From: Greg Brondo <greg@...>
Date: 2003-04-04T01:35:17+09:00
Subject: Re: Newbie question:read file speed

Brian Candler wrote:
> On Thu, Apr 03, 2003 at 12:51:28AM +0900, Greg Brondo wrote:
> 
>>Here they are:
> 
> 
> Cheers. I've run them here under FreeBSD-4.7 running on a Sony Vaio laptop,
> Pentium 266MMX. For the data file, I'm using:
> 
> $ wc /usr/share/dict/words 
>   235881  235881 2493066 /usr/share/dict/words
> 
> (with an average line length of only 10.6 bytes it's perhaps not the most
> realistic example, but it will do)
> 
> Running the code you gave, I get the following times averaged over three
> runs:
> 
> Ruby   (1.6.8)         6.81 secs
> Ruby   (1.8.0p2)       6.57 secs
> Python (2.2.1)         6.72 secs *
> Java (jdk-1.3.1p6_4)  16.76 secs **
> 
> * it printed "Elapsed = 6", so the time given is using the 'time' command;
> this is slightly unfair to python as it includes the interpreter start-up
> time which the Ruby time doesn't.
> 
> ** printed "Elapsed = 16", ditto
> 
> Note however that I am running under X, and it seems quite a lot of time is
> spent just writing the progress messages to the xterm. If I add '>/dev/null'
> to the end of the command line and use unix 'time' then I get:
> 
> Ruby   (1.6.8)         3.8 s
> Ruby   (1.8.0p2)       3.4 s
> Python (2.2.1)         3.7 s
> Java (jdk-1.3.1p6_4)   8.6 s
> 
> So on this basis Ruby stacks up pretty well against the languages you
> mention, running under Unix. From your figures it seems that Ruby is slower
> under Windows, and I would guess that this is somehow related to the way
> Ruby performs I/O, or perhaps to the threading support (e.g. making extra
> calls to select() before I/O operations). Maybe a Windows developer could
> compare the Python and Ruby I/O source code and see if there are significant
> differences in the way they talk to Windows.
> 
> Out of interest, I also ported your code to Perl (attached), and also
> modified the Ruby code to use a more iterative style to be closer to Perl. I
> get:
> 
>                    (to screen)  (to /dev/null)
> Perl (5.005_03)      3.9 secs     2.3 secs
> Ruby (1.6.8)         6.5 secs     3.6 secs
> 
> So it seems that Perl is significantly faster in this simple test, but also
> the block/yield approach does not by itself add a great deal of overhead
> (fortunately!)
> 
> Regards,
> 
> Brian.
> 
> 
> ------------------------------------------------------------------------
> 
> filename=ARGV[0]
> lc = 0
> starttime = Time.now.to_f
> f = File.open(filename)
> while f.gets
>  lc += 1
>  if lc % 1000 == 0
>   puts "Read #{lc} lines"
>  end
> end
> stoptime = Time.now.to_f
>   
> puts "Elapsed = " + (stoptime - starttime).to_s

Hmm.. I tried it under Ruby 1.6.8 compiled with GCC on Solaris 2.8 and 
it was still slow.  I'll try it again on Linux (Debian Unstable) and see 
what I get.