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Id128

Generate 128-bit unique identifiers for various specifications. In particular:

Common Usage

const {
	Ulid,
	UlidMonotonic,
	Uuid,
	Uuid1,
	Uuid4,
	Uuid6,
	UuidNil,
	idCompare,
	idEqual,
} = require('id128');

// Id factories
[
	Ulid,
	UlidMonotonic,
	Uuid1,
	Uuid4,
	Uuid6,
	UuidNil,
].forEach((IdType) => {
	// Identify the factory
	console.log(IdType.name);

	// Generate a new id
	const id = IdType.generate();

	// Get the smallest valid id
	const min = IdType.MIN();

	// Get the largest valid id
	const max = IdType.MAX();

	// Type-check the id
	console.log(id instanceof IdType.type)

	// Compare ids
	console.log(id.equal(id));
	console.log(! id.equal(min));
	console.log(! id.equal(max));
	console.log(id.compare(min) === 1);
	console.log(id.compare(id) === 0);
	console.log(id.compare(max) === -1);

	// Encode the id in its canonical form
	const canonical = id.toCanonical();
	console.log(canonical);

	// Encode the id for efficient db storage
	const raw = id.toRaw();
	console.log(raw);

	// Verify a canonically formatted id
	console.log(IdType.isCanonical(canonical));

	// Decode a valid canonically formatted id
	console.log(id.equal(IdType.fromCanonical(canonical)));

	// Decode a canonically formatted id, skipping validation
	console.log(id.equal(IdType.fromCanonicalTrusted(canonical)));

	// Verify a raw formatted id
	console.log(IdType.isRaw(raw));

	// Decode a valid raw formatted id
	console.log(id.equal(IdType.fromRaw(raw)));

	// Decode a raw formatted id, skipping validation
	console.log(id.equal(IdType.fromRawTrusted(raw)));
});

// Uuid Factory
[0, 1, 4, 6].forEach((version) => {
	// Generate a new id
	const id = Uuid.generate({ version });

	// Get the smallest valid id
	const min = Uuid.MIN({ version });

	// Get the largest valid id
	const max = Uuid.MAX({ version });

	// Type-check the id
	console.log(id instanceof Uuid.type)

	// Encode the id in its canonical form
	const canonical = id.toCanonical();
	console.log(canonical);

	// Encode the id for efficient db storage
	const raw = id.toRaw();
	console.log(raw);

	// Decode a valid canonically formatted id
	console.log(id.equal(Uuid.fromCanonical(canonical)));

	// Decode a canonically formatted id, skipping validation
	console.log(id.equal(Uuid.fromCanonicalTrusted(canonical)));

	// Decode a valid raw formatted id
	console.log(id.equal(Uuid.fromRaw(raw)));

	// Decode a raw formatted id, skipping validation
	console.log(id.equal(Uuid.fromRawTrusted(raw)));
});

// Static Utilities

// Equate arbitrary ids
console.log(idEqual(Ulid.generate(), Uuid4.generate()))

// Compare arbitrary ids
console.log(idCompare(Ulid.generate(), Uuid4.generate()))

Common Factory Properties

name

Return the name of the generated id type.

type

Return the type of the generated id instances for type-checking with the instanceof operator.

Common Factory Methods

.construct(bytes) => id

Return a new id instance without validating the bytes.

.generate() => id

Return a new id instance.

.MIN() => id

Return the id instance with the smallest valid value.

.MAX() => id

Return the id instance with the largest valid value.

.fromCanonical(canonical_string) => id

Decode an id from its canonical representation. Throw InvalidEncoding if the string is undecodable.

.fromCanonicalTrusted(canonical_string) => id

Decode an id from its canonical representation. Skip validation and assume the input is decodable.

.fromRaw(raw_string) => id

Decode an id from its raw representation. Throw InvalidEncoding if the string is undecodable.

.fromRawTrusted(raw_string) => id

Decode an id from its raw representation. Skip validation and assume the input is decodable.

