OpenEuphoria

Re: Size of files

• Posted by Robert Craig <rds at RapidEuphoria.com> Oct 26, 2005
• 469 views

Vincent wrote:
> 
> Juergen Luethje wrote:
> > 
> > Hi all,
> > 
> > how big are the biggest files that Euphoria can handle (especially
> > interesting for me: on Windows)?
> > 
> > I stumbled across the following text in the Eu 2.5 documentation of
> > where():   "i = where(fn)".
> > In the Euphoria documentation, 'i' means an integer, doesn't it?
> > Since where() is zero based(*), this would mean that it works with
> > files up to
> >      MAX_INTEGER+1 bytes = power(2,30) bytes = 1 GB
> > 
> > Does where() actually not work with files > 1 GB?
> > 
> > Regards,
> >    Juergen
> > 
> > (*) This is not mentioned in the documentation of where(), BTW.
> > 
> > -- 
> > Have you read a good program lately?
> > 
> > 
> That was a bug fix in Euphoria 2.4 Alpha:
> 
> bug fixed: where() was not always reporting file positions greater than 1 Gb
> correctly. Arithmetic performed on the position would probably fail. It now
> handles up to 2 Gb. 
> 
> 
> You can use integer atoms up to 32 bits long, but the limit of 2 GB is based
> on the open() routine who's OP uses an obsolete C file routine, I think. Thus
> 2 GB is the limit for Euphoria applications, libraries, opening files, file
> inclusion, EDB files, etc.
> 
> Rob should use newer C file I/O routines in the C backend that offer the full
> 4 GB limit/8 byte offsets or something. Rob should also be thinking about 64
> bit compliant products sooner rather than later.
> 
> 4 GB these days is not very much let alone 2 GB, especially for databases.

That's correct. Thanks.
I should add that the manual uses "i" to indicate 31-bit Euphoria
integers, but seek() and where() can handle a number bigger than
an integer (1Gb). I just re-tested it on some huge files. 
I will update the docs to use "a", to show that
a number greater than 1Gb can be used. Actually, the limit on all
platforms is 2 Gb, due to restrictions in the standard C library routines.
You'd think the limit would be 4Gb, but it's not.
I intend to go well beyond 2Gb or 4Gb, sooner or later, 
but it might not be possible for DOS.

Regards,
   Rob Craig
   Rapid Deployment Software
   http://www.RapidEuphoria.com