KConfig sync speedup patch rev 1

Josef Weidendorfer Josef.Weidendorfer at gmx.de
Wed Sep 10 16:16:26 BST 2003


On Wednesday 10 September 2003 14:23, Ian Reinhart Geiser wrote:
> On Wednesday 10 September 2003 08:08 am, Waldo Bastian wrote:
> > > Now we have this blindingly
> > > slow datastructure and archatecture that seems to be all of our speed
> > > issues.
> >
> > Do you have any data on this?
>
> Well every test I have done shows the greatest time in all operations is in
> KConfig::putData(..).  The real painful operation is QMap::operator[] which
> is noted in the docs as a slow operation.  The end goal of my refactoring

I can't find that note.
QMap's insert/remove/search complexity is logarithmic to the number of entries
in the map, as it uses a tree structure, so it can't be that slow.
Though, I noted myself that there are a lot of Unicode string comparations 
when using QMaps (I'm using QMap myself in KCachegrind).
Perhaps you get it faster by using hash tables, but you always should try to 
meassure real times here to check the improvement.

Josef

> is to fix that problem.
>
> Note other things may be a problem, but this area stands out far above the
> rest in speed lost.
>
> Cheers
> 	-ian reinhart geiser





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