Re: [Tracker] questions

["Samuel Cormier-Iijima" <sciyoshi gmail com>]

On 9/14/06, Jamie McCracken <jamiemcc blueyonder co uk> wrote:
> Samuel Cormier-Iijima wrote:
> > I had a couple of quick questions and comments about Tracker:
> >
> > How come Tracker uses the low-level DBus interface? Exporting a
> > GObject over DBus would be *much* simpler (I've tried it :-),
> > especially for building parameters (GHashTable -> Python dict) and
> > doing signals (GObject signals get mapped to DBus signals) for the
> > eventual live query support. Also, this would automagically give us
> > certain nice things like introspection for free...
>
> Do you mean use the dbus binding tool to generate server side gobjects?
>
> If so it wont work because tracker is multi-threaded and dbus requests
> need to be queued for execution by one or more threads (currently only
> one in the code but its designed for supporting more).

You can use dbus_setup_connection_with_g_main to have DBus requests be
processed from a specific GMainContext, and then use that from
whatever thread you want...

It just seems like it would be a lot less maintenance work, but then
again, "if it ain't broke, don't fix it" :-)

> > Also, the DBus interface seems redundant at times, especially when it
> > asks for a pair of service and uri. I might be missing something here
> > (i.e. correct me if I'm wrong), but shouldn't the uri be unique? Why
> > do we have to pass a service type along with it?
>
> Because when we support emails they will be in a different db or table
> so I will need to use the service name to work out which DB or table to
> use in queries. Storing all services in one table would cause
> performance problems if email count is very large.

ah, good point, although i thought databases could handle pretty large
datasets (are many people going to be indexing more than 50,000 files?
it might get slow even at that number though...)

ok, will see what I can do. if i replaced the DBus calls with
GObjects, what are the chances of the patch being accepted? :-) also,
on that note, like you said, it might be a good idea to get some unit
tests into tracker. i've been coding up some "stress tests" python
scripts, and can send them if you'd like.

cheers,
samuel