Re: autorevert.el

[Luc Teirlinck <teirllm@dms.auburn.edu>]

Eli Zaretskii wrote:

   > For dired buffers, visited-file-modtime works

   Only on Posix systems, btw.  On MS-Windows, the directory's time
   stamp does not change when you add or remove files.

That would mean that on MS-Windows, you also would not always (or even
rarely) get the "Directory has changed on disk; type g to update Dired"
massages by which dired warns you that the information you are getting
is obsolete.  Indeed, the way Auto Revert Mode would check whether a
dired buffer needs reverting _after my patch is applied_ would be
identical to the way Dired decides whether it needs to print that message.

Anyway, I believe I have no choice but to change the current handling
of dired buffers by autorevert, because the present code is wrong and
chews up tons of CPU.  I have the impression that the current code
takes substantially more time checking whether a dired buffer needs
reverting than it would take to actually revert it.  On top of that,
the results of the check are completely incorrect.

What this could mean is that autoreverting of dired buffers may not
work on MS-Windows or maybe that, on MS-windows, one could just
automatically autorevert dired buffers every auto-revert-interval
seconds, assuming one has a reasonably fast computer (admittedly a
very suboptimal solution).

Once I have actually applied my patch, people could experiment and see
what really happens on various operating systems.

Sincerely,

Luc.