an example of caching

gistfile1.txt

class Memcached
  attr_writer :expiration

  def initialize
    @cache = {}
    @expiration = Float::MAX
  end

  def set(key, &value)
    @cache[key] = {value: value.call, time: Time.new}
  end

  def get(key, &value)
    if [email protected]?(key) || (Time.new - @cache[key][:time] >= @expiration)
      @cache[key] = {value: value.call, time: Time.new}
    end
    @cache[key][:value]
  end

end