common/src/test/java/com/datatorrent/common/partitioner/StatelessPartitionerTest.java

/**
 * Copyright (C) 2015 DataTorrent, Inc.
 *
 * 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.datatorrent.common.partitioner;

import java.util.Collection;
import java.util.List;

import org.junit.Assert;
import org.junit.Test;

import com.google.common.collect.Lists;
import com.datatorrent.api.Context.OperatorContext;
import com.datatorrent.api.*;
import com.datatorrent.api.Operator.InputPort;
import com.datatorrent.api.Partitioner.Partition;
import com.datatorrent.api.StringCodec.Object2String;

public class StatelessPartitionerTest
{

  public static class DummyOperator implements Operator
  {
    public final DefaultOutputPort<Integer> output = new DefaultOutputPort<Integer>();

    private Integer value;

    public DummyOperator()
    {
    }

    public DummyOperator(Integer value)
    {
      this.value = value;
    }

    @Override
    public void beginWindow(long windowId)
    {
      //Do nothing
    }

    @Override
    public void endWindow()
    {
      //Do nothing
    }

    @Override
    public void setup(OperatorContext context)
    {
      //Do nothing
    }

    @Override
    public void teardown()
    {
      //Do nothing
    }

    public void setValue(int value)
    {
      this.value = value;
    }

    public int getValue()
    {
      return value;
    }
  }

  @Test
  public void partition1Test()
  {
    DummyOperator dummyOperator = new DummyOperator(5);
    StatelessPartitioner<DummyOperator> statelessPartitioner = new StatelessPartitioner<DummyOperator>();

    Collection<Partition<DummyOperator>> partitions = Lists.newArrayList();
    DefaultPartition<DummyOperator> defaultPartition = new DefaultPartition<DummyOperator>(dummyOperator);
    partitions.add(defaultPartition);

    Collection<Partition<DummyOperator>> newPartitions = statelessPartitioner.definePartitions(partitions, new PartitioningContextImpl(null, 0));
    Assert.assertEquals("Incorrect number of partitions", 1, newPartitions.size());

    for(Partition<DummyOperator> partition: newPartitions) {
      Assert.assertEquals("Incorrect cloned value", 5, partition.getPartitionedInstance().getValue());
    }
  }

  @Test
  public void partition5Test()
  {
    DummyOperator dummyOperator = new DummyOperator(5);
    StatelessPartitioner<DummyOperator> statelessPartitioner = new StatelessPartitioner<DummyOperator>(5);

    Collection<Partition<DummyOperator>> partitions = Lists.newArrayList();
    DefaultPartition<DummyOperator> defaultPartition = new DefaultPartition<DummyOperator>(dummyOperator);
    partitions.add(defaultPartition);

    Collection<Partition<DummyOperator>> newPartitions = statelessPartitioner.definePartitions(partitions, new PartitioningContextImpl(null, 0));
    Assert.assertEquals("Incorrect number of partitions", 5, newPartitions.size());

    for(Partition<DummyOperator> partition: newPartitions) {
      Assert.assertEquals("Incorrect cloned value", 5, partition.getPartitionedInstance().getValue());
    }
  }

  @Test
  public void objectPropertyTest()
  {
    Object2String<StatelessPartitioner<DummyOperator>> propertyReader = new Object2String<StatelessPartitioner<DummyOperator>>();
    StatelessPartitioner<DummyOperator> partitioner = propertyReader.fromString("com.datatorrent.common.partitioner.StatelessPartitioner:3");
    Assert.assertEquals(3, partitioner.getPartitionCount());
  }

  @Test
  public void testParallelPartitionScaleUP()
  {
    DummyOperator dummyOperator = new DummyOperator(5);
    StatelessPartitioner<DummyOperator> statelessPartitioner = new StatelessPartitioner<DummyOperator>();

    Collection<Partition<DummyOperator>> partitions = Lists.newArrayList();
    partitions.add(new DefaultPartition<DummyOperator>(dummyOperator));

    Collection<Partition<DummyOperator>> newPartitions = statelessPartitioner.definePartitions(partitions,
      new PartitioningContextImpl(null, 5));
    Assert.assertEquals("after partition", 5, newPartitions.size());
  }

  @Test
  public void testParallelPartitionScaleDown()
  {
    DummyOperator dummyOperator = new DummyOperator(5);
    StatelessPartitioner<DummyOperator> statelessPartitioner = new StatelessPartitioner<DummyOperator>();

    Collection<Partition<DummyOperator>> partitions = Lists.newArrayList();

    for (int i = 5; i-- > 0; ) {
      partitions.add(new DefaultPartition<DummyOperator>(dummyOperator));
    }

    Collection<Partition<DummyOperator>> newPartitions = statelessPartitioner.definePartitions(partitions,
      new PartitioningContextImpl(null, 1));
    Assert.assertEquals("after partition", 1, newPartitions.size());
  }

  public static class PartitioningContextImpl implements Partitioner.PartitioningContext
  {
    final int parallelPartitionCount;
    final List<InputPort<?>> ports;

    public PartitioningContextImpl(List<InputPort<?>> ports, int parallelPartitionCount)
    {
      this.ports = ports;
      this.parallelPartitionCount = parallelPartitionCount;
    }

    @Override
    public int getParallelPartitionCount()
    {
      return parallelPartitionCount;
    }

    @Override
    public List<InputPort<?>> getInputPorts()
    {
      return ports;
    }
  }

}