Package com.aspose.zip

Class SevenZipPPMdCompressionSettings

java.lang.Object

com.aspose.zip.SevenZipCompressionSettings

com.aspose.zip.SevenZipPPMdCompressionSettings

public final class SevenZipPPMdCompressionSettings
extends SevenZipCompressionSettings

Settings for PPMd compression method within 7z archive.

Constructor Summary

Constructors

Constructor	Description
SevenZipPPMdCompressionSettings()	Instantiates settings for PPMd compression method within 7z archive with default model order and sub-allocator size.
SevenZipPPMdCompressionSettings(int maxOrder, int suballocatorSize)	Instantiates settings for PPMd compression method within 7z archive.

Method Summary

Modifier and Type	Method	Description
byte	getMaxOrder()	Gets the maximum order.
SevenZipCompressionMethod	getMethod()	Gets compression or decompression method.
int	getSuballocatorSize()	Gets the sub-allocator size in MB.

Methods inherited from class java.lang.Object

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

Constructor Detail

SevenZipPPMdCompressionSettings

public SevenZipPPMdCompressionSettings(int maxOrder,
                                       int suballocatorSize)

Instantiates settings for PPMd compression method within 7z archive.

     try (SevenZipArchive archive = new SevenZipArchive(new SevenZipEntrySettings(new SevenZipPPMdCompressionSettings(4, 32)))) {
         archive.createEntry("data.bin", "data.bin");
         archive.save("zipFile.zip");
     }
 

Parameters:

maxOrder - Maximum order.

Bigger model orders almost surely results in better compression and surely more memory and CPU usage.

suballocatorSize - Memory size in MB suballocator may consume.

The PPMd algorithm might need a lot of memory, especially when used on large files and/or used with large model order. If ppmd needs more memory than you give it, the compression will be worse.

Throws:

com.aspose.ms.System.ArgumentOutOfRangeException - maxOrder is not between 2 and 32, or suballocatorSize is not between 1 and 1024.

SevenZipPPMdCompressionSettings

public SevenZipPPMdCompressionSettings()

Instantiates settings for PPMd compression method within 7z archive with default model order and sub-allocator size.

     try (SevenZipArchive archive = new SevenZipArchive(new SevenZipEntrySettings(new SevenZipPPMdCompressionSettings()))) {
         archive.createEntry("data.bin", "data.bin");
         archive.save("sevenZipFile.7z");
     }
 

The default model order is 6 and sub-allocator size is 16MB.

Method Detail

getMethod

public SevenZipCompressionMethod getMethod()

Gets compression or decompression method.

Specified by:

getMethod in class SevenZipCompressionSettings

Returns:

compression or decompression method

getMaxOrder

public final byte getMaxOrder()

Gets the maximum order.

Returns:

the maximum order

getSuballocatorSize

public final int getSuballocatorSize()

Gets the sub-allocator size in MB.

Returns:

the sub-allocator size in MB