/**
* 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.hadoop.mapreduce.task.reduce;
import static org.mockito.Matchers.any;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;
import static org.mockito.Mockito.doAnswer;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import junit.framework.Assert;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.LocalDirAllocator;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.DataInputBuffer;
import org.apache.hadoop.io.RawComparator;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.Counters.Counter;
import org.apache.hadoop.mapred.IFile.Reader;
import org.apache.hadoop.mapred.IFile;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MROutputFiles;
import org.apache.hadoop.mapred.Merger;
import org.apache.hadoop.mapred.Merger.Segment;
import org.apache.hadoop.mapred.RawKeyValueIterator;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapreduce.JobID;
import org.apache.hadoop.mapreduce.MRConfig;
import org.apache.hadoop.mapreduce.TaskAttemptID;
import org.apache.hadoop.mapreduce.TaskID;
import org.apache.hadoop.mapreduce.TaskType;
import org.apache.hadoop.mapreduce.task.reduce.MergeManagerImpl;
import org.apache.hadoop.util.Progress;
import org.apache.hadoop.util.Progressable;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;
public class TestMerger {
private Configuration conf;
private JobConf jobConf;
private FileSystem fs;
@Before
public void setup() throws IOException {
conf = new Configuration();
jobConf = new JobConf();
fs = FileSystem.getLocal(conf);
}
@After
public void cleanup() throws IOException {
fs.delete(new Path(jobConf.getLocalDirs()[0]), true);
}
@Test
public void testInMemoryMerger() throws IOException {
JobID jobId = new JobID("a", 0);
TaskAttemptID reduceId = new TaskAttemptID(
new TaskID(jobId, TaskType.REDUCE, 0), 0);
TaskAttemptID mapId1 = new TaskAttemptID(
new TaskID(jobId, TaskType.MAP, 1), 0);
TaskAttemptID mapId2 = new TaskAttemptID(
new TaskID(jobId, TaskType.MAP, 2), 0);
LocalDirAllocator lda = new LocalDirAllocator(MRConfig.LOCAL_DIR);
MergeManagerImpl<Text, Text> mergeManager = new MergeManagerImpl<Text, Text>(
reduceId, jobConf, fs, lda, Reporter.NULL, null, null, null, null, null,
null, null, new Progress(), new MROutputFiles());
// write map outputs
Map<String, String> map1 = new TreeMap<String, String>();
map1.put("apple", "disgusting");
map1.put("carrot", "delicious");
Map<String, String> map2 = new TreeMap<String, String>();
map1.put("banana", "pretty good");
byte[] mapOutputBytes1 = writeMapOutput(conf, map1);
byte[] mapOutputBytes2 = writeMapOutput(conf, map2);
InMemoryMapOutput<Text, Text> mapOutput1 = new InMemoryMapOutput<Text, Text>(
conf, mapId1, mergeManager, mapOutputBytes1.length, null, true);
InMemoryMapOutput<Text, Text> mapOutput2 = new InMemoryMapOutput<Text, Text>(
conf, mapId2, mergeManager, mapOutputBytes2.length, null, true);
System.arraycopy(mapOutputBytes1, 0, mapOutput1.getMemory(), 0,
mapOutputBytes1.length);
System.arraycopy(mapOutputBytes2, 0, mapOutput2.getMemory(), 0,
mapOutputBytes2.length);
// create merger and run merge
MergeThread<InMemoryMapOutput<Text, Text>, Text, Text> inMemoryMerger =
mergeManager.createInMemoryMerger();
List<InMemoryMapOutput<Text, Text>> mapOutputs =
new ArrayList<InMemoryMapOutput<Text, Text>>();
mapOutputs.add(mapOutput1);
mapOutputs.add(mapOutput2);
inMemoryMerger.merge(mapOutputs);
Assert.assertEquals(1, mergeManager.onDiskMapOutputs.size());
Path outPath = mergeManager.onDiskMapOutputs.iterator().next();
List<String> keys = new ArrayList<String>();
List<String> values = new ArrayList<String>();
readOnDiskMapOutput(conf, fs, outPath, keys, values);
Assert.assertEquals(keys, Arrays.asList("apple", "banana", "carrot"));
Assert.assertEquals(values, Arrays.asList("disgusting", "pretty good", "delicious"));
}
private byte[] writeMapOutput(Configuration conf, Map<String, String> keysToValues)
throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
