iphone - Objective-C : Fowler–Noll–Vo (FNV) Hash implementation -


I have an HTTP connector in my iPhone project, and using a phoner-no-loop in the query, Should be set (FNV) hash

I have a Java implementation that is currently working, this code is: 

  long fnv_prime = 0x811C9DC5; Long hash = 0; For (int i = 0; i & lt; str.length (); i ++) {hash * = fnv_prime; Hash ^ = str.charAt (i); }

Now on the iPhone, I did this: 

  int64_t fnv_prime = 0x811C9DC5; Int64_T hash = 0; For (int i = 0; i & lt; [myString length]; i ++) {hash * = fnv_prime; Hash ^ = [MyStreamColorItindex: I]; }

This script does not give me a single result. Is one of java.

In the first loop, I get this:

hash = 0

hash = 100 (the first letter is "D")

Hash = 1865261300 (like java for hash = 100 and fnv_prime = -2128831035)

Is anyone missing me something?

Thanks in advance for help!

In Java, this line: 

  long fnv_prime = 0x811C9DC5;

will generate the fnv_prime in the numeric value -2128831035, because continuous is interpreted as int , which is 32-bit The value signed in Java is increased if the value is written in long .

In contrast, the purpose-in the C code: 

  int64_t fnv_prime = 0x811C9DC5;   
  0x811C9DC5  is defined as a  unsigned int  static (since it fits in signed 32-bit  int Is not ), with numeric value 2166136261. That value is then written in  fnv_prime , and there is no indication to expand it, as far as the C compiler is concerned, the value is positive. / P> 
 This way you end up with different values ​​for  fnv_prime , which show your specific results. 
 
 This is the " L " suffix in Java, like this: 
 
  long fnv_prime = 0x811C9DC5L;  
 
 that forces the Java compiler to interpret continuously as  long , with the same numerical value that you get from Objective-C code .

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