library/src/main/java/com/datatorrent/lib/stream/ConsolidatorKeyVal.java

/*
 * Copyright (c) 2013 DataTorrent, Inc. ALL Rights Reserved.
 *
 * 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.lib.stream;

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

import com.datatorrent.api.Context.OperatorContext;
import com.datatorrent.api.DefaultInputPort;
import com.datatorrent.api.DefaultOutputPort;
import com.datatorrent.api.Operator;
import com.datatorrent.api.annotation.InputPortFieldAnnotation;
import com.datatorrent.api.annotation.OperatorAnnotation;
import com.datatorrent.api.annotation.OutputPortFieldAnnotation;
import com.datatorrent.lib.util.KeyValPair;

/**
 * <p>
 * An implementation of operator that Aggregates &lt;key,value&gt; input from five ports of different types into
 * &lt;key,array list map&gt; for each key. <br>
 * <p>
 * Operator emits key/array list map at end window, this end window operator. <br>
 * <br>
 * <b>StateFull : Yes</b>, values are collected over application window. <br>
 * <b>Partitions : No</b>, will collect wrong results. <br>
 * <br>
 * <b>Ports : </b><br>
 * <b>Input(s) : </b> 5 max input ports, 3 are optional. <br>
 * <br>
 * @displayName: Consolidator Key Value
 * @category: stream
 * @tag: arraylist, key value
 * @since 0.3.3
 */
@OperatorAnnotation(partitionable = false)
public class ConsolidatorKeyVal<K, V1, V2, V3, V4, V5> implements Operator
{
	/**
	 * key/array values output result.
	 */
	protected HashMap<K, ArrayList<Object>> result;

	@Override
	public void setup(OperatorContext context)
	{
	}

	@Override
	public void teardown()
	{
	}

	/**
	 * <p>
	 * Class operates on <K,V> pair, stores value in given number position in
	 * list. <br>
	 * 
	 * @param <V>
	 *          value type.
	 */
	public class ConsolidatorInputPort<V> extends
			DefaultInputPort<KeyValPair<K, V>>
	{
		/**
		 * Value position in list.
		 */
		private int number;

		/**
		 * Constructor
		 * 
		 * @param oper
		 *          Connected operator.
		 * @param num
		 *          Value position in list.
		 */
		ConsolidatorInputPort(Operator oper, int num)
		{
			super();
			number = num;
		}

		/**
		 * Process key/value pair.
		 */
		@Override
		public void process(KeyValPair<K, V> tuple)
		{
			K key = tuple.getKey();
			ArrayList<Object> list = getObject(key);
			list.set(number, tuple.getValue());
		}

	}

	/**
	 * V1 type value input port.
	 */
	@InputPortFieldAnnotation(name = "in1")
	public final transient ConsolidatorInputPort<V1> in1 = new ConsolidatorInputPort<V1>(
			this, 0);

	/**
	 * V2 type value input port.
	 */
	@InputPortFieldAnnotation(name = "in2")
	public final transient ConsolidatorInputPort<V2> in2 = new ConsolidatorInputPort<V2>(
			this, 1);

	/**
	 * V3 type value input port.
	 */
	@InputPortFieldAnnotation(name = "in3", optional = true)
	public final transient ConsolidatorInputPort<V3> in3 = new ConsolidatorInputPort<V3>(
			this, 2);

	/**
	 * V4 type value input port.
	 */
	@InputPortFieldAnnotation(name = "in4", optional = true)
	public final transient ConsolidatorInputPort<V4> in4 = new ConsolidatorInputPort<V4>(
			this, 3);

	/**
	 * V5 type value input port.
	 */
	@InputPortFieldAnnotation(name = "in5", optional = true)
	public final transient ConsolidatorInputPort<V5> in5 = new ConsolidatorInputPort<V5>(
			this, 4);

	/**
	 * Output port that emits a hashmap of &lt;key,arraylist&gt;.
	 */
	@OutputPortFieldAnnotation(name = "out")
	public final transient DefaultOutputPort<HashMap<K, ArrayList<Object>>> out = new DefaultOutputPort<HashMap<K, ArrayList<Object>>>();

	/**
	 * Get array list object for given key
	 * 
	 * @param k  key
	 * @return array list for key.
	 */
	public ArrayList<Object> getObject(K k)
	{
		ArrayList<Object> val = result.get(k);
		if (val == null) {
			val = new ArrayList<Object>(5);
			val.add(0, null);
			val.add(1, null);
			val.add(2, null);
			val.add(3, null);
			val.add(4, null);
			result.put(k, val);
		}
		return val;
	}

	@Override
	public void beginWindow(long windowId)
	{
		result = new HashMap<K, ArrayList<Object>>();
	}

	/**
	 * Emits merged data
	 */
	@Override
	public void endWindow()
	{
		if (!result.isEmpty()) {
			out.emit(result);
		}
	}
}