Class: Cabriolet::CAB::Extractor

Inherits:
Object
  • Object
show all
Defined in:
lib/cabriolet/cab/extractor.rb

Overview

Extractor handles the extraction of files from cabinets

Defined Under Namespace

Classes: BlockReader

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(io_system, decompressor) ⇒ Extractor

Initialize a new extractor



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# File 'lib/cabriolet/cab/extractor.rb', line 16

def initialize(io_system, decompressor)
  @io_system = io_system
  @decompressor = decompressor

  # State reuse for multi-file extraction (like libmspack self->d)
  @current_folder = nil
  @current_decomp = nil
  @current_input = nil
  @current_offset = 0

  # Cache ENV lookups once at initialization
  @debug_block = ENV.fetch("DEBUG_BLOCK", nil)
end

Instance Attribute Details

#decompressor ⇒ Object (readonly)

Returns the value of attribute decompressor.



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# File 'lib/cabriolet/cab/extractor.rb', line 10

def decompressor
  @decompressor
end

#io_system ⇒ Object (readonly)

Returns the value of attribute io_system.



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# File 'lib/cabriolet/cab/extractor.rb', line 10

def io_system
  @io_system
end

Instance Method Details

#extract_all(cabinet, output_dir, **options) ⇒ Integer

Extract all files from a cabinet

Options Hash (**options):

  • :preserve_paths (Boolean) —

    Preserve directory structure (default: true)

  • :set_timestamps (Boolean) —

    Set file modification times (default: true)

  • :progress (Proc) —

    Progress callback

  • :salvage (Boolean) —

    Skip files that fail to extract (default: false)



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# File 'lib/cabriolet/cab/extractor.rb', line 90

def extract_all(cabinet, output_dir, **options)
  preserve_paths = options.fetch(:preserve_paths, true)
  set_timestamps = options.fetch(:set_timestamps, true)
  progress = options[:progress]
  salvage = options[:salvage] || false

  # Create output directory
  FileUtils.mkdir_p(output_dir) unless ::File.directory?(output_dir)

  count = 0
  failed_count = 0
  cabinet.files.each do |file|
    # Determine output path
    output_path = if preserve_paths
                    ::File.join(output_dir, file.filename)
                  else
                    ::File.join(output_dir,
                                ::File.basename(file.filename))
                  end

    # Extract file (skip if salvage mode and extraction fails)
    begin
      extract_file(file, output_path, **options)
    rescue DecompressionError => e
      if salvage
        warn "Salvage: skipping #{file.filename}: #{e.message}"
        failed_count += 1
        next
      else
        raise
      end
    end

    # Set timestamp if requested
    if set_timestamps && file.modification_time
      ::File.utime(file.modification_time, file.modification_time,
                   output_path)
    end

    # Set file permissions based on attributes
    set_file_attributes(output_path, file)

    count += 1
    progress&.call(file, count, cabinet.files.size)
  end

  warn "Salvage: #{failed_count} file(s) skipped due to extraction errors" if failed_count.positive?

  count
end

#extract_file(file, output_path, **options) ⇒ Integer

Extract a single file from the cabinet

Options Hash (**options):

  • :salvage (Boolean) —

    Enable salvage mode



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# File 'lib/cabriolet/cab/extractor.rb', line 37

def extract_file(file, output_path, **options)
  salvage = options[:salvage] || @decompressor.salvage
  folder = file.folder
  filelen = validate_file_for_extraction(file, folder, salvage)

  # Check for merge requirements
  if folder.needs_prev_merge?
    raise DecompressionError,
          "File requires previous cabinet, cabinet set is incomplete"
  end

  validate_file_in_folder(folder, file.offset, filelen, salvage)

  # Create output directory if needed
  output_dir = ::File.dirname(output_path)
  FileUtils.mkdir_p(output_dir) unless ::File.directory?(output_dir)

  setup_decompressor_for_folder(folder, salvage, file.offset)
  skip_to_file_offset(file.offset, salvage, file.filename)

  # Extract actual file (libmspack lines 1137-1141)
  output_fh = @io_system.open(output_path, Constants::MODE_WRITE)

  begin
    write_file_data(output_fh, filelen)
  rescue DecompressionError
    handle_extraction_error(output_fh, output_path, file.filename, salvage, filelen)
  ensure
    output_fh.close
  end

  filelen
end

#reset_state ⇒ Object

Reset extraction state (used in salvage mode to recover from errors)



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# File 'lib/cabriolet/cab/extractor.rb', line 72

def reset_state
  @current_input&.close
  @current_input = nil
  @current_decomp = nil
  @current_folder = nil
  @current_offset = 0
end