From: "Shawn O. Pearce" <spearce@spearce.org>
To: Avery Pennarun <apenwarr@gmail.com>
Cc: Joshua Juran <jjuran@gmail.com>,
Finn Arne Gangstad <finnag@pvv.org>,
git@vger.kernel.org
Subject: Re: inotify daemon speedup for git [POC/HACK]
Date: Tue, 27 Jul 2010 17:00:09 -0700 [thread overview]
Message-ID: <20100728000009.GE25268@spearce.org> (raw)
In-Reply-To: <AANLkTi=oA33M4DmS5FyDx7Wn1DFrUGcmhSYkvcSYMc2r@mail.gmail.com>
Avery Pennarun <apenwarr@gmail.com> wrote:
>
> While we're here, it's probably worth mentioning that git's index file
> format (which stores a sequential list of full paths in alphabetical
> order, instead of an actual hierarchy) does become a bottleneck when
> you actually have a huge number of files in your repo (like literally
> a million). You can't actually binary search through the index! The
> current implementation of submodules allows you to dodge that
> scalability problem since you end up with multiple smaller index
> files. Anyway, that's fixable too.
Yes.
More than once I've been tempted to rewrite the on-disk (and I guess
in-memory) format of the index. And then I remember how painful that
stuff is in either C git.git or JGit, and I back away slowly. :-)
Ideally the index is organized the same way the trees are, but
you still can't do a really good binary search because of the
ass-backwards name sorting rule for trees. But for performance
reasons you still want to keep the entire index in a single file,
an index per directory (aka SVN/CVS) is too slow for the common
case of <30k files.
--
Shawn.
next prev parent reply other threads:[~2010-07-28 0:00 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-27 12:20 inotify daemon speedup for git [POC/HACK] Finn Arne Gangstad
2010-07-27 23:29 ` Avery Pennarun
2010-07-27 23:39 ` Joshua Juran
2010-07-27 23:51 ` Avery Pennarun
2010-07-28 0:00 ` Shawn O. Pearce [this message]
2010-07-28 0:18 ` Avery Pennarun
2010-07-28 1:14 ` Joshua Juran
2010-07-28 1:31 ` Avery Pennarun
2010-07-28 6:03 ` Sverre Rabbelier
2010-07-28 6:06 ` Jonathan Nieder
2010-07-28 7:44 ` Ævar Arnfjörð Bjarmason
2010-07-28 11:08 ` Theodore Tso
2010-07-28 8:20 ` Nguyen Thai Ngoc Duy
2010-08-13 17:53 ` Enrico Weigelt
2010-07-28 13:09 ` Jakub Narebski
2010-07-28 13:06 ` Jakub Narebski
2010-08-13 17:58 ` Enrico Weigelt
2010-07-27 23:58 ` Sverre Rabbelier
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
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100728000009.GE25268@spearce.org \
--to=spearce@spearce.org \
--cc=apenwarr@gmail.com \
--cc=finnag@pvv.org \
--cc=git@vger.kernel.org \
--cc=jjuran@gmail.com \
/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.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
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 read-only IMAP folder(s) and NNTP newsgroup(s).