memcache.rb

  def top_menu_cache_key
    rounded_time = Time.zone.now.round(30.minutes)
    if Rails.cache.fetch('top_menu_cache_key').nil? || rounded_time != Rails.cache.fetch("rounded_time")
      debugger
      Rails.cache.write('top_menu_cache_key',  "top_menu:#{Product.active.on_sale.maximum(:updated_at)}")
      Rails.cache.write('rounded_time', rounded_time)
    end
    return Rails.cache.fetch('top_menu_cache_key')
  end