Restructure routing into several smaller files. References #10835 [oleganza]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8652 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

6 files changed, 1309 insertions, 0 deletions

diff --git a/actionpack/lib/action_controller/routing/builder.rb b/actionpack/lib/action_controller/routing/builder.rb
new file mode 100644
index 0000000000..69943d4230
--- /dev/null
+++ b/actionpack/lib/action_controller/routing/builder.rb
@@ -0,0 +1,197 @@
+module ActionController
+  module Routing
+    class RouteBuilder #:nodoc:
+      attr_accessor :separators, :optional_separators
+
+      def initialize
+        self.separators = Routing::SEPARATORS
+        self.optional_separators = %w( / )
+      end
+
+      def separator_pattern(inverted = false)
+        "[#{'^' if inverted}#{Regexp.escape(separators.join)}]"
+      end
+
+      def interval_regexp
+        Regexp.new "(.*?)(#{separators.source}|$)"
+      end
+
+      # Accepts a "route path" (a string defining a route), and returns the array
+      # of segments that corresponds to it. Note that the segment array is only
+      # partially initialized--the defaults and requirements, for instance, need
+      # to be set separately, via the #assign_route_options method, and the
+      # #optional? method for each segment will not be reliable until after
+      # #assign_route_options is called, as well.
+      def segments_for_route_path(path)
+        rest, segments = path, []
+
+        until rest.empty?
+          segment, rest = segment_for rest
+          segments << segment
+        end
+        segments
+      end
+
+      # A factory method that returns a new segment instance appropriate for the
+      # format of the given string.
+      def segment_for(string)
+        segment = case string
+          when /\A:(\w+)/
+            key = $1.to_sym
+            case key
+              when :controller then ControllerSegment.new(key)
+              else DynamicSegment.new key
+            end
+          when /\A\*(\w+)/ then PathSegment.new($1.to_sym, :optional => true)
+          when /\A\?(.*?)\?/
+            returning segment = StaticSegment.new($1) do
+              segment.is_optional = true
+            end
+          when /\A(#{separator_pattern(:inverted)}+)/ then StaticSegment.new($1)
+          when Regexp.new(separator_pattern) then
+            returning segment = DividerSegment.new($&) do
+              segment.is_optional = (optional_separators.include? $&)
+            end
+        end
+        [segment, $~.post_match]
+      end
+
+      # Split the given hash of options into requirement and default hashes. The
+      # segments are passed alongside in order to distinguish between default values
+      # and requirements.
+      def divide_route_options(segments, options)
+        options = options.dup
+
+        if options[:namespace]
+          options[:controller] = "#{options[:path_prefix]}/#{options[:controller]}"
+          options.delete(:path_prefix)
+          options.delete(:name_prefix)
+          options.delete(:namespace)
+        end
+
+        requirements = (options.delete(:requirements) || {}).dup
+        defaults     = (options.delete(:defaults)     || {}).dup
+        conditions   = (options.delete(:conditions)   || {}).dup
+
+        path_keys = segments.collect { |segment| segment.key if segment.respond_to?(:key) }.compact
+        options.each do |key, value|
+          hash = (path_keys.include?(key) && ! value.is_a?(Regexp)) ? defaults : requirements
+          hash[key] = value
+        end
+
+        [defaults, requirements, conditions]
+      end
+
+      # Takes a hash of defaults and a hash of requirements, and assigns them to
+      # the segments. Any unused requirements (which do not correspond to a segment)
+      # are returned as a hash.
+      def assign_route_options(segments, defaults, requirements)
+        route_requirements = {} # Requirements that do not belong to a segment
+
+        segment_named = Proc.new do |key|
+          segments.detect { |segment| segment.key == key if segment.respond_to?(:key) }
+        end
+
+        requirements.each do |key, requirement|
+          segment = segment_named[key]
+          if segment
+            raise TypeError, "#{key}: requirements on a path segment must be regular expressions" unless requirement.is_a?(Regexp)
+            if requirement.source =~ %r{\A(\\A|\^)|(\\Z|\\z|\$)\Z}
+              raise ArgumentError, "Regexp anchor characters are not allowed in routing requirements: #{requirement.inspect}"
+            end
+            segment.regexp = requirement
+          else
+            route_requirements[key] = requirement
+          end
+        end
+
+        defaults.each do |key, default|
+          segment = segment_named[key]
+          raise ArgumentError, "#{key}: No matching segment exists; cannot assign default" unless segment
+          segment.is_optional = true
+          segment.default = default.to_param if default
+        end
+
+        assign_default_route_options(segments)
+        ensure_required_segments(segments)
+        route_requirements
+      end
+
+      # Assign default options, such as 'index' as a default for :action. This
+      # method must be run *after* user supplied requirements and defaults have
+      # been applied to the segments.
+      def assign_default_route_options(segments)
+        segments.each do |segment|
+          next unless segment.is_a? DynamicSegment
+          case segment.key
+            when :action
+              if segment.regexp.nil? || segment.regexp.match('index').to_s == 'index'
+                segment.default ||= 'index'
+                segment.is_optional = true
+              end
+            when :id
+              if segment.default.nil? && segment.regexp.nil? || segment.regexp =~ ''
+                segment.is_optional = true
+              end
+          end
+        end
+      end
+
+      # Makes sure that there are no optional segments that precede a required
+      # segment. If any are found that precede a required segment, they are
+      # made required.
+      def ensure_required_segments(segments)
+        allow_optional = true
+        segments.reverse_each do |segment|
+          allow_optional &&= segment.optional?
+          if !allow_optional && segment.optional?
+            unless segment.optionality_implied?
