Re: [PATCH] submodule: use cheaper check for submodule pushes
- Date: Wed, 12 Jul 2017 22:14:34 -0700
- From: Stefan Beller <sbeller@xxxxxxxxxx>
- Subject: Re: [PATCH] submodule: use cheaper check for submodule pushes
On Wed, Jul 12, 2017 at 5:53 PM, Junio C Hamano <gitster@xxxxxxxxx> wrote:
> Jonathan Nieder <jrnieder@xxxxxxxxx> writes:
>>> In the function push_submodule we use add_submodule_odb to determine
>>> if a submodule has been populated. However the function does not work with
>>> the submodules objects that are added, instead a new child process is used
>>> to perform the actual push in the submodule.
>>> Use is_submodule_populated that is cheaper to guard from unpopulated
>>>  'push_submodule' was added in eb21c732d6 (push: teach
>>> --recurse-submodules the on-demand option, 2012-03-29)
>>>  'add_submodule_odb' was introduced in 752c0c2492 (Add the
>>> --submodule option to the diff option family, 2009-10-19)
>>>  'is_submodule_populated' was added in 5688c28d81 (submodules:
>>> add helper to determine if a submodule is populated, 2016-12-16)
>> These footnotes don't answer the question that I really have: why did
>> this use add_submodule_odb in the first place?
>> E.g. did the ref iteration code require access to the object store
>> previously and stop requiring it later?
> Yes, the most important question is if it is safe to lose the access
> to the object store of the submodule. It is an endgame we should
> aim for to get rid of add_submodule_odb(), but does the rest of this
> codepath not require objects in the submodule at all or do we still
> need to change something to make it so?
Yes, as the code in the current form as well as in its first occurrence
used the result of add_submodule_odb to determine if to spawn a child process.