Re: Hideously slow VC status queries fixed

[Tom Tromey <tromey@redhat.com>]

>>>>> "Eric" == Eric S Raymond <esr@snark.thyrsus.com> writes:

Eric> It gives me great pleasure to be able to announce that I have found,
Eric> and fixed, the bug that made C-x v d so godawful much slower than the
Eric> underlying commands.

Nice.  The speed of vc-dired is one reason I'm still using pcl-cvs
(and the un-bundled psvn) for everything.

I optimistically tried the new vc-dired on my killer test case: gcc.
I didn't try the whole trunk (since that is just way too big), but I
tried on 'trunk/gcc' -- unlike running on the whole trunk, this is a
reasonable thing to want to do since most hacking takes place here.

After a few minutes I got this:

    Warning (undo): Buffer `gcc' undo info was 3023389 bytes long.
    The undo info was discarded because it exceeded `undo-outer-limit'.

At that point I interrupted it.

'svn status' in gcc/trunk takes less than a second (when warm -- true
in both these tests).  'svn status -v' takes 12 seconds when printing
to gnome-terminal, less than 2 seconds when printing to 'wc'.

I don't know whether vc-dired is expected to scale to a working
directory with 26,499 files underneath it.  I sure wish it would :-).
FWIW neither pcl-cvs nor psvn handles this case very well either (the
psvn author helpfully provided some ideas for tweaking it, which I
haven't attempted yet).

Tom