Re: Refactor to make use of a common function for GetSubscriptionRelations and GetSubscriptionNotReadyRelations.

On Mon, Jul 25, 2022 at 11:08 AM Michael Paquier <michael(at)paquier(dot)xyz> wrote:
>
> On Sun, Jul 24, 2022 at 09:52:16PM +0530, vignesh C wrote:
> > Thanks for the comments, i have modified it by changing it to a
> > boolean parameter. The attached v4 patch has the changes for the same.
>
> Okay, thanks for the patch. This looks good to me, so let's do as
> Amit suggests. I'll apply that if there are no objections.
> --

OK. I have no objections to just passing a boolean, but here are a
couple of other small review comments for the v4-0001 patch:

======

1. src/backend/catalog/pg_subscription.c

@@ -533,65 +533,14 @@ HasSubscriptionRelations(Oid subid)
}

/*
- * Get all relations for subscription.
+ * Get the relations for subscription.
*
- * Returned list is palloc'ed in current memory context.
+ * If only_not_ready is false, return all the relations for subscription. If
+ * true, return all the relations for subscription that are not in a ready
+ * state. Returned list is palloc'ed in current memory context.
*/

The function comment was describing the new boolean parameter in a
kind of backwards way. It seems more natural to emphasise what true
means.

SUGGESTION
Get the relations for the subscription.

If only_not_ready is true, return only the relations that are not in a
ready state, otherwise return all the subscription relations. The
returned list is palloc'ed in the current memory context.

====

2. <General - calling code>

Perhaps this suggestion is overkill, but given that the param is not
going to be a bitmask or enum anymore, IMO it means the calls are no
longer very self-explanatory.The calling code will be more readable if
the patch introduced some descriptive wrapper functions. e.g.

List *
GetSubscriptionAllRelations(Oid subid)
{
return GetSubscriptionRelations(subid, false);
}

List *
GetSubscriptionNotReadyRelations(Oid subid)
{
return GetSubscriptionRelations(subid, true);
}

------
Kind Regards,
Peter Smith.
Fujitsu Australia