+              warn "Route segment \"#{segment.to_s}\" cannot be optional because it precedes a required segment. This segment will be required."
+            end
+            segment.is_optional = false
+          elsif allow_optional && segment.respond_to?(:default) && segment.default
+            # if a segment has a default, then it is optional
+            segment.is_optional = true
+          end
+        end
+      end
+
+      # Construct and return a route with the given path and options.
+      def build(path, options)
+        # Wrap the path with slashes
+        path = "/#{path}" unless path[0] == ?/
+        path = "#{path}/" unless path[-1] == ?/
+
+        path = "/#{options[:path_prefix].to_s.gsub(/^\//,'')}#{path}" if options[:path_prefix]
+
+        segments = segments_for_route_path(path)
+        defaults, requirements, conditions = divide_route_options(segments, options)
+        requirements = assign_route_options(segments, defaults, requirements)
+
+        route = Route.new
+
+        route.segments = segments
+        route.requirements = requirements
+        route.conditions = conditions
+
+        if !route.significant_keys.include?(:action) && !route.requirements[:action]
+          route.requirements[:action] = "index"
+          route.significant_keys << :action
+        end
+
+        # Routes cannot use the current string interpolation method
+        # if there are user-supplied :requirements as the interpolation
+        # code won't raise RoutingErrors when generating
+        if options.key?(:requirements) || route.requirements.keys.to_set != Routing::ALLOWED_REQUIREMENTS_FOR_OPTIMISATION
+          route.optimise = false
+        end
+
+        if !route.significant_keys.include?(:controller)
+          raise ArgumentError, "Illegal route: the :controller must be specified!"
+        end
+
+        route
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/actionpack/lib/action_controller/routing/optimisations.rb b/actionpack/lib/action_controller/routing/optimisations.rb
new file mode 100644
index 0000000000..ba4aeb4e82
--- /dev/null
+++ b/actionpack/lib/action_controller/routing/optimisations.rb
@@ -0,0 +1,119 @@
+module ActionController
+  module Routing
+    # Much of the slow performance from routes comes from the 
+    # complexity of expiry, :requirements matching, defaults providing
+    # and figuring out which url pattern to use.  With named routes 
+    # we can avoid the expense of finding the right route.  So if 
+    # they've provided the right number of arguments, and have no
+    # :requirements, we can just build up a string and return it.
+    # 
+    # To support building optimisations for other common cases, the 
+    # generation code is separated into several classes 
+    module Optimisation
+      def generate_optimisation_block(route, kind)
+        return "" unless route.optimise?
+        OPTIMISERS.inject("") do |memo, klazz|
+          memo << klazz.new(route, kind).source_code
+          memo
+        end
+      end
+
+      class Optimiser
+        attr_reader :route, :kind
+        def initialize(route, kind)
+          @route = route
+          @kind  = kind
+        end
+
+        def guard_condition
+          'false'
+        end
+
+        def generation_code
+          'nil'
+        end
+
+        def source_code
+          if applicable?
+            "return #{generation_code} if #{guard_condition}\n"
+          else
+            "\n"
+          end
+        end
+
+        # Temporarily disabled :url optimisation pending proper solution to 
+        # Issues around request.host etc.
+        def applicable?
+          true
+        end
+      end
+
+      # Given a route:
+      # map.person '/people/:id'
+      #
+      # If the user calls person_url(@person), we can simply
+      # return a string like "/people/#{@person.to_param}" 
+      # rather than triggering the expensive logic in url_for
+      class PositionalArguments < Optimiser
+        def guard_condition
+          number_of_arguments = route.segment_keys.size
+          # if they're using foo_url(:id=>2) it's one 
+          # argument, but we don't want to generate /foos/id2
+          if number_of_arguments == 1
+            "defined?(request) && request && args.size == 1 && !args.first.is_a?(Hash)"
+          else
+            "defined?(request) && request && args.size == #{number_of_arguments}"
+          end
+        end
+
+        def generation_code
+          elements = []
+          idx = 0
+
+          if kind == :url
+            elements << '#{request.protocol}'
+            elements << '#{request.host_with_port}'
+          end
+
+          elements << '#{request.relative_url_root if request.relative_url_root}'
+
+          # The last entry in route.segments appears to # *always* be a
+          # 'divider segment' for '/' but we have assertions to ensure that
+          # we don't include the trailing slashes, so skip them.
+          (route.segments.size == 1 ? route.segments : route.segments[0..-2]).each do |segment|
+            if segment.is_a?(DynamicSegment)
+              elements << segment.interpolation_chunk("args[#{idx}].to_param")
+              idx += 1
+            else
+              elements << segment.interpolation_chunk
+            end
+          end
+          %("#{elements * ''}")
+        end
+      end
+
+      # This case is mostly the same as the positional arguments case
+      # above, but it supports additional query parameters as the last 
+      # argument
+      class PositionalArgumentsWithAdditionalParams < PositionalArguments
+        def guard_condition
+          "defined?(request) && request && args.size == #{route.segment_keys.size + 1} && !args.last.has_key?(:anchor) && !args.last.has_key?(:port) && !args.last.has_key?(:host)"
+        end
+
+        # This case uses almost the same code as positional arguments, 
+        # but add an args.last.to_query on the end
+        def generation_code
+          super.insert(-2, '?#{args.last.to_query}')
+        end
+
+        # To avoid generating http://localhost/?host=foo.example.com we
+        # can't use this optimisation on routes without any segments
+        def applicable?
