001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.camel.processor.idempotent;
018
019import java.util.Map;
020
021import org.apache.camel.api.management.ManagedAttribute;
022import org.apache.camel.api.management.ManagedOperation;
023import org.apache.camel.api.management.ManagedResource;
024import org.apache.camel.spi.IdempotentRepository;
025import org.apache.camel.support.ServiceSupport;
026import org.apache.camel.util.LRUCache;
027
028/**
029 * A memory based implementation of {@link org.apache.camel.spi.IdempotentRepository}. 
030 * <p/>
031 * Care should be taken to use a suitable underlying {@link Map} to avoid this class being a
032 * memory leak.
033 *
034 * @version 
035 */
036@ManagedResource(description = "Memory based idempotent repository")
037public class MemoryIdempotentRepository extends ServiceSupport implements IdempotentRepository<String> {
038    private Map<String, Object> cache;
039    private int cacheSize;
040
041    public MemoryIdempotentRepository() {
042        this.cache = new LRUCache<String, Object>(1000);
043    }
044
045    public MemoryIdempotentRepository(Map<String, Object> set) {
046        this.cache = set;
047    }
048
049    /**
050     * Creates a new memory based repository using a {@link LRUCache}
051     * with a default of 1000 entries in the cache.
052     */
053    public static IdempotentRepository<String> memoryIdempotentRepository() {
054        return new MemoryIdempotentRepository();
055    }
056
057    /**
058     * Creates a new memory based repository using a {@link LRUCache}.
059     *
060     * @param cacheSize  the cache size
061     */
062    public static IdempotentRepository<String> memoryIdempotentRepository(int cacheSize) {
063        return memoryIdempotentRepository(new LRUCache<String, Object>(cacheSize));
064    }
065
066    /**
067     * Creates a new memory based repository using the given {@link Map} to
068     * use to store the processed message ids.
069     * <p/>
070     * Care should be taken to use a suitable underlying {@link Map} to avoid this class being a
071     * memory leak.
072     *
073     * @param cache  the cache
074     */
075    public static IdempotentRepository<String> memoryIdempotentRepository(Map<String, Object> cache) {
076        return new MemoryIdempotentRepository(cache);
077    }
078
079    @ManagedOperation(description = "Adds the key to the store")
080    public boolean add(String key) {
081        synchronized (cache) {
082            if (cache.containsKey(key)) {
083                return false;
084            } else {
085                cache.put(key, key);
086                return true;
087            }
088        }
089    }
090
091    @ManagedOperation(description = "Does the store contain the given key")
092    public boolean contains(String key) {
093        synchronized (cache) {
094            return cache.containsKey(key);
095        }
096    }
097
098    @ManagedOperation(description = "Remove the key from the store")
099    public boolean remove(String key) {
100        synchronized (cache) {
101            return cache.remove(key) != null;
102        }
103    }
104
105    public boolean confirm(String key) {
106        // noop
107        return true;
108    }
109
110    public Map<String, Object> getCache() {
111        return cache;
112    }
113
114    @ManagedAttribute(description = "The current cache size")
115    public int getCacheSize() {
116        return cache.size();
117    }
118
119    public void setCacheSize(int cacheSize) {
120        this.cacheSize = cacheSize;
121    }
122
123    @Override
124    protected void doStart() throws Exception {
125        if (cacheSize > 0) {
126            cache = new LRUCache<String, Object>(cacheSize);
127        }
128    }
129
130    @Override
131    protected void doStop() throws Exception {
132        cache.clear();
133    }
134}