svg-compressor.rb

#!/usr/bin/env ruby

require "base64"
require "image_optimizer"
require "mini_magick"
require "svgo_wrapper"
require "optparse"
require "fileutils"

ARGV[0].nil? ? quality = 50 : quality = ARGV[0].to_i
ARGV[1].nil? ? backup = false : backup = ARGV[1]
ARGV[2].nil? ? formall = false : formall = ARGV[2]

if backup == "backup"
  backup = true
  budir = ENV['HOME'] + "/Desktop/SVGbackup/"
  puts "Save option passed: backing up original files to " + budir
end

if ARGV.empty?
  puts "Please specify at least a compression quality setting.\n\n"
  puts "Minimum usage:\n\n    svg-compressor.rb 50\n\n"
  puts "This will compress files to 50% quality. For lower quality, use a lower number."
  puts "To create backups of the original SVG, pass the 'backup' option:\n"
  puts "Example:\n\n    svg-compressor.rb 60 backup\n\n"
  exit
end

arr_encoded = []
arr_compressed_jpegs = []

svgs = File.join("**", "*.svg")
# change to **/*.svg or use ARGV
input_files = Dir.glob(svgs)

input_files.each do |file_name|
  # init counters for line count, image count and indexing of compressed images
  line_count = 0 && image_count = 0 && i = 0
  # clear
  arr_encoded.clear
  arr_compressed_jpegs.clear

    File.read(file_name).each_line do |li|
      line_count = line_count + 1
      # Add to array if line matches regex pattern for base64 encoded png
      arr_encoded.push li[/(?<=\/png;base64,).*(?=\")/] if li[/(?<=\/png;base64,).*(?=\")/] && image_count = image_count + 1
    end

  # Check for embedded PNGs one embedded image found
  if image_count > 0
    puts "\nFound " + image_count.to_s + " embedded images in " + file_name.to_s + " -- SVG size: " + (File.size(file_name).to_f / 1024).round(2).to_s + " KB"
    image_count = 0

    svgo = SvgoWrapper.new

    # name outfile file and remove if already existing
    output_SVG = file_name + "comp"
    File.delete(output_SVG) if File.exist?(output_SVG)

    arr_encoded.each { |encoded|
      image_count = image_count + 1
      decoded = Base64.decode64(encoded)
      number = image_count.to_s
      png = file_name + number + ".png"
      jpeg = file_name + number + ".jpg"

      File.open(png, "wb") do |f|
        f.write(decoded)
      end

      image = MiniMagick::Image.open(png)
      image.flatten
      image.format "jpg"
      image.write jpeg
      ImageOptimizer.new(jpeg, quality: quality).optimize

      # read contents of file, not just encode the filename
      data = File.open(jpeg, "rb") {|io| io.read}
      encodedjpg = Base64.encode64(data)
      arr_compressed_jpegs.push encodedjpg

      File.delete(png)
      File.delete(jpeg)
    }

    # Replace with indexed string if pattern found
    File.open(file_name).each_line do |li|
      if li[/(?<=\/png;base64,).*=?(?=\")/]
        jpeg_index = arr_compressed_jpegs[i]
        regex = li.gsub(/png;base64,.*(?=\")/, "jpg;base64,#{jpeg_index}")
        File.open(output_SVG, 'a') { |f| f.write(regex) }
          i = i + 1
        else File.open(output_SVG, 'a') { |f| f.write(li) }
        end
    end

    # original SVG size, end SVG size
    osize = (File.size(file_name).to_f / 1024).round(2)
    esize = (File.size(output_SVG).to_f / 1024).round(2)

    puts "DONE. " + file_name.to_s + " - " + osize.to_s + " KB --> " + esize.to_s + " KB"
    puts "Filesize (before SVG compression) reduced by " + (osize - esize).round(2).to_s + " KB. (" + ( 100 - (esize / osize) * 100).round(2).to_s + "%).\n\n"

    if backup == true
      Dir.mkdir(budir) unless File.exists?(budir)
      t = (Time.now.to_f * 1000).to_i.to_s
      FileUtils.cp(file_name, budir + t + "-" + file_name)
      else
        File.delete(file_name)
    end
    File.rename(output_SVG, file_name)
    formatted = svgo.optimize_images_data(File.read(file_name))
    File.open(file_name, 'w') { |f| f.write(formatted)}
  else
    puts "No embedded PNGs found, skipping " + file_name
  end
end