Yet a cache generator for rubyonrails

machine_gun.rb

# encoding: utf-8

require 'fileutils'

class MachineGun
  class_attribute :page_cache_extension
  self.page_cache_extension ||= '.html'

  class_attribute :page_cache_directory
  self.page_cache_directory ||= File.join(Rails.root, "public")

  class << self
    def touch klass, action, options = {}
      path_info = url_for(klass.controller_path, action, options[:params] || {})

      env = {
        "rack.input"     => StringIO.new(""),
        "REQUEST_METHOD" => "GET",
        "PATH_INFO"      => path_info,
        "QUERY_STRING"   => ""
      }

      status, headers, body = klass.action(action).call env

      if status == 200
        write_cache_page body, path_info
      else
        raise "request error!"
      end
      status
    end

    def url_for controller, action, params = {}
      options = {
        :controller => controller,
        :action     => action,
        :only_path  => true
      }.merge(params)

      Rails.application.routes.url_for options
    end

    private

    def write_cache_page(content, path, extension = nil, gzip = Zlib::BEST_COMPRESSION)
      path = page_cache_path(path, extension)

      FileUtils.makedirs(File.dirname(path))
      File.open(path, "wb+") { |f| f.write(content) }
      if gzip
        Zlib::GzipWriter.open(path + '.gz', gzip) { |f| f.write(content) }
      end
    end

    def page_cache_file(path, extension)
      name = (path.empty? || path == "/") ? "/index" : URI.parser.unescape(path.chomp('/'))
      unless (name.split('/').last || name).include? '.'
        name << (extension || self.page_cache_extension)
      end
      return name
    end

    def page_cache_path(path, extension = nil)
      page_cache_directory.to_s + page_cache_file(path, extension)
    end
  end
end