content: package backtype.storm.coordination;
  
  import backtype.storm.coordination.CoordinatedBolt.FinishedCallback;
  import backtype.storm.coordination.CoordinatedBolt.TimeoutCallback;
  import backtype.storm.task.OutputCollector;
  import backtype.storm.task.TopologyContext;
  import backtype.storm.topology.FailedException;
  import backtype.storm.topology.IRichBolt;
  import backtype.storm.topology.OutputFieldsDeclarer;
  import backtype.storm.tuple.Tuple;
  import backtype.storm.utils.Utils;
  import java.util.HashMap;
  import java.util.Map;
  import org.apache.log4j.Logger;
  
  public class BatchBoltExecutor implements IRichBolt, FinishedCallback, TimeoutCallback {
      public static Logger LOG = Logger.getLogger(BatchBoltExecutor.class);    
  
      byte[] _boltSer;
      Map<Object, IBatchBolt> _openTransactions;
      Map _conf;
      TopologyContext _context;
      BatchOutputCollectorImpl _collector;
      
      public BatchBoltExecutor(IBatchBolt bolt) {
          _boltSer = Utils.serialize(bolt);
      }
      
      @Override
      public void prepare(Map conf, TopologyContext context, OutputCollector collector) {
          _conf = conf;
          _context = context;
          _collector = new BatchOutputCollectorImpl(collector);
          _openTransactions = new HashMap<Object, IBatchBolt>();
      }
  
      @Override
      public void execute(Tuple input) {
          Object id = input.getValue(0);
          IBatchBolt bolt = getBatchBolt(id);
          try {
               bolt.execute(input);
              _collector.ack(input);
          } catch(FailedException e) {
              LOG.error("Failed to process tuple in batch", e);
              _collector.fail(input);                
          }
      }
  
      @Override
      public void cleanup() {
      }
  
      @Override
      public void finishedId(Object id) {
          IBatchBolt bolt = getBatchBolt(id);
          _openTransactions.remove(id);
          bolt.finishBatch();
      }
  
      @Override
      public void timeoutId(Object attempt) {
          _openTransactions.remove(attempt);        
      }    
      
  
      @Override
      public void declareOutputFields(OutputFieldsDeclarer declarer) {
          newTransactionalBolt().declareOutputFields(declarer);
      }
      
      @Override
      public Map<String, Object> getComponentConfiguration() {
          return newTransactionalBolt().getComponentConfiguration();
      }
      
      private IBatchBolt getBatchBolt(Object id) {
          IBatchBolt bolt = _openTransactions.get(id);
          if(bolt==null) {
              bolt = newTransactionalBolt();
              bolt.prepare(_conf, _context, _collector, id);
              _openTransactions.put(id, bolt);            
          }
          return bolt;
      }
      
      private IBatchBolt newTransactionalBolt() {
          return (IBatchBolt) Utils.deserialize(_boltSer);
      }
  }
  