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 org.apache.beam.runners.dataflow.worker.util;
  
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.contains;
  import static org.hamcrest.Matchers.equalTo;
  
  import java.util.Arrays;
  import java.util.List;
  import org.apache.beam.runners.core.DoFnRunner;
  import org.apache.beam.runners.core.InMemoryStateInternals;
  import org.apache.beam.runners.core.NullSideInputReader;
  import org.apache.beam.runners.core.StateInternals;
  import org.apache.beam.runners.core.StateInternalsFactory;
  import org.apache.beam.runners.core.StepContext;
  import org.apache.beam.runners.core.TimerInternals;
  import org.apache.beam.runners.dataflow.worker.GroupAlsoByWindowFnRunner;
  import org.apache.beam.runners.dataflow.worker.util.GroupAlsoByWindowProperties.GroupAlsoByWindowDoFnFactory;
  import org.apache.beam.sdk.options.PipelineOptionsFactory;
  import org.apache.beam.sdk.transforms.windowing.BoundedWindow;
  import org.apache.beam.sdk.transforms.windowing.FixedWindows;
  import org.apache.beam.sdk.transforms.windowing.IntervalWindow;
  import org.apache.beam.sdk.transforms.windowing.PaneInfo;
  import org.apache.beam.sdk.util.WindowedValueReceiver;
  import org.apache.beam.sdk.values.KV;
  import org.apache.beam.sdk.values.TupleTag;
  import org.apache.beam.sdk.values.WindowedValue;
  import org.apache.beam.sdk.values.WindowedValues;
  import org.apache.beam.sdk.values.WindowingStrategy;
  import org.joda.time.Duration;
  import org.joda.time.Instant;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.rules.ExpectedException;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /**
   * Unit tests for {@link BatchGroupAlsoByWindowReshuffleFn}.
   *
   * <p>Note the absence of tests for sessions, as merging window functions are not supported.
   */
  @RunWith(JUnit4.class)
  public class BatchGroupAlsoByWindowReshuffleDoFnTest {
  
    @Rule public final transient ExpectedException thrown = ExpectedException.none();
  
    private static final String STEP_NAME = "GABWStep";
  
    private class GABWReshuffleDoFnFactory
        implements GroupAlsoByWindowDoFnFactory<String, String, Iterable<String>> {
      @Override
      public <W extends BoundedWindow>
          BatchGroupAlsoByWindowFn<String, String, Iterable<String>> forStrategy(
              WindowingStrategy<?, W> windowingStrategy,
              StateInternalsFactory<String> stateInternalsFactory) {
        // ignores windowing strategy.
        return new BatchGroupAlsoByWindowReshuffleFn<String, String, W>();
      }
    }
  
    @SafeVarargs
    private static <K, InputT, OutputT, W extends BoundedWindow>
        List<WindowedValue<KV<K, OutputT>>> runGABW(
            GroupAlsoByWindowDoFnFactory<K, InputT, OutputT> gabwFactory,
            WindowingStrategy<?, W> windowingStrategy,
            K key,
            WindowedValue<InputT>... values) {
  
      TupleTag<KV<K, OutputT>> outputTag = new TupleTag<>();
      ListOutputManager outputManager = new ListOutputManager();
  
      DoFnRunner<KV<K, Iterable<WindowedValue<InputT>>>, KV<K, OutputT>> runner =
          makeRunner(
              gabwFactory, windowingStrategy, output -> outputManager.output(outputTag, output));
  
      runner.startBundle();
  
      if (values.length > 0) {
        runner.processElement(
            new ValueInEmptyWindows<>(
                KV.of(
                    key,
                    (Iterable<WindowedValue<InputT>>) Arrays.<WindowedValue<InputT>>asList(values))));
      }
  
      runner.finishBundle();
  
      List<WindowedValue<KV<K, OutputT>>> result = outputManager.getOutput(outputTag);
  
