ApexStreamUtils.java

package org.apache.samoa.apex.topology.impl;

/*
 * #%L
 * SAMOA
 * %%
 * Copyright (C) 2014 - 2016 Apache Software Foundation
 * %%
 * 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.
 * #L%
 */

import java.io.Serializable;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Random;

import org.apache.samoa.core.ContentEvent;

import com.datatorrent.api.DefaultPartition;
import com.datatorrent.api.Partitioner;
import com.datatorrent.netlet.util.Slice;
import com.datatorrent.api.Operator.InputPort;
import com.datatorrent.stram.plan.logical.DefaultKryoStreamCodec;
import com.esotericsoftware.kryo.serializers.JavaSerializer;
import com.google.common.collect.Lists;

public class ApexStreamUtils {
  public static class KeyBasedStreamCodec<T extends ContentEvent> extends JavaSerializationStreamCodec<T> {
    /**
     * KeyBasedStreamCodec - Distributes tuples to down stream operators such that each tuple with same key goes to same
     * partition
     */
    private static final long serialVersionUID = -7144877905889718517L;

    @Override
    public int getPartition(T t) {
      return t.getKey().hashCode();
    }
  }

  public static class RandomStreamCodec<T extends ContentEvent> extends JavaSerializationStreamCodec<T> {
    /**
     * RandomStreamCodec - Distributes tuples to down stream partitions randomly
     */
    private static final long serialVersionUID = -7522462490354605783L;
    private Random r;

    public RandomStreamCodec() {
      r = new Random();
    }

    @Override
    public int getPartition(T t) {
      return Math.abs(r.nextInt());
    }
  }

  public static class AllPartitioner<T> implements Partitioner<T>, Serializable {
    /**
     * 
     */
    private static final long serialVersionUID = 7203316682043269713L;
    private int newPartitionCount;

    public AllPartitioner(int n) {
      newPartitionCount = n;
    }

    @Override
    public Collection<com.datatorrent.api.Partitioner.Partition<T>> definePartitions(
        Collection<com.datatorrent.api.Partitioner.Partition<T>> partitions,
        com.datatorrent.api.Partitioner.PartitioningContext context) {
      //Get a partition
      DefaultPartition<T> partition = (DefaultPartition<T>) partitions.iterator().next();
      Collection<Partition<T>> newPartitions;

      // first call to define partitions
      newPartitions = Lists.newArrayList();

      for (int partitionCounter = 0; partitionCounter < newPartitionCount; partitionCounter++) {
        newPartitions.add(new DefaultPartition<T>(partition.getPartitionedInstance()));
      }
      List<InputPort<?>> inputPortList = context.getInputPorts();
//      if (inputPortList != null && !inputPortList.isEmpty()) {
//        DefaultPartition.assignPartitionKeys(newPartitions, inputPortList.iterator().next());
//      }

      return newPartitions;
    }

    @Override
    public void partitioned(Map<Integer, com.datatorrent.api.Partitioner.Partition<T>> partitions) {
    }

    public int getNewPartitionCount() {
      return newPartitionCount;
    }

    public void setNewPartitionCount(int newPartitionCount) {
      this.newPartitionCount = newPartitionCount;
    }
  }

  public static class JavaSerializationStreamCodec<T extends ContentEvent> extends DefaultKryoStreamCodec<T> {

    private static final long serialVersionUID = -183071548840076388L;

    public JavaSerializationStreamCodec() {
     super();
     this.kryo.setDefaultSerializer(JavaSerializer.class);
    }

    @Override
    public Slice toByteArray(T info) {
      return super.toByteArray(info);
    }

    @Override
    public Object fromByteArray(Slice fragment) {
      return super.fromByteArray(fragment);
    }
  }
}