[0/2] enable bitmap hash-cache by default

Message

Jeff King March 15, 2019, 6:21 a.m. UTC

On Thu, Mar 14, 2019 at 12:02:56PM -0400, Jeff King wrote:

> On Thu, Mar 14, 2019 at 09:12:54AM +0000, Eric Wong wrote:
> 
> > > The reason it defaults to off is for on-disk compatibility with JGit.
> > 
> > Right.  Our documentation seems to indicate JGit just warns (but
> > doesn't fall over), so maybe that can be considered separately.
> 
> I think it was a hard error in the beginning, but they changed it pretty
> soon after we added more flags. So it might be reasonable to just enable
> it by default (but it wouldn't hurt to double check the behavior).
> 
> I tried running t5310 (which does a back-and-forth with jgit) using this
> patch:

I dug up the actual JGit change, and it was indeed from 2014. So here's
a more complete series to handle that. There's a minor performance
mystery in the second patch, but I think it might be OK to proceed even
without solving it.

Conceptually these go on top of your patch, but they could be applied
separately.

  [1/2]: t5310: correctly remove bitmaps for jgit test
  [2/2]: pack-objects: default to writing bitmap hash-cache

 Documentation/config/pack.txt      | 4 +---
 builtin/pack-objects.c             | 2 +-
 t/perf/p5310-pack-bitmaps.sh       | 3 +--
 t/perf/p5311-pack-bitmaps-fetch.sh | 1 -
 t/t5310-pack-bitmaps.sh            | 5 ++---
 5 files changed, 5 insertions(+), 10 deletions(-)

-Peff