WordCountCompilerTest.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,
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 * See the License for the specific language governing permissions and
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package org.apache.flink.test.optimizer.examples;

import java.util.Arrays;

import org.apache.flink.api.common.ExecutionConfig;
import org.apache.flink.api.common.Plan;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.common.operators.GenericDataSourceBase;
import org.apache.flink.api.common.operators.util.FieldList;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.io.DiscardingOutputFormat;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.optimizer.plan.Channel;
import org.apache.flink.optimizer.plan.OptimizedPlan;
import org.apache.flink.optimizer.plan.SingleInputPlanNode;
import org.apache.flink.optimizer.plan.SinkPlanNode;
import org.apache.flink.runtime.operators.DriverStrategy;
import org.apache.flink.runtime.operators.shipping.ShipStrategyType;
import org.apache.flink.runtime.operators.util.LocalStrategy;
import org.apache.flink.optimizer.util.CompilerTestBase;
import org.junit.Assert;
import org.junit.Test;

public class WordCountCompilerTest extends CompilerTestBase {

	private static final long serialVersionUID = 8988304231385358228L;

	/**
	 * This method tests the simple word count.
	 */
	@Test
	public void testWordCount() {
		checkWordCount(true);
		checkWordCount(false);
	}
	
	private void checkWordCount(boolean estimates) {

		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
		env.setParallelism(DEFAULT_PARALLELISM);

		// get input data
		DataSet<String> lines = env.readTextFile(IN_FILE).name("Input Lines");

		lines
			// dummy map
			.map(new MapFunction<String, Tuple2<String, Integer>>() {
				private static final long serialVersionUID = -3952739820618875030L;
				@Override
				public Tuple2<String, Integer> map(String v) throws Exception {
					return new Tuple2<>(v, 1);
				}
			}).name("Tokenize Lines")
			// count
				.groupBy(0).sum(1).name("Count Words")
			// discard
				.output(new DiscardingOutputFormat<Tuple2<String, Integer>>()).name("Word Counts");

		// get the plan and compile it
		Plan p = env.createProgramPlan();
		p.setExecutionConfig(new ExecutionConfig());

		OptimizedPlan plan;
		if (estimates) {
			GenericDataSourceBase<?,?> source = getContractResolver(p).getNode("Input Lines");
			setSourceStatistics(source, 1024*1024*1024*1024L, 24f);
			plan = compileWithStats(p);
		} else {
			plan = compileNoStats(p);
		}

		// get the optimizer plan nodes
		OptimizerPlanNodeResolver resolver = getOptimizerPlanNodeResolver(plan);
		SinkPlanNode sink = resolver.getNode("Word Counts");
		SingleInputPlanNode reducer = resolver.getNode("Count Words");
		SingleInputPlanNode mapper = resolver.getNode("Tokenize Lines");

		// verify the strategies
		Assert.assertEquals(ShipStrategyType.FORWARD, mapper.getInput().getShipStrategy());
		Assert.assertEquals(ShipStrategyType.PARTITION_HASH, reducer.getInput().getShipStrategy());
		Assert.assertEquals(ShipStrategyType.FORWARD, sink.getInput().getShipStrategy());

		Channel c = reducer.getInput();
		Assert.assertEquals(LocalStrategy.COMBININGSORT, c.getLocalStrategy());
		FieldList l = new FieldList(0);
		Assert.assertEquals(l, c.getShipStrategyKeys());
		Assert.assertEquals(l, c.getLocalStrategyKeys());
		Assert.assertTrue(Arrays.equals(c.getLocalStrategySortOrder(), reducer.getSortOrders(0)));

		// check the combiner
		SingleInputPlanNode combiner = (SingleInputPlanNode) reducer.getPredecessor();
		Assert.assertEquals(DriverStrategy.SORTED_GROUP_COMBINE, combiner.getDriverStrategy());
		Assert.assertEquals(l, combiner.getKeys(0));
		Assert.assertEquals(ShipStrategyType.FORWARD, combiner.getInput().getShipStrategy());
			
	}
	
}