Enumeration benchmark

gistfile1.m

/* All measurements were done on iPhone 4 */

// MRC:
// for loop: 1.891520ms
// NSFastEnumeration: 0.393583ms
// enumerateObjectsUsingBlock: 0.547250ms

// ARC (w/o __unsafe_unretained):
// for loop: 6.889979ms
// NSFastEnumeration: 0.394479ms
// enumerateObjectsUsingBlock: 6.513708ms

// ARC (w/ __unsafe_unretained):
// for loop: 6.899520ms
// NSFastEnumeration: 0.395750ms
// enumerateObjectsUsingBlock: 0.548833ms

- (void) performTests
{
    const NSUInteger ObjectCount = 10000;
    const NSUInteger TestCount = 1000;

    NSMutableArray *data = [NSMutableArray arrayWithCapacity:ObjectCount];
    for (NSUInteger i = 0; i < ObjectCount; ++i)
    {
        [data addObject:[NSNumber numberWithInteger:arc4random_uniform(ObjectCount)]];
    }

    NSLog(@"for loop: %fms", (1. / NSEC_PER_MSEC) * ADVGetMedianExecutionTime(TestCount, ^{
        for (NSUInteger i = 0; i < ObjectCount; ++i)
        {
            if (!data[i]) NSLog(@"impossible!");
        }
    }));

    NSLog(@"NSFastEnumeration: %fms", (1. / NSEC_PER_MSEC) * ADVGetMedianExecutionTime(TestCount, ^{
        for (id object in data)
        {
            if (!object) NSLog(@"impossible!");
        }
    }));

    NSLog(@"enumerateObjectsUsingBlock: %fms", (1. / NSEC_PER_MSEC) * ADVGetMedianExecutionTime(TestCount, ^{
        [data enumerateObjectsUsingBlock:^(/*__unsafe_unretained*/ id object, NSUInteger idx, BOOL *stop) {
            if (!object) NSLog(@"impossible!");
        }];
    }));
}