HDFS-2371. Refactor BlockSender.java for better readability. Contributed by Suresh Srinivas.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1177161 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Suresh Srinivas 2011-09-29 04:40:15 +00:00
parent e9dd78d9fe
commit e90a5b4043
5 changed files with 341 additions and 231 deletions

View File

@ -21,7 +21,8 @@ Trunk (unreleased changes)
IMPROVEMENTS
HADOOP-7524 Change RPC to allow multiple protocols including multuple versions of the same protocol (sanjay Radia)
HADOOP-7524 Change RPC to allow multiple protocols including multuple
versions of the same protocol (sanjay Radia)
HDFS-1620. Rename HdfsConstants -> HdfsServerConstants, FSConstants ->
HdfsConstants. (Harsh J Chouraria via atm)
@ -50,6 +51,8 @@ Trunk (unreleased changes)
HDFS-2355. Federation: enable using the same configuration file across
all the nodes in the cluster. (suresh)
HDFS-2371. Refactor BlockSender.java for better readability. (suresh)
BUG FIXES
HDFS-2287. TestParallelRead has a small off-by-one bug. (todd)

View File

@ -404,7 +404,7 @@ class BlockPoolSliceScanner {
adjustThrottler();
blockSender = new BlockSender(block, 0, -1, false, false, true,
datanode);
datanode, null);
DataOutputStream out =
new DataOutputStream(new IOUtils.NullOutputStream());

View File

@ -41,191 +41,230 @@ import org.apache.hadoop.util.DataChecksum;
/**
* Reads a block from the disk and sends it to a recipient.
*
* Data sent from the BlockeSender in the following format:
* <br><b>Data format:</b> <pre>
* +--------------------------------------------------+
* | ChecksumHeader | Sequence of data PACKETS... |
* +--------------------------------------------------+
* </pre>
* <b>ChecksumHeader format:</b> <pre>
* +--------------------------------------------------+
* | 1 byte CHECKSUM_TYPE | 4 byte BYTES_PER_CHECKSUM |
* +--------------------------------------------------+
* </pre>
* An empty packet is sent to mark the end of block and read completion.
*
* PACKET Contains a packet header, checksum and data. Amount of data
* carried is set by BUFFER_SIZE.
* <pre>
* +-----------------------------------------------------+
* | 4 byte packet length (excluding packet header) |
* +-----------------------------------------------------+
* | 8 byte offset in the block | 8 byte sequence number |
* +-----------------------------------------------------+
* | 1 byte isLastPacketInBlock |
* +-----------------------------------------------------+
* | 4 byte Length of actual data |
* +-----------------------------------------------------+
* | x byte checksum data. x is defined below |
* +-----------------------------------------------------+
* | actual data ...... |
* +-----------------------------------------------------+
*
* Data is made of Chunks. Each chunk is of length <= BYTES_PER_CHECKSUM.
* A checksum is calculated for each chunk.
*
* x = (length of data + BYTE_PER_CHECKSUM - 1)/BYTES_PER_CHECKSUM *
* CHECKSUM_SIZE
*
* CHECKSUM_SIZE depends on CHECKSUM_TYPE (usually, 4 for CRC32)
* </pre>
*
* The client reads data until it receives a packet with
* "LastPacketInBlock" set to true or with a zero length. If there is
* no checksum error, it replies to DataNode with OP_STATUS_CHECKSUM_OK:
* <pre>
* +------------------------------+
* | 2 byte OP_STATUS_CHECKSUM_OK |
* +------------------------------+
* </pre>
*/
class BlockSender implements java.io.Closeable {
public static final Log LOG = DataNode.LOG;
static final Log LOG = DataNode.LOG;
static final Log ClientTraceLog = DataNode.ClientTraceLog;
private ExtendedBlock block; // the block to read from
/** the replica to read from */
private final Replica replica;
/** The visible length of a replica. */
private final long replicaVisibleLength;
private static final boolean is32Bit = System.getProperty("sun.arch.data.model").equals("32");
private InputStream blockIn; // data stream
private long blockInPosition = -1; // updated while using transferTo().