.toCanonical(id) => canonical_string

Encode the given id in the canonical form. Throw InvalidBytes if the id is not 128-bit conformant.

.toRaw(id) => raw_string

Encode the given id in the raw form. Throw InvalidBytes if the id is not 128-bit conformant.

.isCanonical(canonical_string) => (true|false)

Verify if a string is a valid canonical encoding.

.isRaw(raw_string) => (true|false)

Verify if a string is a valid raw encoding.

Common Instance Properties

bytes

Return the actual byte array representing the id.

Common Instance Methods

.clone() => deep_copy

Return a new instance of the id with the same bit signature.

.compare(other) => (-1|0|1)

Determine how this id is ordered against another.

.equal(other) => (true|false)

Determine if this id has the same bytes as another.

.toCanonical() => canonical_string

Encode this id in its canonical form.

.toRaw() => raw_string

Encode this id in its raw form.

Namespace Static Utilities

idCompare(left_id, right_id) => (-1|0|1)

Determine if the left id is less than | equal to | greater than the right id using lexicographical byte order.

idEqual(left_id, right_id) => (true|false)

Determine if 2 ids have the same byte value.

Ulid

const { Ulid } = require('id128');

Ulid, as specified, has some nice properties:

It is useful when you need a distributed domain unique id.

Additional Instance Properties

time

Return a Date object for the epoch milliseconds encoded in the id.

Additional Factory Methods

.generate({ time }) => id

Return a new id instance. Set any argument to null or undefined to trigger its default behavior.

time defaults to the current time. It can be given either as a Date object or epoch milliseconds (milliseconds since January 1st, 1970). Throw InvalidEpoch for times before the epoch or after approximately August 2nd, 10889. This is provided mostly for unit tests.

Byte Format

Format tttt tttt tttt rrrr rrrr rrrr rrrr rrrr where:

UlidMonotonic

const { UlidMonotonic } = require('id128');

UlidMonotonic is inspired by the specification:

It is useful when you need to guarantee a process unique id.

Additional Instance Properties

time

Return a Date object for the epoch milliseconds encoded in the id.

Additional Factory Methods

.generate({ time }) => id

Return a new id instance. Set any argument to null or undefined to trigger its default behavior.

time defaults to the current time. It can be given either as a Date object or epoch milliseconds (milliseconds since January 1st, 1970). Extra caution is required since setting a future time and subsequently calling generate guarantees usage of the clock sequence. Throw InvalidEpoch for times before the epoch or after approximately August 2nd, 10889. Throw ClockSequenceOverflow when the clock sequence is exhausted. This is provided mostly for unit tests.

.reset()

Return the clock sequence to its starting position. This is provided mostly for unit tests.

Byte Format

Format tttt tttt tttt cccc rrrr rrrr rrrr rrrr where:

More specifically, the clock sequence is a counter. When the first id for a new timestamp is generated, the clock sequence is seeded with random bits and the left-most clock sequence bit is set to 0, reserving 2^15 clock ticks. Whenever a time from the past seeds the generator, the previous id's time and clock sequence are used instead, with the clock sequence incremented by 1. This guarantees strict local monotonicity and preserves lexical ordering and general randomness.

Without a seeded time, UlidMonotonic is unlikely to exceed the clock sequence (the clock sequence supports generating a new id every 31 nanoseconds). However, in the unlikely event of an overflow, id generation is aborted.

Uuid1

const { Uuid1 } = require('id128');

Uuid1 implements the RFC 4122 time specification:

While this mostly adheres to the spec, there are a few nuances in the handling of time. Instead of encoding time as 100-nanoseconds since the Gregorian epoch, 48 bits encode milliseconds since the Gregorian epoch time and 12 bits count past time collisions, resetting whenever given a new future time. There are a few benefits:

Additional Instance Properties

clock_sequence

Return the clock sequence encoded in the id.

hires_time

Return the number of prior ids generated while time stood still.

node

Return the MAC address encoded in the id.

time

Return a Date object for the epoch milliseconds encoded in the id.

variant

Return the variant as encoded in the id. Should be 1.

version

Return the version as encoded in the id. Should be 1.

