Class PPMdCompressionSettings

Class PPMdCompressionSettings

Namespace: Aspose.Zip.Saving
Assembly: Aspose.Zip.dll (25.8.0)

Settings needed for compressor or decompressor to work.

public class PPMdCompressionSettings : CompressionSettings

Inheritance

object ← CompressionSettings ← PPMdCompressionSettings

Inherited Members

CompressionSettings.Bzip2 , CompressionSettings.Deflate , CompressionSettings.EnhancedDeflate , CompressionSettings.Store , CompressionSettings.Lzma , CompressionSettings.Xz , CompressionSettings.PPMd , CompressionSettings.Zstd , object.GetType() , object.MemberwiseClone() , object.ToString() , object.Equals(object?) , object.Equals(object?, object?) , object.ReferenceEquals(object?, object?) , object.GetHashCode()

Remarks

PPMd is a data compression algorithm developed by Dmitry Shkarin. This algorithm is based on predictive phrase matching on multiple order contexts.

Constructors

PPMdCompressionSettings(int, int)

Initializes a new instance of the Aspose.Zip.Saving.PPMdCompressionSettings class.

public PPMdCompressionSettings(int modelOrder, int suballocatorSize)

Parameters

modelOrder int

Order of the model.

suballocatorSize int

Memory size in MB suballocator may consume.

Examples 

using (Archive archive = new Archive(new ArchiveEntrySettings(new PPMdCompressionSettings(4, 10))))
{
    archive.CreateEntry("data.bin", "data.bin");                   
    archive.Save(zipFile);
}

Remarks

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

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.

Exceptions

ArgumentOutOfRangeException

modelOrder is not between 2 and 16. - or - suballocatorSize is not between 1 and 256.

PPMdCompressionSettings()

Initializes a new instance of the Aspose.Zip.Saving.PPMdCompressionSettings class with default model order and sub-allocator size.

public PPMdCompressionSettings()

Examples 

using (Archive archive = new Archive(new ArchiveEntrySettings(new PPMdCompressionSettings())))
{
    archive.CreateEntry("data.bin", "data.bin");                   
    archive.Save(zipFile);
}

Remarks

The default model order is 8, and the sub-allocator size is 50MB.

Properties

ModelOrder

Gets the order of the model.

public int ModelOrder { get; }

Property Value

int

SuballocatorSize

Gets the sub-allocator size in MB.

public int SuballocatorSize { get; }

Property Value

int

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