projects-jenz/jenz_ban_detector/html/content/hash/murmurhash3.js

51 lines
1.7 KiB
JavaScript

function murmurhash3_32_gc(key, seed) {
var remainder, bytes, h1, h1b, c1, c2, k1, i;
remainder = key.length & 3; // key.length % 4
bytes = key.length - remainder;
h1 = seed;
c1 = 0xcc9e2d51;
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;
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;
}
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;
}