Re: [PATCH] always start looking up objects in the last used pack first

On 5/30/07, Nicolas Pitre [off-list ref] wrote:

Jon Smirl said:
| Once an object reference hits a pack file it is very likely that
| following references will hit the same pack file. So first place to
| look for an object is the same place the previous object was found.

This is indeed a good heuristic so here it is.  The search always start
with the pack where the last object lookup succeeded.  If the wanted
object is not available there then the search continues with the normal
pack ordering.

Nice numbers for performance,
especially your later email showing this makes
split packs almost as quick as one pack.

Note: the
--max-pack-size to git-repack currently produces packs with old objects
after those containing recent objects.  The pack sort based on
filesystem timestamp is therefore backward for those.  This needs to be
fixed of course, but at least it made me think about this variable for
the test.

Yes,  I was intending to submit a patch to builtin-pack-objects.c
to reverse the timestamps when split packs were created.
Haven't got around to it yet.
-- 
Dana L. How  danahow@gmail.com  +1 650 804 5991 cell