Re: [rfc] new CREATE FUNCTION (and more) - Mailing list pgsql-hackers

From Marko Kreen
Subject Re: [rfc] new CREATE FUNCTION (and more)
Date
Msg-id 20001117041109.B10861@l-t.ee
Whole thread Raw
In response to Re: [rfc] new CREATE FUNCTION (and more)  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Thu, Nov 16, 2000 at 08:06:30PM -0500, Tom Lane wrote:
> Nathan Myers <ncm@zembu.com> writes:
> >  - Keep the name 'C' for both old-style and new-style module declarations.
> >  - Require that new-style modules define a distinguished symbol, such as 
> >    "int __postgresql_call_7_1;".
> 
> I was thinking along the same lines myself.  I'd want to do it on a
> per-function basis, though, rather than assuming that all functions in
> a module must use the same interface.
> 
> I'd be inclined to define a macro that creates the signal object,
> so that you'd write something like
> 
> PG_FUNCTION_API_V2(foo);
> 
> Datum
> foo(PG_FUNCTION_ARGS)
> {
>     ...
> }
> 
> to create a dynamically loadable new-style function.
> 
> Comments?

I like it :)

e.g.
struct pg_function_info_header {    int api_ver;};

and 
PG_FUNCTION_TAG(foo);

expands to
struct pg_function_info_header __pg_function_foo_info = { 0 };

so when we sometimes get around to add more fields to it
we increase the api_ver.  For more info also the macros will
be different.  This _TAG means "no info is given it is only
tagged as newC".

Comments?

-- 
marko



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