Re: Integrating support for GNOME VFS into glibc

[Chipzz <chipzz ULYSSIS Org>]

On Fri, 17 Dec 2004, Nicholas Allen wrote:

> >From what I understand the problem is this: GNOME VFS (or any other
> >
> > similar virtual filesystem) can not provide full POSIX compliance since
> > many protocols simply doesn't support it. So this would break the POSIX
> > compliance of glibc and most likely a considerable amount of
> > applications relying on it. Another reason might be that many people
> > like to keep most of their system (including GNOME VFS and all its
> > dependencies) on a partition not available on boot-time (often located
> > on another host). It would be quite inconvenient with all those extra
> > dependencies even to /sbin/init.
>
> That's why I was thinking of using LD_PRELOAD to do it - to keep the
> dependancies out of glibc. Another approach would be that glibc used dlopen
> and dlsym so there would be no hard dependancy - It would make use of it if
> it was installed otherwise not.
>
> I realize that VFS is not posix compliant but I think that it should be
> possible to emulate features that are missing from VFS that are required by
> POSIX and also if it can't be emulated then to set errno to the most
> appropriate error.
>
> Do you know of any specific problems that couldn't be addressed?

One problem (which admittedly can be addressed) would be seeking. You
would need to keep the whole file in-memory, which may get quite large
(how do you seek on dynamically generated files by http, think slashdot
for example, which may have changed if you re-read the file). mmap'ing
would also be a problem for example.

kr,

Chipzz AKA
Jan Van Buggenhout
-- 

------------------------------------------------------------------------
                 UNIX isn't dead - It just smells funny
                           Chipzz ULYSSIS Org
------------------------------------------------------------------------
"Baldric, you wouldn't recognize a subtle plan if it painted itself pur-
 ple and danced naked on a harpsicord singing 'subtle plans are here a-
 gain'."