Re: [PATCH] make the pack index version configurable

From: Nicolas Pitre <nico@cam.org>
Date: Nov 2, 2007, 04:01 UTC
Message-ID: <alpine.LFD.0.9999.0711012345220.21255@xanadu.home>
In-Reply-To: <ee77f5c20711012042r39c6303em2a8140e8348051d@mail.gmail.com>

On Fri, 2 Nov 2007, David Symonds wrote:

Show 15 quoted lines

> On 11/2/07, Nicolas Pitre <nico@cam.org> wrote:
> >
> > +pack.indexVersion::
> > +       Specify the default pack index version.  Valid values are 1 for
> > +       legacy pack index used by Git versions prior to 1.5.2, and 2 for
> > +       the new pack index with capabilities for packs larger than 4 GB
> > +       as well as proper protection against the repacking of corrupted
> > +       packs.  Version 2 is selected and this config option ignored
> > +       whenever the corresponding pack is larger than 2 GB.  Otherwise
> > +       the default is 1.
> 
> If you're trying to force a previous pack version for some reason
> (backward compatibility, or whatever), this "feature" of automatic
> forcing version 2 for 2 GB packs might come as a nasty suprise.
> Wouldn't it be better to fail with an error?

No. The fact is that you don't know in advance what the pack size will be, and reaching that limit might take a long while already if repacking, or even more so if the pack is fetched over a network connection. That would be wasteful to simply throw away all the whole repack/download with an error which would be an even nastier surprise at that point just because you specified index v1.

And such a pack would be impossible to work with using an old Git version anyway, so the old Git version will happily give you the error, suggesting that you upgrade to a later version.

And this has been the implemented behavior for the last 7 months already.

And the idea is to switch the default to version 2 eventually.

Etc.

Nicolas