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.impl;
018    
019    import java.util.ArrayList;
020    import java.util.List;
021    import java.util.concurrent.CountDownLatch;
022    
023    import org.apache.camel.AsyncCallback;
024    import org.apache.camel.Exchange;
025    import org.apache.camel.spi.Synchronization;
026    import org.apache.camel.spi.UnitOfWork;
027    import org.apache.camel.util.UuidGenerator;
028    
029    /**
030     * The default implementation of {@link UnitOfWork}
031     *
032     * @version $Revision: 45123 $
033     */
034    public class DefaultUnitOfWork implements UnitOfWork {
035        private static final UuidGenerator DEFAULT_ID_GENERATOR = new UuidGenerator();
036    
037        private String id;
038        private List<Synchronization> synchronizations;
039        private List<AsyncCallback> asyncCallbacks;
040        private CountDownLatch latch;
041    
042        public DefaultUnitOfWork() {
043        }
044    
045        public synchronized void addSynchronization(Synchronization synchronization) {
046            if (synchronizations == null) {
047                synchronizations = new ArrayList<Synchronization>();
048            }
049            synchronizations.add(synchronization);
050        }
051    
052        public synchronized void removeSynchronization(Synchronization synchronization) {
053            if (synchronizations != null) {
054                synchronizations.remove(synchronization);
055            }
056        }
057    
058        public void reset() {
059        }
060    
061        public void done(Exchange exchange) {
062            if (synchronizations != null) {
063                boolean failed = exchange.isFailed();
064                for (Synchronization synchronization : synchronizations) {
065                    if (failed) {
066                        synchronization.onFailure(exchange);
067                    } else {
068                        synchronization.onComplete(exchange);
069                    }
070                }
071            }
072        }
073    
074        public boolean isSynchronous() {
075            return asyncCallbacks == null || asyncCallbacks.isEmpty();
076        }
077    
078        public String getId() {
079            if (id == null) {
080                id = DEFAULT_ID_GENERATOR.generateId();
081            }
082            return id;
083        }
084    
085        /**
086         * Register some asynchronous processing step
087         */
088        /*
089        public synchronized AsyncCallback addAsyncStep() {
090            AsyncCallback answer = new AsyncCallback() {
091                public void done(boolean doneSynchronously) {
092                    latch.countDown();
093                }
094            };
095            if (latch == null) {
096                latch = new CountDownLatch(1);
097            }
098            else {
099                // TODO increment latch!
100            }
101            if (asyncCallbacks == null) {
102                asyncCallbacks = new ArrayList<AsyncCallback>();
103            }
104            asyncCallbacks.add(answer);
105            return answer;
106        }
107        */
108    }