Add MurmurHash3

This commit is contained in:
Alice 2024-01-23 13:52:50 -05:00 committed by Allie
parent 56a8e02bb8
commit dc7760247b
2 changed files with 114 additions and 0 deletions

View file

@ -369,6 +369,7 @@
"SHA2",
"SHA3",
"SM3",
"MurmurHash3",
"Keccak",
"Shake",
"RIPEMD",

View file

@ -0,0 +1,113 @@
/**
* @author AliceGrey [alice@grey.systems]
* @copyright Crown Copyright 2024
* @license Apache-2.0
*/
import Operation from "../Operation.mjs";
/**
* MurmurHash3 operation
*/
class MurmurHash3 extends Operation {
/**
* MurmurHash3 constructor
*/
constructor() {
super();
this.name = "MurmurHash3";
this.module = "Default";
this.description = "Generates a MurmurHash v3 for a string input and an optional seed input";
this.infoURL = "https://wikipedia.org/wiki/MurmurHash";
this.inputType = "string";
this.outputType = "number";
this.args = [
{
name: "Seed",
type: "number",
value: 0
}
];
}
/**
* Calculates the MurmurHash3 hash of the input.
* Based on Gary Court's JS MurmurHash implementation
* @see http://github.com/garycourt/murmurhash-js
* @author AliceGrey [alice@grey.systems]
* @param {string} input ASCII only
* @param {number} seed Positive integer only
* @return {number} 32-bit positive integer hash
*/
mmh3(input, seed) {
let h1, h1b, k1, i;
const remainder = input.length & 3; // input.length % 4
const bytes = input.length - remainder;
h1 = seed;
const c1 = 0xcc9e2d51;
const c2 = 0x1b873593;
i = 0;
while (i < bytes) {
k1 =
((input.charCodeAt(i) & 0xff)) |
((input.charCodeAt(++i) & 0xff) << 8) |
((input.charCodeAt(++i) & 0xff) << 16) |
((input.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;
if (remainder === 3) {
k1 ^= (input.charCodeAt(i + 2) & 0xff) << 16;
}
if (remainder === 2) {
k1 ^= (input.charCodeAt(i + 1) & 0xff) << 8;
}
if (remainder === 1) {
k1 ^= (input.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 ^= input.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;
}
/**
* @param {string} input
* @param {Object[]} args
* @returns {number}
*/
run(input, args) {
let seed;
if (args && args.length > 0) {
seed = args[0];
}
return this.mmh3(input, seed);
}
}
export default MurmurHash3;