private DataInputStream checksumIn; // checksum datastream
private DataChecksum checksum; // checksum stream
private long offset; // starting position to read
private long endOffset; // ending position
private int bytesPerChecksum; // chunk size
private int checksumSize; // checksum size
private boolean corruptChecksumOk; // if need to verify checksum
private boolean chunkOffsetOK; // if need to send chunk offset
private long seqno; // sequence number of packet
private boolean transferToAllowed = true;
// set once entire requested byte range has been sent to the client
private boolean sentEntireByteRange;
private boolean verifyChecksum; //if true, check is verified while reading
private DataTransferThrottler throttler;
private final String clientTraceFmt; // format of client trace log message
private static final boolean is32Bit =
System.getProperty("sun.arch.data.model").equals("32");
/**
* Minimum buffer used while sending data to clients. Used only if
* transferTo() is enabled. 64KB is not that large. It could be larger, but
* not sure if there will be much more improvement.
*/
private static final int MIN_BUFFER_WITH_TRANSFERTO = 64*1024;
private static final int TRANSFERTO_BUFFER_SIZE = Math.max(
HdfsConstants.IO_FILE_BUFFER_SIZE, MIN_BUFFER_WITH_TRANSFERTO);
/** the block to read from */
private final ExtendedBlock block;
/** the replica to read from */
private final Replica replica;
/** The visible length of a replica. */
private final long replicaVisibleLength;
/** Stream to read block data from */
private InputStream blockIn;
/** updated while using transferTo() */
private long blockInPosition = -1;
/** Stream to read checksum */
private DataInputStream checksumIn;
/** Checksum utility */
private final DataChecksum checksum;
/** Starting position to read */
private long offset;
/** Position of last byte to read from block file */
private final long endOffset;
/** Number of bytes in chunk used for computing checksum */
private final int chunkSize;
/** Number bytes of checksum computed for a chunk */
private final int checksumSize;
/** If true, failure to read checksum is ignored */
private final boolean corruptChecksumOk;
/** true if chunk offset is needed to be sent in Checksum header */
private final boolean chunkOffsetOK;
/** Sequence number of packet being sent */
private long seqno;
/** Set to true if transferTo is allowed for sending data to the client */
private final boolean transferToAllowed;
/** Set to true once entire requested byte range has been sent to the client */
private boolean sentEntireByteRange;
/** When true, verify checksum while reading from checksum file */
private final boolean verifyChecksum;
/** Format used to print client trace log messages */
private final String clientTraceFmt;
private volatile ChunkChecksum lastChunkChecksum = null;
BlockSender(ExtendedBlock block, long startOffset, long length,
boolean corruptChecksumOk, boolean chunkOffsetOK,
boolean verifyChecksum, DataNode datanode) throws IOException {
this(block, startOffset, length, corruptChecksumOk, chunkOffsetOK,
verifyChecksum, datanode, null);
}
/**
* Constructor
*
* @param block Block that is being read
* @param startOffset starting offset to read from
* @param length length of data to read
* @param corruptChecksumOk
* @param chunkOffsetOK need to send check offset in checksum header
* @param verifyChecksum verify checksum while reading the data
* @param datanode datanode from which the block is being read
* @param clientTraceFmt format string used to print client trace logs
* @throws IOException
*/
BlockSender(ExtendedBlock block, long startOffset, long length,
boolean corruptChecksumOk, boolean chunkOffsetOK,
boolean verifyChecksum, DataNode datanode, String clientTraceFmt)
throws IOException {
try {
this.block = block;
this.chunkOffsetOK = chunkOffsetOK;
this.corruptChecksumOk = corruptChecksumOk;
this.verifyChecksum = verifyChecksum;
this.clientTraceFmt = clientTraceFmt;
synchronized(datanode.data) {
this.replica = datanode.data.getReplica(block.getBlockPoolId(),
block.getBlockId());
if (replica == null) {
throw new ReplicaNotFoundException(block);
}
this.replica = getReplica(block, datanode);
this.replicaVisibleLength = replica.getVisibleLength();
}
long minEndOffset = startOffset + length;
// if this is a write in progress
// if there 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
));
}
long minEndOffset = startOffset + length;
waitForMinLength((ReplicaBeingWritten)replica, minEndOffset);
ReplicaInPipeline rip = (ReplicaInPipeline) replica;
chunkChecksum = rip.getLastChecksumAndDataLen();
}
if (replica.getGenerationStamp() < block.getGenerationStamp()) {
throw new IOException(
"replica.getGenerationStamp() < block.getGenerationStamp(), block="
throw new IOException("Replica gen stamp < block genstamp, block="
+ block + ", replica=" + replica);
}
if (replicaVisibleLength < 0) {
throw new IOException("The replica is not readable, block="
throw new IOException("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;
(!is32Bit || length <= Integer.MAX_VALUE);
if ( !corruptChecksumOk || datanode.data.metaFileExists(block) ) {
DataChecksum csum;
if (!corruptChecksumOk || datanode.data.metaFileExists(block)) {
checksumIn = new DataInputStream(new BufferedInputStream(datanode.data
.getMetaDataInputStream(block), HdfsConstants.IO_FILE_BUFFER_SIZE));
// read and handle the common header here. For now just a version
BlockMetadataHeader header = BlockMetadataHeader.readHeader(checksumIn);
short version = header.getVersion();
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();
csum = 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,
csum = 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.
/*
* If chunkSize 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(),
int size = csum.getBytesPerChecksum();
if (size > 10*1024*1024 && size > replicaVisibleLength) {
csum = DataChecksum.newDataChecksum(csum.getChecksumType(),
Math.max((int)replicaVisibleLength, 10*1024*1024));
bytesPerChecksum = checksum.getBytesPerChecksum();
size = csum.getBytesPerChecksum();
}
chunkSize = size;
checksum = csum;
checksumSize = checksum.getChecksumSize();
if (length < 0) {
length = replicaVisibleLength;
}
length = length < 0 ? replicaVisibleLength : length;
// 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) {
long end = chunkChecksum != null ? chunkChecksum.getDataLength()
: replica.getBytesOnDisk();
if (startOffset < 0 || startOffset > end
|| (length + startOffset) > end) {
String msg = " Offset " + startOffset + " and length " + length
+ " don't match block " + block + " ( blockLen " + endOffset + " )";
+ " don't match block " + block + " ( blockLen " + end + " )";
LOG.warn(datanode.getDNRegistrationForBP(block.getBlockPoolId()) +
":sendBlock() : " + msg);
throw new IOException(msg);
}
offset = (startOffset - (startOffset % bytesPerChecksum));
// Ensure read offset is position at the beginning of chunk
offset = startOffset - (startOffset % chunkSize);
if (length >= 0) {
// Make sure endOffset points to end of a checksumed chunk.
// Ensure endOffset points to end of chunk.
long tmpLen = startOffset + length;
if (tmpLen % bytesPerChecksum != 0) {
tmpLen += (bytesPerChecksum - tmpLen % bytesPerChecksum);
if (tmpLen % chunkSize != 0) {
tmpLen += (chunkSize - tmpLen % chunkSize);
}
if (tmpLen < endOffset) {
if (tmpLen < end) {
// will use on-disk checksum here since the end is a stable chunk
endOffset = tmpLen;
end = tmpLen;
} else if (chunkChecksum != null) {
//in last chunk which is changing. flag that we need to use in-memory
// checksum
// last chunk is changing. flag that we need to use in-memory checksum
this.lastChunkChecksum = chunkChecksum;
}
}
endOffset = end;
// seek to the right offsets
if (offset > 0) {
long checksumSkip = (offset / bytesPerChecksum) * checksumSize;
long checksumSkip = (offset / chunkSize) * checksumSize;
// note blockInStream is seeked when created below
if (checksumSkip > 0) {
// Should we use seek() for checksum file as well?
