001 /**
002 * GRANITE DATA SERVICES
003 * Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
004 *
005 * This file is part of the Granite Data Services Platform.
006 *
007 * Granite Data Services is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * Granite Data Services is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
015 * General Public License for more details.
016 *
017 * You should have received a copy of the GNU Lesser General Public
018 * License along with this library; if not, write to the Free Software
019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
020 * USA, or see <http://www.gnu.org/licenses/>.
021 */
022 package org.granite.tide.data;
023
024 import java.util.ArrayList;
025 import java.util.HashMap;
026 import java.util.List;
027 import java.util.Map;
028 import java.util.Map.Entry;
029
030 import org.granite.clustering.DistributedData;
031 import org.granite.context.GraniteContext;
032 import org.granite.logging.Logger;
033
034 import flex.messaging.messages.AsyncMessage;
035
036
037 /**
038 * Base implementation for data update dispatchers.
039 * It should be built at beginning of each request during initialization of <code>DataContext</code>.
040 * The dispatch is a three step process :
041 *
042 * <ul>
043 * <li>Initialization in the constructor</li>
044 * <li><code>observe()</code> builds the server selector depending on the data that are processed</li>
045 * <li><code>publish()</code> handles the actual publishing</li>
046 * </ul>
047 *
048 * Actual implementations should only override <code>changeDataSelector</code> and <code>publishUpdate</code>/
049 *
050 * @see DataDispatcher
051 * @see DataContext
052 *
053 * @author William Drai
054 */
055 public abstract class AbstractDataDispatcher implements DataDispatcher {
056
057 private static final Logger log = Logger.getLogger(AbstractDataDispatcher.class);
058
059
060 protected boolean enabled;
061 protected String topicName = null;
062 protected DataTopicParams paramsProvider = null;
063 protected String sessionId = null;
064 protected String clientId = null;
065 protected String subscriptionId = null;
066
067
068 public AbstractDataDispatcher(String topicName, Class<? extends DataTopicParams> dataTopicParamsClass) {
069 this.topicName = topicName;
070
071 try {
072 paramsProvider = dataTopicParamsClass.newInstance();
073 }
074 catch (Exception e) {
075 log.error("Could not instantiate class " + dataTopicParamsClass, e);
076 }
077 }
078
079
080 public void observe() {
081 // Prepare the selector even if we are not yet subscribed
082 DataObserveParams params = null;
083 if (paramsProvider != null) {
084 // Collect selector parameters from component
085 params = new DataObserveParams();
086 paramsProvider.observes(params);
087 }
088
089 // Ensure that the current Gravity consumer listens about this data topic and params
090 GraniteContext graniteContext = GraniteContext.getCurrentInstance();
091 if (graniteContext == null)
092 return;
093
094 DistributedData gdd = graniteContext.getGraniteConfig().getDistributedDataFactory().getInstance();
095 if (gdd == null)
096 return; // Session expired
097
098 List<DataObserveParams> selectors = DataObserveParams.fromSerializableForm(gdd.getDestinationDataSelectors(topicName));
099 List<DataObserveParams> newSelectors = new ArrayList<DataObserveParams>(selectors);
100
101 boolean dataSelectorChanged = false;
102 String dataSelector = gdd.getDestinationSelector(topicName);
103 if (params != null) {
104 String newDataSelector = params.updateDataSelector(dataSelector, newSelectors);
105 dataSelectorChanged = !newDataSelector.equals(dataSelector);
106 if (dataSelectorChanged) {
107 log.debug("Data selector changed: %s", newDataSelector);
108 gdd.setDestinationSelector(topicName, newDataSelector);
109 dataSelector = newDataSelector;
110 }
111 }
112
113 if (!DataObserveParams.containsSame(selectors, newSelectors)) {
114 log.debug("Selectors changed: %s", newSelectors);
115 gdd.setDestinationDataSelectors(topicName, DataObserveParams.toSerializableForm(newSelectors));
116 }
117
118 if (!enabled)
119 return;
120
121 if (dataSelectorChanged)
122 changeDataSelector(dataSelector);
123 }
124
125 protected abstract void changeDataSelector(String dataSelector);
126
127
128 public void publish(Object[][] dataUpdates) {
129 if (!enabled)
130 return;
131
132 try {
133 Map<Map<String, String>, List<Object>> updates = new HashMap<Map<String, String>, List<Object>>();
134 if (paramsProvider != null) {
135 for (Object[] dataUpdate : dataUpdates) {
136 DataPublishParams params = new DataPublishParams();
137 paramsProvider.publishes(params, dataUpdate[1]);
138
139 Map<String, String> headers = params.getHeaders();
140 List<Object> list = updates.get(headers);
141 if (list == null) {
142 list = new ArrayList<Object>();
143 updates.put(headers, list);
144 }
145 list.add(dataUpdate);
146 }
147 }
148
149 for (Entry<Map<String, String>, List<Object>> me : updates.entrySet()) {
150 Map<String, String> headers = new HashMap<String, String>(me.getKey());
151 headers.put(AsyncMessage.SUBTOPIC_HEADER, TIDE_DATA_SUBTOPIC);
152 headers.put(GDS_SESSION_ID, sessionId);
153 headers.put(TIDE_DATA_TYPE_KEY, TIDE_DATA_TYPE_VALUE);
154 publishUpdate(headers, me.getValue().toArray());
155 }
156 }
157 catch (Exception e) {
158 log.error(e, "Could not publish data update on topic %s", topicName);
159 }
160 }
161
162 protected abstract void publishUpdate(Map<String, String> params, Object body);
163 }