[Qt-interest] Qt show folder size

[Sean Harmer]

On Friday 18 Sep 2009 13:17:56 Andrei Sebastian Cimpean wrote:
> On Friday 18 September 2009 02:52:28 pm Sean Harmer wrote:
> > On Friday 18 Sep 2009 12:09:02 Andrei Sebastian Cimpean wrote:
> > > This returns a standard size around 4 kb:
> > > QString::number(fileorfolder.size(),10)
> > > Does anyone know how to get the sum of all the items inside the folder?
> > > Thank you
> >
> > Yes, iterate through them and sum the sizes. Should be trivial with
> > QDirIterator and QFileInfo.
> >
> > Sean
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>
> How fast is this way of doing it? 

Try it and find out - should only take approx 10 lines of code if that. ;-)

> I mean for a folder with 100k the number
> of subfolders and files wouldn't it take ages?

Do you really have a dir with 100k items in it? The last time I cloned my 
laptop linux install rsync reported that I only had 1.2 million files for the 
entire image (Gentoo with lots and lots of unpacked source tarballs lying 
around). If you do encounter this type of use case, then you could always 
cache results for sub-dirs and just watch for when individual subdirs change 
with QFileSystemWatcher for e.g.

I know of no other way of finding out the total size of files other than 
querying the size of each and adding them up. This is all that tools like du 
do - plus some additional checking for not counting hardlinked files multiple 
times etc.

Cheers,

Sean