Re: [RFC PATCH 0/5] Add delta islands support
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Jul 24, 2018, 17:18 UTC
- Message-ID
- <xmqqa7qgzh6c.fsf@gitster-ct.c.googlers.com>
- In-Reply-To
- <20180724101627.GC3578@sigill.intra.peff.net>
Jeff King <peff@peff.net> writes:
> I think this is inherent in the scheme (we're losing some delta > opportunities). But I think it's also made worse because the delta > window gets clogged with candidates that are forbidden by the island > config.
Hmph, and the reason why objects that do not even belong to the same island to be usable as a base are in the object list in the first place is...?
> Repacking with a big --window helps (and doesn't take as long > as it otherwise might because we can reject some object pairs based > on islands before doing any computation on the content).
Ah, then yes, a large window with early culling based on the delta island criteria definitely sounds like the right solution to that problem.
> I have replacement code (which we have been running in production) > that is more clever about the threshold, and also can handle gaps in > the continuity (so we might realize we need to send objects 1-5000, > then skip a few, then 5037-8000, and so on).
That vaguely sounds similar to what folks at $DAYJOB runs in their Gerrit/jgit thing.