> On May 3, 2012, at 6:11 PM, Ben Kennedy wrote: > >> Separate from the above, I also have a new performance problem. The loop in >> which I do my cascading updates executes inordinately slowly; simply >> assigning new values for two properties takes about 0.45 seconds when >> iterating a data set of a mere 135 objects. It used to be instantaneous >> before bindings came into the picture. I suspect that all of the KVO >> overhead is to blame (a quick peek in Instruments supports this).
In defence of KVO, I must rescind this hasty conclusion. The real problem occurred to me in the shower this morning: the array controller was constantly re-sorting the data after every property change, by virtue of its sortDescriptors. By temporarily clearing the sortDescriptors before the loop (and restoring afterwards), performance is golden again. I should have realized this earlier. On 03 May 2012, at 8:04 pm, Keary Suska wrote: > Don't get me wrong, I think bindings are great, and I use them extensively in > almost everything I do. But it seems to me they are really built for > straightforward usage and if you need to stretch them they tend to break. Not > to mention that they are completely opaque and are a bear to debug. Having not used bindings much (despite their availability for many years), I appreciate your experience and perspective, because it's in line with the impressions I've nonetheless been forming. (Cocoa bindings sort of remind me of BOOPSI from the Amiga days, akin to a well-intentioned but awkward and gangly teenager.) The motivation for moving my delegate-based table to a bound data source was in part to simplify the code needed for sorting and filtering in the UI -- but I was a bit naïve about the additional work implied by some of the trade-offs. thanks, b -- Ben Kennedy, chief magician Zygoat Creative Technical Services http://www.zygoat.ca _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
