Re: [Gnu-arch-users] Fast commits

[Robin Farine]

Aaron Bentley wrote:

> I think you missed the "no incompatible changes to the archive format" 
> rule.

Right, older versions of tla would not be able to deal with this new 
archive format. The reverse would work though.

> More feasible would be just adding a LAST-REVISION file, that (if 
> present) would be used as a hint about what the last revision was.  If 
> not present, or if wrong, we could fall back to the O(n) techniques.

I agree that the LAST-REVISION (or ++last-revision :-) file solution is 
simpler and completely compatible.  My initial idea was to have the 
exact last revision atomically updated as part of the commit 
transaction. But assuming commits with a tla version aware of the 
LAST_REVISION file happen regularly,  this file would give a starting 
point not far from the actual last revision. Looks good.

Thanks for the comment,

Robin