[KPhotoAlbum] Performance issue: KPA too slow when clicking on "big" supercategories

[Rafael Beccar]

Hi Jesper and everybody, 

I found the following performance issue with latest SVN:

Let's say I have something like this in my "Folders" category:

+ dir1 (2452 images; 33 movies)
	-subdir1
	-subdir2
	-subdir3
+ dir2
	-subdir1
	-subdir2
+dir3
	...

If I click on "dir1", the process of finding the items on the category, takes 
1 minute and 5 seconds to finish (using 99% of processor and 6% of memory 
according to "top"). Then, when the process ends, KPA becames very slow for 
all operations and sometimes it just hangs.

If I do the same with other categories than "Folders" (like "Places" for 
example), KPA becames very slow too but it is still faster that the situation 
described above with "Folders".

Of course the does not happend when clicking on last level categories (no 
matter how big they are).

Notice I'm testing this over AMD64 with 1GB RAM.

May be, if this performance issue can't be easily solved, at least the user 
should be warned when clicking on a big supercategory.

Hope that helps,
Rafael