Additional Factory Methods

.generate({ node, time }) => id

Return a new id instance. Set any argument to null or undefined to trigger its default behavior.

time defaults to the current time. It can be given either as a Date object or Gregorian milliseconds (milliseconds since October 15th, 1582). Extra caution is required since setting a future time and subsequently calling generate guarantees usage of the hi-res counter and clock sequence. Throw InvalidEpoch for times before the Gregorian epoch or after approximately May 17, 10502. This is provided mostly for unit tests.

node defaults to the MAC address, or a random multicast address when the MAC address is unavailable. It can be given as an array of 6 bytes.

.reset()

Return the hi-res counter to its starting position and generate a new random clock sequence seed. This is provided mostly for unit tests.

Byte Format

Format llll lnnn mmmm vhhh tccc aaaa aaaa aaaa where:

Uuid4

const { Uuid4 } = require('id128');

Uuid4 implements the RFC 4122 random uuid specification:

It is useful when you need a well-supported globally unique id.

Additional Instance Properties

variant

Return the variant as encoded in the id. Should be 1.

version

Return the version as encoded in the id. Should be 4.

Byte Format

Format rrrr rrrr rrrr vrrr trrr rrrr rrrr rrrr where:

Uuid6

const { Uuid6 } = require('id128');

Uuid6 implements this controversial blog post:

This is essentially the same implementation as Uuid1, however the time bits are arranged in lexicographical order. If you're looking for a spacial UUID that is optimized for clustered indices, consider Uuid6 as a viable option.

Additional Instance Properties

clock_sequence

Return the clock sequence encoded in the id.

hires_time

Return the number of prior ids generated while time stood still.

node

Return the MAC address encoded in the id.

time

Return a Date object for the epoch milliseconds encoded in the id.

variant

Return the variant as encoded in the id. Should be 1.

version

Return the version as encoded in the id. Should be 6.

Additional Factory Methods

.generate({ node, time }) => id

Return a new id instance. Set any argument to null or undefined to trigger its default behavior.

time defaults to the current time. It can be given either as a Date object or Gregorian milliseconds (milliseconds since October 15th, 1582). Extra caution is required since setting a future time and subsequently calling generate guarantees usage of the hi-res counter and clock sequence. Throw InvalidEpoch for times before the Gregorian epoch or after approximately May 17, 10502. This is provided mostly for unit tests.

node defaults to the MAC address, or a random multicast address when the MAC address is unavailable. It can be given as an array of 6 bytes.

.reset()

Return the hi-res counter to its starting position and generate a new random clock sequence seed. This is provided mostly for unit tests.

Byte Format

Format mmmm mmmm mmmm vnnn tccc aaaa aaaa aaaa where:

UuidNil

const { UuidNil } = require('id128');

UuidNil implements the RFC 4122 nil uuid specification:

It is useful as placeholder for other 128-bit ids.

Additional Instance Properties

variant

Return the variant as encoded in the id. Should be 0.

version

Return the version as encoded in the id. Should be 0.

Byte Format

Format 0000 0000 0000 v000 t000 0000 0000 0000 where:

Uuid

const { Uuid } = require('id128');

Uuid is a factory for generating and decoding UUIDs when the version is unknown until runtime. If the version is supported, it will produce UUIDs of the appropriate type. In exchange for the runtime flexibility, there is a necessary performance degradation. It is recommended to use this for decoding data from uncontrolled sources rather than generating new ids.

Uuid supports all the same methods as the other ID factories. All modifications to typical behavior are noted below.

Factory Properties

versioned_ids

Return the factories of all the supported ids.

Factory Methods

.construct(bytes) => versioned_id

Return a new versioned id instance without validating the bytes. Return a Uuid if an appropriate version does not exist.

