From: Robert Klemme <shortcutter@...>
Date: 2009-06-05T05:45:05+09:00
Subject: Re: Ruby Execution

On 04.06.2009 13:40, Mike Stephens wrote:
> Brian Candler wrote:
>> P.S. If you want to defer loading of classes until when they are used, 
>> have a look at Kernel#autoload
> 
> Is this the norm? I would have thought it would be a real problem 
> parsing big frameworks with myriads of classes everytime you want to 
> make a simple call. Is there a way of keeping a parsed script cached eg 
> for a web site that is handling hundreds of users doing the same sorts 
> of things eg browsing product lists?

Maybe this additional bit of information helps.  When you run a Ruby 
script the first thing that happens is that it is parsed and translated 
into an internal binary representation (which one depends on the version 
and platform used, e.g. ruby 1.9 is differently than 1.8 than JRuby). 
Only then it is executed, which basically means that the internal 
representation is interpreted in some way.  This is typically pretty 
efficient compared to the bourne shell approach of doing the parsing 
line based.

I have no insights into JRuby but knowing the JVM it would even be 
possible that eventually your Ruby code has become machine code when the 
hot spot engine decides it should compile it.

To sum it up: you shouldn't be too concerned about the efficiency of 
that approach.  The issue you are bringing up is rather valid in 
situations where a largish application (i.e. multiple files) is needed 
to execute only small interactions (for example when doing classic CGI 
where a new process is started for each request).

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/