Re: [PATCH v2 0/6] Partial clone part 1: object filtering

From: Jeff Hostetler <git@jeffhostetler.com>
Date: Nov 8, 2017, 14:39 UTC
Message-ID: <de392bf3-bd53-1c17-3a43-c2e1604cbd59@jeffhostetler.com>
In-Reply-To: <xmqq8tfhoai3.fsf@gitster.mtv.corp.google.com>

On 11/7/2017 7:54 PM, Junio C Hamano wrote:

Show 17 quoted lines

> Jonathan Tan <jonathantanmy@google.com> writes:
> 
>> I can see some use for this parameter - for example, when doing a report
>> for statistical purposes (percentage of objects missing, for example) or
>> for a background task that downloads missing objects into a cache. Also,
>> power users who know what they're doing (or normal users in an
>> emergency) can use this option when they have no network connection if
>> they really need to find something out from the local repo.
>>
>> In these cases, the promisor check (after detecting that the object is
>> missing) is indeed not so useful, I think. (Or we can do the
>> --exclude=missing and --exclude=promisor idea that Jeff mentioned -
>> --exclude=missing now, and --exclude=promisor after we add promisor
>> support.)
> 
> This sounds like a reasonable thing to have in the endgame state to
> me.

OK thanks, I'll change it to --exclude=missing in my next version.

Show 13 quoted lines

> 
>> Having said that, I would be OK if we didn't have tolerance (and/or
>> reporting) of missing objects right now. As far as I know, for the
>> initial implementation of partial clone, only the server performs any
>> filtering, and we assume that the server possesses all objects (so it
>> does not need to filter out any missing objects).
> 
> True.  It does not have to exist in an early part, but I do not
> think we would terribly mind if it does, if only to help debugging
> and development.
> 
> Thanks for thinking it through.
>

Right, it could come later, but having it here in part 1 as part of the initial series completes the pre-promisor portion of these commands. Having a print-missing option lets rev-list -- as is -- be used in a bulk-fetch-object pre-checkout hook or as part of a "give me what I need before I go offline" command. This is useful by itself. It does augment the dynamic fetch-object code added in part 2 and the unpack-trees changes in part 3 to call fetch-object.

Jeff