Re: [PATCH] gc --auto: warn garbage collection happens soon

2011/12/29 Jeff King [off-list ref]:

Especially now that prune has learned about progress reporting, it's
easy to see in "git gc" that the "Counting objects" phase of the repack
and the connectivity search in prune are counting the same objects.  It
would obviously be easy to just dump the set of sha1s in packed binary
format, and let git-prune reference that.

But it doesn't work in the general case. Running "git gc" will repack
everything, and so it looks at all reachable objects. But "git gc
--auto" will typically do an incremental pack (unless you have too many
packs), which means its counting objects phase only looks at part of
the graph.  So that result can't be used for object reachability, since
many objects won't be marked[1].

Hmm.. I was thinking of sharing this "counting objects" part when
repack is rewritten in C. I guess I can drop the idea now.
-- 
Duy