From: Teng Long <dyroneteng@gmail.com>
Date: Wed, 02 Nov 2022 05:37:48 GMT
Subject: Re: [PATCH 0/1] pack-bitmap.c: avoid exposing absolute paths
Message-ID: <20221102053748.7366-1-tenglong.tl@alibaba-inc.com>
In-Reply-To: <Y1rt+uOKwlP5PIrT@coredump.intra.peff.net>

Jeff King <peff@peff.net> writes：

> Now this might not be as bad as it seems:
>
>   - in the long run, we might open those idx files anyway, if we have to
>     access those packs. So it's really just overriding the lazy-open
>     behavior.

Sorry, can you explain it a bit more. When we might open idxes anyway? Do you
mean if the pack idx files will be opened sooner or later if a repo serves
git-upload-pack many times in the long run. So, the system-wide table or the
mmap space will not be wasted so much in practice.

>   - in the worst case, the one bitmap file is at the end of the list, so
>     you hit all N anyway. And this is actually pretty common, since we
>     sort in reverse-chronological order, and the bitmap is usually on
>     the oldest and biggest pack.

Yes, in "sort_pack()" I think.

> So it may not be worth worrying about. It does seem like it would be
> easy to reorder open_pack_bitmap_1() to look for a bitmap file first and
> only open the idx if it finds something.

I think it may be worthy if we have lots of packs and the bitmap is refer to
an older one, but I didn't make the test. At least, the scenario is common, I
agree with that, so maybe we could shuffle the sort order in "open_pack_bitmap()".

Thanks.