@ -237,7 +276,6 @@ class BlockSender implements java.io.Closeable {
if (DataNode.LOG.isDebugEnabled()) {
DataNode.LOG.debug("replica=" + replica);
}
blockIn = datanode.data.getBlockInputStream(block, offset); // seek to offset
} catch (IOException ioe) {
IOUtils.closeStream(this);
@ -251,19 +289,17 @@ class BlockSender implements java.io.Closeable {
*/
public void close() throws IOException {
IOException ioe = null;
// close checksum file
if(checksumIn!=null) {
try {
checksumIn.close();
checksumIn.close(); // close checksum file
} catch (IOException e) {
ioe = e;
}
checksumIn = null;
}
// close data file
if(blockIn!=null) {
try {
blockIn.close();
blockIn.close(); // close data file
} catch (IOException e) {
ioe = e;
}
@ -275,6 +311,40 @@ class BlockSender implements java.io.Closeable {
}
}
private static Replica getReplica(ExtendedBlock block, DataNode datanode)
throws ReplicaNotFoundException {
Replica replica = datanode.data.getReplica(block.getBlockPoolId(),
block.getBlockId());
if (replica == null) {
throw new ReplicaNotFoundException(block);
}
return replica;
}
/**
* Wait for rbw replica to reach the length
* @param rbw replica that is being written to
* @param len minimum length to reach
* @throws IOException on failing to reach the len in given wait time
*/
private static void waitForMinLength(ReplicaBeingWritten rbw, long len)
throws IOException {
// Wait for 3 seconds for rbw replica to reach the minimum length
for (int i = 0; i < 30 && rbw.getBytesOnDisk() < len; i++) {
try {
Thread.sleep(100);
} catch (InterruptedException ie) {
throw new IOException(ie);
}
}
long bytesOnDisk = rbw.getBytesOnDisk();
if (bytesOnDisk < len) {
throw new IOException(
String.format("Need %d bytes, but only %d bytes available", len,
bytesOnDisk));
}
}
/**
* Converts an IOExcpetion (not subclasses) to SocketException.
* This is typically done to indicate to upper layers that the error
@ -296,54 +366,43 @@ class BlockSender implements java.io.Closeable {
}
/**
* Sends upto maxChunks chunks of data.
*
* When blockInPosition is >= 0, assumes 'out' is a
* {@link SocketOutputStream} and tries
* {@link SocketOutputStream#transferToFully(FileChannel, long, int)} to
* send data (and updates blockInPosition).
* @param datalen Length of data
* @return number of chunks for data of given size
*/
private int sendChunks(ByteBuffer pkt, int maxChunks, OutputStream out)
throws IOException {
// Sends multiple chunks in one packet with a single write().
private int numberOfChunks(long datalen) {
return (int) ((datalen + chunkSize - 1)/chunkSize);
}
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();
/**
* Sends a packet with up to maxChunks chunks of data.
*
* @param pkt buffer used for writing packet data
* @param maxChunks maximum number of chunks to send
* @param out stream to send data to
* @param transferTo use transferTo to send data
* @param throttler used for throttling data transfer bandwidth
*/
private int sendPacket(ByteBuffer pkt, int maxChunks, OutputStream out,
boolean transferTo, DataTransferThrottler throttler) throws IOException {
int dataLen = (int) Math.min(endOffset - offset,
(chunkSize * (long) maxChunks));
int numChunks = numberOfChunks(dataLen); // Number of chunks be sent in the packet
int checksumDataLen = numChunks * checksumSize;
int packetLen = dataLen + checksumDataLen + 4;
boolean lastDataPacket = offset + dataLen == endOffset && dataLen > 0;
PacketHeader header = new PacketHeader(
packetLen, offset, seqno, (len == 0), len);
header.putInBuffer(pkt);
writePacketHeader(pkt, dataLen, packetLen);
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, 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;
}
}
readChecksum(buf, checksumOff, checksumDataLen);
// write in progress that we need to use to get last checksum
if (lastDataPacket && lastChunkChecksum != null) {
int start = checksumOff + checksumLen - checksumSize;
int start = checksumOff + checksumDataLen - checksumSize;
byte[] updatedChecksum = lastChunkChecksum.getChecksum();
if (updatedChecksum != null) {
@ -352,52 +411,28 @@ class BlockSender implements java.io.Closeable {
}
}
int dataOff = checksumOff + checksumLen;
if (blockInPosition < 0) {
//normal transfer
IOUtils.readFully(blockIn, buf, dataOff, len);
int dataOff = checksumOff + checksumDataLen;
if (!transferTo) { // normal transfer
IOUtils.readFully(blockIn, buf, dataOff, dataLen);
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;
}
verifyChecksum(buf, dataOff, dataLen, numChunks, checksumOff);
}
//writing is done below (mainly to handle IOException)
}
try {
if (blockInPosition >= 0) {
//use transferTo(). Checks on out and blockIn are already done.