+          super && route.segment_keys.size > 0 
+        end
+      end
+
+      OPTIMISERS = [PositionalArguments, PositionalArgumentsWithAdditionalParams]
+    end
+  end
+end
diff --git a/actionpack/lib/action_controller/routing/route.rb b/actionpack/lib/action_controller/routing/route.rb
new file mode 100644
index 0000000000..94134a284e
--- /dev/null
+++ b/actionpack/lib/action_controller/routing/route.rb
@@ -0,0 +1,240 @@
+module ActionController
+  module Routing
+    class Route #:nodoc:
+      attr_accessor :segments, :requirements, :conditions, :optimise
+
+      def initialize
+        @segments = []
+        @requirements = {}
+        @conditions = {}
+        @optimise = true
+      end
+
+      # Indicates whether the routes should be optimised with the string interpolation
+      # version of the named routes methods.
+      def optimise?
+        @optimise && ActionController::Base::optimise_named_routes
+      end
+
+      def segment_keys
+        segments.collect do |segment|
+          segment.key if segment.respond_to? :key
+        end.compact
+      end
+
+      # Write and compile a +generate+ method for this Route.
+      def write_generation
+        # Build the main body of the generation
+        body = "expired = false\n#{generation_extraction}\n#{generation_structure}"
+
+        # If we have conditions that must be tested first, nest the body inside an if
+        body = "if #{generation_requirements}\n#{body}\nend" if generation_requirements
+        args = "options, hash, expire_on = {}"
+
+        # Nest the body inside of a def block, and then compile it.
+        raw_method = method_decl = "def generate_raw(#{args})\npath = begin\n#{body}\nend\n[path, hash]\nend"
+        instance_eval method_decl, "generated code (#{__FILE__}:#{__LINE__})"
+
+        # expire_on.keys == recall.keys; in other words, the keys in the expire_on hash
+        # are the same as the keys that were recalled from the previous request. Thus,
+        # we can use the expire_on.keys to determine which keys ought to be used to build
+        # the query string. (Never use keys from the recalled request when building the
+        # query string.)
+
+        method_decl = "def generate(#{args})\npath, hash = generate_raw(options, hash, expire_on)\nappend_query_string(path, hash, extra_keys(options))\nend"
+        instance_eval method_decl, "generated code (#{__FILE__}:#{__LINE__})"
+
+        method_decl = "def generate_extras(#{args})\npath, hash = generate_raw(options, hash, expire_on)\n[path, extra_keys(options)]\nend"
+        instance_eval method_decl, "generated code (#{__FILE__}:#{__LINE__})"
+        raw_method
+      end
+
+      # Build several lines of code that extract values from the options hash. If any
+      # of the values are missing or rejected then a return will be executed.
+      def generation_extraction
+        segments.collect do |segment|
+          segment.extraction_code
+        end.compact * "\n"
+      end
+
+      # Produce a condition expression that will check the requirements of this route
+      # upon generation.
+      def generation_requirements
+        requirement_conditions = requirements.collect do |key, req|
+          if req.is_a? Regexp
+            value_regexp = Regexp.new "\\A#{req.source}\\Z"
+            "hash[:#{key}] && #{value_regexp.inspect} =~ options[:#{key}]"
+          else
+            "hash[:#{key}] == #{req.inspect}"
+          end
+        end
+        requirement_conditions * ' && ' unless requirement_conditions.empty?
+      end
+
+      def generation_structure
+        segments.last.string_structure segments[0..-2]
+      end
+
+      # Write and compile a +recognize+ method for this Route.
+      def write_recognition
+        # Create an if structure to extract the params from a match if it occurs.
+        body = "params = parameter_shell.dup\n#{recognition_extraction * "\n"}\nparams"
+        body = "if #{recognition_conditions.join(" && ")}\n#{body}\nend"
+
+        # Build the method declaration and compile it
+        method_decl = "def recognize(path, env={})\n#{body}\nend"
+        instance_eval method_decl, "generated code (#{__FILE__}:#{__LINE__})"
+        method_decl
+      end
+
+      # Plugins may override this method to add other conditions, like checks on
+      # host, subdomain, and so forth. Note that changes here only affect route
+      # recognition, not generation.
+      def recognition_conditions
+        result = ["(match = #{Regexp.new(recognition_pattern).inspect}.match(path))"]
+        result << "conditions[:method] === env[:method]" if conditions[:method]
+        result
+      end
+
+      # Build the regular expression pattern that will match this route.
+      def recognition_pattern(wrap = true)
+        pattern = ''
+        segments.reverse_each do |segment|
+          pattern = segment.build_pattern pattern
+        end
+        wrap ? ("\\A" + pattern + "\\Z") : pattern
+      end
+
+      # Write the code to extract the parameters from a matched route.
+      def recognition_extraction
+        next_capture = 1
+        extraction = segments.collect do |segment|
+          x = segment.match_extraction(next_capture)
+          next_capture += Regexp.new(segment.regexp_chunk).number_of_captures
+          x
+        end
+        extraction.compact
+      end
+
+      # Write the real generation implementation and then resend the message.
+      def generate(options, hash, expire_on = {})
+        write_generation
+        generate options, hash, expire_on
+      end
+
+      def generate_extras(options, hash, expire_on = {})
+        write_generation
+        generate_extras options, hash, expire_on
+      end
+
+      # Generate the query string with any extra keys in the hash and append
+      # it to the given path, returning the new path.
+      def append_query_string(path, hash, query_keys=nil)
+        return nil unless path
+        query_keys ||= extra_keys(hash)
+        "#{path}#{build_query_string(hash, query_keys)}"
+      end
+
+      # Determine which keys in the given hash are "extra". Extra keys are
+      # those that were not used to generate a particular route. The extra
+      # keys also do not include those recalled from the prior request, nor
+      # do they include any keys that were implied in the route (like a
+      # :controller that is required, but not explicitly used in the text of
+      # the route.)
