Examples of ERXFetchSpecificationBatchIterator

er.extensions.eof.ERXFetchSpecificationBatchIterator
The goal of the fetch specification batch iterator is to have the ability to iterate through a fetch specification that might fetch one million enterprise objects. Fetching all of the objects into a single editing context is prohibitive in the amount of memory needed and in the time taken to process all of the rows.
The iterator allows one to iterate through the fetched objects only hydrating those objects need in small bite size pieces. The iterator also allows you to swap out editing contexts between calls to nextBatch(), which will allow the garbage collector to collect the old editing context and the previous batch of enterprise objects.
For your convenience, this class also implements Iterator and Enumeration, so you can use it as such.
Be aware that the batch size is primarily intended to govern the number of objects requested from the database at once, and may differ from the number of objects returned by nextBatch(), for instance if the batch size is changed after fetching, or if filtersBatches() is set to true.

Examples of er.extensions.eof.ERXFetchSpecificationBatchIterator

      
      // For demo purposes we will use batches and EC recycling, which would be common for processing huge data sets
      ERXFetchSpecification<ResultItem> fs = taskInfo.fetchSpecificationForResultItems();
      
      // Batch iterator
      ERXFetchSpecificationBatchIterator fsIterator = new ERXFetchSpecificationBatchIterator(fs, ec);


      // Loop for a period of time
      while (fsIterator.hasNext() && !_isStopped) {
        @SuppressWarnings("unchecked")
        NSArray<ResultItem> batch = fsIterator.nextBatch();
        
        for (ResultItem resultItem : batch) {
          resultItem.setWorkflowState(ResultItem.WORKFLOW_CHECKING_FACTORIAL);
          performFactorialProcessing(resultItem);
          resultItem.setWorkflowState(ResultItem.WORKFLOW_PROCESSING_COMPLETE);


          ec.saveChanges();
          
          
          _elapsedTime = System.currentTimeMillis() - startTime;
          
          // Update progress variables
          _countCompleted++;
          _percentComplete = (double)(_countCompleted) / (double)_totalCount;
          _status = wholeNumberFormatter.format(_countCompleted) + " numbers checked for factorial proximity";
          
          if (_isStopped) {
            break;
          }


        }
        
        // Swap in a fresh EC for the next batch to help with memory management
        EOEditingContext freshEC = newEditingContext();
        ec.unlock();
        ec = freshEC;
        freshEC.lock();
        
        fsIterator.setEditingContext(ec);
        
        // We need to refault taskInfo into the new EC after swapping
        taskInfo = (TaskInfo) ec.faultForGlobalID(_taskInfoGID, ec);
        
      }

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Examples of er.extensions.eof.ERXFetchSpecificationBatchIterator

            int treshhold = 10;
            EOEditingContext ec = ERXEC.newEditingContext();
            ec.lock();
            try {
                EOFetchSpecification fs = new EOFetchSpecification(entity.name(), null, null);
                ERXFetchSpecificationBatchIterator iterator = new ERXFetchSpecificationBatchIterator(fs);
                iterator.setEditingContext(ec);
                while(iterator.hasNextBatch()) {
                    NSArray objects = iterator.nextBatch();
                    if(iterator.currentBatchIndex() % treshhold == 0) {
                        ec.unlock();
                        // ec.dispose();
                        ec = ERXEC.newEditingContext();
                        ec.lock();
                        iterator.setEditingContext(ec);
                    }
                    for(Enumeration i = incides.objectEnumerator(); i.hasMoreElements(); ) {
                        ERIndex index = (ERIndex) i.nextElement();
                        index.addObjectsToIndex(ec, objects);
                    }

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Examples of er.extensions.eof.ERXFetchSpecificationBatchIterator

            int treshhold = 10;
            EOEditingContext ec = ERXEC.newEditingContext();
            ec.lock();
            try {
                EOFetchSpecification fs = new EOFetchSpecification(entityName, null, null);
                ERXFetchSpecificationBatchIterator iterator = new ERXFetchSpecificationBatchIterator(fs);
                iterator.setEditingContext(ec);
                while (iterator.hasNextBatch()) {
                    NSArray objects = iterator.nextBatch();
                    if (iterator.currentBatchIndex() % treshhold == 0) {
                        ec.unlock();
                        // ec.dispose();
                        ec = ERXEC.newEditingContext();
                        ec.lock();
                        iterator.setEditingContext(ec);
                    }
                    NSArray<Document> documents = addedDocumentsForObjects(objects);
                    Transaction transaction = new Transaction(ec);
                    handler().addObjectsToIndex(transaction, objects);
                }

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Examples of er.extensions.eof.ERXFetchSpecificationBatchIterator

    if (range == null) {
      objects = editingContext.objectsWithFetchSpecification(fetchSpec);
      results = new Results<T>(objects, 0, -1, objects.count());
    }
    else {
      ERXFetchSpecificationBatchIterator batchIterator = new ERXFetchSpecificationBatchIterator(fetchSpec, editingContext, range.length());
      objects = batchIterator.batchWithRange(range);
      results = new Results<T>(objects, range.location(), range.length(), batchIterator.count());
    }
    return results;
  }

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Examples of er.extensions.eof.ERXFetchSpecificationBatchIterator

         * @return batch iterator for messages to be sent
         */
        public ERXFetchSpecificationBatchIterator batchIteratorForUnsentMessages() {
            EOFetchSpecification fetchSpec = EOFetchSpecification.fetchSpecificationNamed("messagesToBeSent",
                                                                                          "ERCMailMessage");
            return new ERXFetchSpecificationBatchIterator(fetchSpec);
        }

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Examples of er.extensions.eof.ERXFetchSpecificationBatchIterator

     * messages.
     */
    public void processOutgoingMail() {
        if (log.isDebugEnabled())
            log.debug("Starting outgoing mail processing.");
        ERXFetchSpecificationBatchIterator iterator = ERCMailMessage.mailMessageClazz().batchIteratorForUnsentMessages();


        EOEditingContext ec = ERXEC.newEditingContext();
        iterator.setEditingContext(ec);
        ec.lock();
        try {
            iterator.batchCount();
        } finally {
            ec.unlock();
        }
        ec.dispose();
        while (iterator.hasNextBatch()) {
            EOEditingContext temp = ERXEC.newEditingContext();
            temp.lock();
            try {
                iterator.setEditingContext(temp);
                sendMailMessages(iterator.nextBatch());
            } finally {
                temp.unlock();
            }
            temp.dispose();
        }

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