From: Vincent Isambart <vincent.isambart@...>
Date: 2008-01-22T02:56:39+09:00
Subject: Re: an example of performance improvements


On Jan 21, 2008, at 6:32 PM, Kornelius Kalnbach wrote:

> Martin Duerst wrote:
>> Any help (e.g. simple examples where performance is clearly non-
>> linear where it should be close to linear) is appreciated.
> maybe http://groups.google.de/group/ruby-talk-google/msg/922661ab87c88a01

I think this example can be shorten much more to see the real cause of  
the problem. With this example, hard to say the real reason of the  
slowdown (regexps, M17N...?).
I made it shorter:
~/tmp% cat e.rb
require 'benchmark'
include Benchmark

logfile = "\n"*5
bm(12) do |test|
   test.report('Simple:') do
     500000.times do
       logfile.each_line { }
     end
   end
end
~/tmp% ruby -v e.rb
ruby 1.8.6 (2007-09-24 patchlevel 111) [universal-darwin9.0]
                   user     system      total        real
Simple:       1.110000   0.000000   1.110000 (  1.114068)
~/tmp% ruby-1.9 -v e.rb
ruby 1.9.0 (2008-01-19 revision 0) [i686-darwin9.1.0]
                   user     system      total        real
Simple:       6.240000   2.870000   9.110000 (  9.122006)

That way you can see that the reason the code is much slower is the  
each_line.