if (transferTo) {
SocketOutputStream sockOut = (SocketOutputStream)out;
//first write the packet
sockOut.write(buf, 0, dataOff);
sockOut.write(buf, 0, dataOff); // First write checksum
// no need to flush. since we know out is not a buffered stream.
sockOut.transferToFully(((FileInputStream)blockIn).getChannel(),
blockInPosition, len);
blockInPosition += len;
blockInPosition, dataLen);
blockInPosition += dataLen;
} else {
// normal transfer
out.write(buf, 0, dataOff + len);
out.write(buf, 0, dataOff + dataLen);
}
} 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
@ -419,7 +454,70 @@ class BlockSender implements java.io.Closeable {
throttler.throttle(packetLen);
}
return len;
return dataLen;
}
/**
* Read checksum into given buffer
* @param buf buffer to read the checksum into
* @param checksumOffset offset at which to write the checksum into buf
* @param checksumLen length of checksum to write
* @throws IOException on error
*/
private void readChecksum(byte[] buf, final int checksumOffset,
final int checksumLen) throws IOException {
if (checksumSize <= 0 && checksumIn == null) {
return;
}
try {
checksumIn.readFully(buf, checksumOffset, checksumLen);
} catch (IOException e) {
LOG.warn(" Could not read or failed to veirfy checksum for data"
+ " at offset " + offset + " for block " + block, e);
IOUtils.closeStream(checksumIn);
checksumIn = null;
if (corruptChecksumOk) {
if (checksumOffset < checksumLen) {
// Just fill the array with zeros.
Arrays.fill(buf, checksumOffset, checksumLen, (byte) 0);
}
} else {
throw e;
}
}
}
/**
* Compute checksum for chunks and verify the checksum that is read from
* the metadata file is correct.
*
* @param buf buffer that has checksum and data
* @param dataOffset position where data is written in the buf
* @param datalen length of data
* @param numChunks number of chunks corresponding to data
* @param checksumOffset offset where checksum is written in the buf
* @throws ChecksumException on failed checksum verification
*/
public void verifyChecksum(final byte[] buf, final int dataOffset,
final int datalen, final int numChunks, final int checksumOffset)
throws ChecksumException {
int dOff = dataOffset;
int cOff = checksumOffset;
int dLeft = datalen;
for (int i = 0; i < numChunks; i++) {
checksum.reset();
int dLen = Math.min(dLeft, chunkSize);
checksum.update(buf, dOff, dLen);
if (!checksum.compare(buf, cOff)) {
long failedPos = offset + datalen - dLeft;
throw new ChecksumException("Checksum failed at " + failedPos,
failedPos);
}
dLeft -= dLen;
dOff += dLen;
cOff += checksumSize;
}
}
/**
@ -433,70 +531,54 @@ class BlockSender implements java.io.Closeable {
* {@link SocketOutputStream#transferToFully(FileChannel,
* long, int)}.
* @param throttler for sending data.
* @return total bytes reads, including crc.
* @return total bytes read, including checksum data.
*/
long sendBlock(DataOutputStream out, OutputStream baseStream,
DataTransferThrottler throttler) throws IOException {
if( out == null ) {
if (out == null) {
throw new IOException( "out stream is null" );
}
this.throttler = throttler;
long initialOffset = offset;
final long initialOffset = offset;
long totalRead = 0;
OutputStream streamForSendChunks = out;
final long startTime = ClientTraceLog.isInfoEnabled() ? System.nanoTime() : 0;
try {
try {
checksum.writeHeader(out);
if ( chunkOffsetOK ) {
out.writeLong( offset );
}
out.flush();
} catch (IOException e) { //socket error
throw ioeToSocketException(e);
}
writeChecksumHeader(out);
int maxChunksPerPacket;
int pktSize = PacketHeader.PKT_HEADER_LEN;
if (transferToAllowed && !verifyChecksum &&
baseStream instanceof SocketOutputStream &&
blockIn instanceof FileInputStream) {
boolean transferTo = transferToAllowed && !verifyChecksum
&& baseStream instanceof SocketOutputStream
&& blockIn instanceof FileInputStream;
if (transferTo) {
FileChannel fileChannel = ((FileInputStream)blockIn).getChannel();
// blockInPosition also indicates sendChunks() uses transferTo.
