@splitsoftware/splitio-commons
Version:
Split JavaScript SDK common components
63 lines (62 loc) • 2.35 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.bucket = exports.hash = void 0;
/* eslint-disable no-fallthrough */
var common_1 = require("./common");
/*
* +----------------------------------------------------------------------------------+
* | murmurHash3.js v3.0.0 (http://github.com/karanlyons/murmurHash3.js) |
* | A TypeScript/JavaScript implementation of MurmurHash3's hashing algorithms. |
* |----------------------------------------------------------------------------------|
* | Copyright (c) 2012-2020 Karan Lyons. Freely distributable under the MIT license. |
* +----------------------------------------------------------------------------------+
*/
// PUBLIC FUNCTIONS
// ----------------
function hash32(key, seed) {
//
// Given a string and an optional seed as an int, returns a 32 bit hash
// using the x86 flavor of MurmurHash3, as an unsigned int.
//
key = key || '';
seed = seed || 0;
var remainder = key.length % 4;
var bytes = key.length - remainder;
var h1 = seed;
var k1 = 0;
var c1 = 0xcc9e2d51;
var c2 = 0x1b873593;
for (var i = 0; i < bytes; i = i + 4) {
k1 = ((key.charCodeAt(i) & 0xff)) | ((key.charCodeAt(i + 1) & 0xff) << 8) | ((key.charCodeAt(i + 2) & 0xff) << 16) | ((key.charCodeAt(i + 3) & 0xff) << 24);
k1 = (0, common_1.x86Multiply)(k1, c1);
k1 = (0, common_1.x86Rotl)(k1, 15);
k1 = (0, common_1.x86Multiply)(k1, c2);
h1 ^= k1;
h1 = (0, common_1.x86Rotl)(h1, 13);
h1 = (0, common_1.x86Multiply)(h1, 5) + 0xe6546b64;
}
k1 = 0;
switch (remainder) {
case 3:
k1 ^= (key.charCodeAt(i + 2) & 0xff) << 16;
case 2:
k1 ^= (key.charCodeAt(i + 1) & 0xff) << 8;
case 1:
k1 ^= (key.charCodeAt(i) & 0xff);
k1 = (0, common_1.x86Multiply)(k1, c1);
k1 = (0, common_1.x86Rotl)(k1, 15);
k1 = (0, common_1.x86Multiply)(k1, c2);
h1 ^= k1;
}
h1 ^= key.length;
h1 = (0, common_1.x86Fmix)(h1);
return h1 >>> 0;
}
function hash(str, seed) {
return hash32((0, common_1.UTF16ToUTF8)(str), seed >>> 0);
}
exports.hash = hash;
function bucket(str, seed) {
return Math.abs(hash(str, seed) % 100) + 1;
}
exports.bucket = bucket;