From: Robert Klemme <shortcutter@...>
Date: 2008-01-15T00:37:19+09:00
Subject: Re: Counting the files in a directory....

2008/1/14, Siep Korteling <s.korteling@gmail.com>:
> Robert Klemme wrote:
> > 2008/1/12, Siep Korteling <s.korteling@gmail.com>:
> >> > puts folder.Files.count
> > Did you verify that this is faster?  I am skeptical because this call
> > does basically the same: it gets the list of files in the directory
> > and counts them.  I would expect a speedup only if there was an API
> > function that would directly return the number of files.
> >
> > Kind regards
> >
> > robert
>
>  require 'win32ole'
>  require 'benchmark'
>  ldirname = "C:/WINDOWS/system32" #2500+ files
>  mdirname = "C:/ruby/lib/ruby/1.8" #800+ files
>  sdirname="C:/ruby/lib/ruby/1.8/i386-mswin32" # 40+ files
>   @fso = WIN32OLE.new("Scripting.FileSystemObject")
>  n=500
>
>     Benchmark.bmbm do |x|
>
>    x.report("fso_mixed
> |"){n.times{fso(ldirname);fso(mdirname);fso(sdirname)}}
>    x.report("Dir_mixed
> |"){n.times{dir(ldirname);dir(mdirname);dir(sdirname)}}
>    x.report("fso_2500  |"){n.times{fso(ldirname)}}
>    x.report("Dir_2500  |"){n.times{dir(ldirname)}}
>    x.report("fso_800   |"){n.times{fso(mdirname)}}
>    x.report("Dir_800   |"){n.times{dir(mdirname)}}
>    x.report("fso_40    |"){n.times{fso(sdirname)}}
>    x.report("Dir_40    |"){n.times{dir(sdirname)}}
>
>    def fso(dirname)
>      folder = @fso.GetFolder(dirname)
>      count = folder.Files.count
>    end
>
>    def dir(dirname)
>      count =  Dir.entries(dirname).size - 2
>    end
>
> end
>
>
> results in:
>
>                   user     system      total        real
> fso_mixed |   0.360000   1.222000   1.582000 (  1.673000)
> Dir_mixed |   3.635000   1.382000   5.017000 (  5.157000)
> fso_2500  |   0.271000   1.071000   1.342000 (  1.362000)
> Dir_2500  |   3.305000   1.282000   4.587000 (  4.697000)
> fso_800   |   0.040000   0.120000   0.160000 (  0.160000)
> Dir_800   |   0.170000   0.100000   0.270000 (  0.281000)
> fso_40    |   0.020000   0.080000   0.100000 (  0.110000)
> Dir_40    |   0.050000   0.071000   0.121000 (  0.120000)
>
> Apparently, for small directories it doesn't make much difference. For
> large directories it does. (filesystem ntfs).

Amazing.  So there is probably some room for improvement of the
Windows build of Ruby. :-)

Btw, you did not do the subtraction of two - does GetFolder not return
"." and ".."?

Kind regards

robert

-- 
use.inject do |as, often| as.you_can - without end