heron/examples/src/java/com/twitter/heron/examples/spout/RandomIntegerSpout.java

//  Copyright 2017 Twitter. All rights reserved.
//
//  Licensed 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 com.twitter.heron.examples.spout;

import java.util.Map;
import java.util.Random;
import java.util.logging.Logger;

import com.twitter.heron.api.spout.BaseRichSpout;
import com.twitter.heron.api.spout.SpoutOutputCollector;
import com.twitter.heron.api.topology.OutputFieldsDeclarer;
import com.twitter.heron.api.topology.TopologyContext;
import com.twitter.heron.api.tuple.Fields;
import com.twitter.heron.api.tuple.Values;
import com.twitter.heron.api.utils.Utils;

/**
 * Emits a random integer and a timestamp value (offset by one day),
 * every 100 ms. The ts field can be used in tuple time based windowing.
 */
public class RandomIntegerSpout extends BaseRichSpout {
  private static final Logger LOG = Logger.getLogger(RandomIntegerSpout.class.getName());
  private static final long serialVersionUID = 5454291010750852782L;
  private SpoutOutputCollector collector;
  private Random rand;
  private long msgId = 0;

  @Override
  public void declareOutputFields(OutputFieldsDeclarer declarer) {
    declarer.declare(new Fields("value", "ts", "msgid"));
  }

  @Override
  @SuppressWarnings("HiddenField")
  public void open(Map<String, Object> conf, TopologyContext context, SpoutOutputCollector
      collector) {
    this.collector = collector;
    this.rand = new Random();
  }

  @Override
  public void nextTuple() {
    Utils.sleep(100);
    collector.emit(new Values(rand.nextInt(1000),
        System.currentTimeMillis() - (24 * 60 * 60 * 1000), ++msgId), msgId);
  }

  @Override
  @SuppressWarnings("HiddenField")
  public void ack(Object msgId) {
    LOG.fine("Got ACK for msgId : " + msgId);
  }

  @Override
  @SuppressWarnings("HiddenField")
  public void fail(Object msgId) {
    LOG.fine("Got FAIL for msgId : " + msgId);
  }
}