Reduce the cost of using ActionController::Http significantly by:

  * Removing the dependency on AD::Request and AD::Response
  * Moving the logic for the request and response object
    into a new module that is included by default.
  * Changing Renderer and Redirector to use self.headers,
    self.content_type, and self.status, which have very basic
    default implementations on AC::Http. When RackConvenience
    is included (which it is by default on AC::Base), the full
    Request/Response logic is used instead of the simple logic.

actionpack/lib/action_controller/new_base.rb

@@ -4,6 +4,7 @@ module ActionController
   autoload :HideActions,          "action_controller/new_base/hide_actions"
   autoload :Http,                 "action_controller/new_base/http"
   autoload :Layouts,              "action_controller/new_base/layouts"
+  autoload :RackConvenience,      "action_controller/new_base/rack_convenience"
   autoload :Rails2Compatibility,  "action_controller/new_base/compatibility"
   autoload :Redirector,           "action_controller/new_base/redirector"
   autoload :Renderer,             "action_controller/new_base/renderer"

actionpack/lib/action_controller/new_base/base.rb

@@ -14,6 +14,7 @@ class Base < Http
     include ActionController::Renderers::All
     include ActionController::Layouts
     include ActionController::ConditionalGet
+    include ActionController::RackConvenience
 
     # Legacy modules
     include SessionManagement

actionpack/lib/action_controller/new_base/conditional_get.rb

 module ActionController
   module ConditionalGet
+    extend ActiveSupport::DependencyModule
+
+    depends_on RackConvenience
     
     # Sets the etag, last_modified, or both on the response and renders a
     # "304 Not Modified" response if the request is already fresh.

actionpack/lib/action_controller/new_base/http.rb

@@ -6,7 +6,7 @@ class Http < AbstractController::Base
     abstract!
     
     # :api: public
-    attr_internal :request, :response, :params
+    attr_internal :params, :env
 
     # :api: public
     def self.controller_name
@@ -36,32 +36,48 @@ def self.call(env)
       controller.call(env).to_rack
     end
     
-    delegate :headers, :to => "@_response"
+    # The details below can be overridden to support a specific
+    # Request and Response object. The default ActionController::Base
+    # implementation includes RackConvenience, which makes a request
+    # and response object available. You might wish to control the
+    # environment and response manually for performance reasons.
 
-    def params
-      @_params ||= @_request.parameters
+    attr_internal :status, :headers, :content_type
+
+    def initialize(*)
+      @_headers = {}
+      super
+    end
+
+    # Basic implements for content_type=, location=, and headers are
+    # provided to reduce the dependency on the RackConvenience module
+    # in Renderer and Redirector.
+
+    def content_type=(type)
+      headers["Content-Type"] = type.to_s
+    end
+
+    def location=(url)
+      headers["Location"] = url
     end
     
     # :api: private
     def call(name, env)
-      @_request = ActionDispatch::Request.new(env)
-      @_response = ActionDispatch::Response.new
-      @_response.request = request
+      @_env = env
       process(name)
       to_rack
     end
     
+    # :api: private
+    def to_rack
+      [status, headers, response_body]
+    end
+
     def self.action(name)
       @actions ||= {}
       @actions[name.to_s] ||= proc do |env|
         new.call(name, env)
       end
     end
-    
-    # :api: private
-    def to_rack
-      @_response.prepare!
-      @_response.to_a
-    end
   end
 end

actionpack/lib/action_controller/new_base/rack_convenience.rb

+module ActionController
+  module RackConvenience
+    extend ActiveSupport::DependencyModule
+    
+    included do
+      delegate :headers, :status=, :location=, 
+               :status, :location, :content_type, :to => "@_response"
+      attr_internal :request, :response
+    end
+    
+    def call(name, env)
+      @_request = ActionDispatch::Request.new(env)
+      @_response = ActionDispatch::Response.new
+      @_response.request = request
+      super
+    end
+    
+    def params
+      @_params ||= @_request.parameters
+    end
+    
+    # :api: private
+    def to_rack
+      @_response.prepare!
+      @_response.to_a
+    end
+    
+    def response_body=(body)
+      response.body = body if response
+      super
+    end
+    
+  end
+end
\ No newline at end of file

