salsify-experiences-sdk
Version:
SDK to be used by commerce websites to implement product experiences.
65 lines • 2.44 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.murmurHash3 = void 0;
/**
* JS Implementation of MurmurHash3 (r136) (as of May 20, 2011)
*
* @author <a href="mailto:gary.court@gmail.com">Gary Court</a>
* @see http://github.com/garycourt/murmurhash-js
* @author <a href="mailto:aappleby@gmail.com">Austin Appleby</a>
* @see https://github.com/aappleby/smhasher
*
* @param {string} key ASCII only
* @param {number} seed Positive integer only
* @return {number} 32-bit positive integer hash
*/
function murmurHash3(key, seed) {
let k1;
let i;
let h1b;
const remainder = key.length & 3; // key.length % 4
const bytes = key.length - remainder;
let h1 = seed;
const c1 = 0xcc9e2d51;
const c2 = 0x1b873593;
i = 0;
while (i < bytes) {
k1 =
(key.charCodeAt(i) & 0xff) |
((key.charCodeAt(++i) & 0xff) << 8) |
((key.charCodeAt(++i) & 0xff) << 16) |
((key.charCodeAt(++i) & 0xff) << 24);
++i;
k1 = ((k1 & 0xffff) * c1 + ((((k1 >>> 16) * c1) & 0xffff) << 16)) & 0xffffffff;
k1 = (k1 << 15) | (k1 >>> 17);
k1 = ((k1 & 0xffff) * c2 + ((((k1 >>> 16) * c2) & 0xffff) << 16)) & 0xffffffff;
h1 ^= k1;
h1 = (h1 << 13) | (h1 >>> 19);
h1b = ((h1 & 0xffff) * 5 + ((((h1 >>> 16) * 5) & 0xffff) << 16)) & 0xffffffff;
h1 = (h1b & 0xffff) + 0x6b64 + ((((h1b >>> 16) + 0xe654) & 0xffff) << 16);
}
k1 = 0;
/* eslint-disable no-fallthrough */
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 = ((k1 & 0xffff) * c1 + ((((k1 >>> 16) * c1) & 0xffff) << 16)) & 0xffffffff;
k1 = (k1 << 15) | (k1 >>> 17);
k1 = ((k1 & 0xffff) * c2 + ((((k1 >>> 16) * c2) & 0xffff) << 16)) & 0xffffffff;
h1 ^= k1;
}
/* eslint-enable no-fallthrough */
h1 ^= key.length;
h1 ^= h1 >>> 16;
h1 = ((h1 & 0xffff) * 0x85ebca6b + ((((h1 >>> 16) * 0x85ebca6b) & 0xffff) << 16)) & 0xffffffff;
h1 ^= h1 >>> 13;
h1 = ((h1 & 0xffff) * 0xc2b2ae35 + ((((h1 >>> 16) * 0xc2b2ae35) & 0xffff) << 16)) & 0xffffffff;
h1 ^= h1 >>> 16;
return h1 >>> 0;
}
exports.murmurHash3 = murmurHash3;
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