Problems with KService/KBuildSycoca in Comic Dataengine

[Matthias Fuchs]

Am 25.07.2011 10:59, schrieb Aaron J. Seigo:
> On Sunday, July 24, 2011 12:35:05 Matthias Fuchs wrote:
>> Both have to do with KServiceTypeTrader
>
> it's probably kbuildsycoca and kded, not KSTT.

Yes indeed.


> when a comic is installed or removed, kbuildsycoca4 must be run; this will
> automatically happen after some delay as kded4 watches the contents. a run of
> it can be triggered manually by calling recreate() on the /kbuildsycoca DBus
> object of org.kde.kded.
>
> the KSycoca class (a singletone) provides a signal that lets you know when
> things have changed in the database: void databaseChanged(const QStringList&
> changedResources); (where changedResources would contain "services" in the
> case of comics possibly changing)

In a local git branch I connect to that signal though it did not work 
there. The signal was emitted but the changes were not present then. 
Probably because I was not calling recreate manually then.

>
> this assumes, of course, that the comics files appear in one of the services
> directories prior to kbuildsycoca being run.

I fear that that sometimes is not the case at least that would explain 
why it is not always reproduceable here. Not sure if plasmapkg -u has 
some asynchronous elements.

Just a thought -- do not have the time right now to test -- but could 
changing the InstallationCommand in the knsrc file help?
From
plasmapkg -t comic -u %f
to
plasmapkg -t comic -u %f && kbuildsycoca4

>
> iif kbuildsycoca is being run and working properly and still KSTT is not
> returning the correct values then the mmap'd file is getting fouled somehow.
>
>> Now I wonder how I should fix that. Do you have any ideas?
>> The worst case "solution" would be not relying on KServiceTypeTrader at all
>> though I want to avoid that.
>
> that would make very little sense since you'd end up having to do essentially
> the same thing ksycoca does; duplication of code rarely leads to actual
> improvements :)

Definitely and I doubt that it would do it without my share of bugs. ;)