Optimize path helpers.

4 files changed, 67 insertions, 13 deletions

diff --git a/actionpack/lib/action_dispatch/http/url.rb b/actionpack/lib/action_dispatch/http/url.rb
index 80ffbe575b..f9dae5dad7 100644
--- a/actionpack/lib/action_dispatch/http/url.rb
+++ b/actionpack/lib/action_dispatch/http/url.rb
@@ -40,7 +40,9 @@ module ActionDispatch
             rewritten_url << ":#{options.delete(:port)}" if options[:port]
           end
 
-          path = options.delete(:path) || ''
+          path = ""
+          path << options.delete(:script_name).to_s.chomp("/")
+          path << options.delete(:path).to_s
 
           params = options[:params] || {}
           params.reject! {|k,v| v.to_param.nil? }
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index 02a27110e4..80fcdab643 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -446,7 +446,11 @@ module ActionDispatch
             _route = @set.named_routes.routes[name.to_sym]
             _routes = @set
             app.routes.define_mounted_helper(name)
-            app.routes.class_eval do
+            app.routes.singleton_class.class_eval do
+              define_method :mounted? do
+                true
+              end
+
               define_method :_generate_prefix do |options|
                 prefix_options = options.slice(*_route.segment_keys)
                 # we must actually delete prefix segment keys to avoid passing them to next url_for
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index 0ec4e41470..0e5bf46ee4 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -191,14 +191,55 @@ module ActionDispatch
             selector = url_helper_name(name, kind)
             hash_access_method = hash_access_name(name, kind)
 
-            @module.module_eval <<-END_EVAL, __FILE__, __LINE__ + 1
-              remove_possible_method :#{selector}
-              def #{selector}(*args)
-                url_for(#{hash_access_method}(*args))
-              end
-            END_EVAL
+            if optimize_helper?(kind, route)
+              @module.module_eval <<-END_EVAL, __FILE__, __LINE__ + 1
+                remove_possible_method :#{selector}
+                def #{selector}(*args)
+                  if args.size == #{route.required_parts.size} && !args.last.is_a?(Hash) && _optimized_routes?
+                    options = #{options.inspect}.merge!(url_options)
+                    options[:path] = "#{optimized_helper(route)}"
+                    ActionDispatch::Http::URL.url_for(options)
+                  else
+                    url_for(#{hash_access_method}(*args))
+                  end
+                end
+              END_EVAL
+            else
+              @module.module_eval <<-END_EVAL, __FILE__, __LINE__ + 1
+                remove_possible_method :#{selector}
+                def #{selector}(*args)
+                  url_for(#{hash_access_method}(*args))
+                end
+              END_EVAL
+            end
+
             helpers << selector
           end
+
+          # If we are generating a path helper and we don't have a *path segment.
+          # We can optimize the routes generation to a string interpolation if
+          # it meets the appropriated runtime conditions.
+          #
+          # TODO We are enabling this only for path helpers, remove the
+          # kind == :path and fix the failures to enable it for url as well.
+          def optimize_helper?(kind, route) #:nodoc:
+            kind == :path && route.ast.grep(Journey::Nodes::Star).empty?
+          end
+
+          # Generates the interpolation to be used in the optimized helper.
+          def optimized_helper(route)
+            string_route = route.ast.to_s
+
+            while string_route.gsub!(/\([^\)]*\)/, "")
+              true
+            end
+
+            route.required_parts.each_with_index do |part, i|
+              string_route.gsub!(part.inspect, "\#{Journey::Router::Utils.escape_fragment(args[#{i}].to_param)}")
+            end
+
+            string_route
+          end
       end
 
       attr_accessor :formatter, :set, :named_routes, :default_scope, :router
@@ -557,6 +598,10 @@ module ActionDispatch
       RESERVED_OPTIONS = [:host, :protocol, :port, :subdomain, :domain, :tld_length,
                           :trailing_slash, :anchor, :params, :only_path, :script_name]
 
+      def mounted?
+        false
+      end
+
       def _generate_prefix(options = {})
         nil
       end
@@ -568,19 +613,17 @@ module ActionDispatch
 
         user, password = extract_authentication(options)
         path_segments  = options.delete(:_path_segments)
-        script_name    = options.delete(:script_name)
-
-        path = (script_name.blank? ? _generate_prefix(options) : script_name.chomp('/')).to_s
+        script_name    = options.delete(:script_name).presence || _generate_prefix(options)
 
         path_options = options.except(*RESERVED_OPTIONS)
         path_options = yield(path_options) if block_given?
 
-        path_addition, params = generate(path_options, path_segments || {})
-        path << path_addition
+        path, params = generate(path_options, path_segments || {})
         params.merge!(options[:params] || {})
 
         ActionDispatch::Http::URL.url_for(options.merge!({
           :path => path,
+          :script_name => script_name,
           :params => params,
           :user => user,
           :password => password
diff --git a/actionpack/lib/action_dispatch/routing/url_for.rb b/actionpack/lib/action_dispatch/routing/url_for.rb
index ee6616c5d3..191a2cb995 100644
--- a/actionpack/lib/action_dispatch/routing/url_for.rb
+++ b/actionpack/lib/action_dispatch/routing/url_for.rb
@@ -152,6 +152,11 @@ module ActionDispatch
 
       protected
 
+      def _optimized_routes?
+        return @_optimized_routes if defined?(@_optimized_routes)
+        @_optimized_routes = default_url_options.empty? && !_routes.mounted? && _routes.default_url_options.empty?
+      end
+
       def _with_routes(routes)
         old_routes, @_routes = @_routes, routes
         yield