active_support.rb

# Author: Maksim Horbul
# 
# This patch allows to use :expires_in option with the FileStore Cache
#
# Example:
# <% cache :expires_in => 10.minutes %>
#   <div>Cool fragment which is going to be expired in 10 minutes.</div>
# <% end %> 
#

module ActiveSupport
  module Cache
    class FileStore < Store

      def read_with_expiration(name, options = nil)
        expired?(name, options) ? nil : read_without_expiration(name, options)
      end
      alias_method_chain :read, :expiration

      private
        def expired?(name, options = {})
          _expired_at = expires_at(name, options)
          _expired_at ? _expired_at < Time.now : false
        end

        def expires_at(name, options = {})
          _expires_in = expires_in(options)
          if _expires_in > 0
            File.stat(real_file_path(name)).ctime + _expires_in rescue nil
          end
        end

    end
  end
end