crunch-core/src/it/java/org/apache/crunch/CollectionsIT.java

/**
 * 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.crunch;

import static org.junit.Assert.assertTrue;

import java.io.IOException;
import java.util.Collection;

import org.apache.crunch.fn.Aggregators.SimpleAggregator;
import org.apache.crunch.impl.mem.MemPipeline;
import org.apache.crunch.impl.mr.MRPipeline;
import org.apache.crunch.test.TemporaryPath;
import org.apache.crunch.test.TemporaryPaths;
import org.apache.crunch.types.PTypeFamily;
import org.apache.crunch.types.avro.AvroTypeFamily;
import org.apache.crunch.types.writable.WritableTypeFamily;
import org.junit.Rule;
import org.junit.Test;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;

@SuppressWarnings("serial")
public class CollectionsIT {

  private static class AggregateStringListFn extends SimpleAggregator<Collection<String>> {
    private final Collection<String> rtn = Lists.newArrayList();

    @Override
    public void reset() {
      rtn.clear();
    }

    @Override
    public void update(Collection<String> values) {
      rtn.addAll(values);
    }

    @Override
    public Iterable<Collection<String>> results() {
      return ImmutableList.of(rtn);
    }
  }

  private static PTable<String, Collection<String>> listOfCharcters(PCollection<String> lines, PTypeFamily typeFamily) {

    return lines.parallelDo(new DoFn<String, Pair<String, Collection<String>>>() {
      @Override
      public void process(String line, Emitter<Pair<String, Collection<String>>> emitter) {
        for (String word : line.split("\\s+")) {
          Collection<String> characters = Lists.newArrayList();
          for (char c : word.toCharArray()) {
            characters.add(String.valueOf(c));
          }
          emitter.emit(Pair.of(word, characters));
        }
      }
    }, typeFamily.tableOf(typeFamily.strings(), typeFamily.collections(typeFamily.strings())))
        .groupByKey().combineValues(new AggregateStringListFn());
  }

  @Rule
  public TemporaryPath tmpDir = TemporaryPaths.create();

  @Test
  public void testWritables() throws IOException {
    run(new MRPipeline(CollectionsIT.class, tmpDir.getDefaultConfiguration()), WritableTypeFamily.getInstance());
  }

  @Test
  public void testAvro() throws IOException {
    run(new MRPipeline(CollectionsIT.class, tmpDir.getDefaultConfiguration()), AvroTypeFamily.getInstance());
  }

  @Test
  public void testInMemoryWritables() throws IOException {
    run(MemPipeline.getInstance(), WritableTypeFamily.getInstance());
  }

  @Test
  public void testInMemoryAvro() throws IOException {
    run(MemPipeline.getInstance(), AvroTypeFamily.getInstance());
  }

  public void run(Pipeline pipeline, PTypeFamily typeFamily) throws IOException {
    String shakesInputPath = tmpDir.copyResourceFileName("shakes.txt");

    PCollection<String> shakespeare = pipeline.readTextFile(shakesInputPath);
    Iterable<Pair<String, Collection<String>>> lines = listOfCharcters(shakespeare, typeFamily).materialize();

    boolean passed = false;
    for (Pair<String, Collection<String>> line : lines) {
      if (line.first().startsWith("yellow")) {
        passed = true;
        break;
      }
    }
    pipeline.done();
    assertTrue(passed);
  }
}