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;
      }
    
    
  };
</script>

Test runner

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bitwise('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');

numbers('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');

bitwiseconv('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');

numbersconv('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');

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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:

• Revision 1: published by Jelle De Loecker on 29th June 2012
• Revision 2: published on 26th July 2012
• Revision 5: published on 13th September 2012
• Revision 6: published on 14th September 2012
• Revision 8: published on 29th December 2012
• Revision 10: published on 22nd February 2013
• Revision 11: published on 6th March 2013
• Revision 12: published by Erwinus on 17th April 2013
• Revision 13: published by Yehor on 17th April 2013
• Revision 14: published on 10th May 2013
• Revision 17: published 3 weeks ago
• Revision 18: published 3 weeks ago

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