Re: [PATCH] send-pack: use OBJECT_INFO_QUICK to check negative objects

From: Junio C Hamano <gitster@pobox.com>
Date: Dec 4, 2019, 21:37 UTC
Message-ID: <xmqqr21j3h7e.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20191204205353.118168-1-jonathantanmy@google.com>

Jonathan Tan <jonathantanmy@google.com> writes:

Show 9 quoted lines

> As for whether we should do it in the first place, I think that having 2
> orthogonal flags is clearer than having 1 that controls fetch
> (SKIP_FETCH) and 1 that does both (QUICK) without any that recheck
> packed, but I'm quite familiar with this part of the code, so perhaps
> I'm the wrong person to ask - we should optimize for the typical Git
> developer who just wants to access the object store. Judging from the
> frequency in which we encounter this issue (as Peff says), maybe we
> should go ahead and make QUICK imply SKIP_FETCH but not the other way
> around.

Thanks for thinking this through.  I am OK with that direction.

> (It is also possible just to make both imply the other and unify
> QUICK and SKIP_FETCH into one flag - I am not opposed to that -
> although read my email that Peff linked to see why bidirectional
> implication is correct in one sense but incorrect in another.)

Yup, also from the old message:

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> Having said that, perhaps we should consider promisor-remote.c as
> low-level code and expect it to know that objects are fetched into a
> packfile (as opposed to loose objects), so it can safely use QUICK
> (which is documented as checking packed after packed and loose). If no
> one disagrees, I can make such a patch after jt/push-avoid-lazy-fetch is
> merged to master (as is the plan, according to What's Cooking [1]).

I agree that it makes sense to treat promisor-remote.c as the low-level implementation detail that is allowed to be intimately familiar with how its behaviour would interact with QUICK and SKIP_FETCH options.

Thanks.