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     */
017    package org.apache.camel.processor.aggregate;
018    
019    import java.util.Collections;
020    import java.util.Set;
021    import java.util.concurrent.ConcurrentHashMap;
022    import java.util.concurrent.ConcurrentMap;
023    
024    import org.apache.camel.CamelContext;
025    import org.apache.camel.Exchange;
026    import org.apache.camel.spi.OptimisticLockingAggregationRepository;
027    import org.apache.camel.support.ServiceSupport;
028    
029    /**
030     * A memory based {@link org.apache.camel.spi.AggregationRepository} which stores {@link Exchange}s in memory only.
031     *
032     * Supports both optimistic locking and non-optimistic locking modes. Defaults to non-optimistic locking mode.
033     *
034     * @version 
035     */
036    public class MemoryAggregationRepository extends ServiceSupport implements OptimisticLockingAggregationRepository {
037        private final ConcurrentMap<String, Exchange> cache = new ConcurrentHashMap<String, Exchange>();
038        private final boolean optimisticLocking;
039    
040        public MemoryAggregationRepository() {
041            this(false);
042        }
043    
044        public MemoryAggregationRepository(boolean optimisticLocking) {
045            this.optimisticLocking = optimisticLocking;
046        }
047    
048        public Exchange add(CamelContext camelContext, String key, Exchange oldExchange, Exchange newExchange) {
049            if (!optimisticLocking) { throw new UnsupportedOperationException(); }
050            if (oldExchange == null) {
051                if (cache.putIfAbsent(key, newExchange) != null) {
052                    throw new OptimisticLockingException();
053                }
054            } else {
055                if (!cache.replace(key, oldExchange, newExchange)) {
056                    throw new OptimisticLockingException();
057                }
058            }
059            return oldExchange;
060        }
061    
062        public Exchange add(CamelContext camelContext, String key, Exchange exchange) {
063            if (optimisticLocking) { throw new UnsupportedOperationException(); }
064            return cache.put(key, exchange);
065        }
066    
067        public Exchange get(CamelContext camelContext, String key) {
068            return cache.get(key);
069        }
070    
071        public void remove(CamelContext camelContext, String key, Exchange exchange) {
072            if (optimisticLocking) {
073                if (!cache.remove(key, exchange)) {
074                    throw new OptimisticLockingException();
075                }
076            } else {
077                cache.remove(key);
078            }
079        }
080    
081        public void confirm(CamelContext camelContext, String exchangeId) {
082            // noop
083        }
084    
085        public Set<String> getKeys() {
086            // do not allow edits to the set
087            return Collections.unmodifiableSet(cache.keySet());
088        }
089    
090        @Override
091        protected void doStart() throws Exception {
092        }
093    
094        @Override
095        protected void doStop() throws Exception {
096            cache.clear();
097        }
098    
099    }