From: Rob Biedenharn <Rob@...>
Date: 2008-06-25T01:48:36+09:00
Subject: Re: Performance improvement possible?

On Jun 24, 2008, at 12:23 PM, Philip Rhoades wrote:
> People,
>
> I have asked before about Ruby to C conversion programs and other  
> alternatives with no really satisfactory solution for my particular  
> situation.

Are you looking at all solutions?

> I decided to test out a conversion of one of the C programs and see  
> what sort of results I get.  This particular small C program is  
> called 32,000 times from loops within a shell script.  The program  
> then processes a text file, writes a text file and exits.  The same  
> shell script with a Ruby program replacing the C program does  
> exactly the same thing but takes 8.5 times as long (27m/227m).

Can you replace the whole shell script with a ruby program?  Then  
whatever startup cost you have for the Ruby interpreter is paid once  
rather than 32_000 times.

> The profile on ONE execution of the Ruby program produced:
>
>  %   cumulative   self              self     total
> time   seconds   seconds    calls  ms/call  ms/call  name
> 65.18    14.15     14.15        1 14150.00 21700.00  Array#each
> 12.44    16.85      2.70    93792     0.03     0.03  Array#[]
>  8.15    18.62      1.77    62108     0.03     0.03  String#split
>  6.73    20.08      1.46    53215     0.03     0.03  String#==
>  2.58    20.64      0.56       66     8.48    12.73  Range#each
>
> It would be SO much nicer to rewrite some stuff that needs rewriting  
> and write ALL new stuff in Ruby but this looks impossible with these  
> times . .
>
> Any suggestions for performance improvements?
>
> I am using F9.

F9?  Is that some key in an IDE that runs your ruby code?

> Thanks,
>
> Phil.
> -- 
> Philip Rhoades
>
> Pricom Pty Limited  (ACN 003 252 275  ABN 91 003 252 275)
> GPO Box 3411
> Sydney NSW	2001
> Australia
> E-mail:  phil@pricom.com.au

Depending on what your C program has to do and why a shell script is  
calling it in the first place, you might have other benefits from  
using Ruby in place of the shell script.  A couple years back, I  
worked on a similar kind of project that was replacing shell scripts  
with Perl and there were many benefits that Perl could exploit that  
just could not be managed by constructs in the shell.

-Rob

Rob Biedenharn		http://agileconsultingllc.com
Rob@AgileConsultingLLC.com