content: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package storm.trident.spout;
  
  import backtype.storm.coordination.BatchOutputCollector;
  import backtype.storm.task.TopologyContext;
  import backtype.storm.topology.FailedException;
  import backtype.storm.topology.OutputFieldsDeclarer;
  import storm.trident.topology.TransactionAttempt;
  import backtype.storm.tuple.Fields;
  import backtype.storm.tuple.Tuple;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  import java.util.TreeMap;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import storm.trident.operation.TridentCollector;
  import storm.trident.topology.BatchInfo;
  import storm.trident.topology.ITridentBatchBolt;
  import storm.trident.topology.MasterBatchCoordinator;
  import storm.trident.tuple.ConsList;
  
  public class TridentSpoutExecutor implements ITridentBatchBolt {
      public static final String ID_FIELD = "$tx";
      
      public static final Logger LOG = LoggerFactory.getLogger(TridentSpoutExecutor.class);
  
      AddIdCollector _collector;
      ITridentSpout<Object> _spout;
      ITridentSpout.Emitter<Object> _emitter;
      String _streamName;
      String _txStateId;
      
      TreeMap<Long, TransactionAttempt> _activeBatches = new TreeMap<>();
  
      public TridentSpoutExecutor(String txStateId, String streamName, ITridentSpout<Object> spout) {
          _txStateId = txStateId;
          _spout = spout;
          _streamName = streamName;
      }
      
      @Override
      public void prepare(Map conf, TopologyContext context, BatchOutputCollector collector) {
          _emitter = _spout.getEmitter(_txStateId, conf, context);
          _collector = new AddIdCollector(_streamName, collector);
      }
  
      @Override
      public void execute(BatchInfo info, Tuple input) {
          // there won't be a BatchInfo for the success stream
          TransactionAttempt attempt = (TransactionAttempt) input.getValue(0);
          if (input.getSourceStreamId().equals(MasterBatchCoordinator.COMMIT_STREAM_ID)) {
              if (attempt.equals(_activeBatches.get(attempt.getTransactionId()))) {
                  ((ICommitterTridentSpout.Emitter) _emitter).commit(attempt);
                  _activeBatches.remove(attempt.getTransactionId());
              } else {
                  throw new FailedException("Received commit for different transaction attempt");
              }
          } else if (input.getSourceStreamId().equals(MasterBatchCoordinator.SUCCESS_STREAM_ID)) {
              // valid to delete before what's been committed since
              // those batches will never be accessed again
              _activeBatches.headMap(attempt.getTransactionId()).clear();
              _emitter.success(attempt);
          } else {
              _collector.setBatch(info.batchId);
              _emitter.emitBatch(attempt, input.getValue(1), _collector);
              _activeBatches.put(attempt.getTransactionId(), attempt);
          }
      }
  
      @Override
      public void cleanup() {
          _emitter.close();
      }
  
      @Override
      public void declareOutputFields(OutputFieldsDeclarer declarer) {
          List<String> fields = new ArrayList<>(_spout.getOutputFields().toList());
          fields.add(0, ID_FIELD);
          declarer.declareStream(_streamName, new Fields(fields));
      }
  
      @Override
      public Map<String, Object> getComponentConfiguration() {
          return _spout.getComponentConfiguration();
      }
  
      @Override
      public void finishBatch(BatchInfo batchInfo) {
      }
  
      @Override
      public Object initBatchState(String batchGroup, Object batchId) {
          return null;
      }
  
      private static class AddIdCollector implements TridentCollector {
          BatchOutputCollector _delegate;
          Object _id;
          String _stream;
  
          public AddIdCollector(String stream, BatchOutputCollector c) {
              _delegate = c;
              _stream = stream;
          }
  
          public void setBatch(Object id) {
              _id = id;
          }
  
          @Override
          public void emit(List<Object> values) {
              _delegate.emit(_stream, new ConsList(_id, values));
          }
  
          @Override
          public void reportError(Throwable t) {
              _delegate.reportError(t);
          }
      }
  }
  