Hashing strings (v6)

Revision 6 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);
      }
      res = res & res;
      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 hashcode(str) {
      var hash = 0;
      if (str.length == 0) return hash;
      for (var i = 0; i < str.length; i++) {
        var char = str.charCodeAt(i);
        hash = ((hash << 5) - hash) + char;
      }
      hash = hash & hash; // Convert to 32bit integer
      return hash;
    }

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
Java hashCode
hashcode('[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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