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.Collections;
021    import java.util.List;
022    
023    import org.apache.camel.AsyncCallback;
024    import org.apache.camel.Exchange;
025    import org.apache.camel.Service;
026    import org.apache.camel.model.ProcessorDefinition;
027    import org.apache.camel.spi.Synchronization;
028    import org.apache.camel.spi.TraceableUnitOfWork;
029    import org.apache.camel.util.UuidGenerator;
030    
031    /**
032     * The default implementation of {@link org.apache.camel.spi.UnitOfWork}
033     *
034     * @version $Revision: 751655 $
035     */
036    public class DefaultUnitOfWork implements TraceableUnitOfWork, Service {
037        private static final UuidGenerator DEFAULT_ID_GENERATOR = new UuidGenerator();
038    
039        private String id;
040        private List<Synchronization> synchronizations;
041        private List<AsyncCallback> asyncCallbacks;
042        private List<ProcessorDefinition> routeList;
043    
044        public DefaultUnitOfWork() {
045        }
046    
047        public void start() throws Exception {
048            id = null;
049        }
050    
051        public void stop() throws Exception {
052            // need to clean up when we are stopping to not leak memory
053            if (synchronizations != null) {
054                synchronizations.clear();
055            }
056            if (asyncCallbacks != null) {
057                asyncCallbacks.clear();
058            }
059            if (routeList != null) {
060                routeList.clear();
061            }
062        }
063    
064        public synchronized void addSynchronization(Synchronization synchronization) {
065            if (synchronizations == null) {
066                synchronizations = new ArrayList<Synchronization>();
067            }
068            synchronizations.add(synchronization);
069        }
070    
071        public synchronized void removeSynchronization(Synchronization synchronization) {
072            if (synchronizations != null) {
073                synchronizations.remove(synchronization);
074            }
075        }
076    
077        public void done(Exchange exchange) {
078            if (synchronizations != null) {
079                boolean failed = exchange.isFailed();
080                for (Synchronization synchronization : synchronizations) {
081                    if (failed) {
082                        synchronization.onFailure(exchange);
083                    } else {
084                        synchronization.onComplete(exchange);
085                    }
086                }
087            }
088        }
089    
090        public boolean isSynchronous() {
091            return asyncCallbacks == null || asyncCallbacks.isEmpty();
092        }
093    
094        public String getId() {
095            if (id == null) {
096                id = DEFAULT_ID_GENERATOR.generateId();
097            }
098            return id;
099        }
100    
101        public synchronized void addInterceptedNode(ProcessorDefinition node) {
102            if (routeList == null) {
103                routeList = new ArrayList<ProcessorDefinition>();
104            }
105            routeList.add(node);
106        }
107    
108        public synchronized ProcessorDefinition getLastInterceptedNode() {
109            if (routeList == null || routeList.isEmpty()) {
110                return null;
111            }
112            return routeList.get(routeList.size() - 1);
113        }
114    
115        public List<ProcessorDefinition> getInterceptedNodes() {
116            return Collections.unmodifiableList(routeList);
117        }
118    
119        /**
120         * Register some asynchronous processing step
121         */
122        /*
123        public synchronized AsyncCallback addAsyncStep() {
124            AsyncCallback answer = new AsyncCallback() {
125                public void done(boolean doneSynchronously) {
126                    latch.countDown();
127                }
128            };
129            if (latch == null) {
130                latch = new CountDownLatch(1);
131            }
132            else {
133                // TODO increment latch!
134            }
135            if (asyncCallbacks == null) {
136                asyncCallbacks = new ArrayList<AsyncCallback>();
137            }
138            asyncCallbacks.add(answer);
139            return answer;
140        }
141        */
142    }