heron/api/tests/java/com/twitter/heron/api/windowing/WaterMarkEventGeneratorTest.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.api.windowing;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.junit.Before;
import org.junit.Test;

import com.twitter.heron.api.generated.TopologyAPI;

import static org.junit.Assert.*;

/**
 * Unit tests for {@link WaterMarkEventGenerator}
 */
public class WaterMarkEventGeneratorTest {
  private WaterMarkEventGenerator<Integer> waterMarkEventGenerator;
  private WindowManager<Integer> windowManager;
  private List<Event<Integer>> eventList = new ArrayList<>();

  private TopologyAPI.StreamId streamId(String component) {
    return TopologyAPI.StreamId.newBuilder().setComponentName(component).setId("default").build();
  }

  @Before
  public void setUp() {
    windowManager = new WindowManager<Integer>(null) {
      @Override
      public void add(Event<Integer> event) {
        eventList.add(event);
      }
    };
    // set watermark interval to a high value and trigger manually to fix timing issues
    waterMarkEventGenerator = new WaterMarkEventGenerator<>(windowManager, 100000, 5, Collections
        .singleton(streamId("s1")));
    waterMarkEventGenerator.start();
  }

  @Test
  public void testTrackSingleStream() throws Exception {
    waterMarkEventGenerator.track(streamId("s1"), 100);
    waterMarkEventGenerator.track(streamId("s1"), 110);
    waterMarkEventGenerator.run();
    assertTrue(eventList.get(0).isWatermark());
    assertEquals(105, eventList.get(0).getTimestamp());
  }

  @Test
  public void testTrackSingleStreamOutOfOrder() throws Exception {
    waterMarkEventGenerator.track(streamId("s1"), 100);
    waterMarkEventGenerator.track(streamId("s1"), 110);
    waterMarkEventGenerator.track(streamId("s1"), 104);
    waterMarkEventGenerator.run();
    assertTrue(eventList.get(0).isWatermark());
    assertEquals(105, eventList.get(0).getTimestamp());
  }

  @Test
  public void testTrackTwoStreams() throws Exception {
    Set<TopologyAPI.StreamId> streams = new HashSet<>();
    streams.add(streamId("s1"));
    streams.add(streamId("s2"));
    waterMarkEventGenerator = new WaterMarkEventGenerator<>(windowManager, 100000, 5, streams);

    waterMarkEventGenerator.track(streamId("s1"), 100);
    waterMarkEventGenerator.track(streamId("s1"), 110);
    waterMarkEventGenerator.run();
    assertTrue(eventList.isEmpty());
    waterMarkEventGenerator.track(streamId("s2"), 95);
    waterMarkEventGenerator.track(streamId("s2"), 98);
    waterMarkEventGenerator.run();
    assertTrue(eventList.get(0).isWatermark());
    assertEquals(93, eventList.get(0).getTimestamp());
  }

  @Test
  public void testNoEvents() throws Exception {
    waterMarkEventGenerator.run();
    assertTrue(eventList.isEmpty());
  }

  @Test
  public void testLateEvent() throws Exception {
    assertTrue(waterMarkEventGenerator.track(streamId("s1"), 100));
    assertTrue(waterMarkEventGenerator.track(streamId("s1"), 110));
    waterMarkEventGenerator.run();
    assertTrue(eventList.get(0).isWatermark());
    assertEquals(105, eventList.get(0).getTimestamp());
    eventList.clear();
    assertTrue(waterMarkEventGenerator.track(streamId("s1"), 105));
    assertTrue(waterMarkEventGenerator.track(streamId("s1"), 106));
    assertTrue(waterMarkEventGenerator.track(streamId("s1"), 115));
    assertFalse(waterMarkEventGenerator.track(streamId("s1"), 104));
    waterMarkEventGenerator.run();
    assertTrue(eventList.get(0).isWatermark());
    assertEquals(110, eventList.get(0).getTimestamp());
  }
}