Hashing strings

JavaScript performance comparison

Revision 18 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, i, char;
        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, i, char,
           len = str.length;
       for (var i = 0; i < len; i++) {
        char = str.charCodeAt(i)
        res  = res * 31 + char;
       }
       return res;
      }
   
    function bitwiseconv(str){
        var hash = 0, i, char;
        if (str.length == 0) return hash;
        for (i = 0; i < str.length; i++) {
            char  = str.charCodeAt(i);
            hash  = ((hash<<5)-hash)+char;
            hash |= 0; // Convert to 32bit integer
        }
        return hash;
    }
   
    function numbersconv(str) {
       var res = 0,
           len = str.length, i, char;
       for (var i = 0; i < len; i++) {
        char = str.charCodeAt(i)
        res  = res * 31 + char;
        res |= 0;
       }
       return res;
      }
   
};
</script>

Test runner

Warning! For accurate results, please disable Firebug before running the tests. (Why?)

Java applet disabled.

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…

Compare results of other browsers

Revisions

You can edit these tests or add even more tests to this page by appending /edit to the URL. Here’s a list of current revisions for this page:

0 comments

Add a comment