Pass own pool

[jakajancar]

I already have a Postgres connection pool, would be great to be able to just pass it to Chancy to use instead of maintaining its own.

[jakajancar]

@TkTech I suspect part of your response on #71 applies to this feature request.

To justify why this is useful, in addition to needlessly keeping two pools, my current pool is configured to dynamically create database connections using RDS IAM / STS. To support something like this, if not the entire pool, you'd need a configurable connection factory or at least an async conninfo string callback.

Re. the concern that you might get a funky connection in, that's true, but I can also do all sorts of stupid stuff on postgres server-side to break things, and probably nobody worried about that.

Anyways, not super important as probably I will not realistically migrate from Procrastinate to Chancy, but you suggested I take a look in some Hacker News reply, I finally did, and after some evaluation this is the first wall I hit (Procrastinate does allow you to pass your own pool). Otherwise certainly many things very attractive here, including no global state.

[TkTech]

Thanks for the use case, it does help with prioritization. Just to clarify, we'd totally accept this in Chancy as a feature, just with the disclaimer that you need to be aware of what you're doing with that shared pool.

Thanks for giving it a look :)

You can have this functionality pretty easily, something like this would work fine:

class SharedPoolChancy(Chancy):
   def __init__(*, shared_pool_getter, sync_shared_pool_getter, **kwargs):
        self._get_shared_pool = shared_pool_getter
        self._get_shared_sync_pool = sync_shared_pool_getter
        super().__init__(**kwargs)

    @cached_property
    def pool(self):
        return self._get_shared_pool()

    @cached_property
    def sync_pool(self):
         return self._get_shared_sync_pool()