Contents

require 'active_support/concern'

# Memoizes method calls, but only for a specific period of time.
# Useful for supporting HTTP Cache-Control without an external caching layer
# like Rack::Cache
class Frenetic
  module BrieflyMemoizable
    extend ActiveSupport::Concern

    module ClassMethods
      def briefly_memoize( symbol )
        original_method = "_unmemoized_#{symbol}".to_sym
        memoized_ivar   = "@#{symbol}"
        age_ivar        = "@#{symbol}_age"

        class_eval <<-EOS
          if method_defined?(:#{original_method})                                  # if method_defined?(:_unmemoized_mime_type)
            raise "Already memoized #{symbol}"                                     #   raise "Already memoized mime_type"
          end                                                                      # end
          alias #{original_method} #{symbol}                                       # alias _unmemoized_mime_type mime_type

          def #{symbol}(*args)                                                     # def mime_type(*args)
            #{memoized_ivar} = nil if #{age_ivar} && Time.now > #{age_ivar}        #   @mime_type = nil if @mime_type_age && Time.now > @mime_type_age
            #{memoized_ivar} ||= #{original_method}(*args)                         #   @mime_type ||= _unmemoized_mime_type(*args)
          end                                                                      # end

          def reload_#{symbol}!                                                    # def reload_mime_type!
            #{memoized_ivar} = nil                                                 #   @mime_type = nil
          end                                                                      # end
        EOS
      end
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
frenetic-1.0.0.alpha.1	lib/frenetic/briefly_memoizable.rb