Re: More precise tag following

[Nicolas Pitre <nico@cam.org>]

On Sat, 27 Jan 2007, Simon 'corecode' Schubert wrote:

> Maybe I was not clear enough.  I do not propose to change the file format, but
> to extend the information stored.  In which way whatsoever.  However I think
> that keeping this information along with trees in pack files seems very
> sensible.  Or along pack files, whatever.

Along pack files please.

> > Rather, calculate the information you need from the existing data, and if
> > you can reuse it, store it locally. _That_ is flexibility.
> 
> Of course this is flexibility.  But this also means that every consumer has to
> do this for every repo.  Wouldn't it be nice to have it done one time and then
> stored in a pack?

NO!  That would mean that this extra information is now tied to the pack 
format and this is not a good thing to depend on.

Every consumer is already recomputing the pack index locally for every 
repo.  This has the advantage that we can change the pack index format 
as we so choose without having to bother with backward compatibility in 
the pack transfer protocol.

> > And if something is wrong with that "auxillary information", it can be
> > regenerated correctly, without touching the real data -- the commit
> > ancestry.
> 
> Yes, it always can be regenerated.  I never said it should be made part of the
> core structure.

But the pack format is pretty much part of the core structure.  If 
things can be deduced from the pack without adding to it then they 
should.  This way you have the freedom to experiment with any ancillary 
format you wish.


Nicolas