FSDataOutputStream fsdos = new FSDataOutputStream(baos, null);
IFile.Writer<Text, Text> writer = new IFile.Writer<Text, Text>(conf, fsdos,
Text.class, Text.class, null, null);
for (String key : keysToValues.keySet()) {
String value = keysToValues.get(key);
writer.append(new Text(key), new Text(value));
}
writer.close();
return baos.toByteArray();
}
private void readOnDiskMapOutput(Configuration conf, FileSystem fs, Path path,
List<String> keys, List<String> values) throws IOException {
IFile.Reader<Text, Text> reader = new IFile.Reader<Text, Text>(conf, fs,
path, null, null);
DataInputBuffer keyBuff = new DataInputBuffer();
DataInputBuffer valueBuff = new DataInputBuffer();
Text key = new Text();
Text value = new Text();
while (reader.nextRawKey(keyBuff)) {
key.readFields(keyBuff);
keys.add(key.toString());
reader.nextRawValue(valueBuff);
value.readFields(valueBuff);
values.add(value.toString());
}
}
@Test
public void testCompressed() throws IOException {
testMergeShouldReturnProperProgress(getCompressedSegments());
}
@Test
public void testUncompressed() throws IOException {
testMergeShouldReturnProperProgress(getUncompressedSegments());
}
@SuppressWarnings( { "deprecation", "unchecked" })
public void testMergeShouldReturnProperProgress(
List<Segment<Text, Text>> segments) throws IOException {
Path tmpDir = new Path("localpath");
Class<Text> keyClass = (Class<Text>) jobConf.getMapOutputKeyClass();
Class<Text> valueClass = (Class<Text>) jobConf.getMapOutputValueClass();
RawComparator<Text> comparator = jobConf.getOutputKeyComparator();
Counter readsCounter = new Counter();
Counter writesCounter = new Counter();
Progress mergePhase = new Progress();
RawKeyValueIterator mergeQueue = Merger.merge(conf, fs, keyClass,
valueClass, segments, 2, tmpDir, comparator, getReporter(),
readsCounter, writesCounter, mergePhase);
Assert.assertEquals(1.0f, mergeQueue.getProgress().get());
}
private Progressable getReporter() {
Progressable reporter = new Progressable() {
@Override
public void progress() {
}
};
return reporter;
}
private List<Segment<Text, Text>> getUncompressedSegments() throws IOException {
List<Segment<Text, Text>> segments = new ArrayList<Segment<Text, Text>>();
for (int i = 1; i < 1; i++) {
segments.add(getUncompressedSegment(i));
}
return segments;
}
private List<Segment<Text, Text>> getCompressedSegments() throws IOException {
List<Segment<Text, Text>> segments = new ArrayList<Segment<Text, Text>>();
for (int i = 1; i < 1; i++) {
segments.add(getCompressedSegment(i));
}
return segments;
}
private Segment<Text, Text> getUncompressedSegment(int i) throws IOException {
return new Segment<Text, Text>(getReader(i), false);
}
private Segment<Text, Text> getCompressedSegment(int i) throws IOException {
return new Segment<Text, Text>(getReader(i), false, 3000l);
}
@SuppressWarnings("unchecked")
private Reader<Text, Text> getReader(int i) throws IOException {
Reader<Text, Text> readerMock = mock(Reader.class);
when(readerMock.getPosition()).thenReturn(0l).thenReturn(10l).thenReturn(
20l);
when(
readerMock.nextRawKey(any(DataInputBuffer.class)))
.thenAnswer(getKeyAnswer("Segment" + i));
doAnswer(getValueAnswer("Segment" + i)).when(readerMock).nextRawValue(
any(DataInputBuffer.class));
return readerMock;
}
private Answer<?> getKeyAnswer(final String segmentName) {
return new Answer<Object>() {
int i = 0;
public Boolean answer(InvocationOnMock invocation) {
Object[] args = invocation.getArguments();
DataInputBuffer key = (DataInputBuffer) args[0];
if (i++ == 2) {
return false;
}
key.reset(("Segment Key " + segmentName + i).getBytes(), 20);
return true;
}
};
}
private Answer<?> getValueAnswer(final String segmentName) {
return new Answer<Void>() {
int i = 0;
public Void answer(InvocationOnMock invocation) {
Object[] args = invocation.getArguments();
DataInputBuffer key = (DataInputBuffer) args[0];
if (i++ == 2) {
return null;
}
key.reset(("Segment Value " + segmentName + i).getBytes(), 20);
return null;
}
};
}
}