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 backtype.storm.drpc;
  
  import backtype.storm.task.OutputCollector;
  import backtype.storm.task.TopologyContext;
  import backtype.storm.topology.OutputFieldsDeclarer;
  import backtype.storm.topology.base.BaseRichBolt;
  import backtype.storm.tuple.Fields;
  import backtype.storm.tuple.Tuple;
  import backtype.storm.tuple.Values;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class JoinResult extends BaseRichBolt {
      public static Logger LOG = LoggerFactory.getLogger(JoinResult.class);
  
      String returnComponent;
      Map<Object, Tuple> returns = new HashMap<>();
      Map<Object, Tuple> results = new HashMap<>();
      OutputCollector _collector;
  
      public JoinResult(String returnComponent) {
          this.returnComponent = returnComponent;
      }
  
      public void prepare(Map map, TopologyContext context, OutputCollector collector) {
          _collector = collector;
      }
  
      public void execute(Tuple tuple) {
          Object requestId = tuple.getValue(0);
          if (tuple.getSourceComponent().equals(returnComponent)) {
              returns.put(requestId, tuple);
          } else {
              results.put(requestId, tuple);
          }
  
          if (returns.containsKey(requestId) && results.containsKey(requestId)) {
              Tuple result = results.remove(requestId);
              Tuple returner = returns.remove(requestId);
              LOG.debug(result.getValue(1).toString());
              List<Tuple> anchors = new ArrayList<>();
              anchors.add(result);
              anchors.add(returner);
              _collector.emit(anchors, new Values("" + result.getValue(1), returner.getValue(1)));
              _collector.ack(result);
              _collector.ack(returner);
          }
      }
  
      public void declareOutputFields(OutputFieldsDeclarer declarer) {
          declarer.declare(new Fields("result", "return-info"));
      }
  }
  