Package com.aspose.zip

Class SevenZipLZMA2CompressionSettings

java.lang.Object

com.aspose.zip.SevenZipCompressionSettings

com.aspose.zip.SevenZipLZMA2CompressionSettings

public class SevenZipLZMA2CompressionSettings
extends SevenZipCompressionSettings

Settings for LZMA2 compression method within 7z archive.

LZMA2 supports multiple runs of compressed LZMA data and uncompressed data.

See more: Lempel–Ziv–Markov_chain_algorithm

Constructor Summary

Constructors

Constructor	Description
SevenZipLZMA2CompressionSettings()	Instantiates settings for LZMA2 compression method within 7z archive.
SevenZipLZMA2CompressionSettings(int dictionarySize)	Instantiates settings for LZMA2 compression method within 7z archive.
SevenZipLZMA2CompressionSettings(int dictionarySize, int fastBytes)	Instantiates settings for LZMA2 compression method within 7z archive.

Method Summary

Modifier and Type	Method	Description
int	getCompressionThreads()	Gets compression thread count.
int	getDictionarySize()	Dictionary (history buffer) size indicates how many bytes of the recently processed uncompressed data are kept in memory.
int	getFastBytes()	Gets the control number of fast bytes used by the LZMA2 compressor.
SevenZipCompressionMethod	getMethod()	Gets compression or decompression method.
void	setCompressionThreads(int value)	Sets compression thread count.

Methods inherited from class java.lang.Object

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

Constructor Detail

SevenZipLZMA2CompressionSettings

public SevenZipLZMA2CompressionSettings()

Instantiates settings for LZMA2 compression method within 7z archive.

SevenZipLZMA2CompressionSettings

public SevenZipLZMA2CompressionSettings(int dictionarySize)

Instantiates settings for LZMA2 compression method within 7z archive.

Parameters:

dictionarySize - the size of history buffer, must be between 4096 and 1073741824.

The bigger the dictionary, usually the better the compression ratio is - but dictionaries larger than the uncompressed data are a waste of RAM.

Throws:

com.aspose.ms.System.ArgumentOutOfRangeException - dictionarySize is too big or too small.

SevenZipLZMA2CompressionSettings

public SevenZipLZMA2CompressionSettings(int dictionarySize,
                                        int fastBytes)

Instantiates settings for LZMA2 compression method within 7z archive.

Parameters:

dictionarySize - the size of history buffer, must be between 4096 and 1073741824.

The bigger the dictionary, usually the better the compression ratio is - but dictionaries larger than the uncompressed data are a waste of RAM.

fastBytes - controls the number of fast bytes used by the LZMA2 compressors. A larger number of fast bytes can provide a better compression ratio at the expense of compression speed.

Throws:

com.aspose.ms.System.ArgumentOutOfRangeException - dictionarySize is too big or too small, or fastBytes is too big or too small.

Method Detail

getMethod

public SevenZipCompressionMethod getMethod()

Gets compression or decompression method.

Specified by:

getMethod in class SevenZipCompressionSettings

Returns:

compression or decompression method.

getCompressionThreads

public final int getCompressionThreads()

Gets compression thread count. If the value is greater than 1, multithreading compression will be used.

Returns:

compression thread count

setCompressionThreads

public final void setCompressionThreads(int value)

Sets compression thread count. If the value is greater than 1, multithreading compression will be used.

Parameters:

value - compression thread count.

Do not set this number more than CPU cores.

Throws:

com.aspose.ms.System.ArgumentOutOfRangeException - The number of threads is more than 32.

getDictionarySize

public final int getDictionarySize()

Dictionary (history buffer) size indicates how many bytes of the recently processed uncompressed data are kept in memory.

Returns:

dictionary (history buffer) size

getFastBytes

public final int getFastBytes()

Gets the control number of fast bytes used by the LZMA2 compressor.

Returns:

the control number of fast bytes used by the LZMA2 compressor