private void writeHeader(LogSegment segment, byte[] buf) throws IOException {
FileChannel channel = segment.getView().getSecond();
ByteBuffer buffer = ByteBuffer.wrap(buf);
while (buffer.hasRemaining()) {
channel.write(buffer, 0);
}
}
/**
* Closes the {@code segment} and deletes the backing file.
*
* @param segment the {@link LogSegment} that needs to be closed and whose backing file needs to
* be deleted.
* @throws IOException
*/
private void closeSegmentAndDeleteFile(LogSegment segment) throws IOException {
segment.close();
assertFalse("File channel is not closed", segment.getView().getSecond().isOpen());
File segmentFile = new File(tempDir, segment.getName());
assertTrue(
"The segment file [" + segmentFile.getAbsolutePath() + "] could not be deleted",
segmentFile.delete());
}
/**
* Gets a view of the given {@code segment} and verifies the ref count and the data obtained from
* the view against {@code expectedRefCount} and {@code dataInSegment} respectively.
*
* @param segment the {@link LogSegment} to get a view from.
* @param writeStartOffset the offset at which write was started on the segment.
* @param offset the offset for which a view is required.
* @param dataInSegment the entire data in the {@link LogSegment}.
* @param expectedRefCount the expected return value of {@link LogSegment#refCount()} once the
* view is obtained from the {@code segment}
* @throws IOException
*/
private void getAndVerifyView(
LogSegment segment,
long writeStartOffset,
int offset,
byte[] dataInSegment,
long expectedRefCount)
throws IOException {
Random random = new Random();
Pair<File, FileChannel> view = segment.getView();
assertNotNull("File object received in view is null", view.getFirst());
assertNotNull("FileChannel object received in view is null", view.getSecond());
assertEquals("Ref count is not as expected", expectedRefCount, segment.refCount());
int sizeToRead = random.nextInt(dataInSegment.length - offset + 1);
ByteBuffer buffer = ByteBuffer.wrap(new byte[sizeToRead]);
view.getSecond().read(buffer, writeStartOffset + offset);
assertArrayEquals(
"Data read from file does not match data written",
Arrays.copyOfRange(dataInSegment, offset, offset + sizeToRead),
buffer.array());
}
/**
* Tests setting end offset - makes sure legal values are set correctly and illegal values are
* rejected.
*
* @throws IOException
*/
@Test
public void endOffsetTest() throws IOException {
String segmentName = "log_current";
LogSegment segment = getSegment(segmentName, STANDARD_SEGMENT_SIZE, true);
try {
long writeStartOffset = segment.getStartOffset();
int segmentSize = 500;
appendRandomData(segment, segmentSize);
assertEquals(
"End offset is not as expected", writeStartOffset + segmentSize, segment.getEndOffset());
// should be able to set end offset to something >= initial offset and <= file size
int[] offsetsToSet = {(int) (writeStartOffset), segmentSize / 2, segmentSize};
for (int offset : offsetsToSet) {
segment.setEndOffset(offset);
assertEquals("End offset is not equal to what was set", offset, segment.getEndOffset());
assertEquals(
"File channel positioning is incorrect",
offset,
segment.getView().getSecond().position());
}
// cannot set end offset to illegal values (< initial offset or > file size)
int[] invalidOffsets = {(int) (writeStartOffset - 1), (int) (segment.sizeInBytes() + 1)};
for (int offset : invalidOffsets) {
try {
segment.setEndOffset(offset);
fail("Setting log end offset an invalid offset [" + offset + "] should have failed");
} catch (IllegalArgumentException e) {
// expected. Nothing to do.
}
}
} finally {
closeSegmentAndDeleteFile(segment);
}
}
private byte[] getHeader(LogSegment segment) throws IOException {
FileChannel channel = segment.getView().getSecond();
ByteBuffer header = ByteBuffer.allocate(LogSegment.HEADER_SIZE);
channel.read(header, 0);
return header.array();
}
/**
* Tests for bad construction cases of {@link LogSegment}.
*
* @throws IOException
*/
@Test
public void badConstructionTest() throws IOException {
// try to construct with a file that does not exist.
String name = "log_non_existent";
File file = new File(tempDir, name);
try {
new LogSegment(name, file, STANDARD_SEGMENT_SIZE, metrics, true);
fail("Construction should have failed because the backing file does not exist");
} catch (IllegalArgumentException e) {
// expected. Nothing to do.
}
try {
new LogSegment(name, file, metrics);
fail("Construction should have failed because the backing file does not exist");
} catch (IllegalArgumentException e) {
// expected. Nothing to do.
}
// try to construct with a file that is a directory
name = tempDir.getName();
file = new File(tempDir.getParent(), name);
try {
new LogSegment(name, file, STANDARD_SEGMENT_SIZE, metrics, true);
fail("Construction should have failed because the backing file does not exist");
} catch (IllegalArgumentException e) {
// expected. Nothing to do.
}
name = tempDir.getName();
file = new File(tempDir.getParent(), name);
try {
new LogSegment(name, file, metrics);
fail("Construction should have failed because the backing file does not exist");
} catch (IllegalArgumentException e) {
// expected. Nothing to do.
}
// unknown version
LogSegment segment = getSegment("dummy_log", STANDARD_SEGMENT_SIZE, true);
file = segment.getView().getFirst();
byte[] header = getHeader(segment);
byte savedByte = header[0];
// mess with version
header[0] = (byte) (header[0] + 10);
writeHeader(segment, header);
try {
new LogSegment(name, file, metrics);
fail("Construction should have failed because version is unknown");
} catch (IllegalArgumentException e) {
// expected. Nothing to do.
}
// bad CRC
// fix version but mess with data after version
header[0] = savedByte;
header[2] = header[2] == (byte) 1 ? (byte) 0 : (byte) 1;
writeHeader(segment, header);
try {
new LogSegment(name, file, metrics);
fail("Construction should have failed because crc check should have failed");
} catch (IllegalStateException e) {
// expected. Nothing to do.
}
closeSegmentAndDeleteFile(segment);
}