Typhoeus batch download with fibers (Ruby 1.9)

@@hydra ||= Typhoeus::Hydra.new( max_concurrency: 100 )

def batch_download(pages)
  fibers = pages.map(&:uncached_download_fiber).compact
  requests = fibers.map(&:resume)
  requests.each {|req| @@hydra.queue req }
  @@hydra.run
  requests.map.with_index {|req,i| fibers[i].resume(req.response) }
end

def uncached_download_fiber
  cached? ? nil : process_markup
end

def process_markup
  request = Typhoeus::Request.new(url)
  Fiber.new do
    response = Fiber.yield(request)
    response.code == 200 and File.open(file_path, 'w') {|f| f.puts(remote_markup) }
  end
end