CanCan -- HowTo cache the ability.rb file

ability.rb

class Ability
  include CanCan::Ability

  def marshal_dump
    #blocks cannot be cached
    @rules.reject{|rule| rule.instance_variable_get :@block }.map{|rule| Marshal.dump(rule) }
  end
  def marshal_load array
    #blocks cannot be cached, so blocks must be re-defined
    can :read, Comment do |comment|
      comment.length > 100
    end
    @rules += array.map{|rule| Marshal.load(rule) }
  end
end

application_controller.rb

class ApplicationController < ActionController::Base
  if !Rails.env.development?
    def current_ability
      cached_ability = Rails.cache.read("#{current_user.cache_key}::ability")
      if cached_ability.present?
        ability = Marshal.load( cached_ability )
        ability.user = current_user
      else
        ability = super
        Rails.cache.write("#{current_user.cache_key}::ability", Marshal.dump( ability ))
      end
      @current_ability = ability
    end
  end
end

HACK!!!