Re: Proposal: SET ROLE hook

2016-03-01 16:52 GMT+01:00 Joe Conway <mail(at)joeconway(dot)com>:

> On 03/01/2016 02:09 AM, Pavel Stehule wrote:
> > 2016-02-29 2:40 GMT+01:00 Joe Conway <mail(at)joeconway(dot)com
> > <mailto:mail(at)joeconway(dot)com>>:
> >
> > On 01/07/2016 09:08 AM, Joe Conway wrote:
> > > On 01/06/2016 10:36 AM, Tom Lane wrote:
> > >> I think a design that was actually somewhat robust would require
> two
> > >> hooks, one at check_role and one at assign_role, wherein the
> first one
> > >> would do any potentially-failing work and package all required
> info into
> > >> a blob that could be passed through to the assign hook.
>
> > I see following issues:
> >
> > 1. Missing the possibility to pass custom data from SetRoleCheck_hook to
> > SetRoleAssign_hook. Tom mentioned it in his comment.
>
> You can pass the data between the two plugin hook functions in your
> extension itself, so I see no need to try to pass custom data through
> the backend. Do any of the other hooks even do that?
>

I don't know about it, but these hooks are specific. is it ensured a order
of calls of these hooks?

>
> I think the main point was to have two hooks. The potentially-failing
> work could be done during the check_role() hook and the collected info
> could be used during the assign_role() hook. This works fine with the
> patch as-is.
>
> > 2. Missing little bit more comments and an explanation why and when to
> > use these hooks.
>
> Doesn't look all that different from existing user hooks to me, but
> sure, I'll add a bit more to the comments.
>
>
I would to see more lines about just corner cases. Can/cannot to raise a
exception there, can/cannot to access system catalogue there. I have
negative experience with missing these corner cases with log hook :).

some like "I think the main point was to have two hooks. The
potentially-failing
work could be done during the check_role() hook and the collected info
could be used during the assign_role() hook."

The thing I wish we had was a place in the docs where we list all the
> user plugin hooks. But as far as I know that doesn't exist (please
> correct me if I'm wrong) and I am not volunteering to create it just for
> the sake of this patch ;-)
>

This doc can be nice, but it is out of scope of this patch, and I don't
require it :)

Regards

Pavel

>
> Thanks for the review!
>
> Joe
>
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