Re: Add "--show-all" revision walker flag for debugging

From: Nicolas Pitre <nico@cam.org>
Date: Feb 10, 2008, 01:28 UTC
Message-ID: <alpine.LFD.1.00.0802092016540.2732@xanadu.home>
In-Reply-To: <alpine.LSU.1.00.0802100110450.11591@racer.site>

On Sun, 10 Feb 2008, Johannes Schindelin wrote:

Show 14 quoted lines

> Hi,
> 
> On Sat, 9 Feb 2008, Linus Torvalds wrote:
> 
> > I'm starting to free up some resources to look at the interesting 
> > problem with screwed-up commit dates confusing our commit walker into 
> > thinking that some uninteresting commit isn't actually uninteresting due 
> > to not traversing the uninteresting chain deep enough.
> 
> I was thinking the other night why I did not like the generation header.  
> And I found out why: it is redundant information.
> 
> So why not have some local "cache" which maintains the generation numbers 
> for the commits?  (Much like the "notes" cache I showed last year?)

Absolutely.

I, too, have some reservations about adding any kind of generation header to commit objects. First because it can be generated and maintained locally, just like the pack index. But also because its usefulness has not been proven in all possible graph topologies, and adding it to the commit header pretty much deny any further modifications/improvements on it, if for example some other kind of generation notation becomes advantageous to use.

So please don't put it into the commit object format. The object database should ultimately contain only data that cannot be regenerated.

Nicolas