedHashMap;
import java.util.Map;

@SuppressWarnings("checkstyle:AbbreviationAsWordInName")
public class LRUMap<A, B> extends LinkedHashMap<A, B> {
    private int maxSize;

    public LRUMap(int maxSize) {
        super(maxSize + 1, 1.0f, true);
        this.maxSize = maxSize;
    }

    @Override
    protected boolean removeEldestEntry(final Map.Entry<A, B> eldest) {
        return size() > maxSize;
    }
}