blockInPosition = fileChannel.position();
streamForSendChunks = baseStream;
maxChunksPerPacket = numberOfChunks(TRANSFERTO_BUFFER_SIZE);
// assure a mininum buffer size.
maxChunksPerPacket = (Math.max(HdfsConstants.IO_FILE_BUFFER_SIZE,
MIN_BUFFER_WITH_TRANSFERTO)
+ bytesPerChecksum - 1)/bytesPerChecksum;
// allocate smaller buffer while using transferTo().
// Smaller packet size to only hold checksum when doing transferTo
pktSize += checksumSize * maxChunksPerPacket;
} else {
maxChunksPerPacket = Math.max(1, (HdfsConstants.IO_FILE_BUFFER_SIZE
+ bytesPerChecksum - 1) / bytesPerChecksum);
pktSize += (bytesPerChecksum + checksumSize) * maxChunksPerPacket;
maxChunksPerPacket = Math.max(1,
numberOfChunks(HdfsConstants.IO_FILE_BUFFER_SIZE));
// Packet size includes both checksum and data
pktSize += (chunkSize + checksumSize) * maxChunksPerPacket;
}
ByteBuffer pktBuf = ByteBuffer.allocate(pktSize);
while (endOffset > offset) {
long len = sendChunks(pktBuf, maxChunksPerPacket,
streamForSendChunks);
long len = sendPacket(pktBuf, maxChunksPerPacket, streamForSendChunks,
transferTo, throttler);
offset += len;
totalRead += len + ((len + bytesPerChecksum - 1)/bytesPerChecksum*
checksumSize);
totalRead += len + (numberOfChunks(len) * checksumSize);
seqno++;
}
try {
// send an empty packet to mark the end of the block
sendChunks(pktBuf, maxChunksPerPacket, streamForSendChunks);
sendPacket(pktBuf, maxChunksPerPacket, streamForSendChunks, transferTo,
throttler);
out.flush();
} catch (IOException e) { //socket error
throw ioeToSocketException(e);
@ -506,14 +588,39 @@ class BlockSender implements java.io.Closeable {
} finally {
if (clientTraceFmt != null) {
final long endTime = System.nanoTime();
ClientTraceLog.info(String.format(clientTraceFmt, totalRead, initialOffset, endTime - startTime));
ClientTraceLog.info(String.format(clientTraceFmt, totalRead,
initialOffset, endTime - startTime));
}
close();
}
return totalRead;
}
/**
* Write checksum header to the output stream
*/
private void writeChecksumHeader(DataOutputStream out) throws IOException {
try {
checksum.writeHeader(out);
if (chunkOffsetOK) {
out.writeLong(offset);
}
out.flush();
} catch (IOException e) { //socket error
throw ioeToSocketException(e);
}
}
/**
* Write packet header into {@code pkt}
*/
private void writePacketHeader(ByteBuffer pkt, int dataLen, int packetLen) {
pkt.clear();
PacketHeader header = new PacketHeader(packetLen, offset, seqno,
(dataLen == 0), dataLen);
header.putInBuffer(pkt);
}
boolean didSendEntireByteRange() {
return sentEntireByteRange;
}

View File

@ -2058,7 +2058,7 @@ public class DataNode extends Configured
out = new DataOutputStream(new BufferedOutputStream(baseStream,
HdfsConstants.SMALL_BUFFER_SIZE));
blockSender = new BlockSender(b, 0, b.getNumBytes(),
false, false, false, DataNode.this);
false, false, false, DataNode.this, null);
DatanodeInfo srcNode = new DatanodeInfo(bpReg);
//

View File

@ -597,7 +597,7 @@ class DataXceiver extends Receiver implements Runnable {
try {
// check if the block exists or not
blockSender = new BlockSender(block, 0, -1, false, false, false,
datanode);
datanode, null);
// set up response stream
OutputStream baseStream = NetUtils.getOutputStream(