ActiveSupport::Cache::MemoryStoreWithExpiry

module ActiveSupport
  module Cache
    class MemoryStoreWithExpiry < MemoryStore

      def initialize
        super
        @times = {}
      end

      def write(name, value, options = nil)
        if options && options[:expires_in]
          @times[name] = { :cached_at => Time.now, :expires_in => options[:expires_in] }
        end
        super
      end

      def read(name, options = nil)
        return if expired?(name)
        super
      end

      private 

        def expired?(name)
          return false unless @times[name]
          (Time.now - @times[name][:cached_at]) > @times[name][:expires_in]
        end
    end
  end
end