actionpack/lib/action_controller/new_base/redirector.rb

@@ -11,8 +11,8 @@ module Redirector
     def redirect_to(url, status) #:doc:
       raise AbstractController::DoubleRenderError if response_body
       logger.info("Redirected to #{url}") if logger && logger.info?
-      response.status = status
-      response.location = url.gsub(/[\r\n]/, '')
+      self.status = status
+      self.location = url.gsub(/[\r\n]/, '')
       self.response_body = "<html><body>You are being <a href=\"#{CGI.escapeHTML(url)}\">redirected</a>.</body></html>"
     end
   end

actionpack/lib/action_controller/new_base/render_options.rb

@@ -57,7 +57,7 @@ module Json
       def _render_json(json, options)
         json = ActiveSupport::JSON.encode(json) unless json.respond_to?(:to_str)
         json = "#{options[:callback]}(#{json})" unless options[:callback].blank?
-        response.content_type ||= Mime::JSON
+        self.content_type ||= Mime::JSON
         self.response_body = json
       end      
     end
@@ -67,7 +67,7 @@ module Js
       register_renderer :js
 
       def _render_js(js, options)
-        response.content_type ||= Mime::JS
+        self.content_type ||= Mime::JS
         self.response_body = js
       end
     end
@@ -77,7 +77,7 @@ module Xml
       register_renderer :xml
 
       def _render_xml(xml, options)
-        response.content_type ||= Mime::XML
+        self.content_type ||= Mime::XML
         self.response_body  = xml.respond_to?(:to_xml) ? xml.to_xml : xml
       end
     end
@@ -88,7 +88,7 @@ module Rjs
 
       def _render_update(proc, options)
         generator = ActionView::Helpers::PrototypeHelper::JavaScriptGenerator.new(_action_view, &proc)
-        response.content_type = Mime::JS
+        self.content_type = Mime::JS
         self.response_body = generator.to_s
       end
     end

actionpack/lib/action_controller/new_base/renderer.rb

@@ -8,16 +8,11 @@ def process_action(*)
       self.formats = request.formats.map {|x| x.to_sym}
       super
     end
-    
-    def response_body=(body)
-      response.body = body if response
-      super
-    end
 
     def render(options)
       super
       options[:_template] ||= _action_view._partial
-      response.content_type ||= begin
+      self.content_type ||= begin
         mime = options[:_template].mime_type
         formats.include?(mime && mime.to_sym) || formats.include?(:all) ? mime : Mime::Type.lookup_by_extension(formats.first)
       end
@@ -76,9 +71,9 @@ def _render_partial(partial, options)
   
     def _process_options(options)
       status, content_type, location = options.values_at(:status, :content_type, :location)
-      response.status = status if status
-      response.content_type = content_type if content_type
-      response.headers["Location"] = url_for(location) if location
+      self.status = status if status
+      self.content_type = content_type if content_type
+      self.headers["Location"] = url_for(location) if location
     end
   end
 end

actionpack/lib/action_controller/new_base/session.rb

 module ActionController
   module Session
+    extend ActiveSupport::DependencyModule
+
+    depends_on RackConvenience
+
     def session
       @_request.session
     end

actionpack/lib/action_controller/new_base/testing.rb

@@ -2,6 +2,8 @@ module ActionController
   module Testing
     extend ActiveSupport::DependencyModule
 
+    depends_on RackConvenience
+
     # OMG MEGA HAX
     def process_with_new_base_test(request, response)
       @_request = request

actionpack/lib/action_controller/new_base/url_for.rb

 module ActionController
   module UrlFor
+    extend ActiveSupport::DependencyModule
+
+    depends_on RackConvenience
+
     def process_action(*)
       initialize_current_url
       super