Example 1 of slow and fast NSDictionary access

slow_kvo_dictionary_example2.m

//  Created by Benedikt Terhechte on 07.12.11.
//  Appventure.me
//

#import <Foundation/Foundation.h>

#define AKeyPathDictionary(dictionary, A) [dictionary objectForKey:@A]
#define BKeyPathDictionary(dictionary, A, B) [AKeyPathDictionary(dictionary, A) objectForKey:@B]
#define CKeyPathDictionary(dictionary, A, B, C) [BKeyPathDictionary(dictionary, A, B) objectForKey:@C]
#define DKeyPathDictionary(dictionary, A, B, C, D) [CKeyPathDictionary(dictionary, A, B, C) objectForKey:@D]
#define EKeyPathDictionary(dictionary, A, B, C, D, E) [DKeyPathDictionary(dictionary, A, B, C, D) objectForKey:@E]
#define FKeyPathDictionary(dictionary, A, B, C, D, E, F) [EKeyPathDictionary(dictionary, A, B, C, D, E) objectForKey:@F]
#define GKeyPathDictionary(dictionary, A, B, C, D, E, F, G) [FKeyPathDictionary(dictionary, A, B, C, D, E, F) objectForKey:@G]
#define HKeyPathDictionary(dictionary, A, B, C, D, E, F, G, H) [GKeyPathDictionary(dictionary, A, B, C, D, E, F, G) objectForKey:@H]

#define PP_NARG(...) PP_NARG_(__VA_ARGS__,PP_RSEQ_N()) 
#define PP_NARG_(...) PP_ARG_N(__VA_ARGS__) 
#define PP_ARG_N(_1,_2,_3,_4,_5,_6,_7,_8,_9,N,...) N 
#define PP_RSEQ_N() HKeyPathDictionary,GKeyPathDictionary,FKeyPathDictionary,EKeyPathDictionary,DKeyPathDictionary,CKeyPathDictionary,BKeyPathDictionary,AKeyPathDictionary,0 

#define KeyPathDictionary(...) PP_NARG(__VA_ARGS__)(__VA_ARGS__)


int main (int argc, const char * argv[])
{
  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
  NSDictionary *aDictionary = [NSDictionary dictionaryWithObject:
    [NSDictionary dictionaryWithObject:
      [NSDictionary dictionaryWithObject:
        [NSDictionary dictionaryWithObject: @"Magnus Enzensberger" forKey:@"friend"]
      forKey: @"data"]
     forKey: @"likes"]
    forKey: @"data"];
    
  // All benchmarks on a 2.7Ghy i7 MBP
  int i;
  for(i=0;i<5000000; i++) {
    // The slow & easy approach
    // Benchmark: 11.93 sec.
    [aDictionary valueForKeyPath:@"data.likes.data.friend"];
      
    // The fast but ugly and cumbersome approach
    // Benchmark: 1.53 sec.
    [[[[aDictionary objectForKey:@"data"] objectForKey:@"likes"] objectForKey: @"data"] objectForKey: @"friend"];      
    
    // The fast and beautiful approach
    // Benchmark: 1.55 sec.
    KeyPathDictionary(aDictionary, "data", "likes", "data", "friend");
  }
     
  [pool release];
  
  return 0;
}