serve

# File actionpack/lib/action_dispatch/journey/router.rb, line 25
      def serve(req)
        find_routes(req).each do |match, parameters, route|
          set_params  = req.path_parameters
          path_info   = req.path_info
          script_name = req.script_name

          unless route.path.anchored
            req.script_name = (script_name.to_s + match.to_s).chomp('/')
            req.path_info = match.post_match
            req.path_info = "/" + req.path_info unless req.path_info.start_with? "/"
          end

          req.path_parameters = set_params.merge parameters

          status, headers, body = route.app.serve(req)

          if 'pass' == headers['X-Cascade']
            req.script_name     = script_name
            req.path_info       = path_info
            req.path_parameters = set_params
            next
          end

          return [status, headers, body]
        end

        return [404, {'X-Cascade' => 'pass'}, ['Not Found']]
      end