Package org.mariadb.jdbc.internal.io.output

Class CompressPacketOutputStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

org.mariadb.jdbc.internal.io.output.AbstractPacketOutputStream

org.mariadb.jdbc.internal.io.output.CompressPacketOutputStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable, PacketOutputStream

public class CompressPacketOutputStream
extends AbstractPacketOutputStream

Field Summary

Fields

Modifier and Type	Field	Description
private int	compressSeqNo
private static byte[]	EMPTY_ARRAY
private byte[]	header
private boolean	lastPacketExactMaxPacketLength
private static Logger	logger
private static int	MAX_PACKET_LENGTH
private int	maxPacketLength
private static float	MIN_COMPRESSION_RATIO
private static int	MIN_COMPRESSION_SIZE
private byte[]	remainingData
private byte[]	subHeader

Fields inherited from class org.mariadb.jdbc.internal.io.output.AbstractPacketOutputStream

buf, cmdLength, maxAllowedPacket, maxQuerySizeToLog, permitTrace, pos, seqNo, serverThreadLog, threadId, traceCache

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

Constructors

Constructor	Description
CompressPacketOutputStream(java.io.OutputStream out, int maxQuerySizeToLog, long threadId)

Method Summary

Modifier and Type	Method	Description
protected void	flushBuffer(boolean commandEnd)	Flush the internal buffer.
int	getMaxPacketLength()
int	initialPacketPos()
void	setMaxAllowedPacket(int maxAllowedPacket)
void	startPacket(int compressSeqNo)
void	writeEmptyPacket()	Write an empty packet.

Methods inherited from class org.mariadb.jdbc.internal.io.output.AbstractPacketOutputStream

bufferIsDataAfterMark, checkMaxAllowedLength, checkRemainingSize, exceedMaxLength, flush, flushBufferStopAtMark, getMaxAllowedPacket, getOutputStream, isMarked, mark, permitTrace, resetMark, setServerThreadId, setTraceCache, write, write, write, write, write, write, write, write, write, writeBytes, writeBytesEscaped, writeEmptyPacket, writeFieldLength, writeInt, writeLong, writeShort

Methods inherited from class java.io.FilterOutputStream

close

Methods inherited from class java.io.OutputStream

nullOutputStream

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.mariadb.jdbc.internal.io.output.PacketOutputStream

close

Field Detail

logger

private static final Logger logger

MAX_PACKET_LENGTH

private static final int MAX_PACKET_LENGTH

See Also:

Constant Field Values

EMPTY_ARRAY

private static final byte[] EMPTY_ARRAY

MIN_COMPRESSION_SIZE

private static final int MIN_COMPRESSION_SIZE

See Also:

Constant Field Values

MIN_COMPRESSION_RATIO

private static final float MIN_COMPRESSION_RATIO

See Also:

Constant Field Values

header

private final byte[] header

subHeader

private final byte[] subHeader

maxPacketLength

private int maxPacketLength

compressSeqNo

private int compressSeqNo

remainingData

private byte[] remainingData

lastPacketExactMaxPacketLength

private boolean lastPacketExactMaxPacketLength

Constructor Detail

CompressPacketOutputStream

public CompressPacketOutputStream(java.io.OutputStream out,
                                  int maxQuerySizeToLog,
                                  long threadId)

Method Detail

getMaxPacketLength

public int getMaxPacketLength()

Specified by:

getMaxPacketLength in class AbstractPacketOutputStream

setMaxAllowedPacket

public void setMaxAllowedPacket(int maxAllowedPacket)

Specified by:

setMaxAllowedPacket in interface PacketOutputStream

Specified by:

setMaxAllowedPacket in class AbstractPacketOutputStream

startPacket

public void startPacket(int compressSeqNo)

Specified by:

startPacket in interface PacketOutputStream

Specified by:

startPacket in class AbstractPacketOutputStream

initialPacketPos

public int initialPacketPos()

flushBuffer

protected void flushBuffer(boolean commandEnd)
                    throws java.io.IOException

Flush the internal buffer.

Compression add a 7 header :

1. 3 byte compression length
2. 1 byte compress sequence number
3. 3 bytes uncompress length

in case packet isn't compressed (last 3 bytes == 0):

1. 3 byte uncompress length
2. 1 byte compress sequence number
3. 3 bytes with 0 value

Content correspond to standard content.

1. 3 byte length
2. 1 byte sequence number (!= than compress sequence number)
3. sub-content

Problem is when standard content is bigger than 16mb : content will not send 4byte standard header + 16mb content, since packet are limited to 16mb then 4 bytes standard header + 16mb - 4 bytes content. the ending 4 bytes are waiting to be send. next packet will then send the waiting data before next packet, putting more waiting data is needed. if ending data is exactly MAX_PACKET_LENGTH length, then an empty packet must be send.

Specified by:

flushBuffer in class AbstractPacketOutputStream

Parameters:

commandEnd - command end

Throws:

java.io.IOException - id connection error occur.

writeEmptyPacket

public void writeEmptyPacket()
                      throws java.io.IOException

Write an empty packet.

Specified by:

writeEmptyPacket in interface PacketOutputStream

Specified by:

writeEmptyPacket in class AbstractPacketOutputStream

Throws:

java.io.IOException - if socket error occur.