Re: D-Bus

["Gustavo J. A. M. " Carneiro <gjc inescporto pt>]

On Qui, 2003-02-27 at 18:33, Havoc Pennington wrote:
> On Thu, Feb 27, 2003 at 06:20:08PM +0000, Gustavo J. A. M.  Carneiro wrote: 
> >   [Disclaimer: this is just my mostly-uninformed opinion.]
> 
> You should read the message-bus-list/xdg-list archives, and probably
> also if we want to discuss this the thread should start with a
> detailed analysis of the big picture. This piecemeal discussion isn't
> going to be very informative or get us to a conclusion.

  It probably would cost me too much time, and I'm too lazy. Besides,
where are those lists anyway? I can't find either of them on
mail.gnome.org.

> 
> >   If you have IDL and stubs/skels, then is it much different from
> >   CORBA?
> 
> In some ways it is, in others it isn't. 
>  
> >   Is ORBit slow? If it is:
> > 	1. I'm sure it can be optimized.
> > 	2. It doesn't matter *that* much. Even if you made ORBit 10x faster,
> > would it make GNOME faster? I doubt anyone would notice the
> > difference.
> 
> No, in fact I expect D-BUS to be slower than ORBit. D-BUS is currently
> about 2x slower than ORBit in the peer-to-peer case, and introducing a
> message bus in the middle gives you three processes instead of two so
> is slower than that. Optimization will probably bring D-BUS into a
> similar performance range as ORBit but it's not going to be faster.
> 
> The only performance win for D-BUS may be that it has more of a focus
> on avoiding round trips.
>  
> >   Does unification at this level bring any end-user advantage?
> 
> It certainly does. Of the Linux desktop usability problems right now,
> quite a few of them are caused by lack of standard ways of doing
> various things, such that all apps are living in their own little
> world.
> 
> Take "recent documents" feature of GNOME 2.2 - it completely sucks
> because of the big-three end user apps Mozilla, OpenOffice, and
> Evolution, exactly zero of them use the "recent documents" feature.
> There's a file-format-based spec for recent files now, and I guess
> people are adding OpenOffice support, but it would have been much
> easier with a D-BUS style system.

  Even if there is a need for a more "agnostic" communications library
(but I think CORBA is as much agnostic as you can get), I think that
GNOME apps and libraries should not be exposed to that. I suggest
something like  following:

	Gnome_DBus dbus;
	dbus = bonobo_get_object("OAFIID:Gnome_DBus", "IDL:Gnome/DBus:1.0");
	...
	Gnome_DBus_msgSend(dbus, whatever)
	foo = Gnome_DBus_msgReceive(dbus, NULL)

  OAFIID:Gnome_DBus would be a CORBA/DBus routing daemon.

  I'm still mostly uninformed. I wish someone O:-) would inform us all
of the main reasons why D/Bus is needed and the main differences to
ORBit.

-- 
Gustavo Joćo Alves Marques Carneiro
<gjc inescporto pt> <gustavo users sourceforge net>