.generate({ version, ... }) => versioned_id

Return a new versioned id instance. All additional arguments are passed through to the associated version. Throw UnsupportedVersion if no associated version exists.

.MIN({ version }) => versioned_id

Return the versioned id instance with the smallest valid value. Throw UnsupportedVersion if no associated version exists.

.MAX({ version }) => versioned_id

Return the versioned id instance with the largest valid value. Throw UnsupportedVersion if no associated version exists.

.fromCanonical(canonical_string) => versioned_id

Decode a versioned id from its canonical representation. Return a Uuid if an appropriate version does not exist. Throw InvalidEncoding if the string is undecodable.

.fromCanonicalTrusted(canonical_string) => versioned_id

Decode a versioned id from its canonical representation. Return a Uuid if an appropriate version does not exist. Skip validation and assume the input is decodable.

.fromRaw(raw_string) => versioned_id

Decode a versioned id from its raw representation. Return a Uuid if an appropriate version does not exist. Throw InvalidEncoding if the string is undecodable.

.fromRawTrusted(raw_string) => versioned_id

Decode a versioned id from its raw representation. Return a Uuid if an appropriate version does not exist. Skip validation and assume the input is decodable.

Exceptions

const { Exception } = require('id128');

All exceptions are namespaced under Exception for clarity.

Id128Error

const { Exception: { Id128Error } } = require('id128');

Base exception class for generic error catching.

ClockSequenceOverflow

const { Exception: { ClockSequenceOverflow } } = require('id128');

Incrementing the clock sequence is impossible. Should not happen unless manually seeding #generate.

InvalidBytes

const { Exception: { InvalidBytes } } = require('id128');

Encoding something other than 16 bytes. Likely to happen when encoding untrusted user input.

InvalidEncoding

const { Exception: { InvalidEncoding } } = require('id128');

Decoding an invalid format or non-string object. Likely to happen when decoding untrusted user input.

InvalidEpoch

const { Exception: { InvalidEpoch } } = require('id128');

Generating an id with an invalid timestamp. Should not happen unless manually seeding #generate.

UnsupportedVersion

const { Exception: { UnsupportedVersion } } = require('id128');

Failed to find a factory for the desired version. Likely to happen when decoding untrusted user input.

Browser Support

This module supports browser compilation though Webpack/Browserify with a few caveats:

This library is intended for modern browsers that keep pace with Javascript's growing ecosystem. I philosophically object to supporting efforts of companies to pour more money into broken browsers that only cause headaches for developers to support. I expect these caveats to be unnecessary within the next 5 years.

All that said, please notify me of any issues with modern browsers and I'll do my best to support you.

Typescript Support

This module includes Typescript bindings for all primary usage patterns. I'd like to highlight some design decisions:

Id Types and Factory Types

Each factory is exported as an instance using the same name as the type of id it produces. In Javascript, this is desirable as it provides a uniform interface regardless of the implementation. However, this complicates the Typescript type imports.

For simple cases, like constructing an id and passing it around the program, this will behave exactly as desired:

import { Ulid } from 'id128'

const id: Ulid = Ulid.generate()

When you need to check the type of the id, you should use the type attribute:

import { Ulid } from 'id128'

const id: Ulid = Ulid.generate()
if (id instanceof Ulid.type) { ... }

If you wish to pass around the factory itself, you can import the factory type:

import { Ulid } from 'id128'
import type { UlidFactory } from 'id128'

function doSomething(factory: UlidFactory) { ... }
doSomething(Ulid)

Finally, if you need to operate on any id or id factory, you can import base types:

import type { Id, AnyIdFactory } from 'id128'

function makeOne(factory: AnyIdFactory): Id {
	return factory.generate()
}

Exception Handling

Exception classes are designed to be checked using instanceof. Unfortunately, Typescript broke instanceof Error support for a more compliant compilation. Fortunately, the included exceptions bypass the issues caused by inheriting from the native Error by never overriding the constructor and implementing name as a readonly getter, As a consequence, the exceptions actually violate the standard Error interface, but they fulfill the standard Function interface. Therefore, you can safely use instanceof as intended:

import { UlidMonotonic } from 'id128'
import { Exception } from 'id128'

try { UlidMonotonic.generate() }
catch (err) {
	if (err instanceof Exception.ClockSequenceOverflow ) { ... }
}

