/**
* Sends upto maxChunks chunks of data.
*
* <p>When blockInPosition is >= 0, assumes 'out' is a {@link SocketOutputStream} and tries {@link
* SocketOutputStream#transferToFully(FileChannel, long, int)} to send data (and updates
* blockInPosition).
*/
private int sendChunks(ByteBuffer pkt, int maxChunks, OutputStream out) throws IOException {
// Sends multiple chunks in one packet with a single write().
int len = (int) Math.min(endOffset - offset, (((long) bytesPerChecksum) * ((long) maxChunks)));
int numChunks = (len + bytesPerChecksum - 1) / bytesPerChecksum;
int packetLen = len + numChunks * checksumSize + 4;
boolean lastDataPacket = offset + len == endOffset && len > 0;
pkt.clear();
PacketHeader header = new PacketHeader(packetLen, offset, seqno, (len == 0), len);
header.putInBuffer(pkt);
int checksumOff = pkt.position();
int checksumLen = numChunks * checksumSize;
byte[] buf = pkt.array();
if (checksumSize > 0 && checksumIn != null) {
try {
checksumIn.readFully(buf, checksumOff, checksumLen);
} catch (IOException e) {
LOG.warn(
" Could not read or failed to veirfy checksum for data"
+ " at offset "
+ offset
+ " for block "
+ block
+ " got : "
+ StringUtils.stringifyException(e));
IOUtils.closeStream(checksumIn);
checksumIn = null;
if (corruptChecksumOk) {
if (checksumOff < checksumLen) {
// Just fill the array with zeros.
Arrays.fill(buf, checksumOff, checksumLen, (byte) 0);
}
} else {
throw e;
}
}
// write in progress that we need to use to get last checksum
if (lastDataPacket && lastChunkChecksum != null) {
int start = checksumOff + checksumLen - checksumSize;
byte[] updatedChecksum = lastChunkChecksum.getChecksum();
if (updatedChecksum != null) {
System.arraycopy(updatedChecksum, 0, buf, start, checksumSize);
}
}
}
int dataOff = checksumOff + checksumLen;
if (blockInPosition < 0) {
// normal transfer
IOUtils.readFully(blockIn, buf, dataOff, len);
if (verifyChecksum) {
int dOff = dataOff;
int cOff = checksumOff;
int dLeft = len;
for (int i = 0; i < numChunks; i++) {
checksum.reset();
int dLen = Math.min(dLeft, bytesPerChecksum);
checksum.update(buf, dOff, dLen);
if (!checksum.compare(buf, cOff)) {
long failedPos = offset + len - dLeft;
throw new ChecksumException("Checksum failed at " + failedPos, failedPos);
}
dLeft -= dLen;
dOff += dLen;
cOff += checksumSize;
}
}
// writing is done below (mainly to handle IOException)
}
try {
if (blockInPosition >= 0) {
// use transferTo(). Checks on out and blockIn are already done.
SocketOutputStream sockOut = (SocketOutputStream) out;
// first write the packet
sockOut.write(buf, 0, dataOff);
// no need to flush. since we know out is not a buffered stream.
sockOut.transferToFully(((FileInputStream) blockIn).getChannel(), blockInPosition, len);
blockInPosition += len;
} else {
// normal transfer
out.write(buf, 0, dataOff + len);
}
} catch (IOException e) {
/* Exception while writing to the client. Connection closure from
* the other end is mostly the case and we do not care much about
* it. But other things can go wrong, especially in transferTo(),
* which we do not want to ignore.
*
* The message parsing below should not be considered as a good
* coding example. NEVER do it to drive a program logic. NEVER.
* It was done here because the NIO throws an IOException for EPIPE.
