From: Pablo Sabater <pabloosabaterr@gmail.com>
Date: Sat, 27 Jun 2026 17:52:59 GMT
Subject: Re: [PATCH GSoC v14 09/13] serve: advertise object-info feature
Message-ID: <CAN5EUNTrdNArd5SX9df6x9bOhRfzE4c7dLOuNu7ONUdn4TLsUA@mail.gmail.com>
In-Reply-To: <CAOLa=ZShTcHOekT+NuxMwZz-7P5i9aSWXSL6MW9_9aKkNwqsig@mail.gmail.com>

El sáb, 27 jun 2026 a las 0:23, Karthik Nayak
(<karthik.188@gmail.com>) escribió:
>
> Pablo Sabater <pabloosabaterr@gmail.com> writes:
>
> > From: Calvin Wan <calvinwan@google.com>
> >
> > In order for a client to know what object-info components a server can
> > provide, advertise supported object-info features. This will allow a
> > client to decide whether to query the server for object-info or fetch
> > as a fallback.
> >
> > Helped-by: Jonathan Tan <jonathantanmy@google.com>
> > Helped-by: Christian Couder <chriscool@tuxfamily.org>
> > Signed-off-by: Calvin Wan <calvinwan@google.com>
> > Signed-off-by: Eric Ju <eric.peijian@gmail.com>
> > Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
> > ---
> >  serve.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/serve.c b/serve.c
> > index 49a6e39b1d..2b07d922b3 100644
> > --- a/serve.c
> > +++ b/serve.c
> > @@ -89,7 +89,7 @@ static void session_id_receive(struct repository *r UNUSED,
> >       trace2_data_string("transfer", NULL, "client-sid", client_sid);
> >  }
> >
> > -static int object_info_advertise(struct repository *r, struct strbuf *value UNUSED)
> > +static int object_info_advertise(struct repository *r, struct strbuf *value)
> >  {
> >       if (advertise_object_info == -1 &&
> >           repo_config_get_bool(r, "transfer.advertiseobjectinfo",
> > @@ -97,6 +97,9 @@ static int object_info_advertise(struct repository *r, struct strbuf *value UNUS
> >               /* disabled by default */
> >               advertise_object_info = 0;
> >       }
> > +     /* Currently only size is supported */
> > +     if (value && advertise_object_info)
> > +             strbuf_addstr(value, "size");
>
> So is the plan that further options will be added here to value? If so,
> whats the format we will follow?

Hi!
The current documented format is at `gitprotocol-v2.adoc`, however I
think it could be improved. I have a more complete version in the
not-yet-sent %(objecttype) support series, but since the question
comes up here, I will update the format documentation in this series
for size only:

oid <oid>
  Indicates to the server an object which the client wants to obtain
- information for.
+ information for. They must be full object IDs.

- info = PKT-LINE(attrs) LF)
+ info = PKT-LINE(attrs LF)
       *PKT-LINE(obj-info LF)

  attrs = attr | attrs SP attrs

+ obj-size = 1*DIGIT
+
  attr = "size"

- obj-info = obj-id SP obj-size
+ obj-info = obj-id SP [obj-size]
+
+If the server does not recognize the object id, the response will be
+`obj-id SP` regardless of the number of attributes requested.

About the names `size` and future ones `type` they are arbitrarily
chosen, so for example: `delta:base` could be `delta`. They are
appended to the buffer so in case of adding `type`, it would look
like:

strbuf_addstr(value, "size type");

What do you think?

Thanks for the review,
Pablo.

>
> >       return advertise_object_info;
> >  }
> >
> >
> > --
> > 2.54.0