001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.shiro.cache;
020
021import org.apache.shiro.lang.util.SoftHashMap;
022
023/**
024 * Simple memory-only based {@link CacheManager CacheManager} implementation usable in production
025 * environments.  It will not cause memory leaks as it produces {@link Cache Cache}s backed by
026 * {@link SoftHashMap SoftHashMap}s which auto-size themselves based on the runtime environment's memory
027 * limitations and garbage collection behavior.
028 * <p/>
029 * While the {@code Cache} instances created are thread-safe, they do not offer any enterprise-level features such as
030 * cache coherency, optimistic locking, failover or other similar features.  For more enterprise features, consider
031 * using a different {@code CacheManager} implementation backed by an enterprise-grade caching product (Hazelcast,
032 * EhCache, TerraCotta, Coherence, GigaSpaces, etc., etc.).
033 *
034 * @since 1.0
035 */
036public class MemoryConstrainedCacheManager extends AbstractCacheManager {
037
038    /**
039     * Returns a new {@link MapCache MapCache} instance backed by a {@link SoftHashMap}.
040     *
041     * @param name the name of the cache
042     * @return a new {@link MapCache MapCache} instance backed by a {@link SoftHashMap}.
043     */
044    @Override
045    protected <K, V> Cache<K, V> createCache(String name) {
046        return new MapCache<>(name, new SoftHashMap<>());
047    }
048}