Re: Ada.Streams.Stream_IO.Stream_Access

[alex_seymour@lineone.net (Alex)]

Martin Krischik <martin@krischik.com> wrote in message news:<8880854.x4B7rzzIl0@linux1.krischik.com>...
> Alex wrote:
> 
> > Hi,
> > 
> > I am having a problem with ADA Streams.
> > 
> > I need to access a file which is >2Gb and read data from it in chunks.
> > 
> > Firstly I was having problems getting the file size as
> > Ada.Streams.Stream_IO.Size didn't seem to want to go over Integer'last
> > (2*31)
> > Worked fine for files up until the 2Gb range and then it went funny!
> > 
> > I had to call a 'c' routine (returned an Integer64...i.e. 2*63) to get
> > the file size and decide how many chunks I wanted.
> > 
> > Ok, now I try to read from the huge file....and bang I am getting a
> > Constraint error. Is this a case that I just can't use ADA Streams on
> > files bigger then 2*31 bytes??
> > 
> > This is driving me nuts and I don't want to call 'c' routines again
> > and spoil my ADA :)
> 
> I take it that you are not a AdaCore customer - otherwise you would not ask
> here. However there is a communication channel for non customer as well:
> "GNAT Discussion List" <gnatlist@lyris.seas.gwu.edu>. You might want to
> raise the point there.
> 
> With Regards
> 
> Martin

Thanks,

I am not an ADACORE custumer, just a frustrated ADA programmer trying
to read from a <2Gb file.

Not ADA related, but as a side issue, I am new to 64 bit
representation.
I understand it is split into High/Low (high-order 32 bits and low
order 32 bits
representations of the value). At the moment for files 3Gb in size,
High
is always zero, however, what happens if both High and Low have value?