library/src/main/java/com/datatorrent/lib/testbench/CountOccurance.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.testbench;

import java.util.Date;
import java.util.HashMap;
import java.util.Map;

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

/**
 * <p>A base implementation of an operator which does count occurrence.</p>
 * <p>
 * @displayName: Count Occurrence
 * @category: testbench
 * @tag: count
 * @since 0.3.2
 */
public class CountOccurance<k> extends BaseOperator
{
	private Map<k, Integer> collect;
	public final transient DefaultInputPort<k> inport = new DefaultInputPort<k>() {
    @Override
    public void process(k s) {
    	if (collect.containsKey(s))
    	{
    		Integer value = (Integer)collect.remove(s);
    		collect.put(s, new Integer(value+1));
    	} else {
    		collect.put(s, new Integer(1));
    	}
    }
	};

	@Override
	public void setup(OperatorContext context)
	{
	}

	@Override
	public void teardown()
	{
	}

	@Override
	public void beginWindow(long windowId)
	{
		collect  = new HashMap<k, Integer>();
	}
	
	/**
	 * Output port that emits a map of integer values.
	 */
	public final transient DefaultOutputPort<Map<k, Integer>> outport = new DefaultOutputPort<Map<k, Integer>>();
        
        /**
	 * Output dimensions port that emits a map of &lt;string,object&gt; values.
	 */
	public final transient DefaultOutputPort<Map<String, Object>> dimensionOut = new DefaultOutputPort<Map<String, Object>>();
	
        /**
	 * Output total port that emits a map of &lt;string,integer&gt; count values.
	 */
        public final transient DefaultOutputPort<Map<String,Integer>> total = new DefaultOutputPort<Map<String,Integer>>();
	
	@Override
	public void endWindow()
	{
		outport.emit(collect);
		long timestamp = new Date().getTime();
		int allcount = 0;
		for(Map.Entry<k, Integer> entry : collect.entrySet())
		{
			Map<String, Object> map = new HashMap<String, Object>();
			map.put("timestamp", timestamp);
			map.put("item", entry.getKey());
			map.put("view", entry.getValue());
			dimensionOut.emit(map);
			allcount += entry.getValue();
		}
		Map<String, Integer> map = new HashMap<String, Integer>();
		map.put("total", new Integer(allcount));
		total.emit(map);
		collect = null;
		collect  = new HashMap<k, Integer>();
	}
}