Re: define pg_structiszero(addr, s, r)

Hi,

On Wed, Sep 18, 2024 at 03:07:15PM +0900, Michael Paquier wrote:
> On Wed, Sep 18, 2024 at 04:16:12AM +0000, Bertrand Drouvot wrote:
> > The macro is created in pgstat_internal.h as it looks like that "only" the 
> > statistics related code would benefit of it currently (could be moved to other
> > header file later on if needed).
> 
> I'm OK to add a helper macro in pgstat_internal.h as this is a pattern
> used only for some stats kinds (the other one I'm aware of is the
> allzero check for pages around bufmgr.c), cleaning up all these static
> declarations to make the memcpy() calls cheaper.  That can also be
> useful for anybody doing a custom pgstats kind, fixed or
> variable-numbered.

Thanks for looking at it!

> 
> #define pg_structiszero(addr, s, r)                                 \
> 
> Locating that at the top of pgstat_internal.h seems a bit out of order
> to me.  Perhaps it would be better to move it closer to the inline
> functions?

Makes sense, done that way in v2 attached.

> 
> Also, is this the best name to use here?  Right, this is something
> that may be quite generic.  However, if we limit its scope in the
> stats, perhaps this should be named pgstat_entry_all_zeros() or
> something like that?

Agree, we could still rename it later on if there is a need outside of
the statistics code area. Done in v2.

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
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