com.mindbright.ssh2

Class SSH2CompressorZLib

java.lang.Object

com.mindbright.ssh2.SSH2Compressor

com.mindbright.ssh2.SSH2CompressorZLib

Direct Known Subclasses:

SSH2CompressorZLibOpenSSH

public class SSH2CompressorZLib
extends SSH2Compressor

Implements the zlib compression algorithm as described in the ssh protocol draft. It uses the jzlib provided by JCraft to handle the actual compression/uncompression.

Field Summary

Fields inherited from class com.mindbright.ssh2.SSH2Compressor

COMPRESS_MODE, UNCOMPRESS_MODE

Constructor Summary

Constructors

Constructor and Description
SSH2CompressorZLib()

Method Summary

Methods

Modifier and Type	Method and Description
void	compress(SSH2DataBuffer data) Compress a block of data.
void	init(int mode, int level) Initialize the compressor.
long	numOfCompressedBytes() Get the total number of bytes compressed.
long	numOfUncompressedBytes() Get the total number of bytes uncompressed.
int	uncompress(SSH2DataBuffer data, int len) Uncompress a block of data.

Methods inherited from class com.mindbright.ssh2.SSH2Compressor

authSucceeded, getInstance

Methods inherited from class java.lang.Object

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

Constructor Detail

SSH2CompressorZLib

public SSH2CompressorZLib()

Method Detail

init

public void init(int mode,
        int level)

Description copied from class: SSH2Compressor

Initialize the compressor. Sets the mode (compress or uncompress) as well as the desired level of compression.

Specified by:

init in class SSH2Compressor

Parameters:

mode - Either COMPRESS_MODE or UNCOMPRESS_MODE.

level - The level of compression. The exact meaning of this is algorithm dependent.

compress

public void compress(SSH2DataBuffer data)
              throws SSH2CompressionException

Description copied from class: SSH2Compressor

Compress a block of data.

Specified by:

compress in class SSH2Compressor

Parameters:

data - The block of data to compress. The compressed data is left in the same buffer.

Throws:

SSH2CompressionException

uncompress

public int uncompress(SSH2DataBuffer data,
             int len)
               throws SSH2CompressionException

Description copied from class: SSH2Compressor

Uncompress a block of data. The uncompressed data is stored in the SSH2DataBuffer given so this one has to be big enough to fit the uncompressed data block.

Specified by:

uncompress in class SSH2Compressor

Parameters:

data - The block of data to uncompress.

len - How much data can be stored in the given buffer.

Throws:

SSH2CompressionException

numOfCompressedBytes

public long numOfCompressedBytes()

Description copied from class: SSH2Compressor

Get the total number of bytes compressed.

Specified by:

numOfCompressedBytes in class SSH2Compressor

Returns:

The number of bytes sent into the algorithm.

numOfUncompressedBytes

public long numOfUncompressedBytes()

Description copied from class: SSH2Compressor

Get the total number of bytes uncompressed.

Specified by:

numOfUncompressedBytes in class SSH2Compressor

Returns:

The number of bytes output by the algorithm.