[Eric] understanding eric4 slowness

[Detlev Offenbach]

On Freitag, 13. April 2007, Andreas Pakulat wrote:
> On 13.04.07 19:26:28, Detlev Offenbach wrote:
> > On Mittwoch, 11. April 2007, Andreas Pakulat wrote:
> > > c) How do I do performance tests on eric4? I tried the profile project
> > > option in eric3 but after the splash screen vanishes nothing seems to
> > > happen.
> >
> > Over here it took some time to show up on the first run.
>
> I'll try that again some time.
>
> > > All in all eric3 seems to be much faster than eric4.
> >
> > That is what I observed as well. However, I was not able to find the real
> > cause. All in all I have the impression, that Qt4 is slower than Qt3. I
> > have observed this with other (pure) Qt applications as well (both at
> > work and at home, both on Linux and on win32). I got the impression, that
> > the problem is worse on Linux.
>
> Hmm, I don't think I have a Qt4 app with a larger model, however I do
> have experience with KDE4 and at least their filesystem-model is pretty
> fast. So I'm not so 100% sure its just the Qt4 model/view stuff, it may
> still be related to how the models are implemented. Anyway, I'll try to
> get some profiling data and see what it can tell me...
>
> Andreas

It might not really be the model/view stuff. I have the impression it is 
painting the data to the screen. If you load a really huge file in 
QScintilla2 (e.g. ViewManager.py or UserInterface.py) and enter some text at 
the beginning of the file, you shouldn't type too fast or you'll lose some 
keystrokes. This is just an example. I have seen slow paintings in various 
areas. As I said, this was observed in other Qt4 applications as well.

Detlev
-- 
Detlev Offenbach
detlev at die-offenbachs.de