+      def extra_keys(hash, recall={})
+        (hash || {}).keys.map { |k| k.to_sym } - (recall || {}).keys - significant_keys
+      end
+
+      # Build a query string from the keys of the given hash. If +only_keys+
+      # is given (as an array), only the keys indicated will be used to build
+      # the query string. The query string will correctly build array parameter
+      # values.
+      def build_query_string(hash, only_keys = nil)
+        elements = []
+
+        (only_keys || hash.keys).each do |key|
+          if value = hash[key]
+            elements << value.to_query(key)
+          end
+        end
+
+        elements.empty? ? '' : "?#{elements.sort * '&'}"
+      end
+
+      # Write the real recognition implementation and then resend the message.
+      def recognize(path, environment={})
+        write_recognition
+        recognize path, environment
+      end
+
+      # A route's parameter shell contains parameter values that are not in the
+      # route's path, but should be placed in the recognized hash.
+      #
+      # For example, +{:controller => 'pages', :action => 'show'} is the shell for the route:
+      #
+      #   map.connect '/page/:id', :controller => 'pages', :action => 'show', :id => /\d+/
+      #
+      def parameter_shell
+        @parameter_shell ||= returning({}) do |shell|
+          requirements.each do |key, requirement|
+            shell[key] = requirement unless requirement.is_a? Regexp
+          end
+        end
+      end
+
+      # Return an array containing all the keys that are used in this route. This
+      # includes keys that appear inside the path, and keys that have requirements
+      # placed upon them.
+      def significant_keys
+        @significant_keys ||= returning [] do |sk|
+          segments.each { |segment| sk << segment.key if segment.respond_to? :key }
+          sk.concat requirements.keys
+          sk.uniq!
+        end
+      end
+
+      # Return a hash of key/value pairs representing the keys in the route that
+      # have defaults, or which are specified by non-regexp requirements.
+      def defaults
+        @defaults ||= returning({}) do |hash|
+          segments.each do |segment|
+            next unless segment.respond_to? :default
+            hash[segment.key] = segment.default unless segment.default.nil?
+          end
+          requirements.each do |key,req|
+            next if Regexp === req || req.nil?
+            hash[key] = req
+          end
+        end
+      end
+
+      def matches_controller_and_action?(controller, action)
+        unless defined? @matching_prepared
+          @controller_requirement = requirement_for(:controller)
+          @action_requirement = requirement_for(:action)
+          @matching_prepared = true
+        end
+
+        (@controller_requirement.nil? || @controller_requirement === controller) &&
+        (@action_requirement.nil? || @action_requirement === action)
+      end
+
+      def to_s
+        @to_s ||= begin
+          segs = segments.inject("") { |str,s| str << s.to_s }
+          "%-6s %-40s %s" % [(conditions[:method] || :any).to_s.upcase, segs, requirements.inspect]
+        end
+      end
+
+    protected
+      def requirement_for(key)
+        return requirements[key] if requirements.key? key
+        segments.each do |segment|
+          return segment.regexp if segment.respond_to?(:key) && segment.key == key
+        end
+        nil
+      end
+
+    end
+  end
+end
\ No newline at end of file
diff --git a/actionpack/lib/action_controller/routing/route_set.rb b/actionpack/lib/action_controller/routing/route_set.rb
new file mode 100644
index 0000000000..83903aff85
--- /dev/null
+++ b/actionpack/lib/action_controller/routing/route_set.rb
@@ -0,0 +1,439 @@
+module ActionController
+  module Routing
+    class RouteSet #:nodoc: 
+      # Mapper instances are used to build routes. The object passed to the draw
+      # block in config/routes.rb is a Mapper instance.
+      #
+      # Mapper instances have relatively few instance methods, in order to avoid
+      # clashes with named routes.
+      class Mapper #:doc:
+        def initialize(set) #:nodoc:
+          @set = set
+        end
+
+        # Create an unnamed route with the provided +path+ and +options+. See
+        # ActionController::Routing for an introduction to routes.
+        def connect(path, options = {})
+          @set.add_route(path, options)
+        end
+
+        # Creates a named route called "root" for matching the root level request.
+        def root(options = {})
+          named_route("root", '', options)
+        end
+
+        def named_route(name, path, options = {}) #:nodoc:
+          @set.add_named_route(name, path, options)
+        end
+
+        # Enables the use of resources in a module by setting the name_prefix, path_prefix, and namespace for the model.
+        # Example:
+        #
+        #   map.namespace(:admin) do |admin|
+        #     admin.resources :products,
+        #       :has_many => [ :tags, :images, :variants ]
+        #   end
+        #
+        # This will create +admin_products_url+ pointing to "admin/products", which will look for an Admin::ProductsController.
+        # It'll also create +admin_product_tags_url+ pointing to "admin/products/#{product_id}/tags", which will look for
+        # Admin::TagsController.
+        def namespace(name, options = {}, &block)
+          if options[:namespace]
+            with_options({:path_prefix => "#{options.delete(:path_prefix)}/#{name}", :name_prefix => "#{options.delete(:name_prefix)}#{name}_", :namespace => "#{options.delete(:namespace)}#{name}/" }.merge(options), &block)
+          else
+            with_options({:path_prefix => name, :name_prefix => "#{name}_", :namespace => "#{name}/" }.merge(options), &block)
+          end
+        end
+
+        def method_missing(route_name, *args, &proc) #:nodoc:
+          super unless args.length >= 1 && proc.nil?
