From: Charlotte <c.f.curtis@...>
Date: 2006-04-13T04:24:02+09:00
Subject: Re: First script seems slow - What's a better way to write t

Brian Mitchell wrote:

> I get something like this on 1.8 cvs:
> 
>                       user     system      total        real
> foo               4.920000   0.080000   5.000000 (  5.581873)
> bar               4.610000   0.060000   4.670000 (  5.457461)
> qux              15.280000   0.280000  15.560000 ( 17.514639)

Just for fun, I tried it too... I get

>                      user     system      total        real
>foo               5.141000   0.000000   5.141000 (  5.157000)
>bar               4.765000   0.032000   4.797000 (  4.812000)
>qux              22.219000   1.593000  23.812000 ( 23.906000)

Hmm... I know for a fact that my (work) computer is messed up, but still 
- it's 3.0Ghz HT P4 with 1Gb RAM.  Running Windows XP, as much disabled 
as I can to try and convince the thing to run quickly.

Also, I tried the YAML version - at first it told me that I couldn't 
modify a frozen string.  I read somewhere about this happening if you 
try to modify an ARGV value, so I changed

>   i = ARGV.shift || STDIN
>   o = ARGV.shift || STDOUT
to
>   i = File.open(ARGV[0], 'r')
>   o = File.new(ARGV[1], 'w')

I don't know if that has an effect on the speed or not, but it worked.

Speed results:
    My script: 450 seconds
    YAML script: 156 seconds

My bottleneck definitely seems to be iterating through each line in the 
input file:

 %   cumulative   self              self     total
time   seconds   seconds    calls  ms/call  ms/call  name
70.25   316.08    316.08      327   966.61  1369.08  IO#each
15.07   383.88     67.79   991826     0.07     0.07  String#[]
14.15   447.56     63.69   984426     0.06     0.06  String#+
0.11    448.05      0.49        2   243.00   406.50  Hash#sort
... etc.

Hmm... seems like it would be worthwhile to learn all that 
lambda/map/#&@^#* gibberish.  Thanks!


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