Hashing strings (v33)

Revision 33 of this benchmark created on

Description

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

Setup

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 reduce(str) {
      return str.split("").reduce(function(a, b) {
        a = ((a << 5) - a) + b.charCodeAt(0);
        return a & a
      }, 0);
    }
    
    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 numbersor(str) {
      var res = 0,
        len = str.length;
      for (var i = 0; i < len; i++) {
        res = res * 31 + str.charCodeAt(i);
        res = res | 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
Number based function (OR)
numbersor('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');
ready
Reduce (for modern browsers)
reduce('[LOG] This is a a not-too-long log message, once that will commonly pop up in my application');
ready

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.