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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.shiro.cache;
20  
21  import org.apache.shiro.util.SoftHashMap;
22  
23  /**
24   * Simple memory-only based {@link CacheManager CacheManager} implementation usable in production
25   * environments.  It will not cause memory leaks as it produces {@link Cache Cache}s backed by
26   * {@link SoftHashMap SoftHashMap}s which auto-size themselves based on the runtime environment's memory
27   * limitations and garbage collection behavior.
28   * <p/>
29   * While the {@code Cache} instances created are thread-safe, they do not offer any enterprise-level features such as
30   * cache coherency, optimistic locking, failover or other similar features.  For more enterprise features, consider
31   * using a different {@code CacheManager} implementation backed by an enterprise-grade caching product (Hazelcast,
32   * EhCache, TerraCotta, Coherence, GigaSpaces, etc, etc).
33   *
34   * @since 1.0
35   */
36  public class MemoryConstrainedCacheManager extends AbstractCacheManager {
37  
38      /**
39       * Returns a new {@link MapCache MapCache} instance backed by a {@link SoftHashMap}.
40       *
41       * @param name the name of the cache
42       * @return a new {@link MapCache MapCache} instance backed by a {@link SoftHashMap}.
43       */
44      @Override
45      protected Cache createCache(String name) {
46          return new MapCache<Object, Object>(name, new SoftHashMap<Object, Object>());
47      }
48  }