Re: [RFC] Cache negative delta pairs

On Thu, 29 Jun 2006, Linus Torvalds wrote:

On Thu, 29 Jun 2006, Nicolas Pitre wrote:

quoted

On Thu, 29 Jun 2006, Linus Torvalds wrote:

quoted

Instead of having a separate cache, wouldn't it be much better to just 
take the hint from the previous pack-file?

DOH!  ;-)

Btw, I think this could do with a flag to turn it on/off (but probably 
default to on).

I think it should simply be coupled with the --no-reuse-delta flag.

The advantage of this patch is that it should guarantee that if everything 
is already packed, a repack will basically keep the pack identical. 

However, that is obviously also the dis-advantage, since it means that 
repacking cannot improve packing. So adding a flag to say "please try to 
incrementally improve the pack" might well be worth it, even if this new 
behaviour would be the _default_.

Actually, the delta reusing already prevents those deltas from being 
improved.  So your patch only extend this notion to the non-deltified 
objects as well.  And the way out is to provide the --no-reuse-delta 
flag.


Nicolas