From: Ryan Leavengood <leavengood@...>
Date: 2005-11-04T06:44:20+09:00
Subject: Re: Ruby Performance vs. Java

On 11/3/05, Ryan Leavengood <leavengood@gmail.com> wrote:
>
> Also, I would suspect that Mr. Kumar's Ruby code could benefit from
> some tweaking by the experts on this list. Recent threads have shown
> that smarter algorithms can make Ruby code much, much faster. In my
> opinion his run against his log files seems absurdly slow.

To respond to myself, it seems the main culprit is Mr. Kumar's
LogEntry class, whose source code can be gotten here:
http://www.pankaj-k.net/archives/ruby_java/logentry.rb

I've done some benchmarking and the biggest CPU hog is the call to
DateTime.strptime. By changing that call to just DateTime.new
(arguably removing some functionality from the class), the runtime
performance of 10,000 iterations of calling LogEntry.new goes from
24.18 seconds to 7.39 seconds, on my laptop (P4 2.8 GHz, 1 GB RAM,
Windows XP, similar to his test system.)

I believe his regular expressions could be improved as well. Anyone up
to the challenge of making this LogEntry class much faster?

Ryan