Re: [PATCH iproute2-next 3/9] dcb: app: modify dcb-app print functions for dcb-rewr reuse

[<Daniel.Machon@microchip.com>]

> Daniel Machon <daniel.machon@microchip.com> writes:
> 
> > -static void dcb_app_print_filtered(const struct dcb_app_table *tab,
> > -                                bool (*filter)(const struct dcb_app *),
> > -                                int (*print_key)(__u16 protocol),
> > -                                const char *json_name,
> > -                                const char *fp_name)
> > +void dcb_app_print_filtered(const struct dcb_app_table *tab,
> > +                         bool (*filter)(const struct dcb_app *),
> > +                         int (*print_pid)(__u16 protocol),
> > +                         const char *json_name, const char *fp_name)
> >  {
> >       bool first = true;
> >       size_t i;
> > @@ -439,8 +437,14 @@ static void dcb_app_print_filtered(const struct dcb_app_table *tab,
> >               }
> >
> >               open_json_array(PRINT_JSON, NULL);
> > -             print_key(app->protocol);
> > -             print_uint(PRINT_ANY, NULL, "%d ", app->priority);
> > +             if (tab->attr == DCB_ATTR_IEEE_APP_TABLE) {
> > +                     print_pid(app->protocol);
> > +                     print_uint(PRINT_ANY, NULL, ":%d", app->priority);
> > +             } else {
> > +                     print_uint(PRINT_ANY, NULL, "%d:", app->priority);
> > +                     print_pid(app->protocol);
> > +             }
> 
> I really dislike the attribute dispatch. I feels too much like mixing
> abstraction layers. I think the callback should take a full struct
> dcb_app pointer and format it as appropriate. Then you can model the
> rewrite table differently from the app table by providing a callback
> that invokes the print_ helpers in the correct order.
> 
> The app->protocol field as such is not really necessary IMHO, because
> the function that invokes the helpers understands what kind of table it
> is dealing with and could provide it as a parameter. But OK, I guess it
> makes sense and probably saves some boilerplate parameterization.

Roger. And actually, yeah, the callbacks are used heavily throughout
DCB, so that fits better. Will incorporate CB approach in next v. I
think this applies more or less to your comments in patch #3, #4 and #5
too :)