HDFS-3531. EditLogFileOutputStream#preallocate should check for incomplete writes. Contributed by Colin Patrick McCabe

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1349616 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Eli Collins 2012-06-13 02:42:52 +00:00
parent 5a2e0ee4d2
commit 07b8584431
4 changed files with 81 additions and 3 deletions

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@ -20,6 +20,9 @@
import java.io.*;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.WritableByteChannel;
import org.apache.commons.logging.Log;
@ -245,4 +248,34 @@ public void write(byte[] b, int off, int len) throws IOException {
public void write(int b) throws IOException {
}
}
/**
* Write a ByteBuffer to a WritableByteChannel, handling short writes.
*
* @param bc The WritableByteChannel to write to
* @param buf The input buffer
* @throws IOException On I/O error
*/
public static void writeFully(WritableByteChannel bc, ByteBuffer buf)
throws IOException {
do {
bc.write(buf);
} while (buf.remaining() > 0);
}
/**
* Write a ByteBuffer to a FileChannel at a given offset,
* handling short writes.
*
* @param fc The FileChannel to write to
* @param buf The input buffer
* @param offset The offset in the file to start writing at
* @throws IOException On I/O error
*/
public static void writeFully(FileChannel fc, ByteBuffer buf,
long offset) throws IOException {
do {
offset += fc.write(buf, offset);
} while (buf.remaining() > 0);
}
}

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@ -21,9 +21,13 @@
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import org.junit.Test;
import org.mockito.Mockito;
@ -32,6 +36,7 @@
* Test cases for IOUtils.java
*/
public class TestIOUtils {
private static final String TEST_FILE_NAME = "test_file";
@Test
public void testCopyBytesShouldCloseStreamsWhenCloseIsTrue() throws Exception {
@ -110,4 +115,41 @@ public void testCopyBytesWithCountShouldThrowOutTheStreamClosureExceptions()
Mockito.verify(outputStream, Mockito.atLeastOnce()).close();
}
@Test
public void testWriteFully() throws IOException {
final int INPUT_BUFFER_LEN = 10000;
final int HALFWAY = 1 + (INPUT_BUFFER_LEN / 2);
byte[] input = new byte[INPUT_BUFFER_LEN];
for (int i = 0; i < input.length; i++) {
input[i] = (byte)(i & 0xff);
}
byte[] output = new byte[input.length];
try {
RandomAccessFile raf = new RandomAccessFile(TEST_FILE_NAME, "rw");
FileChannel fc = raf.getChannel();
ByteBuffer buf = ByteBuffer.wrap(input);
IOUtils.writeFully(fc, buf);
raf.seek(0);
raf.read(output);
for (int i = 0; i < input.length; i++) {
assertEquals(input[i], output[i]);
}
buf.rewind();
IOUtils.writeFully(fc, buf, HALFWAY);
for (int i = 0; i < HALFWAY; i++) {
assertEquals(input[i], output[i]);
}
raf.seek(0);
raf.read(output);
for (int i = HALFWAY; i < input.length; i++) {
assertEquals(input[i - HALFWAY], output[i]);
}
} finally {
File f = new File(TEST_FILE_NAME);
if (f.exists()) {
f.delete();
}
}
}
}

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@ -328,6 +328,9 @@ Branch-2 ( Unreleased changes )
HDFS-3522. If a namenode is in safemode, it should throw SafeModeException
when getBlockLocations has zero locations. (Brandon Li via szetszwo)
HDFS-3531. EditLogFileOutputStream#preallocate should check for
incomplete writes. (Colin Patrick McCabe via eli)
BREAKDOWN OF HDFS-3042 SUBTASKS
HDFS-2185. HDFS portion of ZK-based FailoverController (todd)

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@ -206,10 +206,10 @@ private void preallocate() throws IOException {
+ fc.size());
}
fill.position(0);
int written = fc.write(fill, position);
IOUtils.writeFully(fc, fill, position);
if(FSNamesystem.LOG.isDebugEnabled()) {
FSNamesystem.LOG.debug("Edit log size is now " + fc.size() +
" written " + written + " bytes " + " at offset " + position);
" written " + fill.capacity() + " bytes " + " at offset " + position);
}
}
}