hey mike the final thought put me on to an easy solution, thanks. i just stopped the controller automaticallly rearranging the content, then called [arrayController rearrangeContent] after a batch of search results has arrived. it still is quite heavy on the processor, but the results arrive in a timely fashion and the ui does not freeze, so good enough i think.
On Thu, Dec 17, 2009 at 11:29 PM, Mike Abdullah <cocoa...@mikeabdullah.net>wrote: > Aha, now we're talking! > > So the problem is that after ever change to your model, the controller must > rearrange its content to match. It knows the change is needed because it > receives a Key-Value Observing notification of the change. It's got no way > to know that more changes are about to happen again very shortly and so > shouldn't bother rearranging just yet. > > Ways to fix: > > A) Implement manual KVO notifications so that you can do: > 1. willChangeValueForKey:… > 2. Make all the changes in one go > 3. didChangeValueForKey:… > > B) Temporarily unbind the controller, make your changes, rebind it. > > C) Make your changes using the controller's own methods. > -insertObject:atArrangedObjectsIndex: etc. It's intelligent enough to know > not to rearrange the entire content. > > Final thought, is -automaticallyRearrangesObjects set to YES? I think if > that is turned off, the controller won't need to observe every single object > in the array. > > On 17 Dec 2009, at 19:30, Richard wrote: > > > jens, this sounds reasonable, i will give it a try. > > > > mike, i did give it a shot in instruments, comparing the same search with > > and without sorting. i'm not really sure what to make of the results > > however. when sorting is enabled, nearly all the execution time is taken > up > > with [NSArrayController setContent:] with the time shared evenly over > > [NSObject removeObserver] and [NSObject addObserver], with only a small > > fraction of the time taken up by actual sorting. > > > > so, it would seem that the extra workload is in the array controller > > stopping observing the old content, then reobserving the new content. not > > sure what can be done to alleviate this, any suggestions? > > > > On Thu, Dec 17, 2009 at 5:50 PM, Mike Abdullah < > cocoa...@mikeabdullah.net>wrote: > > > >> As with every performance question. Don't "assume", MEASURE. Fire up > >> Instruments and find out what is using up the CPU. > >> > >> On 17 Dec 2009, at 15:22, Richard wrote: > >> > >>> hey > >>> > >>> i have an app that performs searches over a network connection. the app > >> uses > >>> core data to manage all the search requests (currently using an in > memory > >>> store), with an array controller and table view bound to the relevant > >>> results. a search query produces up to about 10000 results, and they > are > >>> added to the data model in batches of 10 or so. this all works well, > >> until i > >>> add sorting to the array controller. i then find that the CPU use of > the > >>> application stays at 100% and things go pretty slowly from that point > on. > >>> > >>> i assume this is because with each new search result that is being > >> retrieved > >>> and added to the core data model, the array controller is resorting the > >>> entire collection of search results? can anyone suggest a solution to > >> this > >>> problem? > >>> > >>> thanks > >>> _______________________________________________ > >>> > >>> Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > >>> > >>> Please do not post admin requests or moderator comments to the list. > >>> Contact the moderators at cocoa-dev-admins(at)lists.apple.com > >>> > >>> Help/Unsubscribe/Update your Subscription: > >>> > >> > http://lists.apple.com/mailman/options/cocoa-dev/cocoadev%40mikeabdullah.net > >>> > >>> This email sent to cocoa...@mikeabdullah.net > >> > >> > > _______________________________________________ > > > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > > > Please do not post admin requests or moderator comments to the list. > > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > > > Help/Unsubscribe/Update your Subscription: > > > http://lists.apple.com/mailman/options/cocoa-dev/cocoadev%40mikeabdullah.net > > > > This email sent to cocoa...@mikeabdullah.net > > _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
