Re: [PATCH 02/13] refs: introduce `.ref` field for the base iterator

From: Patrick Steinhardt <ps@pks.im>
Date: Oct 8, 2025, 13:44 UTC
Message-ID: <aOZqsM2TKv3g8lJ3@pks.im>
In-Reply-To: <CAOLa=ZR0KWkpB4kjFm2g8F-PK_LWpE20P21rmJGOLONCkfN7yA@mail.gmail.com>

On Tue, Oct 07, 2025 at 07:24:01AM -0700, Karthik Nayak wrote:

Show 20 quoted lines

> Patrick Steinhardt <ps@pks.im> writes:
> 
> > The base iterator has a couple of fields that tracks the name, target,
> > object ID and flags for the current reference. Due do this design we
> > have to create a new `struct reference` whenever we want to hand over
> > that reference to the callback function, which is tedious and not very
> > efficient.
> >
> > Convert the structure to instead contain a `stuct reference` as member.
> 
> s/stuct/struct
> 
> > This member is expected to be populated by the implementations of the
> > iterator and is handed over to the callback directly.
> >
> 
> Wouldn't this also add the burden on each backend to ensure we don't
> serve stale data for each '_advance()' call?
> 
> Would it make sense to reset this data in `ref_iterator_advance()`?

Yeah, that's true indeed. I was a bit hesitant to do such a change though because the ref iterator is part of a bunch of hot loops. I'll do some benchmarking here to figure out whether a memset(3p) would have a negative impact on performance.

Patrick