Lightcord/DiscordJS/src/util/Snowflake.ts

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2020-05-21 13:32:22 +02:00
'use strict';
import Util = require('../util/util');
// Discord epoch (2015-01-01T00:00:00.000Z)
const EPOCH = 1420070400000;
let INCREMENT = 0;
/**
* A container for useful snowflake-related methods.
*/
export default class SnowflakeUtil {
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
*/
/**
* Generates a Discord snowflake.
* <info>This hardcodes the worker ID as 1 and the process ID as 0.</info>
* @param {number|Date} [timestamp=Date.now()] Timestamp or date of the snowflake to generate
* @returns {Snowflake} The generated snowflake
*/
static generate(timestamp: number | Date = Date.now()): Snowflake {
if (timestamp instanceof Date) timestamp = timestamp.getTime();
if (typeof timestamp !== 'number' || isNaN(timestamp)) {
throw new TypeError(
`"timestamp" argument must be a number (received ${isNaN(timestamp) ? 'NaN' : typeof timestamp})`,
);
}
if (INCREMENT >= 4095) INCREMENT = 0;
// eslint-disable-next-line max-len
const BINARY = `${(timestamp - EPOCH).toString(2).padStart(42, '0')}0000100000${(INCREMENT++)
.toString(2)
.padStart(12, '0')}`;
return Util.binaryToID(BINARY);
}
/**
* 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: Snowflake): DeconstructedSnowflake {
const BINARY = Util.idToBinary(snowflake)
.toString()
.padStart(64, '0');
const res = {
timestamp: parseInt(BINARY.substring(0, 42), 2) + 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 as DeconstructedSnowflake;
}
}
type DeconstructedSnowflake = {
timestamp: number,
workerID: number,
processID: number,
increment: number,
binary: string,
readonly date: Date
}
type Snowflake = string