memoizable,rails2.2

railscast memorizable
Easy Memoization
A Guide to Memoization
<br />#sudo gem install rails<br />#sudo gem update --system<br />#sudo gem install rubygems-update<br />#sudo update_rubygems<br />#gem -v<br /><br />lass Product < ActiveRecord::Base<br /> extend ActiveSupport::Memoizable<br /> <br /> belongs_to :category<br /> <br /> def filesize(num = 1)<br /> # some expensive operation<br /> sleep 2<br /> 12345789 * num<br /> end<br /> memoize :filesize<br />end<br />