From: William James <w_a_x_man@...>
Date: 2007-09-24T20:15:08+09:00
Subject: Re: I am new to Ruby and I could use some expert advice as to how I can make this code run faster.


Ruby Maniac wrote:
> On Sep 22, 3:16 am, William James <w_a_x_...@yahoo.com> wrote:
> > On Sep 20, 5:02 pm, Ruby Maniac <raych...@hotmail.com> wrote:
> >
> >
> >
> >
> >
> > > I am new to Ruby and I could use some expert advice as to how I can
> > > make this code run faster.
> >
> > > def scramble(fname)
> > >     f = File.new(fname, "rb")
> > >     _fname = fname + ".scrambled"
> > >     begin
> > >         File.exist?(_fname) if File.delete(_fname)
> > >     rescue
> > >     end
> > >     ff = File.new(_fname, "wb+")
> > >     for l in f
> > >         l.each_byte{|c| ff.write((c | 0x80).chr) }
> > >     end
> > >     f.close()
> > >     ff.close()
> > > end
> >
> > If you actually want speed, use a compiled language.
> > This FreeBasic code is about 160 times as fast and
> > demonstrates that using Python for any reason
> > whatsoever is unjustified.
> >
> > Use Ruby when ease of programming is paramount;
> > use something like FreeBasic or LuaJIT when speed
> > is paramount.  Never submit to Python perversion.
> >
> > sub scramble( filename as string )
> >   dim outname as string
> >   dim as integer  in_handle, out_handle, i, size
> >   dim bytes(1 to 4096) as byte
> >
> >   outname = filename & ".scrambled"
> >   in_handle = freefile
> >   open filename for binary access read  as in_handle
> >   out_handle = freefile
> >   open outname for binary access write  as out_handle
> >   while not eof( in_handle )
> >     size = seek( in_handle )
> >     get #in_handle, , bytes()
> >     size = seek( in_handle ) - size
> >     for i = 1 to size
> >       bytes(i) = bytes(i) or &h80
> >     next
> >     put #out_handle, , bytes(1), size
> >   wend
> >   close
> > end sub- Hide quoted text -
> >
> > - Show quoted text -
>
> Okay I downloaded Free BASIC and installed it but your code does not
> work !
>
> On the one hand, FreeBASIC is certainly worth looking into but on the
> other hand - there ain't no debugger than I know of unless you know of
> a debugger for FreeBASIC.

Did it compile without errors?  Did you make sure that no lines of the
source were broken by your newsgroup program?  (If using google,
click on "More options" and "Show original".)  I didn't include code
to invoke the subroutine; I left that up to you.

Debuggers are crutches; I never use them.

Here's a complete program.  Change the filename that is read by
the program.


function scramble( filename as string ) as double
  dim as integer  in_handle, out_handle, i, size
  dim bytes(1 to 4096) as byte

  in_handle = freefile
  open filename for binary  access read  as in_handle
  out_handle = freefile
  open filename & ".scrambled" for binary access write as out_handle
  while not eof( in_handle )
    size = seek( in_handle )
    get #in_handle, , bytes()
    size = seek( in_handle ) - size
    for i = 1 to size
      bytes(i) = bytes(i) or &h80
    next
    put #out_handle, , bytes(1), size
  wend
  close  '-- Caution. Closes all open files.
  return 0.0
end function

print "! ";
print -timer + scramble("testjunk.csv") + timer