Class: Abqari::ImagePipeline::ShellBackend

Inherits:
Object
  • Object
show all
Defined in:
lib/abqari/image_pipeline.rb

Overview

Shell-out to vips or magick CLI. Used when ruby-vips isn't available — slower per invocation (~150–300 ms each) but works without the FFI dep.

Instance Method Summary collapse

Constructor Details

#initialize(cli, strip:) ⇒ ShellBackend

Returns a new instance of ShellBackend.



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# File 'lib/abqari/image_pipeline.rb', line 746

def initialize(cli, strip:)
  @cli   = cli # 'vips' or 'magick'
  @strip = strip
end

Instance Method Details

#dimensions(src) ⇒ Object 



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# File 'lib/abqari/image_pipeline.rb', line 765

def dimensions(src)
  case @cli
  when 'vips'
    w = `vipsheader -f width #{src.shellescape} 2>/dev/null`.strip.to_i
    h = `vipsheader -f height #{src.shellescape} 2>/dev/null`.strip.to_i
    [w, h] if w.positive? && h.positive?
  when 'magick'
    out = `magick identify -format "%w %h" #{src.shellescape} 2>/dev/null`.strip
    dims = out.split.map(&:to_i)
    dims.size == 2 && dims.all?(&:positive?) ? dims : nil
  end
end

#name ⇒ Object 



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# File 'lib/abqari/image_pipeline.rb', line 751

def name
  "shell-#{@cli}"
end

#thumbnail(src, dest, width, format, quality) ⇒ Object 



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# File 'lib/abqari/image_pipeline.rb', line 755

def thumbnail(src, dest, width, format, quality)
  cmd = case @cli
        when 'vips'   then vips_cmd(src, dest, width, format, quality)
        when 'magick' then magick_cmd(src, dest, width, format, quality)
        end

  success = system(*cmd, out: File::NULL, err: File::NULL)
  raise "Image processing failed: #{cmd.shelljoin}" unless success
end