From: Jeff King <peff@peff.net>
To: Shawn Pearce <spearce@spearce.org>
Cc: marcnarc@xiplink.com, "Ævar Arnfjörð" <avarab@gmail.com>,
"Angelo Borsotti" <angelo.borsotti@gmail.com>,
git <git@vger.kernel.org>
Subject: Re: push race
Date: Tue, 16 Oct 2012 00:51:18 -0400 [thread overview]
Message-ID: <20121016045118.GA21359@sigill.intra.peff.net> (raw)
In-Reply-To: <CAJo=hJu=eqgUhJvvpMLJ05AT6o+nVUDcm+tHV8en8OCX2-2qgA@mail.gmail.com>
On Mon, Oct 15, 2012 at 07:09:52PM -0700, Shawn O. Pearce wrote:
> On Mon, Oct 15, 2012 at 11:56 AM, Jeff King <peff@peff.net> wrote:
> > Right. The only thing that needs locking is the refs, because the object
> > database is add-only for normal operations, and by definition collisions
> > mean you have the same content (or are astronomically unlucky, but your
> > consolation prize is that you can write a paper on how you found a sha1
> > collision).
>
> Its worth nothing that a SHA-1 collision can be identified at the
> server because the server performs a byte-for-byte compare of both
> copies of the object to make sure they match exactly in every way. Its
> not fast, but its safe. :-)
Do we? I thought early versions of git did that, but we did not
double-check collisions any more for performance reasons. You don't
happen to remember where that code is, do you (not that it really
matters, but I am just curious)?
-Peff
next prev parent reply other threads:[~2012-10-16 4:51 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-15 9:14 push race Angelo Borsotti
2012-10-15 11:05 ` Matthieu Moy
2012-10-15 11:53 ` Nguyen Thai Ngoc Duy
[not found] ` <CAPc5daUon3eLTDT=3wo_=rTCJWVe=ufCvmSzrjD=0T17Dxkpqw@mail.gmail.com>
2012-10-15 11:50 ` Angelo Borsotti
2012-10-15 14:09 ` Ævar Arnfjörð Bjarmason
2012-10-15 14:13 ` demerphq
2012-10-15 14:29 ` Marc Branchaud
2012-10-15 15:50 ` Angelo Borsotti
2012-10-15 18:58 ` Jeff King
2012-10-15 18:56 ` Jeff King
2012-10-16 2:09 ` Shawn Pearce
2012-10-16 4:51 ` Jeff King [this message]
2012-10-16 5:15 ` Nguyen Thai Ngoc Duy
2012-10-16 5:37 ` Jeff King
2012-10-16 10:45 ` Nguyen Thai Ngoc Duy
2012-10-16 17:02 ` Jeff King
2012-10-16 17:21 ` Junio C Hamano
2012-10-16 17:25 ` Jeff King
2012-10-16 19:09 ` Junio C Hamano
2012-10-16 6:35 ` Angelo Borsotti
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20121016045118.GA21359@sigill.intra.peff.net \
--to=peff@peff.net \
--cc=angelo.borsotti@gmail.com \
--cc=avarab@gmail.com \
--cc=git@vger.kernel.org \
--cc=marcnarc@xiplink.com \
--cc=spearce@spearce.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).