+          @set.add_named_route(route_name, *args)
+        end
+      end
+
+      # A NamedRouteCollection instance is a collection of named routes, and also
+      # maintains an anonymous module that can be used to install helpers for the
+      # named routes.
+      class NamedRouteCollection #:nodoc:
+        include Enumerable
+        include ActionController::Routing::Optimisation
+        attr_reader :routes, :helpers
+
+        def initialize
+          clear!
+        end
+
+        def clear!
+          @routes = {}
+          @helpers = []
+
+          @module ||= Module.new
+          @module.instance_methods.each do |selector|
+            @module.class_eval { remove_method selector }
+          end
+        end
+
+        def add(name, route)
+          routes[name.to_sym] = route
+          define_named_route_methods(name, route)
+        end
+
+        def get(name)
+          routes[name.to_sym]
+        end
+
+        alias []=   add
+        alias []    get
+        alias clear clear!
+
+        def each
+          routes.each { |name, route| yield name, route }
+          self
+        end
+
+        def names
+          routes.keys
+        end
+
+        def length
+          routes.length
+        end
+
+        def reset!
+          old_routes = routes.dup
+          clear!
+          old_routes.each do |name, route|
+            add(name, route)
+          end
+        end
+
+        def install(destinations = [ActionController::Base, ActionView::Base], regenerate = false)
+          reset! if regenerate
+          Array(destinations).each do |dest|
+            dest.send! :include, @module
+          end
+        end
+
+        private
+          def url_helper_name(name, kind = :url)
+            :"#{name}_#{kind}"
+          end
+
+          def hash_access_name(name, kind = :url)
+            :"hash_for_#{name}_#{kind}"
+          end
+
+          def define_named_route_methods(name, route)
+            {:url => {:only_path => false}, :path => {:only_path => true}}.each do |kind, opts|
+              hash = route.defaults.merge(:use_route => name).merge(opts)
+              define_hash_access route, name, kind, hash
+              define_url_helper route, name, kind, hash
+            end
+          end
+
+          def define_hash_access(route, name, kind, options)
+            selector = hash_access_name(name, kind)
+            @module.module_eval <<-end_eval # We use module_eval to avoid leaks
+              def #{selector}(options = nil)
+                options ? #{options.inspect}.merge(options) : #{options.inspect}
+              end
+              protected :#{selector}
+            end_eval
+            helpers << selector
+          end
+
+          def define_url_helper(route, name, kind, options)
+            selector = url_helper_name(name, kind)
+            # The segment keys used for positional paramters
+
+            hash_access_method = hash_access_name(name, kind)
+
+            # allow ordered parameters to be associated with corresponding
+            # dynamic segments, so you can do
+            #
+            #   foo_url(bar, baz, bang)
+            #
+            # instead of
+            #
+            #   foo_url(:bar => bar, :baz => baz, :bang => bang)
+            #
+            # Also allow options hash, so you can do
+            #
+            #   foo_url(bar, baz, bang, :sort_by => 'baz')
+            #
+            @module.module_eval <<-end_eval # We use module_eval to avoid leaks
+              def #{selector}(*args)
+                #{generate_optimisation_block(route, kind)}
+
+                opts = if args.empty? || Hash === args.first
+                  args.first || {}
+                else
+                  options = args.extract_options!
+                  args = args.zip(#{route.segment_keys.inspect}).inject({}) do |h, (v, k)|
+                    h[k] = v
+                    h
+                  end
+                  options.merge(args)
+                end
+
+                url_for(#{hash_access_method}(opts))
+              end
+              protected :#{selector}
+            end_eval
+            helpers << selector
+          end
+      end
+
+      attr_accessor :routes, :named_routes
+
+      def initialize
+        self.routes = []
+        self.named_routes = NamedRouteCollection.new
+      end
+
+      # Subclasses and plugins may override this method to specify a different
+      # RouteBuilder instance, so that other route DSL's can be created.
+      def builder
+        @builder ||= RouteBuilder.new
+      end
+
+      def draw
+        clear!
+        yield Mapper.new(self)
+        install_helpers
+      end
+
+      def clear!
+        routes.clear
+        named_routes.clear
+        @combined_regexp = nil
+        @routes_by_controller = nil
+      end
+
+      def install_helpers(destinations = [ActionController::Base, ActionView::Base], regenerate_code = false)
+        Array(destinations).each { |d| d.module_eval { include Helpers } }
+        named_routes.install(destinations, regenerate_code)
+      end
+
+      def empty?
+        routes.empty?
+      end
+
+      def load!
+        Routing.use_controllers! nil # Clear the controller cache so we may discover new ones
+        clear!
+        load_routes!
+        install_helpers
+      end
+
+      # reload! will always force a reload whereas load checks the timestamp first
+      alias reload! load!
+
+      def reload
+        if @routes_last_modified && defined?(RAILS_ROOT)
+          mtime = File.stat("#{RAILS_ROOT}/config/routes.rb").mtime
+          # if it hasn't been changed, then just return
+          return if mtime == @routes_last_modified
+          # if it has changed then record the new time and fall to the load! below
+          @routes_last_modified = mtime
+        end
+        load!
+      end
+
+      def load_routes!
+        if defined?(RAILS_ROOT) && defined?(::ActionController::Routing::Routes) && self == ::ActionController::Routing::Routes
+          load File.join("#{RAILS_ROOT}/config/routes.rb")
+          @routes_last_modified = File.stat("#{RAILS_ROOT}/config/routes.rb").mtime
+        else
+          add_route ":controller/:action/:id"
+        end
+      end
+
+      def add_route(path, options = {})
+        route = builder.build(path, options)
+        routes << route
+        route
+      end
+
+      def add_named_route(name, path, options = {})
+        # TODO - is options EVER used?
