[GitHub] zhaijack commented on issue #1452: reachedEndOfTopic is called twice if a topic has been terminated before subscription

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zhaijack commented on issue #1452: reachedEndOfTopic is called twice if a topic has been terminated before subscription
URL: https://github.com/apache/incubator-pulsar/issues/1452#issuecomment-376527587
 
 
   looked into the code. Seems the 2 calling happens like this:
   1st call happened when create consumer in `PersistentSubscription.java`
   ```
      public synchronized void addConsumer(Consumer consumer) throws BrokerServiceException {
           ...
           if (topic.getManagedLedger().isTerminated() && cursor.getNumberOfEntriesInBacklog() == 0) {
               // Immediately notify the consumer that there are no more available messages
               consumer.reachedEndOfTopic();    
                           < ====1,  Here is the first time
           }
          ...
           dispatcher.addConsumer(consumer);   < ==== 2, add into dispatcher
       }
   ```
   
   Since consumer has been added into dispatcher, then second call is in dispatcher readEntriesFailed:
   ```
       public synchronized void readEntriesFailed(ManagedLedgerException exception, Object ctx) {
           ....
           if (exception instanceof NoMoreEntriesToReadException) {
               if (cursor.getNumberOfEntriesInBacklog() == 0) {
                   // Topic has been terminated and there are no more entries to read
                   // Notify the consumer only if all the messages were already acknowledged
                   consumers.forEach(Consumer::reachedEndOfTopic);     
                               < ==== second call
               }
           } 
             ...
   }
   ```
   
   Seems both are valid?

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