Re: [PATCH 15/17] khash: rename oid helper functions

> On Thu, Jun 20, 2019 at 10:44:17AM -0700, Junio C Hamano wrote:
>
>> Jeff King <peff@peff.net> writes:
>>
>>> For use in object_id hash tables, we have oid_hash() and oid_equal().
>>> But these are confusingly similar to the existing oideq() and the
>>> oidhash() we plan to add to replace sha1hash().
>>>
>>> The big difference from those functions is that rather than accepting a
>>> const pointer to the "struct object_id", we take the arguments by value
>>> (which is a khash internal convention). So let's make that obvious by
>>> calling them oidhash_by_value() and oideq_by_value().
>>>
>>> Those names are fairly horrendous to type, but we rarely need to do so;
>>> they are passed to the khash implementation macro and then only used
>>> internally. Callers get to use the nice kh_put_oid_map(), etc.
>>
>> The pass-by-value interface feels a bit unforunate but hopefully
>> "static inline" would help us avoid actually copying the struct left
>> and right as we make calls to them X-<.
>
> Yeah, exactly. I think it should end up quite fast, though if anybody
> (René?) wants to try tweaking khash and timing it, be my guest.
>
> I do think if it took the more usual pass-by-const-pointer we'd probably
> still end up with the exact same code from an optimizing compiler, since
> all of the references and dereferences would cancel out once it was
> inlined.