Class: Omnizip::Formats::Rar::Rar5::MultiVolume::VolumeSplitter

Inherits:
Object
  • Object
show all
Defined in:
lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb

Overview

Volume splitter for multi-volume archives

This class handles splitting compressed data streams across multiple volumes while respecting size boundaries and file atomicity.

Examples:

Split data across volumes

splitter = VolumeSplitter.new(max_volume_size: 10_485_760)
splitter.start_volume(1)
splitter.write_to_current_volume(file1_data)
if !splitter.can_fit_in_current_volume?(file2_data.bytesize)
  splitter.finalize_volume
  splitter.start_volume(2)
end

Constant Summary collapse

HEADER_OVERHEAD =

Minimum space reserved for headers (signature + main + end headers)

1024

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(max_volume_size:) ⇒ VolumeSplitter

Initialize volume splitter

Parameters:

  • max_volume_size (Integer) —

    Maximum size per volume in bytes



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# File 'lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb', line 40

def initialize(max_volume_size:)
  @max_volume_size = max_volume_size
  @current_volume_number = 0
  @current_volume_bytes = 0
  @current_volume_data = []
  @volumes = []
end

Instance Attribute Details

#current_volume_bytes ⇒ Integer (readonly)

Returns Bytes written to current volume.

Returns:

  • (Integer) —

    Bytes written to current volume



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# File 'lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb', line 29

def current_volume_bytes
  @current_volume_bytes
end

#current_volume_number ⇒ Integer (readonly)

Returns Current volume number (1-based).

Returns:

  • (Integer) —

    Current volume number (1-based)



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# File 'lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb', line 26

def current_volume_number
  @current_volume_number
end

#max_volume_size ⇒ Integer (readonly)

Returns Maximum size per volume in bytes.

Returns:

  • (Integer) —

    Maximum size per volume in bytes



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# File 'lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb', line 23

def max_volume_size
  @max_volume_size
end

#volumes ⇒ Array<Hash> (readonly)

Returns Volume metadata.

Returns:

  • (Array<Hash>) —

    Volume metadata



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# File 'lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb', line 32

def volumes
  @volumes
end

Class Method Details

.needs_splitting?(total_size, max_volume_size) ⇒ Boolean

Check if archive needs splitting

Parameters:

  • total_size (Integer) —

    Total archive size

Returns:

  • (Boolean) —

    true if splitting needed



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# File 'lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb', line 147

def self.needs_splitting?(total_size, max_volume_size)
  total_size > max_volume_size
end

Instance Method Details

#calculate_file_distribution(files) ⇒ Array<Array<Integer>>

Calculate optimal file distribution across volumes

This method determines how to distribute files across volumes to minimize volume count while respecting atomicity.

Parameters:

  • files (Array<Hash>) —

    File information with :compressed_size

Returns:

  • (Array<Array<Integer>>) —

    Volume assignments (file indices per volume)



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# File 'lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb', line 108

def calculate_file_distribution(files)
  distribution = []
  current_volume_files = []
  current_volume_used = HEADER_OVERHEAD

  files.each_with_index do |file, idx|
    file_size = file[:compressed_size] + file[:header_size]

    # Check if file fits in current volume
    if (current_volume_used + file_size) <= @max_volume_size
      current_volume_files << idx
      current_volume_used += file_size
    else
      # Start new volume
      distribution << current_volume_files unless current_volume_files.empty?
      current_volume_files = [idx]
      current_volume_used = HEADER_OVERHEAD + file_size

      # Check if single file exceeds volume size
      if current_volume_used > @max_volume_size
        # File must span multiple volumes (not implemented yet)
        # For now, just place it in its own volume
        distribution << [idx]
        current_volume_files = []
        current_volume_used = HEADER_OVERHEAD
      end
    end
  end

  # Add final volume if not empty
  distribution << current_volume_files unless current_volume_files.empty?

  distribution
end

#can_fit_in_current_volume?(data_size) ⇒ Boolean

Check if data can fit in current volume

Parameters:

  • data_size (Integer) —

    Size of data to write

Returns:

  • (Boolean) —

    true if data fits, false if new volume needed



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# File 'lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb', line 62

def can_fit_in_current_volume?(data_size)
  (@current_volume_bytes + data_size) <= @max_volume_size
end

#finalize_volume ⇒ Hash

Finalize current volume

Returns:

  • (Hash) —

    Volume metadata



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# File 'lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb', line 90

def finalize_volume
  volume_info = {
    number: @current_volume_number,
    size: @current_volume_bytes,
    data: @current_volume_data.join,
  }

  @volumes << volume_info
  volume_info
end

#remaining_space ⇒ Integer

Get remaining space in current volume

Returns:

  • (Integer) —

    Bytes available



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# File 'lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb', line 69

def remaining_space
  @max_volume_size - @current_volume_bytes
end

#start_volume(volume_number) ⇒ void

This method returns an undefined value.

Start a new volume

Parameters:

  • volume_number (Integer) —

    Volume number (1-based)



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# File 'lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb', line 52

def start_volume(volume_number)
  @current_volume_number = volume_number
  @current_volume_bytes = HEADER_OVERHEAD # Reserve space for headers
  @current_volume_data = []
end

#write_to_current_volume(data) ⇒ void

This method returns an undefined value.

Write data to current volume

Parameters:

  • data (String) —

    Data to write

Raises:

  • (RuntimeError) —

    if no volume is active

  • (RuntimeError) —

    if data doesn't fit



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# File 'lib/omnizip/formats/rar/rar5/multi_volume/volume_splitter.rb', line 79

def write_to_current_volume(data)
  raise "No active volume" if @current_volume_number.zero?
  raise "Data doesn't fit in current volume" unless can_fit_in_current_volume?(data.bytesize)

  @current_volume_data << data
  @current_volume_bytes += data.bytesize
end