Re: On login trigger: take three

On Mon, Oct 16, 2023 at 6:36 AM Alexander Korotkov <aekorotkov(at)gmail(dot)com> wrote:
>
> > On Mon, Oct 16, 2023 at 02:47:03AM +0300, Alexander Korotkov wrote:
> > > The attached revision fixes test failures spotted by
> > > commitfest.cputube.org. Also, perl scripts passed perltidy.
>
> You are very fast and sharp eye!
> Thank you for fixing the indentation. I just pushed fixes for the rest.

I noticed some typos related to this feature.

While on this, the event trigger example for C programming language
shown in the docs doesn't compile as-is. fmgr.h is needed.

Please see the attached patch.

[1]
2024-02-06 05:31:24.453 UTC [1401414] LOG: tag LOGIN, event login

#include "postgres.h"

#include "commands/event_trigger.h"
#include "fmgr.h"

PG_MODULE_MAGIC;

PG_FUNCTION_INFO_V1(onlogin);

Datum
onlogin(PG_FUNCTION_ARGS)
{
EventTriggerData *trigdata;

if (!CALLED_AS_EVENT_TRIGGER(fcinfo)) /* internal error */
elog(ERROR, "not fired by event trigger manager");

trigdata = (EventTriggerData *) fcinfo->context;

elog(LOG, "tag %s, event %s", GetCommandTagName(trigdata->tag),
trigdata->event);

PG_RETURN_NULL();
}

gcc -shared -fPIC -I /home/ubuntu/postgres/pg17/include/server -o
login_trigger.so login_trigger.c

LOAD '/home/ubuntu/postgres/login_trigger.so';

CREATE FUNCTION onlogin() RETURNS event_trigger
AS '/home/ubuntu/postgres/login_trigger' LANGUAGE C;

CREATE EVENT TRIGGER onlogin ON login
EXECUTE FUNCTION onlogin();

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com