Is dbus good for heavy applications?

[Colin Walters]

On Tue, Apr 1, 2008 at 2:55 AM, Huang Peng <phuang at redhat.com> wrote:
> Hi DBus hackers,
>
>  I am designing a new IM (input method) platform. I am considering using
>  dbus as transport layer in the IM platform. The platform will provide
>  input services for applications for CJK and other non English users. In
>  the platform, when users type the keyboard, applications will send key
>  events to IM manager (the dbus service), and then the IM manager will
>  translate input key sequence to unicode chars and send them back to
>  applications. In this use case, user will press about 30 to 120 key in
>  one minute. The service will reply results to application about 60 ~ 240
>  times in one minute. I don't know whether dbus is proper for this heavy
>  use case. Can somebody tell me the performance of dbus and give me some
>  suggestions?

My guess here is that the problem in this is round trips; e.g. if on
pressing a single key
it goes from:

X server -> application -> session bus -> IM platform service ->
session bus -> application -> X server

That could be expensive.  You could cut it down by having the
application open a direct DBus unix socket channel to the IM
service, avoiding the session bus.  See DBusServer in the docs.

I'd mention this project on say gtk-devel-list and get feedback about
your proposed architecture.