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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      https://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.jexl3;
18  
19  import java.util.Map;
20  
21  import org.apache.commons.jexl3.internal.SoftCache;
22  
23  import com.googlecode.concurrentlinkedhashmap.ConcurrentLinkedHashMap;
24  
25  /**
26   * A cache whose underlying map is a ConcurrentLinkedHashMap.
27   *
28   * @param <K> the cache key entry type
29   * @param <V> the cache key value type
30   */
31  public class ConcurrentCache<K, V> extends SoftCache<K, V> {
32    /**
33     * Creates a new instance of a concurrent cache.
34     *
35     * @param theSize the cache size
36     */
37    public ConcurrentCache(final int theSize) {
38      super(theSize);
39    }
40  
41    @Override
42    protected <K, V> Map<K, V> createMap(final int cacheSize) {
43      return  new ConcurrentLinkedHashMap.Builder<K, V>()
44          .concurrencyLevel(Runtime.getRuntime().availableProcessors())
45          .maximumWeightedCapacity(cacheSize)
46          .build();
47    }
48  }
49