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;
  
  import static org.hamcrest.MatcherAssert.assertThat;
  import static org.hamcrest.Matchers.is;
  
  import org.apache.beam.sdk.Pipeline;
  import org.apache.beam.sdk.coders.KvCoder;
  import org.apache.beam.sdk.coders.StringUtf8Coder;
  import org.apache.beam.sdk.coders.VarIntCoder;
  import org.apache.beam.sdk.runners.AppliedPTransform;
  import org.apache.beam.sdk.runners.PTransformMatcher;
  import org.apache.beam.sdk.runners.TransformHierarchy;
  import org.apache.beam.sdk.testing.TestPipeline;
  import org.apache.beam.sdk.transforms.Combine;
  import org.apache.beam.sdk.transforms.CombineWithContext;
  import org.apache.beam.sdk.transforms.CombineWithContext.Context;
  import org.apache.beam.sdk.transforms.Create;
  import org.apache.beam.sdk.transforms.GroupByKey;
  import org.apache.beam.sdk.transforms.View;
  import org.apache.beam.sdk.values.KV;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.PCollectionView;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Tests for {@link DataflowPTransformMatchers}. */
  @RunWith(JUnit4.class)
  public class DataflowPTransformMatchersTest {
  
    /**
     * Test the cases that the matcher should successfully match against. In this case, it should
     * match against {@link Combine.GroupedValues} on their own and as part of an expanded {@link
     * Combine.PerKey} transform.
     */
    @Test
    public void combineValuesWithoutSideInputsSuccessfulMatches() {
      PTransformMatcher matcher =
          new DataflowPTransformMatchers.CombineValuesWithoutSideInputsPTransformMatcher();
      AppliedPTransform<?, ?, ?> groupedValues;
  
      groupedValues = getCombineGroupedValuesFrom(createCombineGroupedValuesPipeline());
      assertThat(matcher.matches(groupedValues), is(true));
  
      groupedValues = getCombineGroupedValuesFrom(createCombinePerKeyPipeline());
      assertThat(matcher.matches(groupedValues), is(true));
    }
  
    /**
     * Test significant cases that the matcher should not match against. In this case, this explicitly
     * tests that any {@link Combine.GroupedValues} with side inputs should not match.
     */
    @Test
    public void combineValuesWithoutSideInputsSkipsNonmatching() {
      PTransformMatcher matcher =
          new DataflowPTransformMatchers.CombineValuesWithoutSideInputsPTransformMatcher();
      AppliedPTransform<?, ?, ?> groupedValues;
  
      groupedValues = getCombineGroupedValuesFrom(createCombineGroupedValuesWithSideInputsPipeline());
      assertThat(matcher.matches(groupedValues), is(false));
  
      groupedValues = getCombineGroupedValuesFrom(createCombinePerKeyWithSideInputsPipeline());
      assertThat(matcher.matches(groupedValues), is(false));
    }
  
    /**
     * Test the cases that the matcher should successfully match against. In this case, it should
     * match against {@link Combine.GroupedValues} that are part of an expanded {@link Combine.PerKey}
     * transform.
     */
    @Test
    public void combineValuesWithParentCheckSuccessfulMatches() {
      PTransformMatcher matcher =
          new DataflowPTransformMatchers.CombineValuesWithParentCheckPTransformMatcher();
      AppliedPTransform<?, ?, ?> groupedValues;
  
      groupedValues = getCombineGroupedValuesFrom(createCombinePerKeyPipeline());
      assertThat(matcher.matches(groupedValues), is(true));
    }
  
    /**
     * Test significant cases that the matcher should not match against. In this case, this tests that
     * any {@link Combine.GroupedValues} with side inputs should not match, and that a {@link
     * Combine.GroupedValues} without an encompassing {@link Combine.PerKey} will not match.
     */
    @Test
    public void combineValuesWithParentCheckSkipsNonmatching() {
      PTransformMatcher matcher =
          new DataflowPTransformMatchers.CombineValuesWithParentCheckPTransformMatcher();
      AppliedPTransform<?, ?, ?> groupedValues;
  
      groupedValues = getCombineGroupedValuesFrom(createCombineGroupedValuesPipeline());
      assertThat(matcher.matches(groupedValues), is(false));
  
      groupedValues = getCombineGroupedValuesFrom(createCombineGroupedValuesWithSideInputsPipeline());
      assertThat(matcher.matches(groupedValues), is(false));
  
      groupedValues = getCombineGroupedValuesFrom(createCombinePerKeyWithSideInputsPipeline());
      assertThat(matcher.matches(groupedValues), is(false));
    }
  
