From: Mike Harris <GENIE@...>
Date: 2006-07-22T00:09:20+09:00
Subject: Re: [ANN] Cache Decorator

Jake McArthur wrote:

> This isn't really anything that hasn't been done before, but I have  
> yet to see some public Ruby code that provides a nice, easy way to  
> cache the results of methods with this much flexibility and  
> convenience. Simply wrap an object in a CacheDecorator object, and  
> cache away. Method results are stored for each set of arguments that  
> are passed to it. You can choose which methods of the object are  
> cached, invalidate caches manually, stop caching methods, set whether  
> the caches expire after some amount of time, and even set some  
> methods to invalidate the caches of other methods of the same object.  
> We cache things pretty often when things are too slow, but let's not  
> use a bunch of those extra variables that make code so much harder to  
> read. Simple example:
>
> obj = CacheDecorator.new(obj)
> obj.cache :foo # caches foo
> obj.cache :bar, 5 # caches bar with an expiry time of 5 seconds
> loop do
>     puts obj.foo # stays the same the whole time
>     puts obj.bar # changes every five seconds
> end
>
> This is actually something I worked on a long time ago. I just didn't  
> ever announce it. Also, it's been a long time since it was updated,  
> but I intend to add a few more features/conveniences to it pretty soon.
>
> Get it here: http://rubyforge.org/projects/cache-decorator/
>
> - Jake McArthur
>
>
What do you feel are the pros and cons vs. memoize?