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.sdk.util.construction;
  
  import static org.hamcrest.MatcherAssert.assertThat;
  
  import java.util.HashSet;
  import java.util.Set;
  import org.apache.beam.sdk.Pipeline.PipelineVisitor;
  import org.apache.beam.sdk.io.CountingSource;
  import org.apache.beam.sdk.io.Read;
  import org.apache.beam.sdk.io.Read.Bounded;
  import org.apache.beam.sdk.io.Read.Unbounded;
  import org.apache.beam.sdk.runners.TransformHierarchy.Node;
  import org.apache.beam.sdk.testing.TestPipeline;
  import org.apache.beam.sdk.transforms.Flatten;
  import org.apache.beam.sdk.values.PCollection;
  import org.apache.beam.sdk.values.PCollectionList;
  import org.apache.beam.sdk.values.PValue;
  import org.hamcrest.Matchers;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.junit.runners.JUnit4;
  
  /** Tests for {@link UnconsumedReads}. */
  @RunWith(JUnit4.class)
  public class UnconsumedReadsTest {
    @Rule public TestPipeline pipeline = TestPipeline.create().enableAbandonedNodeEnforcement(false);
  
    @Test
    public void matcherProducesUnconsumedValueBoundedRead() {
      Bounded<Long> transform = Read.from(CountingSource.upTo(20L));
      pipeline.apply(transform);
      UnconsumedReads.ensureAllReadsConsumed(pipeline);
      validateConsumed();
    }
  
    @Test
    public void matcherProducesUnconsumedValueUnboundedRead() {
      Unbounded<Long> transform = Read.from(CountingSource.unbounded());
      pipeline.apply(transform);
      UnconsumedReads.ensureAllReadsConsumed(pipeline);
      validateConsumed();
    }
  
    @Test
    public void doesNotConsumeAlreadyConsumedRead() {
      Unbounded<Long> transform = Read.from(CountingSource.unbounded());
      final PCollection<Long> output = pipeline.apply(transform);
      final Flatten.PCollections<Long> consumer = Flatten.pCollections();
      PCollectionList.of(output).apply(consumer);
      UnconsumedReads.ensureAllReadsConsumed(pipeline);
      pipeline.traverseTopologically(
          new PipelineVisitor.Defaults() {
            @Override
            public void visitPrimitiveTransform(Node node) {
              // The output should only be consumed by a single consumer
              if (node.getInputs().values().contains(output)) {
                assertThat(node.getTransform(), Matchers.is(consumer));
              }
            }
          });
    }
  
    private void validateConsumed() {
      final Set<PValue> consumedOutputs = new HashSet<>();
      final Set<PValue> allReadOutputs = new HashSet<>();
      pipeline.traverseTopologically(
          new PipelineVisitor.Defaults() {
            @Override
            public void visitPrimitiveTransform(Node node) {
              consumedOutputs.addAll(node.getInputs().values());
            }
  
            @Override
            public void visitValue(PValue value, Node producer) {
              if (producer.getTransform() instanceof Read.Bounded
                  || producer.getTransform() instanceof Read.Unbounded) {
                allReadOutputs.add(value);
              }
            }
          });
      assertThat(consumedOutputs, Matchers.hasItems(allReadOutputs.toArray(new PValue[0])));
    }
  }
  