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MAWeakDictionary.m
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MAWeakDictionary.m
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//
// MAWeakDictionary.m
// ZeroingWeakRef
//
// Created by Mike Ash on 7/13/10.
//
#import "MAWeakDictionary.h"
#import "MAZeroingWeakRef.h"
@implementation MAWeakDictionary
- (id)init
{
if((self = [super init]))
{
_dict = [[NSMutableDictionary alloc] init];
}
return self;
}
- (void)dealloc
{
[_dict release];
[super dealloc];
}
- (NSUInteger)count
{
return [_dict count];
}
- (id)objectForKey: (id)aKey
{
MAZeroingWeakRef *ref = [_dict objectForKey: aKey];
id obj = [ref target];
// clean out keys whose objects have gone away
if(ref && !obj)
[_dict removeObjectForKey: aKey];
return obj;
}
- (NSEnumerator *)keyEnumerator
{
// enumerate over a copy because -objectForKey: mutates
// which could cause an exception in code that should
// appear to be correct
return [[_dict allKeys] objectEnumerator];
}
- (void)removeObjectForKey: (id)aKey
{
[_dict removeObjectForKey: aKey];
}
- (void)setObject: (id)anObject forKey: (id)aKey
{
[_dict setObject: [MAZeroingWeakRef refWithTarget: anObject]
forKey: aKey];
}
@end