Re: [PATCH] Support 64-bit indexes for pack files.

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Feb 27, 2007, 20:35 UTC
Message-ID: <Pine.LNX.4.63.0702272134040.22628@wbgn013.biozentrum.uni-wuerzburg.de>
In-Reply-To: <F4EA27AD-EF1C-4BF2-8D52-945E0AE51006@adacore.com>

Hi,

On Tue, 27 Feb 2007, Geert Bosch wrote:

Show 16 quoted lines

> 
> On Feb 27, 2007, at 15:05, Johannes Schindelin wrote:
> > On Tue, 27 Feb 2007, Geert Bosch wrote:
> > 
> > > The object-count at the beginning of the pack is a little strange 
> > > for local on-disk pack files, as it is data that can easily be 
> > > derived.
> > 
> > The SHA1 is also easily derived. So think of it as a doubly secure way 
> > to ensure integrity.
> > 
> > Remember, there were some people unable to accept that SHA1 collisions 
> > are _unlikely_...
> 
> Ah, you include the count because you don't trust the SHA1 and now you 
> can count that you got the right number of objects ;-)

I don't know if it was included for that reason, but you can excuse it that way. :-)

> It's just that I don't see a use for the count in a local on-disk pack. 
> In these cases we'll always have an index. We can keep the current 
> protocol for sending/receiving packs, no need to ever upgrade to v4 
> there.

But the protocol expects a valid pack! (Including a count...)

Besides, the pack index is a purely local thin, reconstructed from the pack when fetching...

Ciao, Dscho