Re: [RFC PATCH] Re: Empty directories...

From: David Kastrup <dak@gnu.org>
Date: Jul 21, 2007, 05:15 UTC
Message-ID: <85sl7i9w1j.fsf@lola.goethe.zz>
In-Reply-To: <alpine.LFD.0.999.0707202135450.27249@woody.linux-foundation.org>

Linus Torvalds <torvalds@linux-foundation.org> writes:

Show 9 quoted lines

> On Sat, 21 Jul 2007, David Kastrup wrote:
>> 
>> Ok, I have now acquired enough passing familiarity with the code
>> that I find part of my way around it.  Most of your patch looks
>> like it caters for the S_ISDIR type not previously in use in the
>> index (how about the repository?).
>
> The object database has always had S_ISDIR (well, "always" is since
> very early on, when I realized that flat trees didn't cut it).

Then I think I have a bit of a problem: I should think that S_ISDIR in the repository presumably marks a tree object (still very fuzzy around the concepts here). An explicitly checked-in directory (under my scheme always named "." inside of its tree) would presumably also have S_ISDIR in the repository but behave quite differently.

> As far as I can tell, it would have been exactly the same thing as the 
> S_IFDIR, just instead of the S_IFDIR check, you'd have had to check the 
> end of the filename for being '/'.

Relative file name of ".", more or less. Both names satisfy S_IFDIR in the filesystem, though.

> Otherwise? Exactly the same.

> The more important thing is in many ways the object storage, and
> that's also the reason for doing the index the way I did - it more
> closely matches what the object storage does (ie the "index" ends up
> mirroring a linearized and unpacked "tree" object).

I still have to get enough of a clue about the object store to see how this pans out. I would not want to have the "." objects marked as type "tree" and empty if I can avoid it. It seems unclean, would need extra case separations all over the place, violate the "empty trees evaporate" property and also waste a good place for tracking permissions or other attributes in future.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum