Re: [PATCH] Introduce light weight commit annotations

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Jun 10, 2007, 23:00 UTC
Message-ID: <Pine.LNX.4.64.0706102333050.4059@racer.site>
In-Reply-To: <7v4plf7948.fsf@assigned-by-dhcp.cox.net>

Hi,

On Sun, 10 Jun 2007, Junio C Hamano wrote:

Show 20 quoted lines

> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
> 
> > With the provided script, edit-commit-annotations, you can add
> > after-the-fact annotations to commits, which will be shown by
> > the log if the config variable core.showannotations is set.
> >
> > The annotations are tracked in a new ref, refs/annotations/commits,
> > in the same fan-out style as .git/objects/??/*, only that they only
> > exist in the object database now.
> >
> > Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> > ---
> >
> > 	I have the hunch that this will be relatively fast and scalable,
> > 	since the tree objects are sorted by name (the name being the
> > 	object name of the to-be-annotated commit).
> 
> The entries of tree are sorted but not necessarily of uniform
> length so you end up needing linear search anyway.  The fan-out
> would help with the current tree objects.

I do not understand... the entries of a tree object are sorted alphabetically, right? Including the convention that if one is a prefix of another, it is "smaller".

While I think that the length would not be any problem, the entries' names of refs/annotations/commit^{tree} are _all_ of length two, and point to other tree objects. _Those_ tree objects contain _only_ entries whose names contain exactly 38 characters.

> It will hurt _if_ we introduce a new tree object format that would give 
> you a quick random-access at an entry, but it is premature to worry 
> about that now.

I do not see that. Care to enlighten me?

Ciao, Dscho