gistfile1.rb

      return nil if uploaded_file.nil?
      extension = File.extname(uploaded_file.original_filename).downcase
      @queued_for_write[:original]   = to_tempfile(uploaded_file)
      instance_write(:file_name,       "#{Time.now.strftime("%Y%m%d%H%M%S")}#{rand(1000)}#{extension}")
      instance_write(:content_type,    uploaded_file.content_type.to_s.strip)
      instance_write(:file_size,       uploaded_file.size.to_i)
      instance_write(:fingerprint,     generate_fingerprint(uploaded_file))
      instance_write(:updated_at,      Time.now)