+        name = options[:name_prefix] + name.to_s if options[:name_prefix]
+        named_routes[name.to_sym] = add_route(path, options)
+      end
+
+      def options_as_params(options)
+        # If an explicit :controller was given, always make :action explicit
+        # too, so that action expiry works as expected for things like
+        #
+        #   generate({:controller => 'content'}, {:controller => 'content', :action => 'show'})
+        #
+        # (the above is from the unit tests). In the above case, because the
+        # controller was explicitly given, but no action, the action is implied to
+        # be "index", not the recalled action of "show".
+        #
+        # great fun, eh?
+
+        options_as_params = options.clone
+        options_as_params[:action] ||= 'index' if options[:controller]
+        options_as_params[:action] = options_as_params[:action].to_s if options_as_params[:action]
+        options_as_params
+      end
+
+      def build_expiry(options, recall)
+        recall.inject({}) do |expiry, (key, recalled_value)|
+          expiry[key] = (options.key?(key) && options[key].to_param != recalled_value.to_param)
+          expiry
+        end
+      end
+
+      # Generate the path indicated by the arguments, and return an array of
+      # the keys that were not used to generate it.
+      def extra_keys(options, recall={})
+        generate_extras(options, recall).last
+      end
+
+      def generate_extras(options, recall={})
+        generate(options, recall, :generate_extras)
+      end
+
+      def generate(options, recall = {}, method=:generate)
+        named_route_name = options.delete(:use_route)
+        generate_all = options.delete(:generate_all)
+        if named_route_name
+          named_route = named_routes[named_route_name]
+          options = named_route.parameter_shell.merge(options)
+        end
+
+        options = options_as_params(options)
+        expire_on = build_expiry(options, recall)
+
+        if options[:controller]
+          options[:controller] = options[:controller].to_s
+        end
+        # if the controller has changed, make sure it changes relative to the
+        # current controller module, if any. In other words, if we're currently
+        # on admin/get, and the new controller is 'set', the new controller
+        # should really be admin/set.
+        if !named_route && expire_on[:controller] && options[:controller] && options[:controller][0] != ?/
+          old_parts = recall[:controller].split('/')
+          new_parts = options[:controller].split('/')
+          parts = old_parts[0..-(new_parts.length + 1)] + new_parts
+          options[:controller] = parts.join('/')
+        end
+
+        # drop the leading '/' on the controller name
+        options[:controller] = options[:controller][1..-1] if options[:controller] && options[:controller][0] == ?/
+        merged = recall.merge(options)
+
+        if named_route
+          path = named_route.generate(options, merged, expire_on)
+          if path.nil?
+            raise_named_route_error(options, named_route, named_route_name)
+          else
+            return path
+          end
+        else
+          merged[:action] ||= 'index'
+          options[:action] ||= 'index'
+
+          controller = merged[:controller]
+          action = merged[:action]
+
+          raise RoutingError, "Need controller and action!" unless controller && action
+
+          if generate_all
+            # Used by caching to expire all paths for a resource
+            return routes.collect do |route|
+              route.send!(method, options, merged, expire_on)
+            end.compact
+          end
+
+          # don't use the recalled keys when determining which routes to check
+          routes = routes_by_controller[controller][action][options.keys.sort_by { |x| x.object_id }]
+
+          routes.each do |route|
+            results = route.send!(method, options, merged, expire_on)
+            return results if results && (!results.is_a?(Array) || results.first)
+          end
+        end
+
+        raise RoutingError, "No route matches #{options.inspect}"
+      end
+
+      # try to give a helpful error message when named route generation fails
+      def raise_named_route_error(options, named_route, named_route_name)
+        diff = named_route.requirements.diff(options)
+        unless diff.empty?
+          raise RoutingError, "#{named_route_name}_url failed to generate from #{options.inspect}, expected: #{named_route.requirements.inspect}, diff: #{named_route.requirements.diff(options).inspect}"
+        else
+          required_segments = named_route.segments.select {|seg| (!seg.optional?) && (!seg.is_a?(DividerSegment)) }
+          required_keys_or_values = required_segments.map { |seg| seg.key rescue seg.value } # we want either the key or the value from the segment
+          raise RoutingError, "#{named_route_name}_url failed to generate from #{options.inspect} - you may have ambiguous routes, or you may need to supply additional parameters for this route.  content_url has the following required parameters: #{required_keys_or_values.inspect} - are they all satisfied?"
+        end
+      end
+
+      def recognize(request)
+        params = recognize_path(request.path, extract_request_environment(request))
+        request.path_parameters = params.with_indifferent_access
+        "#{params[:controller].camelize}Controller".constantize
+      end
+
+      def recognize_path(path, environment={})
+        routes.each do |route|
+          result = route.recognize(path, environment) and return result
+        end
+
+        allows = HTTP_METHODS.select { |verb| routes.find { |r| r.recognize(path, :method => verb) } }
+
+        if environment[:method] && !HTTP_METHODS.include?(environment[:method])
+          raise NotImplemented.new(*allows)
+        elsif !allows.empty?
