1   /*
2    * Copyright 2017 LINE Corporation
3    *
4    * LINE Corporation licenses this file to you under the Apache License,
5    * version 2.0 (the "License"); you may not use this file except in compliance
6    * with the License. You may obtain a copy of the License at:
7    *
8    *   https://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13   * License for the specific language governing permissions and limitations
14   * under the License.
15   */
16  
17  package com.linecorp.centraldogma.server.internal.storage.repository.git;
18  
19  import java.util.LinkedHashMap;
20  import java.util.Map;
21  
22  final class LruMap<K, V> extends LinkedHashMap<K, V> {
23  
24      private static final long serialVersionUID = 8533922512014170929L;
25  
26      static <K, V> ThreadLocal<LruMap<K, V>> newThreadLocal(int maxEntries) {
27          return ThreadLocal.withInitial(() -> new LruMap<>(maxEntries));
28      }
29  
30      private final int maxEntries;
31  
32      private LruMap(int maxEntries) {
33          super(maxEntries, 0.75f, true);
34          this.maxEntries = maxEntries;
35      }
36  
37      @Override
38      protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
39          return size() > maxEntries;
40      }
41  }