    /** Creates a simple pipeline with a {@link Combine.PerKey}. */
    private static TestPipeline createCombinePerKeyPipeline() {
      TestPipeline pipeline = TestPipeline.create().enableAbandonedNodeEnforcement(false);
      PCollection<KV<String, Integer>> input =
          pipeline
              .apply(Create.of(KV.of("key", 1)))
              .setCoder(KvCoder.of(StringUtf8Coder.of(), VarIntCoder.of()));
      input.apply(Combine.perKey(new SumCombineFn()));
  
      return pipeline;
    }
  
    /** Creates a simple pipeline with a {@link Combine.PerKey} with side inputs. */
    private static TestPipeline createCombinePerKeyWithSideInputsPipeline() {
      TestPipeline pipeline = TestPipeline.create().enableAbandonedNodeEnforcement(false);
      PCollection<KV<String, Integer>> input =
          pipeline
              .apply(Create.of(KV.of("key", 1)))
              .setCoder(KvCoder.of(StringUtf8Coder.of(), VarIntCoder.of()));
      PCollection<String> sideInput = pipeline.apply(Create.of("side input"));
      PCollectionView<String> sideInputView = sideInput.apply(View.asSingleton());
  
      input.apply(
          Combine.<String, Integer, Integer>perKey(new SumCombineFnWithContext())
              .withSideInputs(sideInputView));
  
      return pipeline;
    }
  
    /** Creates a simple pipeline with a {@link Combine.GroupedValues}. */
    private static TestPipeline createCombineGroupedValuesPipeline() {
      TestPipeline pipeline = TestPipeline.create().enableAbandonedNodeEnforcement(false);
      PCollection<KV<String, Integer>> input =
          pipeline
              .apply(Create.of(KV.of("key", 1)))
              .setCoder(KvCoder.of(StringUtf8Coder.of(), VarIntCoder.of()));
      input.apply(GroupByKey.create()).apply(Combine.groupedValues(new SumCombineFn()));
  
      return pipeline;
    }
  
    /** Creates a simple pipeline with a {@link Combine.GroupedValues} with side inputs. */
    private static TestPipeline createCombineGroupedValuesWithSideInputsPipeline() {
      TestPipeline pipeline = TestPipeline.create().enableAbandonedNodeEnforcement(false);
      PCollection<KV<String, Integer>> input =
          pipeline
              .apply(Create.of(KV.of("key", 1)))
              .setCoder(KvCoder.of(StringUtf8Coder.of(), VarIntCoder.of()));
      PCollection<String> sideInput = pipeline.apply(Create.of("side input"));
      PCollectionView<String> sideInputView = sideInput.apply(View.asSingleton());
  
      input
          .apply(GroupByKey.create())
          .apply(
              Combine.<String, Integer, Integer>groupedValues(new SumCombineFnWithContext())
                  .withSideInputs(sideInputView));
  
      return pipeline;
    }
  
    /** Traverse the pipeline and return the first {@link Combine.GroupedValues} found. */
    private static AppliedPTransform<?, ?, ?> getCombineGroupedValuesFrom(TestPipeline pipeline) {
      final AppliedPTransform<?, ?, ?>[] transform = new AppliedPTransform<?, ?, ?>[1];
      pipeline.traverseTopologically(
          new Pipeline.PipelineVisitor.Defaults() {
            @Override
            public CompositeBehavior enterCompositeTransform(TransformHierarchy.Node node) {
              if (!node.isRootNode()
                  && node.toAppliedPTransform(getPipeline())
                      .getTransform()
                      .getClass()
                      .equals(Combine.GroupedValues.class)) {
                transform[0] = node.toAppliedPTransform(getPipeline());
                return CompositeBehavior.DO_NOT_ENTER_TRANSFORM;
              }
              return CompositeBehavior.ENTER_TRANSFORM;
            }
          });
      return transform[0];
    }
  
    private static class SumCombineFn extends Combine.CombineFn<Integer, Integer, Integer> {
      @Override
      public Integer createAccumulator() {
        return 0;
      }
  
      @Override
      public Integer addInput(Integer accum, Integer input) {
        return accum + input;
      }
  
      @Override
      public Integer mergeAccumulators(Iterable<Integer> accumulators) {
        Integer sum = 0;
        for (Integer accum : accumulators) {
          sum += accum;
        }
        return sum;
      }
  
      @Override
      public Integer extractOutput(Integer accumulator) {
        return accumulator;
      }
    }
  
    private static class SumCombineFnWithContext
        extends CombineWithContext.CombineFnWithContext<Integer, Integer, Integer> {
      SumCombineFn delegate;
  
      @Override
      public Integer createAccumulator(Context c) {
        return delegate.createAccumulator();
      }
  
      @Override
      public Integer addInput(Integer accum, Integer input, Context c) {
        return delegate.addInput(accum, input);
      }
  
      @Override
      public Integer mergeAccumulators(Iterable<Integer> accumulators, Context c) {
        return delegate.mergeAccumulators(accumulators);
      }
  
      @Override
      public Integer extractOutput(Integer accumulator, Context c) {
        return delegate.extractOutput(accumulator);
      }
    }
  }
  