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

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Here is the source code for com.tdunning.plume.local.lazy.MapRedBypassTest.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.strings;
import static com.tdunning.plume.Plume.tableOf;
import static org.junit.Assert.assertEquals;

import java.io.File;
import java.io.IOException;
import java.util.List;
import java.util.Map;

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

import com.google.common.base.Charsets;
import com.google.common.collect.Maps;
import com.google.common.io.Files;
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 asserts that bypass channels as described in FlumeJava paper work for Plume MSCRs.
 */
public class MapRedBypassTest {

    /**
     * In this example we open a file and apply two functions to it. One of them performs a group by key and the other one
     *  just adds as output the result of the second function (bypass channel).
     */
    public static class MapRedBypassWorkflow extends PlumeWorkflow {

        public MapRedBypassWorkflow() {
        }

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

            LazyPlume plume = new LazyPlume();
            PCollection input;
            try {
                // Read input
                input = plume.readFile("/tmp/input-wordcount.txt", collectionOf(strings()));
                // Add it as workflow's input
                addInput(input);
            } catch (IOException e) {
                throw new RuntimeException();
            }

            PCollection bypassTransform = input.map(new DoFn() {
                @Override
                public void process(Object v, EmitFn emitter) {
                    Text t = (Text) v;
                    emitter.emit(Pair.create(new Text(t + "-blah"), new Text(t + "-bloh")));
                }
            }, tableOf(strings(), strings()));

            addOutput(bypassTransform);

            PCollection groupedTransform = input.map(new DoFn() {
                @Override
                public void process(Object v, EmitFn emitter) {
                    Text t = (Text) v;
                    emitter.emit(Pair.create(t, new Text("foo")));
                }
            }, tableOf(strings(), strings())).groupByKey();

            addOutput(groupedTransform);
        }
    }

    @Test
    public void test() throws Exception {
        String outputPath = "/tmp/output-plume-bypasstest";
        String inputPath = "/tmp/input-wordcount.txt";
        // 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
        MapRedBypassWorkflow workFlow = new MapRedBypassWorkflow();
        // Execute it
        MapRedExecutor executor = new MapRedExecutor();
        executor.execute(workFlow, outputPath);

        List<String> str = Files.readLines(new File(outputPath + "/1_1/1-r-00000"), Charsets.UTF_8);
        Map<String, String> m = Maps.newHashMap();
        for (String line : str) {
            m.put(line.split("\t")[0], line.split("\t")[1]); // not super-optimal, but less code
        }
        assertEquals(m.get("To test text processing with some simple-blah"),
                "To test text processing with some simple-bloh");
        assertEquals(m.get("some simple text-blah"), "some simple text-bloh");
        assertEquals(m.get("is is-blah"), "is is-bloh");

        str = Files.readLines(new File(outputPath + "/1_2/2-r-00000"), Charsets.UTF_8);
        m = Maps.newHashMap();
        for (String line : str) {
            m.put(line.split("\t")[0], line.split("\t")[1]); // not super-optimal, but less code
        }
        assertEquals(m.get("To test text processing with some simple"), "foo");
        assertEquals(m.get("some simple text"), "foo");
        assertEquals(m.get("is is"), "foo");
    }
}