      // Sanity check for corruption
      for (WindowedValue<KV<K, OutputT>> elem : result) {
        assertThat(elem.getValue().getKey(), equalTo(key));
      }
  
      return result;
    }
  
    private static <K, InputT, OutputT, W extends BoundedWindow>
        DoFnRunner<KV<K, Iterable<WindowedValue<InputT>>>, KV<K, OutputT>> makeRunner(
            GroupAlsoByWindowDoFnFactory<K, InputT, OutputT> fnFactory,
            WindowingStrategy<?, W> windowingStrategy,
            WindowedValueReceiver<KV<K, OutputT>> outputManager) {
  
      final StepContext stepContext = new TestStepContext(STEP_NAME);
  
      StateInternalsFactory<K> stateInternalsFactory = key -> stepContext.stateInternals();
  
      BatchGroupAlsoByWindowFn<K, InputT, OutputT> fn =
          fnFactory.forStrategy(windowingStrategy, stateInternalsFactory);
  
      return new GroupAlsoByWindowFnRunner<>(
          PipelineOptionsFactory.create(),
          fn,
          NullSideInputReader.empty(),
          outputManager,
          stepContext);
    }
  
    private static BoundedWindow window(long start, long end) {
      return new IntervalWindow(new Instant(start), new Instant(end));
    }
  
    @Test
    public void testEmptyInputEmptyOutput() throws Exception {
      GroupAlsoByWindowProperties.emptyInputEmptyOutput(new GABWReshuffleDoFnFactory());
    }
  
    /**
     * Tests that for a simple sequence of elements on the same key, {@link
     * BatchGroupAlsoByWindowReshuffleFn} fires each element in a single pane.
     */
    @Test
    public void testReshuffleFiresEveryElement() throws Exception {
      GABWReshuffleDoFnFactory gabwFactory = new GABWReshuffleDoFnFactory();
  
      WindowingStrategy<?, IntervalWindow> windowingStrategy =
          WindowingStrategy.of(FixedWindows.of(Duration.millis(10)));
  
      List<WindowedValue<KV<String, Iterable<String>>>> result =
          runGABW(
              gabwFactory,
              windowingStrategy,
              "key",
              WindowedValues.of(
                  "v1", new Instant(1), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING),
              WindowedValues.of(
                  "v2", new Instant(2), Arrays.asList(window(0, 10)), PaneInfo.NO_FIRING),
              WindowedValues.of(
                  "v3", new Instant(13), Arrays.asList(window(10, 20)), PaneInfo.NO_FIRING));
  
      assertThat(result.size(), equalTo(3));
  
      WindowedValue<KV<String, Iterable<String>>> item0 = result.get(0);
      assertThat(item0.getValue().getValue(), contains("v1"));
      assertThat(item0.getTimestamp(), equalTo(new Instant(1)));
      assertThat(item0.getWindows(), contains(window(0, 10)));
  
      WindowedValue<KV<String, Iterable<String>>> item1 = result.get(1);
      assertThat(item1.getValue().getValue(), contains("v2"));
      assertThat(item1.getTimestamp(), equalTo(new Instant(2)));
      assertThat(item1.getWindows(), contains(window(0, 10)));
  
      WindowedValue<KV<String, Iterable<String>>> item2 = result.get(2);
      assertThat(item2.getValue().getValue(), contains("v3"));
      assertThat(item2.getTimestamp(), equalTo(new Instant(13)));
      assertThat(item2.getWindows(), contains(window(10, 20)));
    }
  
    private static final class TestStepContext implements StepContext {
      private StateInternals stateInternals;
  
      private TestStepContext(String stepName) {
        this.stateInternals = InMemoryStateInternals.forKey(stepName);
      }
  
      @Override
      public TimerInternals timerInternals() {
        throw new UnsupportedOperationException();
      }
  
      @Override
      public StateInternals stateInternals() {
        return stateInternals;
      }
    }
  }
  