From: Shawn O. Pearce <spearce@spearce.org>
Date: Tue, 07 Jul 2009 20:13:26 GMT
Subject: Re: What's cooking in git.git (Jul 2009, #01; Mon, 06)
Message-ID: <20090707201326.GB11191@spearce.org>
In-Reply-To: <alpine.DEB.1.00.0907072206170.3155@pacific.mpi-cbg.de>

Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> On Mon, 6 Jul 2009, Junio C Hamano wrote:
> 
> > * jh/notes (Sat May 16 13:44:17 2009 +0200) 5 commits
> >  - Teach "-m <msg>" and "-F <file>" to "git notes edit"
> >  - Add an expensive test for git-notes
> >  - Speed up git notes lookup
> >  - Add a script to edit/inspect notes
> >  - Introduce commit notes
> > 
> > Dscho asked about the performance implications of this; I do not think I 
> > saw any progress on that yet...
> 
> Neither did I.

I was thinking about this the other day.  We could use a hash of
the commit timestamp as the top level directory.  E.g. if we take
the commit time of the commit and convert it to a date string,
we could make the note path e.g.:

  YYYY/MM/COMMITSHA1

The advantage is we only need to scan and hash the subtrees for
the range of commits we are currently producing output for.  As we
go further back in time, we can evict entries for newer dates and
hash the older dates.

-- 
Shawn.