Re: Knowing when a NSArrayController is ready
Re: Knowing when a NSArrayController is ready
- Subject: Re: Knowing when a NSArrayController is ready
- From: Matt Neuburg <email@hidden>
- Date: Sat, 24 Jan 2009 10:41:21 -0800
- Thread-topic: Knowing when a NSArrayController is ready
On or about 1/24/09 10:17 AM, thus spake "email@hidden"
<email@hidden>:
> I am also having horrible performance problems.
> A data set of 1500 items with a total on disk size of 1.8MB is taking
> more than 30 secs to load.
> Maybe NSArrayController -fetchWithRequest will improve things.
I would ask you the same question I just asked someone else on the list: are
you using the XML persistent storage format? Because, if so, you must expect
some delay, since even before you fetch any objects the entire XML file must
be loaded into memory and parsed.
I use XML because I want human readability for my data, so startup speed is
a sacrifice I am prepared to make. My data consists of about 5000 items, but
they are very simple; dealing with complex objects would take considerably
longer, one assumes. In order to cave-man-instrument the startup procedure
via NSLog, I do NOT prepare content or even bind my array controller's
managed object content in the nib; instead, I do it all manually in
awakeFromNib. Here are some NSLog timings:
2009-01-24 10:37:09.157 [788] awakening from nib
2009-01-24 10:37:09.269 [788] binding to MOC
2009-01-24 10:37:09.359 [788] creating whole shebang
2009-01-24 10:37:09.360 [788] adding persistent store
2009-01-24 10:37:13.877 [788] calling fetch
2009-01-24 10:37:14.192 [788] done calling fetch
Notice the big delay between "adding persistent store" and "calling fetch";
that consists a single line of code (calling addPersistentStoreWithType:).
So the delay there is nothing but the XML file being loaded and parsed. m.
--
matt neuburg, phd = email@hidden, http://www.tidbits.com/matt/
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