/**
* 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.hdfs;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import java.io.DataOutputStream;
import java.io.IOException;
import java.util.Random;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.ChecksumFileSystem;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
import org.junit.Test;
/**
* This class tests the presence of seek bug as described
* in HADOOP-508
*/
public class TestSeekBug {
static final long seed = 0xDEADBEEFL;
static final int ONEMB = 1 << 20;
private void writeFile(FileSystem fileSys, Path name) throws IOException {
// create and write a file that contains 1MB
DataOutputStream stm = fileSys.create(name);
byte[] buffer = new byte[ONEMB];
Random rand = new Random(seed);
rand.nextBytes(buffer);
stm.write(buffer);
stm.close();
}
private void checkAndEraseData(byte[] actual, int from, byte[] expected, String message) {
for (int idx = 0; idx < actual.length; idx++) {
assertEquals(message+" byte "+(from+idx)+" differs. expected "+
expected[from+idx]+" actual "+actual[idx],
actual[idx], expected[from+idx]);
actual[idx] = 0;
}
}
private void seekReadFile(FileSystem fileSys, Path name) throws IOException {
FSDataInputStream stm = fileSys.open(name, 4096);
byte[] expected = new byte[ONEMB];
Random rand = new Random(seed);
rand.nextBytes(expected);
// First read 128 bytes to set count in BufferedInputStream
byte[] actual = new byte[128];
stm.read(actual, 0, actual.length);
// Now read a byte array that is bigger than the internal buffer
actual = new byte[100000];
IOUtils.readFully(stm, actual, 0, actual.length);
checkAndEraseData(actual, 128, expected, "First Read Test");
// now do a small seek, within the range that is already read
stm.seek(96036); // 4 byte seek
actual = new byte[128];
IOUtils.readFully(stm, actual, 0, actual.length);
checkAndEraseData(actual, 96036, expected, "Seek Bug");
// all done
stm.close();
}
/*
* Read some data, skip a few bytes and read more. HADOOP-922.
*/
private void smallReadSeek(FileSystem fileSys, Path name) throws IOException {
if (fileSys instanceof ChecksumFileSystem) {
fileSys = ((ChecksumFileSystem)fileSys).getRawFileSystem();
}
// Make the buffer size small to trigger code for HADOOP-922
FSDataInputStream stmRaw = fileSys.open(name, 1);
byte[] expected = new byte[ONEMB];
Random rand = new Random(seed);
rand.nextBytes(expected);
// Issue a simple read first.
byte[] actual = new byte[128];
stmRaw.seek(100000);
stmRaw.read(actual, 0, actual.length);
checkAndEraseData(actual, 100000, expected, "First Small Read Test");
// now do a small seek of 4 bytes, within the same block.
int newpos1 = 100000 + 128 + 4;
stmRaw.seek(newpos1);
stmRaw.read(actual, 0, actual.length);
checkAndEraseData(actual, newpos1, expected, "Small Seek Bug 1");
// seek another 256 bytes this time
int newpos2 = newpos1 + 256;
stmRaw.seek(newpos2);
stmRaw.read(actual, 0, actual.length);
checkAndEraseData(actual, newpos2, expected, "Small Seek Bug 2");
// all done
stmRaw.close();
}
private void cleanupFile(FileSystem fileSys, Path name) throws IOException {
assertTrue(fileSys.exists(name));
fileSys.delete(name, true);
assertTrue(!fileSys.exists(name));
}
/**
* Test if the seek bug exists in FSDataInputStream in DFS.
*/
@Test
public void testSeekBugDFS() throws IOException {
Configuration conf = new HdfsConfiguration();
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
FileSystem fileSys = cluster.getFileSystem();
try {
Path file1 = new Path("seektest.dat");
writeFile(fileSys, file1);
seekReadFile(fileSys, file1);
smallReadSeek(fileSys, file1);
cleanupFile(fileSys, file1);
} finally {
fileSys.close();
cluster.shutdown();
}
}
/**
* Test (expected to throw IOE) for negative
* <code>FSDataInpuStream#seek</code> argument
*/
@Test (expected=IOException.class)
public void testNegativeSeek() throws IOException {
Configuration conf = new HdfsConfiguration();
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
FileSystem fs = cluster.getFileSystem();
try {
Path seekFile = new Path("seekboundaries.dat");
DFSTestUtil.createFile(
fs,
seekFile,
ONEMB,
fs.getDefaultReplication(seekFile),
seed);
FSDataInputStream stream = fs.open(seekFile);
// Perform "safe seek" (expected to pass)
stream.seek(65536);
assertEquals(65536, stream.getPos());
// expect IOE for this call
stream.seek(-73);
} finally {
fs.close();
cluster.shutdown();
}
}
/**
* Test (expected to throw IOE) for <code>FSDataInpuStream#seek</code>
* when the position argument is larger than the file size.
*/
@Test (expected=IOException.class)
public void testSeekPastFileSize() throws IOException {
Configuration conf = new HdfsConfiguration();
MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).build();
FileSystem fs = cluster.getFileSystem();
try {
Path seekFile = new Path("seekboundaries.dat");
DFSTestUtil.createFile(
fs,
seekFile,
ONEMB,
fs.getDefaultReplication(seekFile),
seed);
FSDataInputStream stream = fs.open(seekFile);
// Perform "safe seek" (expected to pass)
stream.seek(65536);
assertEquals(65536, stream.getPos());
// expect IOE for this call
stream.seek(ONEMB + ONEMB + ONEMB);
} finally {
fs.close();
cluster.shutdown();
}
}
/**
* Tests if the seek bug exists in FSDataInputStream in LocalFS.
*/
@Test
public void testSeekBugLocalFS() throws IOException {
Configuration conf = new HdfsConfiguration();
FileSystem fileSys = FileSystem.getLocal(conf);
try {
Path file1 = new Path("build/test/data", "seektest.dat");
writeFile(fileSys, file1);
seekReadFile(fileSys, file1);
cleanupFile(fileSys, file1);
} finally {
fileSys.close();
}
}
}