Vencord/src/utils/intlHash.ts
2024-11-05 16:50:26 -03:00

52 lines
1.8 KiB
TypeScript

/* eslint-disable simple-header/header */
/**
* discord-intl
*
* @copyright 2024 Discord, Inc.
* @link https://github.com/discord/discord-intl
* @license MIT
*/
import { hash as h64 } from "@intrnl/xxhash64";
const BASE64_TABLE = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".split("");
const IS_BIG_ENDIAN = (() => {
const array = new Uint8Array(4);
const view = new Uint32Array(array.buffer);
return !((view[0] = 1) & array[0]);
})();
function numberToBytes(number: number | bigint) {
number = BigInt(number);
const array: number[] = [];
const byteCount = Math.ceil(Math.floor(Math.log2(Number(number)) + 1) / 8);
for (let i = 0; i < byteCount; i++) {
array.unshift(Number((number >> BigInt(8 * i)) & BigInt(255)));
}
const bytes = new Uint8Array(array);
// The native `hashToMessageKey` always works in Big/Network Endian bytes, so this array
// needs to be converted to the same endianness to get the same base64 result.
return IS_BIG_ENDIAN ? bytes : bytes.reverse();
}
/**
* Returns a consistent, short hash of the given key by first processing it through a hash digest,
* then encoding the first few bytes to base64.
*
* This function is specifically written to mirror the native backend hashing function used by
* `@discord/intl-loader-core`, to be able to hash names at runtime.
*/
export function runtimeHashMessageKey(key: string): string {
const hash = h64(key, 0);
const bytes = numberToBytes(hash);
return [
BASE64_TABLE[bytes[0] >> 2],
BASE64_TABLE[((bytes[0] & 0x03) << 4) | (bytes[1] >> 4)],
BASE64_TABLE[((bytes[1] & 0x0f) << 2) | (bytes[2] >> 6)],
BASE64_TABLE[bytes[2] & 0x3f],
BASE64_TABLE[bytes[3] >> 2],
BASE64_TABLE[((bytes[3] & 0x03) << 4) | (bytes[3] >> 4)],
].join("");
}