studio.raptor.sqlparser.util.LRUCache Maven / Gradle / Ivy

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/*
 * Copyright 1999-2017 Alibaba Group Holding Ltd.
 *
 * 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 studio.raptor.sqlparser.util;

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

public class LRUCache extends LinkedHashMap {

  private static final long serialVersionUID = 1L;
  private final int maxSize;

  public LRUCache(int maxSize) {
    this(maxSize, 16, 0.75f, false);
  }

  public LRUCache(int maxSize, int initialCapacity, float loadFactor, boolean accessOrder) {
    super(initialCapacity, loadFactor, accessOrder);
    this.maxSize = maxSize;
  }

  protected boolean removeEldestEntry(Map.Entry eldest) {
    return this.size() > this.maxSize;
  }
}