Review Request 111398: Fix O(N^2) complexity issue in KItemListView::slotItemsRemoved

[Commit Hook]

-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
http://git.reviewboard.kde.org/r/111398/#review35647
-----------------------------------------------------------


This review has been submitted with commit 6c157fcbb8b851d8075ec8555466e6ab32dff3c5 by Frank Reininghaus to branch master.

- Commit Hook


On July 4, 2013, 10:10 p.m., Frank Reininghaus wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://git.reviewboard.kde.org/r/111398/
> -----------------------------------------------------------
> 
> (Updated July 4, 2013, 10:10 p.m.)
> 
> 
> Review request for Dolphin.
> 
> 
> Description
> -------
> 
> In a directory which is shown in Dolphin, try the following (where N is a large number > 100000):
> 
> touch {1..N}.png
> touch {1..N}.jpg
> 
> (wait until all files are shown in the view)
> 
> rm *.jpg
> 
> This will freeze Dolphin for quite some time (if not, try to increase the number of files). This is because KItemListView::slotItemsRemoved() has a loop over all removed item ranges (100000 in this case), and in each loop, it has another loop that iterates through all items and tries to find visible ones. This is bad because there is always only a small number of visible items, so we better just iterate over those (similar to the approach in KItemListView::slotItemsInserted).
> 
> 
> Diffs
> -----
> 
>   dolphin/src/kitemviews/kitemlistview.cpp 2ea6657 
> 
> Diff: http://git.reviewboard.kde.org/r/111398/diff/
> 
> 
> Testing
> -------
> 
> Dolphin takes a lot less time to remove many item ranges.
> 
> 
> Thanks,
> 
> Frank Reininghaus
> 
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.kde.org/mailman/private/kfm-devel/attachments/20130705/157abf43/attachment.htm>