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The official Couchbase JVM Core IO Library

There is a newer version: 2.7.0

/*
 * Copyright (c) 2019 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.core.util;

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

/**
 * Implements a generic LRU cache which evicts after the max size is reached.
 *
 * @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(final Map.Entry eldest) {
    return super.size() > maxCapacity;
  }

}