/** 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);
}
/**
* Test of {@link FileQueue} can identify compressed file and provide readers to extract
* uncompressed data only if input-compression is enabled.
*/
@Test
public void testFileQueueDecompression() throws IOException {
JobConf conf = new JobConf();
FileSystem lfs = FileSystem.getLocal(conf);
String inputLine = "Hi Hello!";
CompressionEmulationUtil.setCompressionEmulationEnabled(conf, true);
CompressionEmulationUtil.setInputCompressionEmulationEnabled(conf, true);
org.apache.hadoop.mapred.FileOutputFormat.setCompressOutput(conf, true);
org.apache.hadoop.mapred.FileOutputFormat.setOutputCompressorClass(conf, GzipCodec.class);
// 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, "TestFileQueueDecompression");
lfs.delete(tempDir, true);
// create a compressed file
Path compressedFile = new Path(tempDir, "test");
OutputStream out =
CompressionEmulationUtil.getPossiblyCompressedOutputStream(compressedFile, conf);
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(out));
writer.write(inputLine);
writer.close();
compressedFile = compressedFile.suffix(".gz");
// now read back the data from the compressed stream using FileQueue
long fileSize = lfs.listStatus(compressedFile)[0].getLen();
CombineFileSplit split =
new CombineFileSplit(new Path[] {compressedFile}, new long[] {fileSize});
FileQueue queue = new FileQueue(split, conf);
byte[] bytes = new byte[inputLine.getBytes().length];
queue.read(bytes);
queue.close();
String readLine = new String(bytes);
assertEquals("Compression/Decompression error", inputLine, readLine);
}