1 | package omq.common.event; |
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2 | |
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3 | import java.util.HashMap; |
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4 | import java.util.Map; |
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5 | import java.util.Properties; |
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6 | import java.util.Vector; |
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7 | |
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8 | import omq.common.broker.Broker; |
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9 | import omq.common.util.ParameterQueue; |
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10 | import omq.common.util.Serializer; |
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11 | |
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12 | import org.apache.log4j.Logger; |
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13 | |
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14 | import com.rabbitmq.client.Channel; |
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15 | import com.rabbitmq.client.ConsumerCancelledException; |
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16 | import com.rabbitmq.client.QueueingConsumer; |
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17 | import com.rabbitmq.client.QueueingConsumer.Delivery; |
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18 | import com.rabbitmq.client.ShutdownSignalException; |
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19 | |
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20 | /** |
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21 | * This class dispatches the events received in the client side and stores them |
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22 | * into the different listeners that could exists among the different proxies |
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23 | * generated |
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24 | * |
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25 | * @author Sergi Toda <sergi.toda@estudiants.urv.cat> |
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26 | * |
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27 | */ |
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28 | @SuppressWarnings("rawtypes") |
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29 | public class EventDispatcher extends Thread { |
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30 | private static final Logger logger = Logger.getLogger(EventDispatcher.class.getName()); |
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31 | |
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32 | private Broker broker; |
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33 | private Serializer serializer; |
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34 | private Map<String, Vector<EventListener>> listeners; |
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35 | private Channel channel; |
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36 | private QueueingConsumer consumer; |
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37 | private Properties env; |
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38 | private boolean killed = false; |
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39 | |
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40 | public EventDispatcher(Broker broker) throws Exception { |
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41 | this.broker = broker; |
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42 | env = broker.getEnvironment(); |
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43 | serializer = broker.getSerializer(); |
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44 | |
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45 | // Declare the listeners map |
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46 | listeners = new HashMap<String, Vector<EventListener>>(); |
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47 | |
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48 | startEventQueue(); |
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49 | } |
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50 | |
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51 | private void startEventQueue() throws Exception { |
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52 | // Get a new connection and a new channel |
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53 | channel = broker.getNewChannel(); |
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54 | |
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55 | String event_queue = env.getProperty(ParameterQueue.EVENT_REPLY_QUEUE); |
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56 | boolean durable = Boolean.parseBoolean(env.getProperty(ParameterQueue.DURABLE_QUEUES, "false")); |
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57 | channel.queueDeclare(event_queue, durable, false, false, null); |
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58 | logger.info("EventDispatcher creating queue: " + event_queue + ", durable: " + durable); |
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59 | |
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60 | // Declare a new consumer |
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61 | consumer = new QueueingConsumer(channel); |
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62 | channel.basicConsume(event_queue, true, consumer); |
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63 | } |
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64 | |
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65 | public void kill() throws Exception { |
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66 | logger.warn("Stopping EventDispatcher"); |
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67 | setListeners(null); |
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68 | killed = true; |
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69 | interrupt(); |
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70 | channel.close(); |
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71 | } |
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72 | |
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73 | @Override |
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74 | public void run() { |
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75 | logger.info("EventDispatcher started"); |
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76 | Delivery delivery; |
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77 | Event event; |
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78 | |
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79 | while (!killed) { |
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80 | try { |
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81 | // Get the delivery |
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82 | delivery = consumer.nextDelivery(); |
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83 | |
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84 | // Get the event |
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85 | event = serializer.deserializeEvent(delivery.getBody()); |
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86 | |
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87 | logger.info("Event received -> Topic: " + event.getTopic() + "CorrId: " + event.getCorrId()); |
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88 | |
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89 | // Dispatch it |
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90 | dispatch(event.getTopic(), event); |
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91 | } catch (InterruptedException i) { |
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92 | logger.error(i); |
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93 | } catch (ShutdownSignalException e) { |
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94 | logger.error(e); |
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95 | try { |
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96 | if (channel.isOpen()) { |
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97 | channel.close(); |
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98 | } |
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99 | startEventQueue(); |
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100 | } catch (Exception e1) { |
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101 | try { |
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102 | long milis = Long.parseLong(env.getProperty(ParameterQueue.RETRY_TIME_CONNECTION, "2000")); |
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103 | Thread.sleep(milis); |
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104 | } catch (InterruptedException e2) { |
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105 | logger.error(e2); |
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106 | } |
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107 | logger.error(e1); |
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108 | } |
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109 | } catch (ConsumerCancelledException e) { |
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110 | logger.error(e); |
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111 | } catch (Exception e) { |
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112 | logger.error(e); |
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113 | } |
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114 | } |
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115 | } |
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116 | |
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117 | public int addListener(EventListener e) throws Exception { |
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118 | // Map<String, ArrayList<EventListener<Event>>> mListeners = |
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119 | // listeners.get(e.getTopic()); |
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120 | // if(mListeners == null){ |
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121 | // mListeners = new HashMap<String, ArrayList<EventListener<Event>>>(); |
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122 | // |
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123 | // String queueName = env.getProperty(ParameterQueue.EVENT_REPLY_QUEUE); |
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124 | // String reference = e.getTopic(); |
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125 | // channel.exchangeDeclare(reference, "fanout"); |
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126 | // channel.queueBind(queueName, reference, ""); |
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127 | // } |
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128 | |
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129 | Vector<EventListener> vListeners = listeners.get(e.getTopic()); |
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130 | if (vListeners == null) { |
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131 | vListeners = new Vector<EventListener>(); |
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132 | |
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133 | String queueName = env.getProperty(ParameterQueue.EVENT_REPLY_QUEUE); |
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134 | String reference = e.getTopic(); |
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135 | |
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136 | logger.info("Declaring fanout -> " + reference + " Binding with: " + queueName); |
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137 | |
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138 | channel.exchangeDeclare(reference, "fanout"); |
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139 | channel.queueBind(queueName, reference, ""); |
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140 | } |
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141 | vListeners.add(e); |
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142 | listeners.put(e.getTopic(), vListeners); |
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143 | |
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144 | return vListeners.size(); |
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145 | } |
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146 | |
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147 | public int removeListener(EventListener e) { |
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148 | Vector<EventListener> vListeners = listeners.get(e.getTopic()); |
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149 | if (vListeners != null) { |
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150 | // TODO: removeListener -> remove(e) override equals? |
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151 | vListeners.remove(e); |
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152 | } |
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153 | |
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154 | return vListeners.size(); |
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155 | } |
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156 | |
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157 | /** |
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158 | * This method dispatches the events. Every time an event is received, this |
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159 | * method is launched. This method creates a new thread and executes the |
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160 | * notifyEvent function of the listeners associated to this event |
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161 | * |
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162 | * @param topic |
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163 | * @param event |
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164 | */ |
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165 | public void dispatch(String topic, final Event event) { |
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166 | if (listeners.containsKey(topic)) { |
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167 | for (final EventListener listener : listeners.get(topic)) { |
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168 | new Thread() { |
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169 | @SuppressWarnings("unchecked") |
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170 | public void run() { |
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171 | listener.notifyEvent(event); |
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172 | } |
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173 | }.start(); |
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174 | } |
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175 | } |
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176 | } |
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177 | |
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178 | public Map<String, Vector<EventListener>> getListeners() { |
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179 | return listeners; |
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180 | } |
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181 | |
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182 | public void setListeners(Map<String, Vector<EventListener>> listeners) { |
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183 | this.listeners = listeners; |
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184 | } |
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185 | |
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186 | } |
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