parallel_assets_compiler.gemspec

# -*- encoding: utf-8 -*-

Gem::Specification.new do |s|
  s.name        = 'parallel_assets_compiler'
  s.version     = '0.2.0'
  s.platform    = Gem::Platform::RUBY
  s.author      = 'Jørgen Orehøj Erichsen'
  s.email       = 'joe@erichsen.net'
  s.summary     = 'Compile assets in parallel'
  s.description = 'Compile assets in parallel to speed up deployment'

  s.files         = ['parallel_assets_compiler.rb']
  s.require_path  = '.'

  s.add_dependency('parallel')
  s.add_dependency('actionpack')
end

parallel_assets_compiler.rb

# Compile assets in parallel to speed up deployment
#
# Works by monkey patching to sprockets-rails 2.0.0 (for Rails 4.0.0)
#
# Use it by adding this to your Gemfile and run bundle install
#
# gem 'parallel_assets_compiler', :git => 'git://gist.github.com/2873091.git'
#
# Inspired by
# https://gist.github.com/joerichsen/2873091
# https://github.com/steel/sprockets/commit/6327afc3341e34efd1dfdcfad08e3b9d85f7fd4a
# https://github.com/hornairs/sprockets-rails-parallel

require 'sprockets/manifest'
require 'parallel'

module Sprockets
  class Manifest
    def compile(*args)
      raise Error, "manifest requires environment for compilation" unless environment

      paths = environment.each_logical_path(*args).to_a +
        args.flatten.select { |fn| Pathname.new(fn).absolute? if fn.is_a?(String)}

      local_assets = []
      paths.each do |path|
        if asset = find_asset(path)
          files[asset.digest_path] = {
            'logical_path' => asset.logical_path,
            'mtime'        => asset.mtime.iso8601,
            'size'         => asset.bytesize,
            'digest'       => asset.digest
          }
          assets[asset.logical_path] = asset.digest_path
          local_assets << asset
        end
      end

      Parallel.each(local_assets) do |asset|
        target = File.join(dir, asset.digest_path)

        if File.exist?(target)
          logger.debug "Skipping #{target}, already exists"
        else
          logger.info "Writing #{target}"
          asset.write_to target
          asset.write_to "#{target}.gz" if asset.is_a?(BundledAsset)
        end

        save
      end
    end
  end
end