To fix the line

_cache = [NSMutableDictionary dictionaryWithCapacity:MAX_CACHED_IMAGES];

to

_cache = [[NSMutableDictionary dictionaryWithCapacity:MAX_CACHED_IMAGES] retain];

Warren is correct when he points out that doing so will leak this object, because the cache dictionary is never released. However, since it’s a static it will only leak one dictionary and that will be released when your app exits.

I’ll revisit this code and see if I can’t come up with a way to solve this issue without loosing the simplicity of the existing solution (ie, no classes to create, etc.).

Thanks for the feedback guys, apologies it took so long to reply (new job and all ).

-lane

My only concern is (and this may be something I introduced in adapting your example), it seems like the dictionary you get from dictionaryWithCapacity: is autoreleased, and the code doesn’t retain it. I saw a situation where my app crashed because the cache was dealloc’d while in use because of this. Adding a call to retain prevents this, but also introduces a small leak as long as the program is running.

You mention your own objections to using a static variable in an accessor, but I think this is still the most pragmatic approach since using +initialize with a static global will still introduce an object that persists until the application is exiting.

2010-05-03 17:11:32.695 base1[9629:6417] *** _NSAutoreleaseNoPool(): Object 0x1566a90 of class NSCFDictionary autoreleased with no pool in place – just leaking
Stack: (0x305a2e6f 0×30504682 0x4d543 0x4d5be 0x3050a79d 0x3050a338 0x909c4a19 0x909c489e)
2010-05-03 17:11:32.695 base1[9629:5a13] *** _NSAutoreleaseNoPool(): Object 0x1566dd0 of class NSCFDictionary autoreleased with no pool in place – just leaking
Stack: (0x305a2e6f 0×30504682 0x4d543 0x4d5be 0x3050a79d 0x3050a338 0x909c4a19 0x909c489e)
2010-05-03 17:11:32.695 base1[9629:5813] *** _NSAutoreleaseNoPool(): Object 0×1567130 of class NSCFDictionary autoreleased with no pool in place – just leaking
Stack: (0x305a2e6f 0×30504682 0x4d543 0x4d5be 0x3050a79d 0x3050a338 0x909c4a19 0x909c489e)
2010-05-03 17:11:32.698 base1[9629:4917] *** _NSAutoreleaseNoPool(): Object 0×1567460 of class NSCFDictionary autoreleased with no pool in place – just leaking
Stack: (0x305a2e6f 0×30504682 0x4d543 0x4d5be 0x3050a79d 0x3050a338 0x909c4a19 0x909c489e)

You will have to have iMovie ’09 however, which is an additional purchase if you don’t already have it. However, the iLife package is worth it imho.

Anyway, with iMove ’09 I was able to simply attach my Panasonic Lumix camera to the Mac via the USB connection and iMovie downloaded all of the movies without a hitch, even at HD sizes.

So glad I am now able to use my camera!