/**
* Writes the current checksum to the stream. If <i>reset</i> is true, then resets the checksum.
*
* @return number of bytes written. Will be equal to getChecksumSize();
*/
public int writeValue(DataOutputStream out, boolean reset) throws IOException {
if (size <= 0) {
return 0;
}
if (type == CHECKSUM_CRC32) {
out.writeInt((int) summer.getValue());
} else {
throw new IOException("Unknown Checksum " + type);
}
if (reset) {
reset();
}
return size;
}
/**
* Writes the current checksum to a buffer. If <i>reset</i> is true, then resets the checksum.
*
* @return number of bytes written. Will be equal to getChecksumSize();
*/
public int writeValue(byte[] buf, int offset, boolean reset) throws IOException {
if (size <= 0) {
return 0;
}
if (type == CHECKSUM_CRC32) {
int checksum = (int) summer.getValue();
buf[offset + 0] = (byte) ((checksum >>> 24) & 0xff);
buf[offset + 1] = (byte) ((checksum >>> 16) & 0xff);
buf[offset + 2] = (byte) ((checksum >>> 8) & 0xff);
buf[offset + 3] = (byte) (checksum & 0xff);
} else {
throw new IOException("Unknown Checksum " + type);
}
if (reset) {
reset();
}
return size;
}
/**
* 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;
}
