001    /**
002     *
003     * Licensed to the Apache Software Foundation (ASF) under one or more
004     * contributor license agreements.  See the NOTICE file distributed with
005     * this work for additional information regarding copyright ownership.
006     * The ASF licenses this file to You under the Apache License, Version 2.0
007     * (the "License"); you may not use this file except in compliance with
008     * 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, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    package org.apache.camel.processor.idempotent;
019    
020    import org.apache.camel.util.LRUCache;
021    
022    import java.util.Set;
023    import java.util.HashSet;
024    import java.util.Map;
025    import java.util.HashMap;
026    import java.util.LinkedHashMap;
027    
028    /**
029     * A memory based implementation of {@link MessageIdRepository}.
030     * Care should be taken to use a suitable underlying {@link Map} to avoid this class being a memory leak
031     *
032     * @version $Revision: 1.1 $
033     */
034    public class MemoryMessageIdRepository implements MessageIdRepository {
035        private Map cache;
036    
037        /**
038         * Creates a new MemoryMessageIdRepository with a memory based respository. <b>Warning</b> this
039         * method should only really be used for testing as it will involve keeping all message IDs in RAM.
040         */
041        public static MessageIdRepository memoryMessageIdRepository() {
042            return memoryMessageIdRepository(new HashMap());
043        }
044    
045        /**
046         * Creates a new MemoryMessageIdRepository with a memory based respository. <b>Warning</b> this
047         * method should only really be used for testing as it will involve keeping all message IDs in RAM.
048         */
049        public static MessageIdRepository memoryMessageIdRepository(int cacheSize) {
050            return memoryMessageIdRepository(new LRUCache(cacheSize));
051        }
052    
053        /**
054         * Creates a new MemoryMessageIdRepository using the given {@link Map} to use to store the
055         * processed Message ID objects. Warning be cafeful of the implementation of Map you use as
056         * if you are not careful it could be a memory leak.
057         */
058        public static MessageIdRepository memoryMessageIdRepository(Map cache) {
059            return new MemoryMessageIdRepository(cache);
060        }
061    
062        public MemoryMessageIdRepository(Map set) {
063            this.cache = set;
064        }
065    
066        public boolean contains(String messageId) {
067            synchronized (cache) {
068                if (cache.containsKey(messageId)) {
069                    return true;
070                }
071                else {
072                    cache.put(messageId, messageId);
073                    return false;
074                }
075            }
076        }
077    }