Fun with Akonadi Dataengine

[Sebastian Kügler]

Hi David,

On Tuesday 17 February 2009 21:47:46 David Baron wrote:
> On Tuesday 17 February 2009 22:01:18 David Baron wrote:
> > Latest from playground SVN.
> >
> > I re-downloaded and compared with the older code. The only real
> > difference besides the volume of diagnostic printout is that the
> > ContactCollection-# list is made at a completion event rather than
> > immediately on
> > connectSource(ContactCollections).

That should work as expected now.

> > Such could alleviate some of the panel delay I encountered when doing
> > this directly in init(). However, this is a small amount of data at this
> > point. The delay was more from the log-jam on kde/plasma startup. For
> > example, with the older dataengine, it took almost 90 seconds before I
> > got the contacts to start dataUpdate-ing. Later on, run from the
> > plasmoidviewer, this same thing completes in several seconds.

Just comment out the kDebug() lines that generate this. I've commented out and 
removed most of it.

> > With the new code, I will not have any useful return from query until I
> > have the equivalent in dataUpdate. This is why it did not work. I should
> > recode it so it would work either way.
>
> To get it to "work" either way, I still use the QTimer.  I MUST repeat the
> connectSource( ContactCollections ) or a least wait the second before the
> 1st call since the console shows no further such calls. When I get
> dataUpdated from this call, I connect the ContactCollection-#,, and then
> have the QTimer call connectAllSources and I get my contacts.

I've re-read the API docs and found a note that setData() needs to be 
initialized with empty data when we return true there. I've committed that 
change, it makes it work as expected now. I've also added sources() to the 
engine which makes it easier to find out what to do with it.

I've also found a weirdness (expectedness?) in the dataengine. Apparently, I 
cannot connect to sources from different classes, somehow everything ends up 
calling the dataUpdated() in MailExtender, while I connect to the source 
"EmailCollection" from the applet itself (LionMail). For now, I'm just 
relaying the data in that case and call dataUpdated() in the applet using it. 
Still, something to keep in mind.

> HOWEVER, the new code will crash the applet in plasmoidviewer just as it
> crashed the explorer. This may be due to the increased volume of "printed"
> contacts information or it may be something else. The applet in the panel
> apparently did not crash (the desktop and panel came up) even though the
> "plasma" command certainly showed all that stuff. In any event, I am going
> back to the older code until the problem is resolved since I cannot test
> the applet or dataengine with the new code.

Do you have a backtrace for this crash?

BTW, thanks for your patience in getting it sorted how we want the akonadi 
engine to behave. As Aaron said, we should design it for actual usecases, you 
happen to be the first (well, second ;)) one to come across this, hence the 
immaturity of the akonadi engine.

I had a chat with some of the Akonadi people tonight, giving me some more 
perspective of where we can go. Something I'd like to have is "give me the 
contact for this email address" (or telephone number, in your case), but 
Akonadi doesn't support this yet. Something that could be considered together 
with more Nepomuk integration in Akonadi, as I was told.
-- 
sebas

 http://www.kde.org | http://vizZzion.org |  GPG Key ID: 9119 0EF9