[Development] Qt 5.2 Beta - is it really much slower to parse qml/javascript on android?

Cornelius Hald hald at icandy.de
Sat Nov 2 07:52:46 CET 2013


Thanks for the link BogDan!

Cheers,
Conny

Am Freitag, den 01.11.2013, 14:44 -0700 schrieb BogDan:
> Hi,
> 
> https://bugreports.qt-project.org/browse/QTBUG-34464
> 
> Cheers,
> BogDan.
> 
> Trimis din Yahoo! Mail pe Android
> 
> 
> 
> 
> ______________________________________________________________________
> From: Cornelius Hald <hald at icandy.de>; 
> To: BogDan <bog_dan_ro at yahoo.com>; 
> Cc: development at qt-project.org <development at qt-project.org>; 
> Subject: Re: [Development] Qt 5.2 Beta - is it really much slower to
> parse qml/javascript on android? 
> Sent: Fri, Nov 1, 2013 4:48:49 PM 
> 
> 
> Hi,
> 
> is there a ticket to track this issue? I'd like to get an update when
> it's fixed :)
> 
> Thanks!
> Conny
> 
> On Wed, 2013-10-30 at 07:06 -0700, BogDan wrote:
> > Hi,
> > 
> >  I just checked the Qt5 assets implementation and for some reason
> that I fail to understand the assets cache mechanism from Qt4 is not
> there ... that is the reason why Necessitas is way much faster than
> Qt5.x :)
> > I'll add the cache mechanism ASAP. 
> > 
> > Thanks!
> > 
> > Cheers,
> > BogDan.
> > 
> > 
> > >
> > >
> > >OK. You just nailed it! After moving the files into a resource file
> the "startup" went from a little over 4 seconds to less than half
> second.  Just for context: my application has 18qml files, 2 small
> javascript files and 20 or so images and not all of them are loaded on
> startup!
> > >
> > >
> > >A little surprising and a lot disappointing is that my main phone
> (android 4.1.2) seems to make the problem even worst. I tried on a
> Nexus7 (android 4.3) and a 2+year old HTC inspire (android 4.2.2) and
> both are much quicker when not using the resource file (there is the
> possibility that the actual android has been improved since both of
> these devices have newer versions of it). They are still much slower
> than using the resource file.
> > >
> > >
> > >On hindsight: 
> > >1. my original qml 1.0 version uses the resource file - didn't
> occur to me that this could make such a difference!
> > >
> > >2. The Qt 5.1 document on android suggests using the resource
> (http://qt-project.org/doc/qt-5.1/qtdoc/android-support.html) and even
> states "The most convenient option is to bundle the resources into a
> qrc file, which gets built into the application binary. This approach
> reduces the porting effort considerably and provides faster access to
> the resources. It is also a cross-platform approach, which makes
> porting to other platforms easier.". For the 5.2 version I think we
> should make it stand out with some "big bold red blinking letters
> (TM)" and also change the wizard template to use resources by default
> for android. It can be the difference between a "useless" application
> that takes forever to start and "Qt/qml is really great even on
> android"!
> > >
> > >
> > >Thanks all!
> > >Felipe
> > >
> > >
> > >
> > >On Wed, Oct 30, 2013 at 4:09 AM, BogDan <bog_dan_ro at yahoo.com>
> wrote:
> > >
> > >Hi,
> > >>
> > >>Android's assets are indeed slower (~2X) than Qt's resource
> system,
> > >>but not that slow ! :)
> > >>
> > >>If I recall correctly in the beginning of this thread Kai said
> that using
> > >>Necessitas SDK it was ok, and I don't think he is using another
> technique
> > >> to store the qml files than he is using for Necessitas. Also the
> assets 
> > >>implementation should be pretty much the same ... unless me (or
> someone else)
> > >>screw the implementation in Qt 5.2 :).
> > >>
> > >>Cheers,
> > >>BogDan.
> > >>
> > >>
> > >>
> > >>
> > >>>
> > >>> I think i know whats the issue if its still not fixed.
> > >>>
> > >>> My guess is that you don't use the resource system of Qt but the
> android
> > >>> application assets to store your components, the last time i had
> issues
> > >>> with this all the time was lost in the horrible slow fileengine
> for assets on
> > >>> android. It looked to me it was reopening the assets all the
> time which seems
> > >>> expensive.
> > >>>
> > >>> I haven't tried it since 5.1 but if it is not fixed its very
> likely the
> > >>> cause
> > >>> of your problem.
> > >>>
> > >>> Björn
> > >>> Am Mittwoch, 30. Oktober 2013, 07:07:41 schrieb Koehne Kai:
> > >>>
> > >>>>  > -----Original Message-----
> > >>>>  > From: development-bounces
> +kai.koehne=digia.com at qt-project.org
> > >>>>  > [mailto:development-bounces
> +kai.koehne=digia.com at qt-project.org] On
> > >>>>  > Behalf Of Felipe Crochik
> > >>>>  > Sent: Tuesday, October 29, 2013 7:13 PM
> > >>>>  > To: Hausmann Simon
> > >>>>  > Cc: development at qt-project.org
> > >>>>  > Subject: Re: [Development] Qt 5.2 Beta - is it really much
> slower to
> > >>> parse
> > >>>>  > qml/javascript on android?
> > >>>>  >
> > >>>>  > Simon,
> > >>>>  > Quick update:
> > >>>>  > I tried arm7va and got almost the same results (a very small
> > >>> improvement
> > >>>>  > but still over 3seconds).
> > >>>>  >
> > >>>>  > It doesn't seem to be related at all to my code. It seems
> that it
> > >>> is
> > >>>>  > adding some "fixed amount" of time for each component than
> > >>> has to parse.
> > >>>>  > It doesn't look like is related to what they are or how
> complex.
> > >>> For
> > >>>>  > instance in one of my tests I had a component that was a
> Rectangle
> > >>> with a
> > >>>>  > Text inside, by just refactoring the Text to become another
> component
> > >>> I
> > >>>>  > went from 1.2s load time to almost 2. The example does not
> include any
> > >>>>  > javascript!!!!
> > >>>>
> > >>>>  Have you tried running the app with the QML Profiler attached?
> > >>>>
> > >>>>  See
> > >>>>
> > >>>>
> > >>>
> http://qt-project.org/doc/qtcreator-2.8/creator-qml-performance-monitor.html
> > >>>>
> > >>>>  Regards
> > >>>>
> > >>>>  Kai
> > >>>>
> > >>>>  _______________________________________________
> > >>>>  Development mailing list
> > >>>>  Development at qt-project.org
> > >>>>  http://lists.qt-project.org/mailman/listinfo/development
> > >>>
> > >>> --
> > >>> Björn Breitmeyer | bjoern.breitmeyer at kdab.com | Software
> Engineer
> > >>> KDAB (Deutschland) GmbH&Co KG, a KDAB Group company
> > >>> Germany: +49-30-521325470, Sweden (HQ): +46-563-540090
> > >>> KDAB - Qt Experts - Platform-independent software solutions
> 
> > >>>
> > >>> _______________________________________________
> > >>> Development mailing list
> > >>> Development at qt-project.org
> > >>> http://lists.qt-project.org/mailman/listinfo/development
> > >>>
> > >>_______________________________________________
> > >>Development mailing list
> > >>Development at qt-project.org
> > >>http://lists.qt-project.org/mailman/listinfo/development
> > >>
> > >
> > >
> > >
> > _______________________________________________
> > Development mailing list
> > Development at qt-project.org
> > http://lists.qt-project.org/mailman/listinfo/development
> 
> 
> 





More information about the Development mailing list