Run results for: Hashes: JavaString, DJB2, Cyr53

Run details:

User agent: Mozilla/5.0 (Android 14; Mobile; rv:120.0) Gecko/120.0 Firefox/120.0

Browser: Firefox Mobile 120

Operating system: Android

Device Platform: Mobile

Date tested: 2 years ago

Test name	Executions per second
✓ Java String Hash	41,263,196 Ops/sec
DJB2	40,112,576 Ops/sec
cyrb53	15,406,565 Ops/sec
DJB2 - reduce	6,993,726 Ops/sec

Script Preparation code:

var input = "Hello World!";

function javaStringHash(str) {
    var hash = 0;
    for (var i = 0; i < str.length; i++) {
        hash = ((hash << 5) - hash) + str.charCodeAt(i);
        hash |= 0; // Convert to 32bit integer
    }
    return hash;
}

function djb2(str) {
    var hash = 5381;
    for (var i = 0; i < str.length; i++) {
        hash = ((hash << 5) + hash) + str.charCodeAt(i);
        hash |= 0; // Convert to 32bit integer
    }
    return hash;
}

function djb2Reduce(str) {
    return str.split("").reduce(function(a, b) {
        a = ((a << 5) + a) + b.charCodeAt(0);
        return a & a;
    }, 0);
}


function cyrb53(str, seed) {
    var h1 = 0xdeadbeef ^ seed;
    var h2 = 0x41c6ce57 ^ seed;
    for (var i = 0; i < str.length; i++) {
        var ch = str.charCodeAt(i);
        h1 = Math.imul(h1 ^ ch, 2654435761);
        h2 = Math.imul(h2 ^ ch, 1597334677);
    }

    h1 = Math.imul(h1 ^ (h1 >>> 16), 2246822507) ^ Math.imul(h2 ^ (h2 >>> 13), 3266489909);
    h2 = Math.imul(h2 ^ (h2 >>> 16), 2246822507) ^ Math.imul(h1 ^ (h1 >>> 13), 3266489909);

    return 4294967296 * (2097151 & h2) + (h1 >>> 0);
};

Run results for: Hashes: JavaString, DJB2, Cyr53

Compares different hash functions in javascript Cyrb53 - see https://github.com/bryc/code/blob/master/jshash/experimental/cyrb53.js

Java String Hash

DJB2

cyrb53

DJB2 - reduce