serve

# File actionpack/lib/action_dispatch/middleware/static.rb, line 54
    def serve(request)
      path      = request.path_info
      gzip_path = gzip_file_path(path)

      if gzip_path && gzip_encoding_accepted?(request)
        request.path_info           = gzip_path
        status, headers, body       = @file_server.call(request.env)
        if status == 304
          return [status, headers, body]
        end
        headers["Content-Encoding"] = "gzip"
        headers["Content-Type"]     = content_type(path)
      else
        status, headers, body = @file_server.call(request.env)
      end

      headers["Vary"] = "Accept-Encoding" if gzip_path

      return [status, headers, body]
    ensure
      request.path_info = path
    end