spacebar/util/src/util/Snowflake.ts
2021-10-08 10:43:43 +02:00

128 lines
3.6 KiB
TypeScript

// @ts-nocheck
import * as cluster from "cluster";
// https://github.com/discordjs/discord.js/blob/master/src/util/Snowflake.js
// Apache License Version 2.0 Copyright 2015 - 2021 Amish Shah
("use strict");
// Discord epoch (2015-01-01T00:00:00.000Z)
/**
* A container for useful snowflake-related methods.
*/
export class Snowflake {
static readonly EPOCH = 1420070400000;
static INCREMENT = 0n; // max 4095
static processId = BigInt(process.pid % 31); // max 31
static workerId = BigInt((cluster.worker?.id || 0) % 31); // max 31
constructor() {
throw new Error(`The ${this.constructor.name} class may not be instantiated.`);
}
/**
* A Twitter snowflake, except the epoch is 2015-01-01T00:00:00.000Z
* ```
* If we have a snowflake '266241948824764416' we can represent it as binary:
*
* 64 22 17 12 0
* 000000111011000111100001101001000101000000 00001 00000 000000000000
* number of ms since Discord epoch worker pid increment
* ```
* @typedef {string} Snowflake
*/
/**
* Transforms a snowflake from a decimal string to a bit string.
* @param {Snowflake} num Snowflake to be transformed
* @returns {string}
* @private
*/
static idToBinary(num) {
let bin = "";
let high = parseInt(num.slice(0, -10)) || 0;
let low = parseInt(num.slice(-10));
while (low > 0 || high > 0) {
bin = String(low & 1) + bin;
low = Math.floor(low / 2);
if (high > 0) {
low += 5000000000 * (high % 2);
high = Math.floor(high / 2);
}
}
return bin;
}
/**
* Transforms a snowflake from a bit string to a decimal string.
* @param {string} num Bit string to be transformed
* @returns {Snowflake}
* @private
*/
static binaryToID(num) {
let dec = "";
while (num.length > 50) {
const high = parseInt(num.slice(0, -32), 2);
const low = parseInt((high % 10).toString(2) + num.slice(-32), 2);
dec = (low % 10).toString() + dec;
num =
Math.floor(high / 10).toString(2) +
Math.floor(low / 10)
.toString(2)
.padStart(32, "0");
}
num = parseInt(num, 2);
while (num > 0) {
dec = (num % 10).toString() + dec;
num = Math.floor(num / 10);
}
return dec;
}
static generate() {
var time = BigInt(Date.now() - Snowflake.EPOCH) << 22n;
var worker = Snowflake.workerId << 17n;
var process = Snowflake.processId << 12n;
var increment = Snowflake.INCREMENT++;
return (time | worker | process | increment).toString();
}
/**
* A deconstructed snowflake.
* @typedef {Object} DeconstructedSnowflake
* @property {number} timestamp Timestamp the snowflake was created
* @property {Date} date Date the snowflake was created
* @property {number} workerID Worker ID in the snowflake
* @property {number} processID Process ID in the snowflake
* @property {number} increment Increment in the snowflake
* @property {string} binary Binary representation of the snowflake
*/
/**
* Deconstructs a Discord snowflake.
* @param {Snowflake} snowflake Snowflake to deconstruct
* @returns {DeconstructedSnowflake} Deconstructed snowflake
*/
static deconstruct(snowflake) {
const BINARY = Snowflake.idToBinary(snowflake).toString(2).padStart(64, "0");
const res = {
timestamp: parseInt(BINARY.substring(0, 42), 2) + Snowflake.EPOCH,
workerID: parseInt(BINARY.substring(42, 47), 2),
processID: parseInt(BINARY.substring(47, 52), 2),
increment: parseInt(BINARY.substring(52, 64), 2),
binary: BINARY,
};
Object.defineProperty(res, "date", {
get: function get() {
return new Date(this.timestamp);
},
enumerable: true,
});
return res;
}
}