library/src/main/java/org/apache/apex/malhar/lib/window/accumulation/CoGroup.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.apex.malhar.lib.window.accumulation;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;

/**
 * CoGroup Join Accumulation.
 *
 * @since 3.6.0
 */
public class CoGroup<T> extends InnerJoin<T>
{
  public CoGroup()
  {
    //for kryo
  }


  @Override
  public List<List<T>> getOutput(List<Set<T>> accumulatedValue)
  {
    List<List<T>> result = new ArrayList<>();
    for (int i = 0; i < 2; i++) {
      result.add(new ArrayList<T>(accumulatedValue.get(i)));
    }
    return result;
  }
}