@Override
protected void cleanup(Context context) throws IOException, InterruptedException {
val.setSeed(r.nextLong());
while (factory.next(null, val)) {
context.write(NullWritable.get(), val);
val.setSeed(r.nextLong());
}
}
/** Test compressible {@link GridmixRecord}. */
@Test
public void testCompressibleGridmixRecord() throws IOException {
JobConf conf = new JobConf();
CompressionEmulationUtil.setCompressionEmulationEnabled(conf, true);
CompressionEmulationUtil.setInputCompressionEmulationEnabled(conf, true);
FileSystem lfs = FileSystem.getLocal(conf);
int dataSize = 1024 * 1024 * 10; // 10 MB
float ratio = 0.357F;
// define the test's root temp directory
Path rootTempDir =
new Path(System.getProperty("test.build.data", "/tmp"))
.makeQualified(lfs.getUri(), lfs.getWorkingDirectory());
Path tempDir = new Path(rootTempDir, "TestPossiblyCompressibleGridmixRecord");
lfs.delete(tempDir, true);
// define a compressible GridmixRecord
GridmixRecord record = new GridmixRecord(dataSize, 0);
record.setCompressibility(true, ratio); // enable compression
conf.setClass(FileOutputFormat.COMPRESS_CODEC, GzipCodec.class, CompressionCodec.class);
org.apache.hadoop.mapred.FileOutputFormat.setCompressOutput(conf, true);
// write the record to a file
Path recordFile = new Path(tempDir, "record");
OutputStream outStream =
CompressionEmulationUtil.getPossiblyCompressedOutputStream(recordFile, conf);
DataOutputStream out = new DataOutputStream(outStream);
record.write(out);
out.close();
outStream.close();
// open the compressed stream for reading
Path actualRecordFile = recordFile.suffix(".gz");
InputStream in =
CompressionEmulationUtil.getPossiblyDecompressedInputStream(actualRecordFile, conf, 0);
// get the compressed file size
long compressedFileSize = lfs.listStatus(actualRecordFile)[0].getLen();
GridmixRecord recordRead = new GridmixRecord();
recordRead.readFields(new DataInputStream(in));
assertEquals(
"Record size mismatch in a compressible GridmixRecord", dataSize, recordRead.getSize());
assertTrue(
"Failed to generate a compressible GridmixRecord",
recordRead.getSize() > compressedFileSize);
// check if the record can generate data with the desired compression ratio
float seenRatio = ((float) compressedFileSize) / dataSize;
assertEquals(
CompressionEmulationUtil.standardizeCompressionRatio(ratio),
CompressionEmulationUtil.standardizeCompressionRatio(seenRatio),
1.0D);
}
@Override
public void map(NullWritable ignored, GridmixRecord rec, Context context)
throws IOException, InterruptedException {
acc += ratio;
while (acc >= 1.0 && !reduces.isEmpty()) {
key.setSeed(r.nextLong());
val.setSeed(r.nextLong());
final int idx = r.nextInt(reduces.size());
final RecordFactory f = reduces.get(idx);
if (!f.next(key, val)) {
reduces.remove(idx);
continue;
}
context.write(key, val);
acc -= 1.0;
}
}
@Override
public boolean nextKeyValue() throws IOException {
val.setSeed(r.nextLong());
return factory.next(null, val);
}