Hashing strings

JavaScript performance comparison

Revision 2 of this test case created

Info

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

Preparation code

 
<script>
Benchmark.prototype.setup = function() {
    function bitwise(str){
        var hash = 0;
        if (str.length == 0) return hash;
        for (i = 0; i < str.length; i++) {
            char = str.charCodeAt(i);
            hash = ((hash<<5)-hash)+char;
        }
        return hash;
    }
   
    function numbers(str) {
       var res = 0,
           len = str.length;
       for (var i = 0; i < len; i++) {
        res = res * 31 + str.charCodeAt(i);
       }
       return res;
      }
   
    function bitwiseconv(str){
        var hash = 0;
        if (str.length == 0) return hash;
        for (i = 0; i < str.length; i++) {
            char = str.charCodeAt(i);
            hash = ((hash<<5)-hash)+char;
            hash = hash & hash; // Convert to 32bit integer
        }
        return hash;
    }
   
    function numbersconv(str) {
       var res = 0,
           len = str.length;
       for (var i = 0; i < len; i++) {
        res = res * 31 + str.charCodeAt(i);
        res = res & res;
       }
       return res;
      }
   
    function smallconv(e){
       for(var  r = 0, i = 0; i < e.length; i++)
          r = ( r << 5 ) - r + e.charCodeAt(i), r& = r ;
       return r}
};
</script>

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Testing in unknown unknown
Test Ops/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');
pending…
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');
pending…
Bitwise based function
bitwiseconv('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');
pending…
Number based function
numbersconv('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');
pending…
Small version
smallconv('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');
pending…

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