com.couchbase.client.java.util.LRUCache Maven / Gradle / Ivy

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/*
 * Copyright (c) 2016 Couchbase, Inc.
 *
 * Licensed 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.couchbase.client.java.util;

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

/**
 * Implements a generic LRU cache which evicts after the max size is reached.
 *
 * @author Michael Nitschinger
 * @since 2.2.0
 */
public class LRUCache extends LinkedHashMap {

    private final int maxCapacity;

    public LRUCache(final int maxCapacity) {
        super(maxCapacity + 1, 1.0f, true);
        this.maxCapacity = maxCapacity;
    }

    @Override
    protected boolean removeEldestEntry(Map.Entry eldest) {
        return super.size() > maxCapacity;
    }

}