Hashing strings (v14)

Revision 14 of this benchmark created on

Description

Looking for the fastest hash function to get a unique id of a string.

Setup

// Erwin Haantjes, optimize code and use while loops
    
    function bitwise(str){
        var hash = 0,i=(str && str.length)?str.length:0;
        while(i--) { hash = ((hash<<5)-hash)+str.charCodeAt(i); }
        return hash;
    }
    
    function numbers(str) {
       var res = 0,i=(str && str.length)?str.length:0;
       while(i--) { res = res * 31 + str.charCodeAt(i); }
       return res;
      }
    
    function dodgyNumbers(str) {
       var res = 0,i=(str && str.length)?str.length:0;
       while(i -= 4 > 0) { res = res * 31 + str.charCodeAt(i); }
       return res;
      }
    
    
    function bitwiseconv(str){
        var hash = 0,i=(str && str.length)?str.length:0; 
        while(i--)
        {
            hash = ((hash<<5)-hash)+str.charCodeAt(i);
            hash = hash & hash; // Convert to 32bit integer
        }
        return hash;
    }
    
    function numbersconv(str) {
      for(var res = 0, len = str && str.length || 0, j = 0; j < len; j++){
        res = (res * 31 + str.charCodeAt(j)) | 0;
      }
      return res;
    }

Test runner

Ready to run.

Testing in
TestOps/sec
Bitwise based function (No integer conversion)
bitwise('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');
ready
Number based function (No integer conversion)
numbers('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');
ready
Bitwise based function
bitwiseconv('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');
ready
Number based function
numbersconv('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');
ready
Dodgy numbers
dodgyNumbers('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');
ready

Revisions

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