library/src/main/java/org/apache/apex/malhar/lib/testbench/RedisSumOper.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 com.datatorrent.lib.testbench;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

import com.datatorrent.api.Context.OperatorContext;
import com.datatorrent.api.DefaultInputPort;
import com.datatorrent.api.DefaultOutputPort;
import com.datatorrent.common.util.BaseOperator;

/**
 * This operator collects integer tuples, then emits their sum at the end of the window.
 *
 * @displayName Redis Sum Operator
 * @category Test Bench
 * @tags count
 * @since 0.3.2
 */
public class RedisSumOper extends BaseOperator
{
  private ArrayList<Integer> collect;

  /**
   * This is the input port which receives integer tuples to be summed.
   */
  public final transient DefaultInputPort<Integer> inport = new DefaultInputPort<Integer>()
  {
    @Override
    public void process(Integer s)
    {
      collect.add(s);
    }
  };

  @Override
  public void setup(OperatorContext context)
  {
  }

  @Override
  public void teardown()
  {
  }

  @Override
  public void beginWindow(long windowId)
  {
    collect  = new ArrayList<Integer>();
  }

  /**
   * This is the output port which emits the summed tuples.
   */
  public final transient DefaultOutputPort<Map<Integer, Integer>> outport = new DefaultOutputPort<Map<Integer, Integer>>();

  @Override
  public void endWindow()
  {
    Integer sum = 0;
    for (Integer entry : collect) {
      sum += entry;
    }
    Map<Integer, Integer> tuple = new HashMap<Integer, Integer>();
    tuple.put(1, sum);
    outport.emit(tuple);
  }
}