com.tdunning.plume.local.lazy.MapRedMultipleGroupsTest.java Source code

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Here is the source code for com.tdunning.plume.local.lazy.MapRedMultipleGroupsTest.java

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/*
 * 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.tdunning.plume.local.lazy;

import static com.tdunning.plume.Plume.collectionOf;
import static com.tdunning.plume.Plume.integers;
import static com.tdunning.plume.Plume.strings;
import static com.tdunning.plume.Plume.tableOf;
import static org.junit.Assert.assertTrue;

import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableComparable;
import org.junit.Test;

import com.google.common.io.Resources;
import com.tdunning.plume.DoFn;
import com.tdunning.plume.EmitFn;
import com.tdunning.plume.PCollection;
import com.tdunning.plume.Pair;

/**
 * This test shows how three different group by's can be performed using Plume API which output three different
 * things and end up being executed in a single Map/Red job.
 */
public class MapRedMultipleGroupsTest extends BaseTestClass {

    /**
     * The PlumeWorkflow class is extendend so that it can be instantiated via reflection at hadoop mappers/reducers
     */
    public static class MultipleGroupsWorkflow extends PlumeWorkflow {

        @SuppressWarnings("unchecked")
        @Override
        public void build() {
            init();

            // Get one input file
            LazyPlume plume = new LazyPlume();
            PCollection input;
            try {
                input = plume.readFile("/tmp/input-wordcount.txt", collectionOf(strings()));
                // Add as input
                addInput(input);
            } catch (IOException e) {
                throw new RuntimeException();
            }

            final IntWritable one = new IntWritable(1);

            // Define a map that counts and group by #chars of line
            PCollection po1 = input.map(new DoFn() {
                @Override
                public void process(Object v, EmitFn emitter) {
                    StringTokenizer itr = new StringTokenizer(v.toString());
                    int length = 0;
                    while (itr.hasMoreTokens()) {
                        length += itr.nextToken().length();
                    }
                    emitter.emit(Pair.create(new IntWritable(length), one));
                }
            }, tableOf(integers(), integers())).groupByKey().map(countReduceToText, tableOf(integers(), strings()));

            // Define a map that counts and group by #tokens of line
            PCollection po2 = input.map(new DoFn() {
                @Override
                public void process(Object v, EmitFn emitter) {
                    StringTokenizer itr = new StringTokenizer(v.toString());
                    int length = 0;
                    while (itr.hasMoreTokens()) {
                        length++;
                        itr.nextToken();
                    }
                    emitter.emit(Pair.create(new IntWritable(length), one));
                }
            }, tableOf(integers(), integers())).groupByKey().map(countReduceToText, tableOf(integers(), strings()));

            // Define a map that counts appearances of chars
            PCollection po3 = input.map(new DoFn() {
                @Override
                public void process(Object v, EmitFn emitter) {
                    StringTokenizer itr = new StringTokenizer(v.toString());
                    while (itr.hasMoreTokens()) {
                        String token = itr.nextToken();
                        for (int i = 0; i < token.length(); i++) {
                            emitter.emit(Pair.create(new Text(token.charAt(i) + ""), one));
                        }
                    }
                }
            }, tableOf(strings(), integers())).groupByKey().map(countReduceToText, tableOf(strings(), strings()));

            // Add the output of the three group by's to this workflow's outputs
            addOutput(po1);
            addOutput(po2);
            addOutput(po3);
        }
    }

    @Test
    public void test() throws IOException, InterruptedException, ClassNotFoundException {
        String inputPath = "/tmp/input-wordcount.txt";
        String outputPath = "/tmp/output-plume-complex";
        // Prepare input for test
        FileSystem system = FileSystem.getLocal(new Configuration());
        system.copyFromLocalFile(new Path(Resources.getResource("simple-text.txt").getPath()), new Path(inputPath));
        // Prepare output for test
        system.delete(new Path(outputPath), true);
        // Prepare workflow
        MultipleGroupsWorkflow workFlow = new MultipleGroupsWorkflow();
        // Execute it
        MapRedExecutor executor = new MapRedExecutor();
        executor.execute(workFlow, outputPath);

        // Just assert that 3 output files were written and have content
        /**
         * TODO This test has to check the actual results of the 3 outputs
         */
        for (int i = 1; i <= 3; i++) {
            File f = new File(outputPath + "/1_" + i + "/" + i + "-r-00000");
            assertTrue(f.exists());
            assertTrue(f.length() > 64);
        }
    }
}