From: Robert Klemme <bob.news@...>
Date: 2003-04-11T02:25:48+09:00
Subject: Re: Need IO Optimization help


"Jim Freeze" <jim@freeze.org> schrieb im Newsbeitrag
news:20030410124342.A7291@freeze.org...
> On Friday, 11 April 2003 at  1:27:25 +0900, nobu.nokada@softhome.net
wrote:
> > Hi,
> >
> > At Fri, 11 Apr 2003 01:03:08 +0900,
> > Jim Freeze wrote:
> > > The Ruby code is below. I know there have been multiple
> > > posts on ruby-talk about this with discussions about
> > > sysread and read, but not being an IO expert, I have
> > > only been able to follow these at a high level.
> >
> > You can use File.cp in ftools.rb or FileUtils.cp in
> > fileutils.rb.
>
>
> I see the syswrite src.sysread(bsize) in copy_stream, but
> I need the data line by line to process. It's just that
> for our tests we are not doing any processing.
> So, while a direct copy may be fast, it is not exactly
> what I want.
>
>   def copy_stream( src, dest )
>     bsize = fu_stream_blksize(src, dest)
>     begin
>       while true
>         dest.syswrite src.sysread(bsize)
>       end
>     rescue EOFError
>     end
>   end
>
>
> Is there a system call that reads line by line?

Not as far as I know. But you can simulate this with String#each by
reading the whole file in one go and then iterating:

contents = f.read()
contents.each {|line|
  # processing...
}

or work directly on contents by using String#sub!

Did you try to use "file.sync= false" in conjunction with "file.flush"?
Did you try reading the whole file in with "contents = file.read()" and
then do line by line processing by doing "contents.each { |line| .... }?

And: did you make sure that IO is the problem and not the processing part?

Regards

    robert