+          raise MethodNotAllowed.new(*allows)
+        else
+          raise RoutingError, "No route matches #{path.inspect} with #{environment.inspect}"
+        end
+      end
+
+      def routes_by_controller
+        @routes_by_controller ||= Hash.new do |controller_hash, controller|
+          controller_hash[controller] = Hash.new do |action_hash, action|
+            action_hash[action] = Hash.new do |key_hash, keys|
+              key_hash[keys] = routes_for_controller_and_action_and_keys(controller, action, keys)
+            end
+          end
+        end
+      end
+
+      def routes_for(options, merged, expire_on)
+        raise "Need controller and action!" unless controller && action
+        controller = merged[:controller]
+        merged = options if expire_on[:controller]
+        action = merged[:action] || 'index'
+
+        routes_by_controller[controller][action][merged.keys]
+      end
+
+      def routes_for_controller_and_action(controller, action)
+        selected = routes.select do |route|
+          route.matches_controller_and_action? controller, action
+        end
+        (selected.length == routes.length) ? routes : selected
+      end
+
+      def routes_for_controller_and_action_and_keys(controller, action, keys)
+        selected = routes.select do |route|
+          route.matches_controller_and_action? controller, action
+        end
+        selected.sort_by do |route|
+          (keys - route.significant_keys).length
+        end
+      end
+
+      # Subclasses and plugins may override this method to extract further attributes
+      # from the request, for use by route conditions and such.
+      def extract_request_environment(request)
+        { :method => request.method }
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/actionpack/lib/action_controller/routing/routing_ext.rb b/actionpack/lib/action_controller/routing/routing_ext.rb
new file mode 100644
index 0000000000..2ad20ee699
--- /dev/null
+++ b/actionpack/lib/action_controller/routing/routing_ext.rb
@@ -0,0 +1,46 @@
+
+class Object
+  def to_param
+    to_s
+  end
+end
+
+class TrueClass
+  def to_param
+    self
+  end
+end
+
+class FalseClass
+  def to_param
+    self
+  end
+end
+
+class NilClass
+  def to_param
+    self
+  end
+end
+
+class Regexp #:nodoc:
+  def number_of_captures
+    Regexp.new("|#{source}").match('').captures.length
+  end
+
+  class << self
+    def optionalize(pattern)
+      case unoptionalize(pattern)
+        when /\A(.|\(.*\))\Z/ then "#{pattern}?"
+        else "(?:#{pattern})?"
+      end
+    end
+
+    def unoptionalize(pattern)
+      [/\A\(\?:(.*)\)\?\Z/, /\A(.|\(.*\))\?\Z/].each do |regexp|
+        return $1 if regexp =~ pattern
+      end
+      return pattern
+    end
+  end
+end
diff --git a/actionpack/lib/action_controller/routing/segments.rb b/actionpack/lib/action_controller/routing/segments.rb
new file mode 100644
index 0000000000..efac2df1cb
--- /dev/null
+++ b/actionpack/lib/action_controller/routing/segments.rb
@@ -0,0 +1,268 @@
+module ActionController
+  module Routing
+    class Segment #:nodoc:
+      RESERVED_PCHAR = ':@&=+$,;'
+      UNSAFE_PCHAR = Regexp.new("[^#{URI::REGEXP::PATTERN::UNRESERVED}#{RESERVED_PCHAR}]", false, 'N').freeze
+
+      attr_accessor :is_optional
+      alias_method :optional?, :is_optional
+
+      def initialize
+        self.is_optional = false
+      end
+
+      def extraction_code
+        nil
+      end
+
+      # Continue generating string for the prior segments.
+      def continue_string_structure(prior_segments)
+        if prior_segments.empty?
+          interpolation_statement(prior_segments)
+        else
+          new_priors = prior_segments[0..-2]
+          prior_segments.last.string_structure(new_priors)
+        end
+      end
+
+      def interpolation_chunk
+        URI.escape(value, UNSAFE_PCHAR)
+      end
+
+      # Return a string interpolation statement for this segment and those before it.
+      def interpolation_statement(prior_segments)
+        chunks = prior_segments.collect { |s| s.interpolation_chunk }
+        chunks << interpolation_chunk
+        "\"#{chunks * ''}\"#{all_optionals_available_condition(prior_segments)}"
+      end
+
+      def string_structure(prior_segments)
+        optional? ? continue_string_structure(prior_segments) : interpolation_statement(prior_segments)
+      end
+
+      # Return an if condition that is true if all the prior segments can be generated.
+      # If there are no optional segments before this one, then nil is returned.
+      def all_optionals_available_condition(prior_segments)
+        optional_locals = prior_segments.collect { |s| s.local_name if s.optional? && s.respond_to?(:local_name) }.compact
+        optional_locals.empty? ? nil : " if #{optional_locals * ' && '}"
+      end
+
+      # Recognition
+
+      def match_extraction(next_capture)
+        nil
+      end
+
+      # Warning
+
+      # Returns true if this segment is optional? because of a default. If so, then
+      # no warning will be emitted regarding this segment.
+      def optionality_implied?
+        false
+      end
+    end
+
+    class StaticSegment < Segment #:nodoc:
+      attr_accessor :value, :raw
+      alias_method :raw?, :raw
+
+      def initialize(value = nil)
+        super()
+        self.value = value
+      end
+
+      def interpolation_chunk
+        raw? ? value : super
+      end
+
+      def regexp_chunk
+        chunk = Regexp.escape(value)
+        optional? ? Regexp.optionalize(chunk) : chunk
+      end
+
+      def build_pattern(pattern)
+        escaped = Regexp.escape(value)
+        if optional? && ! pattern.empty?
+          "(?:#{Regexp.optionalize escaped}\\Z|#{escaped}#{Regexp.unoptionalize pattern})"
+        elsif optional?
+          Regexp.optionalize escaped
+        else
+          escaped + pattern
+        end
+      end
+
+      def to_s
+        value
+      end
+    end
+
+    class DividerSegment < StaticSegment #:nodoc:
+      def initialize(value = nil)
+        super(value)
+        self.raw = true
+        self.is_optional = true
+      end
+
+      def optionality_implied?
