1 files changed, 153 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/journey/router.rb b/actionpack/lib/action_dispatch/journey/router.rb
new file mode 100644
index 0000000000..89a164f968
--- /dev/null
+++ b/actionpack/lib/action_dispatch/journey/router.rb
@@ -0,0 +1,153 @@
+# frozen_string_literal: true
+
+require "action_dispatch/journey/router/utils"
+require "action_dispatch/journey/routes"
+require "action_dispatch/journey/formatter"
+
+before = $-w
+$-w = false
+require "action_dispatch/journey/parser"
+$-w = before
+
+require "action_dispatch/journey/route"
+require "action_dispatch/journey/path/pattern"
+
+module ActionDispatch
+  module Journey # :nodoc:
+    class Router # :nodoc:
+      attr_accessor :routes
+
+      def initialize(routes)
+        @routes = routes
+      end
+
+      def eager_load!
+        # Eagerly trigger the simulator's initialization so
+        # it doesn't happen during a request cycle.
+        simulator
+        nil
+      end
+
+      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
+
+          parameters = route.defaults.merge parameters.transform_values { |val|
+            val.dup.force_encoding(::Encoding::UTF_8)
+          }
+
+          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
+
+        [404, { "X-Cascade" => "pass" }, ["Not Found"]]
+      end
+
+      def recognize(rails_req)
+        find_routes(rails_req).each do |match, parameters, route|
+          unless route.path.anchored
+            rails_req.script_name = match.to_s
+            rails_req.path_info   = match.post_match.sub(/^([^\/])/, '/\1')
+          end
+
+          parameters = route.defaults.merge parameters
+          yield(route, parameters)
+        end
+      end
+
+      def visualizer
+        tt     = GTG::Builder.new(ast).transition_table
+        groups = partitioned_routes.first.map(&:ast).group_by(&:to_s)
+        asts   = groups.values.map(&:first)
+        tt.visualizer(asts)
+      end
+
+      private
+
+        def partitioned_routes
+          routes.partition { |r|
+            r.path.anchored && r.ast.grep(Nodes::Symbol).all? { |n| n.default_regexp?  }
+          }
+        end
+
+        def ast
+          routes.ast
+        end
+
+        def simulator
+          routes.simulator
+        end
+
+        def custom_routes
+          routes.custom_routes
+        end
+
+        def filter_routes(path)
+          return [] unless ast
+          simulator.memos(path) { [] }
+        end
+
+        def find_routes(req)
+          routes = filter_routes(req.path_info).concat custom_routes.find_all { |r|
+            r.path.match(req.path_info)
+          }
+
+          routes =
+            if req.head?
+              match_head_routes(routes, req)
+            else
+              match_routes(routes, req)
+            end
+
+          routes.sort_by!(&:precedence)
+
+          routes.map! { |r|
+            match_data = r.path.match(req.path_info)
+            path_parameters = {}
+            match_data.names.zip(match_data.captures) { |name, val|
+              path_parameters[name.to_sym] = Utils.unescape_uri(val) if val
+            }
+            [match_data, path_parameters, r]
+          }
+        end
+
+        def match_head_routes(routes, req)
+          verb_specific_routes = routes.select(&:requires_matching_verb?)
+          head_routes = match_routes(verb_specific_routes, req)
+
+          if head_routes.empty?
+            begin
+              req.request_method = "GET"
+              match_routes(routes, req)
+            ensure
+              req.request_method = "HEAD"
+            end
+          else
+            head_routes
+          end
+        end
+
+        def match_routes(routes, req)
+          routes.select { |r| r.matches?(req) }
+        end
+    end
+  end
+end