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.planner.processor;
  
  import backtype.storm.task.TopologyContext;
  import backtype.storm.tuple.Fields;
  import java.util.Map;
  import storm.trident.planner.ProcessorContext;
  import storm.trident.planner.TridentProcessor;
  import storm.trident.planner.TupleReceiver;
  import storm.trident.tuple.TridentTuple;
  import storm.trident.tuple.TridentTuple.Factory;
  import storm.trident.tuple.TridentTupleView.ProjectionFactory;
  
  public class ProjectedProcessor implements TridentProcessor {
      Fields _projectFields;
      ProjectionFactory _factory;
      TridentContext _context;
  
      public ProjectedProcessor(Fields projectFields) {
          _projectFields = projectFields;
      }
  
      @Override
      public void prepare(Map conf, TopologyContext context, TridentContext tridentContext) {
          if (tridentContext.getParentTupleFactories().size() != 1) {
              throw new RuntimeException("Projection processor can only have one parent");
          }
          _context = tridentContext;
          _factory = new ProjectionFactory(tridentContext.getParentTupleFactories().get(0), _projectFields);
      }
  
      @Override
      public void cleanup() {
      }
  
      @Override
      public void startBatch(ProcessorContext processorContext) {
      }
  
      @Override
      public void execute(ProcessorContext processorContext, String streamId, TridentTuple tuple) {
          TridentTuple toEmit = _factory.create(tuple);
          for (TupleReceiver r : _context.getReceivers()) {
              r.execute(processorContext, _context.getOutStreamId(), toEmit);
          }
      }
  
      @Override
      public void finishBatch(ProcessorContext processorContext) {
      }
  
      @Override
      public Factory getOutputFactory() {
          return _factory;
      }
  }
  