Class: Vectory::GhostscriptWrapper

Inherits:
Object
  • Object
show all
Defined in:
lib/vectory/ghostscript_wrapper.rb

Overview

GhostscriptWrapper converts PS and EPS files to PDF using Ghostscript

Uses Ukiryu for platform-adaptive command execution.

Constant Summary collapse

SUPPORTED_INPUT_FORMATS = 
%w[ps eps].freeze

Class Method Summary collapse

Class Method Details

.available? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/vectory/ghostscript_wrapper.rb', line 15

def available?
  ghostscript_tool
  true
rescue GhostscriptNotFoundError
  false
end

.convert(content, options = {}) ⇒ Object

Raises:



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# File 'lib/vectory/ghostscript_wrapper.rb', line 31

def convert(content, options = {})
  raise GhostscriptNotFoundError unless available?

  eps_crop = options.fetch(:eps_crop, false)
  input_ext = eps_crop ? ".eps" : ".ps"

  # Create temporary input file
  input_file = Tempfile.new(["gs_input", input_ext])
  output_file = Tempfile.new(["gs_output", ".pdf"])

  begin
    # Write content and close the input file so GhostScript can read it
    input_file.binmode
    input_file.write(content)
    input_file.flush
    input_file.close

    # Close output file so GhostScript can write to it
    output_file.close

    # Get the tool and execute
    tool = ghostscript_tool
    params = build_convert_params(input_file.path, output_file.path,
                                  eps_crop: eps_crop)

    result = tool.execute(:convert,
                          execution_timeout: Configuration.instance.timeout,
                          **params)

    unless result.success?
      raise ConversionError,
            "GhostScript conversion failed. " \
            "Command: #{result.command}, " \
            "Exit status: #{result.status}, " \
            "stdout: '#{result.stdout.strip}', " \
            "stderr: '#{result.stderr.strip}'"
    end

    unless File.exist?(output_file.path)
      raise ConversionError,
            "GhostScript did not create output file: #{output_file.path}"
    end

    output_content = File.binread(output_file.path)

    # Check if the PDF is valid (should be more than just the header)
    if output_content.size < 100
      raise ConversionError,
            "GhostScript created invalid PDF (#{output_content.size} bytes). " \
            "Command: #{result.command}, " \
            "stdout: '#{result.stdout.strip}', " \
            "stderr: '#{result.stderr.strip}'"
    end

    output_content
  ensure
    # Clean up temp files
    input_file.close unless input_file.closed?
    input_file.unlink
    output_file.close unless output_file.closed?
    output_file.unlink
  end
end

.pdf_to_eps(pdf_content) ⇒ String

Convert PDF content to PostScript

This is useful as a fallback when Inkscape’s PDF import fails. Ghostscript can reliably convert PDF to EPS, and Inkscape can then import the EPS file.

Parameters:

  • pdf_content (String) —

    the PDF content to convert

Returns:

  • (String) —

    the EPS content

Raises:



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# File 'lib/vectory/ghostscript_wrapper.rb', line 105

def pdf_to_eps(pdf_content)
  raise GhostscriptNotFoundError unless available?

  input_file = Tempfile.new(["pdf_input", ".pdf"])
  output_file = Tempfile.new(["eps_output", ".eps"])

  begin
    input_file.binmode
    input_file.write(pdf_content)
    input_file.flush
    input_file.close
    output_file.close

    tool = ghostscript_tool
    params = {
      inputs: [input_file.path],
      device: :eps2write,
      output: output_file.path,
      batch: true,
      no_pause: true,
      quiet: true,
    }

    result = tool.execute(:convert,
                          execution_timeout: Configuration.instance.timeout,
                          **params)

    unless result.success?
      raise ConversionError,
            "GhostScript PDF to EPS conversion failed. " \
            "Command: #{result.command}, " \
            "Exit status: #{result.status}, " \
            "stdout: '#{result.stdout.strip}', " \
            "stderr: '#{result.stderr.strip}'"
    end

    unless File.exist?(output_file.path)
      raise ConversionError,
            "GhostScript did not create output file: #{output_file.path}"
    end

    File.binread(output_file.path)
  ensure
    input_file.close unless input_file.closed?
    input_file.unlink
    output_file.close unless output_file.closed?
    output_file.unlink
  end
end

.version ⇒ Object 



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# File 'lib/vectory/ghostscript_wrapper.rb', line 22

def version
  return nil unless available?

  tool = ghostscript_tool
  tool.version
rescue StandardError
  nil
end