Motivation

Originally, I was looking for an id that is independent of the database, but plays nice with database indices and data types. Most databases have built-in support for storing UUIDs efficiently, but UUID v4 does not cluster well and the other UUIDs require bit manipulation to get good performance, which will likely cause future maintenance headaches.

After a bit of research, ULID was determined to nicely solve the problem. However, the javascript implementation had 2 major issues:

  1. lacks database support
  2. it's slow, which in a single-threaded Node server is deadly

I considered sending in a patch, however I saw an opportunity for a more expressive interface, which is typically a bit harder to modify once a project is in wide use. There was also a clear pattern for encoding 128-bit ids into various formats, which seems generally useful.

Ultimately, this library strives to be:

Tests

To run the tests:

npm install
npm run test-all

Benchmarks

Competitive benchmarks have been moved to benchmark-guid

To run the benchmarks:

npm install
npm run benchmark

Platform info:
==============
   Darwin 18.2.0 x64
   Node.JS: 15.0.0
   V8: 8.6.395.16-node.15
   Intel(R) Core(TM) i7-4578U CPU @ 3.00GHz × 4

Ulid
====
   generate:                  (4,590,833rps)   (avg: 217ns)
   MIN:                      (12,491,186rps)   (avg: 80ns)
   MAX:                      (12,669,223rps)   (avg: 78ns)
   fromCanonical:             (1,707,717rps)   (avg: 585ns)
   fromCanonicalTrusted:      (2,078,278rps)   (avg: 481ns)
   fromRaw:                   (1,483,373rps)   (avg: 674ns)
   fromRawTrusted:            (1,979,964rps)   (avg: 505ns)
   toCanonical:               (3,256,155rps)   (avg: 307ns)
   toRaw:                     (6,012,244rps)   (avg: 166ns)

UlidMonotonic
=============
   generate:                  (3,787,685rps)   (avg: 264ns)
   MIN:                       (6,306,928rps)   (avg: 158ns)
   MAX:                       (6,301,217rps)   (avg: 158ns)
   fromCanonical:             (1,423,104rps)   (avg: 702ns)
   fromCanonicalTrusted:      (1,722,958rps)   (avg: 580ns)
   fromRaw:                   (1,381,296rps)   (avg: 723ns)
   fromRawTrusted:            (1,698,639rps)   (avg: 588ns)
   toCanonical:               (3,205,394rps)   (avg: 311ns)
   toRaw:                     (5,774,288rps)   (avg: 173ns)

Uuid1
=====
   generate:                  (4,984,699rps)   (avg: 200ns)
   MIN:                      (12,888,384rps)   (avg: 77ns)
   MAX:                      (12,817,435rps)   (avg: 78ns)
   fromCanonical:             (1,226,007rps)   (avg: 815ns)
   fromCanonicalTrusted:      (1,578,429rps)   (avg: 633ns)
   fromRaw:                   (1,306,295rps)   (avg: 765ns)
   fromRawTrusted:            (1,626,095rps)   (avg: 614ns)
   toCanonical:               (5,859,714rps)   (avg: 170ns)
   toRaw:                     (5,973,139rps)   (avg: 167ns)

Uuid4
=====
   generate:                  (6,492,849rps)   (avg: 154ns)
   MIN:                       (6,400,528rps)   (avg: 156ns)
   MAX:                       (6,617,714rps)   (avg: 151ns)
   fromCanonical:             (1,286,561rps)   (avg: 777ns)
   fromCanonicalTrusted:      (1,625,362rps)   (avg: 615ns)
   fromRaw:                   (1,313,004rps)   (avg: 761ns)
   fromRawTrusted:            (1,672,463rps)   (avg: 597ns)
   toCanonical:               (6,103,543rps)   (avg: 163ns)
   toRaw:                     (6,235,448rps)   (avg: 160ns)

