93 lines
3.0 KiB
JavaScript
93 lines
3.0 KiB
JavaScript
'use strict';
|
|
|
|
// Discord epoch (2015-01-01T00:00:00.000Z)
|
|
const EPOCH = 1_420_070_400_000;
|
|
let INCREMENT = BigInt(0);
|
|
|
|
/**
|
|
* A container for useful snowflake-related methods.
|
|
*/
|
|
class SnowflakeUtil extends null {
|
|
/**
|
|
* A {@link https://developer.twitter.com/en/docs/twitter-ids 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 milliseconds since Discord epoch worker pid increment
|
|
* ```
|
|
* @typedef {string} Snowflake
|
|
*/
|
|
|
|
/**
|
|
* Generates a Discord snowflake.
|
|
* <info>This hardcodes the worker's id as 1 and the process's 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 = Date.now()) {
|
|
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 >= 4095n) INCREMENT = BigInt(0);
|
|
|
|
// Assign WorkerId as 1 and ProcessId as 0:
|
|
return ((BigInt(timestamp - EPOCH) << 22n) | (1n << 17n) | 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 The worker's id in the snowflake
|
|
* @property {number} processId The process's 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}
|
|
*/
|
|
static deconstruct(snowflake) {
|
|
const bigIntSnowflake = BigInt(snowflake);
|
|
return {
|
|
timestamp: Number(bigIntSnowflake >> 22n) + EPOCH,
|
|
get date() {
|
|
return new Date(this.timestamp);
|
|
},
|
|
workerId: Number((bigIntSnowflake >> 17n) & 0b11111n),
|
|
processId: Number((bigIntSnowflake >> 12n) & 0b11111n),
|
|
increment: Number(bigIntSnowflake & 0b111111111111n),
|
|
binary: bigIntSnowflake.toString(2).padStart(64, '0'),
|
|
};
|
|
}
|
|
|
|
/**
|
|
* Retrieves the timestamp field's value from a Discord snowflake.
|
|
* @param {Snowflake} snowflake Snowflake to get the timestamp value from
|
|
* @returns {number}
|
|
*/
|
|
static timestampFrom(snowflake) {
|
|
return Number(BigInt(snowflake) >> 22n) + EPOCH;
|
|
}
|
|
|
|
/**
|
|
* Discord's epoch value (2015-01-01T00:00:00.000Z).
|
|
* @type {number}
|
|
* @readonly
|
|
*/
|
|
static get EPOCH() {
|
|
return EPOCH;
|
|
}
|
|
}
|
|
|
|
module.exports = SnowflakeUtil;
|