From: Paul Mackerras <paulus@samba.org>
Date: Sun, 24 Feb 2008 01:55:48 GMT
Subject: Re: Rewriting boundary parents when path-limiting
Message-ID: <18368.52900.408974.782802@cargo.ozlabs.ibm.com>
In-Reply-To: <alpine.LFD.1.00.0802190921460.7833@woody.linux-foundation.org>

Linus Torvalds writes:

> Quite frankly, I suspect it's not worth it, and maybe you just shouldn't 
> do that optimization and limit the commits in other ways instead (ie you 
> might try to limit them *numerically* instead of by using negative 
> commits, and do one first run with the number of commits limited to <n>, 
> and then if that wasn't enough to re-connect the trees, you do the whole 
> thing)

OK.  I have fixed the problem in gitk by making it do:

    git rev-list --first-parent --max-count=1 $id -- paths...

for each id that it gets while updating that is a boundary commit, if
we are doing path limiting and the id is one that isn't in the graph.
If what we get back is a commit that is already in the graph, then we
use it instead.  That seems to do what I want.

Currently gitk executes that git rev-list synchronously, but if that
causes noticeable pauses, it could be done asynchronously instead.

Paul.