Re: Display csv in a tableView with bindings
Re: Display csv in a tableView with bindings
- Subject: Re: Display csv in a tableView with bindings
- From: "Adam R. Maxwell" <email@hidden>
- Date: Sun, 26 Jul 2009 14:52:20 -0700
On Jul 26, 2009, at 2:38 PM, I. Savant wrote:
On Jul 26, 2009, at 3:52 PM, Aaron Burghardt wrote:
Not necessarily. If the keys are NSStrings, then they are copied
when added to the dictionary, but a copy of an immutable string is
optimized to just retain it, so the data isn't duplicated (assuming
all rows have the same columns in the same order, an assumption you
don't seem to be making).
Actually, I temporarily take back my "you're probably right"
response. :-) I can't find a reference to this anywhere, but I
admittedly only looked in the NSString API reference, the
Introduction to Strings Programming Guide for Core Foundation and
quickly perused the The Objective-C 2.0 Programming Language.
Would you mind directing me to where this is stated? I'm not saying
you're wrong - it sounds plausible - I'm just not sure you're
right. :-)
"CFString objects perform other “tricks” to conserve memory, such as
incrementing the reference count when a CFString is copied."
http://developer.apple.com/documentation/CoreFoundation/Conceptual/CFStrings/Articles/StringStorage.html#//apple_ref/doc/uid/20001179
It's not unreasonable, and we don't know the OP's performance
requirements.
No, it's not unreasonable, but since we don't know the OP's
performance requirements, the original blanket statement that
NSDictionary is better won't do without these caveats (ie, "it's
easier for bindings, but dog-slow on reasonably large files").
Rather than just say "there's more to it than that" as a drive-by
correction, I wanted to provide a helpful explanation and
workaround, since this is an area in which I have recent and
detailed experience. :-)
"Reasonably large files" is reasonably vague :). We have an
application that keeps an array of bibliographic references, where
each is an NSMutableDictionary with other properties. The largest
file I recall throwing at it is ~20K items, and the main problem at
that point was a beachball when using SearchKit...which was a nuisance
to work around. It doesn't use bindings, but there really aren't any
lazy loading tricks either.
Attachment:
smime.p7s
Description: S/MIME cryptographic signature
_______________________________________________
Cocoa-dev mailing list (email@hidden)
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:
This email sent to email@hidden