+        true
+      end
+    end
+
+    class DynamicSegment < Segment #:nodoc:
+      attr_accessor :key, :default, :regexp
+
+      def initialize(key = nil, options = {})
+        super()
+        self.key = key
+        self.default = options[:default] if options.key? :default
+        self.is_optional = true if options[:optional] || options.key?(:default)
+      end
+
+      def to_s
+        ":#{key}"
+      end
+
+      # The local variable name that the value of this segment will be extracted to.
+      def local_name
+        "#{key}_value"
+      end
+
+      def extract_value
+        "#{local_name} = hash[:#{key}] && hash[:#{key}].to_param #{"|| #{default.inspect}" if default}"
+      end
+      def value_check
+        if default # Then we know it won't be nil
+          "#{value_regexp.inspect} =~ #{local_name}" if regexp
+        elsif optional?
+          # If we have a regexp check that the value is not given, or that it matches.
+          # If we have no regexp, return nil since we do not require a condition.
+          "#{local_name}.nil? || #{value_regexp.inspect} =~ #{local_name}" if regexp
+        else # Then it must be present, and if we have a regexp, it must match too.
+          "#{local_name} #{"&& #{value_regexp.inspect} =~ #{local_name}" if regexp}"
+        end
+      end
+      def expiry_statement
+        "expired, hash = true, options if !expired && expire_on[:#{key}]"
+      end
+
+      def extraction_code
+        s = extract_value
+        vc = value_check
+        s << "\nreturn [nil,nil] unless #{vc}" if vc
+        s << "\n#{expiry_statement}"
+      end
+
+      def interpolation_chunk(value_code = "#{local_name}")
+        "\#{URI.escape(#{value_code}.to_s, ActionController::Routing::Segment::UNSAFE_PCHAR)}"
+      end
+
+      def string_structure(prior_segments)
+        if optional? # We have a conditional to do...
+          # If we should not appear in the url, just write the code for the prior
+          # segments. This occurs if our value is the default value, or, if we are
+          # optional, if we have nil as our value.
+          "if #{local_name} == #{default.inspect}\n" +
+            continue_string_structure(prior_segments) +
+          "\nelse\n" + # Otherwise, write the code up to here
+            "#{interpolation_statement(prior_segments)}\nend"
+        else
+          interpolation_statement(prior_segments)
+        end
+      end
+
+      def value_regexp
+        Regexp.new "\\A#{regexp.source}\\Z" if regexp
+      end
+      def regexp_chunk
+        regexp ? "(#{regexp.source})" : "([^#{Routing::SEPARATORS.join}]+)"
+      end
+
+      def build_pattern(pattern)
+        chunk = regexp_chunk
+        chunk = "(#{chunk})" if Regexp.new(chunk).number_of_captures == 0
+        pattern = "#{chunk}#{pattern}"
+        optional? ? Regexp.optionalize(pattern) : pattern
+      end
+      def match_extraction(next_capture)
+        # All non code-related keys (such as :id, :slug) are URI-unescaped as
+        # path parameters.
+        default_value = default ? default.inspect : nil
+        %[
+          value = if (m = match[#{next_capture}])
+            URI.unescape(m)
+          else
+            #{default_value}
+          end
+          params[:#{key}] = value if value
+        ]
+      end
+
+      def optionality_implied?
+        [:action, :id].include? key
+      end
+
+    end
+
+    class ControllerSegment < DynamicSegment #:nodoc:
+      def regexp_chunk
+        possible_names = Routing.possible_controllers.collect { |name| Regexp.escape name }
+        "(?i-:(#{(regexp || Regexp.union(*possible_names)).source}))"
+      end
+
+      # Don't URI.escape the controller name since it may contain slashes.
+      def interpolation_chunk(value_code = "#{local_name}")
+        "\#{#{value_code}.to_s}"
+      end
+
+      # Make sure controller names like Admin/Content are correctly normalized to
+      # admin/content
+      def extract_value
+        "#{local_name} = (hash[:#{key}] #{"|| #{default.inspect}" if default}).downcase"
+      end
+
+      def match_extraction(next_capture)
+        if default
+          "params[:#{key}] = match[#{next_capture}] ? match[#{next_capture}].downcase : '#{default}'"
+        else
+          "params[:#{key}] = match[#{next_capture}].downcase if match[#{next_capture}]"
+        end
+      end
+    end
+
+    class PathSegment < DynamicSegment #:nodoc:
+      RESERVED_PCHAR = "#{Segment::RESERVED_PCHAR}/"
+      UNSAFE_PCHAR = Regexp.new("[^#{URI::REGEXP::PATTERN::UNRESERVED}#{RESERVED_PCHAR}]", false, 'N').freeze
+
+      def interpolation_chunk(value_code = "#{local_name}")
+        "\#{URI.escape(#{value_code}.to_s, ActionController::Routing::PathSegment::UNSAFE_PCHAR)}"
+      end
+
+      def default
+        ''
+      end
+
+      def default=(path)
+        raise RoutingError, "paths cannot have non-empty default values" unless path.blank?
+      end
+
+      def match_extraction(next_capture)
+        "params[:#{key}] = PathSegment::Result.new_escaped((match[#{next_capture}]#{" || " + default.inspect if default}).split('/'))#{" if match[" + next_capture + "]" if !default}"
+      end
+
+      def regexp_chunk
+        regexp || "(.*)"
+      end
+
+      def optionality_implied?
+        true
+      end
+
+      class Result < ::Array #:nodoc:
+        def to_s() join '/' end
+        def self.new_escaped(strings)
+          new strings.collect {|str| URI.unescape str}
+        end
+      end
+    end
+  end
+end