*/
String ioem = e.getMessage();
if (!ioem.startsWith("Broken pipe") && !ioem.startsWith("Connection reset")) {
LOG.error("BlockSender.sendChunks() exception: ", e);
}
throw ioeToSocketException(e);
}
if (throttler != null) { // rebalancing so throttle
throttler.throttle(packetLen);
}
return len;
}
BlockSender(
Block block,
long startOffset,
long length,
boolean corruptChecksumOk,
boolean chunkOffsetOK,
boolean verifyChecksum,
DataNode datanode,
String clientTraceFmt)
throws IOException {
try {
this.block = block;
synchronized (datanode.data) {
this.replica = datanode.data.getReplica(block.getBlockId());
if (replica == null) {
throw new ReplicaNotFoundException(block);
}
this.replicaVisibleLength = replica.getVisibleLength();
}
long minEndOffset = startOffset + length;
// if this is a write in progress
ChunkChecksum chunkChecksum = null;
if (replica instanceof ReplicaBeingWritten) {
for (int i = 0; i < 30 && replica.getBytesOnDisk() < minEndOffset; i++) {
try {
Thread.sleep(100);
} catch (InterruptedException ie) {
throw new IOException(ie);
}
}
long currentBytesOnDisk = replica.getBytesOnDisk();
if (currentBytesOnDisk < minEndOffset) {
throw new IOException(
String.format(
"need %d bytes, but only %d bytes available", minEndOffset, currentBytesOnDisk));
}
ReplicaInPipeline rip = (ReplicaInPipeline) replica;
chunkChecksum = rip.getLastChecksumAndDataLen();
}
if (replica.getGenerationStamp() < block.getGenerationStamp()) {
throw new IOException(
"replica.getGenerationStamp() < block.getGenerationStamp(), block="
+ block
+ ", replica="
+ replica);
}
if (replicaVisibleLength < 0) {
throw new IOException(
"The replica is not readable, block=" + block + ", replica=" + replica);
}
if (DataNode.LOG.isDebugEnabled()) {
DataNode.LOG.debug("block=" + block + ", replica=" + replica);
}
this.chunkOffsetOK = chunkOffsetOK;
this.corruptChecksumOk = corruptChecksumOk;
this.verifyChecksum = verifyChecksum;
// transferToFully() fails on 32 bit platforms for block sizes >= 2GB,
// use normal transfer in those cases
this.transferToAllowed =
datanode.transferToAllowed && (!is32Bit || length < (long) Integer.MAX_VALUE);
this.clientTraceFmt = clientTraceFmt;
if (!corruptChecksumOk || datanode.data.metaFileExists(block)) {
checksumIn =
new DataInputStream(
new BufferedInputStream(datanode.data.getMetaDataInputStream(block), BUFFER_SIZE));
// read and handle the common header here. For now just a version
BlockMetadataHeader header = BlockMetadataHeader.readHeader(checksumIn);
short version = header.getVersion();
if (version != FSDataset.METADATA_VERSION) {
LOG.warn(
"Wrong version (" + version + ") for metadata file for " + block + " ignoring ...");
}
checksum = header.getChecksum();
} else {
LOG.warn("Could not find metadata file for " + block);
// This only decides the buffer size. Use BUFFER_SIZE?
checksum = DataChecksum.newDataChecksum(DataChecksum.CHECKSUM_NULL, 16 * 1024);
}
/* If bytesPerChecksum is very large, then the metadata file
* is mostly corrupted. For now just truncate bytesPerchecksum to
* blockLength.
*/
bytesPerChecksum = checksum.getBytesPerChecksum();
if (bytesPerChecksum > 10 * 1024 * 1024 && bytesPerChecksum > replicaVisibleLength) {
checksum =
DataChecksum.newDataChecksum(
checksum.getChecksumType(), Math.max((int) replicaVisibleLength, 10 * 1024 * 1024));
bytesPerChecksum = checksum.getBytesPerChecksum();
}
checksumSize = checksum.getChecksumSize();
if (length < 0) {
length = replicaVisibleLength;
}
// end is either last byte on disk or the length for which we have a
// checksum
if (chunkChecksum != null) {
endOffset = chunkChecksum.getDataLength();
} else {
endOffset = replica.getBytesOnDisk();
}
if (startOffset < 0 || startOffset > endOffset || (length + startOffset) > endOffset) {
String msg =
" Offset "
+ startOffset
+ " and length "
+ length
+ " don't match block "
+ block
+ " ( blockLen "
+ endOffset
+ " )";
LOG.warn(datanode.dnRegistration + ":sendBlock() : " + msg);
throw new IOException(msg);
}
offset = (startOffset - (startOffset % bytesPerChecksum));
if (length >= 0) {
// Make sure endOffset points to end of a checksumed chunk.
long tmpLen = startOffset + length;
if (tmpLen % bytesPerChecksum != 0) {
tmpLen += (bytesPerChecksum - tmpLen % bytesPerChecksum);
}
if (tmpLen < endOffset) {
// will use on-disk checksum here since the end is a stable chunk
endOffset = tmpLen;
} else if (chunkChecksum != null) {
// in last chunk which is changing. flag that we need to use in-memory
// checksum
this.lastChunkChecksum = chunkChecksum;
}
}
// seek to the right offsets
if (offset > 0) {
long checksumSkip = (offset / bytesPerChecksum) * checksumSize;
// note blockInStream is seeked when created below
if (checksumSkip > 0) {
// Should we use seek() for checksum file as well?
IOUtils.skipFully(checksumIn, checksumSkip);
}
}
seqno = 0;
if (DataNode.LOG.isDebugEnabled()) {
DataNode.LOG.debug("replica=" + replica);
}
blockIn = datanode.data.getBlockInputStream(block, offset); // seek to offset
} catch (IOException ioe) {
IOUtils.closeStream(this);
IOUtils.closeStream(blockIn);
throw ioe;
}
}