Uuid6
=====
   generate:                  (3,466,357rps)   (avg: 288ns)
   MIN:                       (5,244,292rps)   (avg: 190ns)
   MAX:                       (5,151,746rps)   (avg: 194ns)
   fromCanonical:             (1,324,905rps)   (avg: 754ns)
   fromCanonicalTrusted:      (1,676,541rps)   (avg: 596ns)
   fromRaw:                   (1,357,353rps)   (avg: 736ns)
   fromRawTrusted:            (1,717,530rps)   (avg: 582ns)
   toCanonical:               (5,061,822rps)   (avg: 197ns)
   toRaw:                     (4,839,125rps)   (avg: 206ns)

UuidNil
=======
   generate:                  (9,312,932rps)   (avg: 107ns)
   MIN:                       (5,158,703rps)   (avg: 193ns)
   MAX:                       (8,795,275rps)   (avg: 113ns)
   fromCanonical:             (1,293,946rps)   (avg: 772ns)
   fromCanonicalTrusted:      (1,629,605rps)   (avg: 613ns)
   fromRaw:                   (1,472,042rps)   (avg: 679ns)
   fromRawTrusted:            (1,780,904rps)   (avg: 561ns)
   toCanonical:               (5,169,323rps)   (avg: 193ns)
   toRaw:                     (5,196,170rps)   (avg: 192ns)

Uuid processing Uuid1
=====================
   generate:                  (4,159,340rps)   (avg: 240ns)
   MIN:                       (4,877,918rps)   (avg: 205ns)
   MAX:                       (4,907,348rps)   (avg: 203ns)
   fromCanonical:             (1,045,214rps)   (avg: 956ns)
   fromCanonicalTrusted:      (1,255,223rps)   (avg: 796ns)
   fromRaw:                   (1,021,436rps)   (avg: 979ns)
   fromRawTrusted:            (1,268,213rps)   (avg: 788ns)

Uuid processing Uuid4
=====================
   generate:                  (5,695,823rps)   (avg: 175ns)
   MIN:                       (4,886,337rps)   (avg: 204ns)
   MAX:                       (4,907,325rps)   (avg: 203ns)
   fromCanonical:             (1,047,372rps)   (avg: 954ns)
   fromCanonicalTrusted:      (1,292,729rps)   (avg: 773ns)
   fromRaw:                   (1,031,590rps)   (avg: 969ns)
   fromRawTrusted:            (1,266,122rps)   (avg: 789ns)

Uuid processing Uuid6
=====================
   generate:                  (4,122,279rps)   (avg: 242ns)
   MIN:                       (4,744,102rps)   (avg: 210ns)
   MAX:                       (4,860,271rps)   (avg: 205ns)
   fromCanonical:             (1,066,004rps)   (avg: 938ns)
   fromCanonicalTrusted:      (1,298,925rps)   (avg: 769ns)
   fromRaw:                   (1,053,871rps)   (avg: 948ns)
   fromRawTrusted:            (1,286,373rps)   (avg: 777ns)

Uuid processing UuidNil
=======================
   generate:                  (8,140,742rps)   (avg: 122ns)
   MIN:                       (4,717,779rps)   (avg: 211ns)
   MAX:                       (8,261,012rps)   (avg: 121ns)
   fromCanonical:             (1,052,765rps)   (avg: 949ns)
   fromCanonicalTrusted:      (1,285,968rps)   (avg: 777ns)
   fromRaw:                   (1,130,468rps)   (avg: 884ns)
   fromRawTrusted:            (1,312,878rps)   (avg: 761ns)

Acknowledgments

Much of this library would not exist without the great work and documentation of other engineers. In particular:

Also, thank you:

Contributing

Feel free to make a branch and send a pull request through github

Issues

Please report any issues or bugs through github