Class: Omnizip::Algorithms::XZLZMA2

Inherits:
Omnizip::Algorithm show all
Defined in:
lib/omnizip/algorithms/xz_lzma2.rb

Overview

XZ Utils LZMA2 compression algorithm.

This algorithm uses the XZ Utils implementation of LZMA2, which provides full compatibility with xz command-line tools.

Examples:

Compress data

algorithm = Omnizip::AlgorithmRegistry.get(:xz_lzma2).new(
  dict_size: 8 * 1024 * 1024
)
algorithm.compress(input_io, output_io)

Decompress data

algorithm = Omnizip::AlgorithmRegistry.get(:xz_lzma2).new
algorithm.decompress(input_io, output_io)

Instance Attribute Summary

Attributes inherited from Omnizip::Algorithm

#filter, #options

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Omnizip::Algorithm

inherited, #initialize, #with_filter

Constructor Details

This class inherits a constructor from Omnizip::Algorithm

Class Method Details

.metadata ⇒ Models::AlgorithmMetadata

Get algorithm metadata.

Returns:



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# File 'lib/omnizip/algorithms/xz_lzma2.rb', line 43

def self.metadata
  Models::AlgorithmMetadata.new.tap do |meta|
    meta.name = "xz_lzma2"
    meta.description = "LZMA2 compression (XZ Utils implementation)"
    meta.version = "1.0.0"
  end
end

Instance Method Details

#compress(input, output) ⇒ void

This method returns an undefined value.

Compress data using XZ Utils LZMA2.

Parameters:

  • input (IO, String) —

    Input data

  • output (IO) —

    Output stream



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# File 'lib/omnizip/algorithms/xz_lzma2.rb', line 56

def compress(input, output)
  input_data = if input.is_a?(String)
                 input
               elsif input.respond_to?(:read)
                 input.read
               else
                 raise ArgumentError, "Input must be a String or IO"
               end

  # Apply filter if set
  if @filter
    input_data = @filter.encode(input_data)
  end

  # Get encoding options
  dict_size = @options.fetch(:dict_size, 8 * 1024 * 1024)
  lc = @options.fetch(:lc, 3)
  lp = @options.fetch(:lp, 0)
  pb = @options.fetch(:pb, 2)
  standalone = @options.fetch(:standalone, false)

  # Create encoder and compress
  encoder = Implementations::XZUtils::LZMA2::Encoder.new(
    dict_size: dict_size,
    lc: lc,
    lp: lp,
    pb: pb,
    standalone: standalone,
  )

  compressed = encoder.encode(input_data)
  output.write(compressed)
end

#decompress(input, output) ⇒ void

This method returns an undefined value.

Decompress data using XZ Utils LZMA2.

Parameters:

  • input (IO) —

    Input stream

  • output (IO) —

    Output stream



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# File 'lib/omnizip/algorithms/xz_lzma2.rb', line 95

def decompress(input, output)
  dict_size = @options.fetch(:dict_size, 8 * 1024 * 1024)

  decoder = Implementations::XZUtils::LZMA2::Decoder.new(input,
                                                         raw_mode: true, dict_size: dict_size)
  decompressed = decoder.decode_stream

  # Reverse filter if set
  if @filter
    decompressed = @filter.decode(decompressed)
  end

  output.write(decompressed)
end