examples/uniquecount/src/main/java/org/apache/apex/examples/uniquecount/UniqueKeyValCountExample.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.examples.uniquecount;

import org.apache.apex.malhar.lib.algo.UniqueCounter;
import org.apache.apex.malhar.lib.converter.MapToKeyHashValuePairConverter;
import org.apache.apex.malhar.lib.io.ConsoleOutputOperator;
import org.apache.apex.malhar.lib.util.KeyValPair;
import org.apache.hadoop.conf.Configuration;

import com.datatorrent.api.Context;
import com.datatorrent.api.DAG;
import com.datatorrent.api.DAG.Locality;
import com.datatorrent.api.StreamingApplication;
import com.datatorrent.api.annotation.ApplicationAnnotation;

import com.datatorrent.common.partitioner.StatelessPartitioner;

/**
 * <p>UniqueKeyValCountExample class.</p>
 *
 * @since 1.0.2
 */
@ApplicationAnnotation(name = "UniqueKeyValueCountExample")
public class UniqueKeyValCountExample implements StreamingApplication
{

  @Override
  public void populateDAG(DAG dag, Configuration entries)
  {
        /* Generate random key-value pairs */
    RandomDataGenerator randGen = dag.addOperator("randomgen", new RandomDataGenerator());

        /* Initialize with three partition to start with */
    UniqueCounter<KeyValPair<String, Object>> uniqCount =
        dag.addOperator("uniqevalue", new UniqueCounter<KeyValPair<String, Object>>());
    MapToKeyHashValuePairConverter<KeyValPair<String, Object>, Integer> converter = dag.addOperator("converter", new MapToKeyHashValuePairConverter());
    uniqCount.setCumulative(false);
    dag.setAttribute(randGen, Context.OperatorContext.PARTITIONER, new StatelessPartitioner<UniqueCounter<KeyValPair<String, Object>>>(3));

    ConsoleOutputOperator output = dag.addOperator("output", new ConsoleOutputOperator());

    dag.addStream("datain", randGen.outPort, uniqCount.data);
    dag.addStream("convert", uniqCount.count, converter.input).setLocality(Locality.THREAD_LOCAL);
    dag.addStream("consoutput", converter.output, output.input);
  }
}