Id128

Generate 128-bit unique identifiers for various specifications. In particular:
- ULID
- Monotonic ULID
- UUID 1 (Variant 1 Version 1)
- UUID 4 (Variant 1 Version 4)
- UUID 6 (Variant 1 Version 6)
- Nil UUID (Variant 0 Version 0)
- Uuid (Unknown Variant and Version)

Common Usage

``es6
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

$3

Return the name of the generated id type.

$3

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

Common Factory Methods

$3

Return a new id instance without validating the bytes.

$3

Return a new id instance.

$3

Return the id instance with the smallest valid value.

$3

Return the id instance with the largest valid value.

$3

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

$3

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

$3

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

$3

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

$3

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

$3

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

$3

Verify if a string is a valid canonical encoding.

$3

Verify if a string is a valid raw encoding.

Common Instance Properties

$3

Return the actual byte array representing the id.

Common Instance Methods

$3

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

$3

Determine how this id is ordered against another.

$3

Determine if this id has the same bytes as another.

$3

Encode this id in its canonical form.

$3

Encode this id in its raw form.

Namespace Static Utilities

$3

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

$3

Determine if 2 ids have the same byte value.

Ulid

`es6
const { Ulid } = require('id128');
`

Ulid, as specified, has some nice properties:
- collision resistant: 80-bits of randomness
- k-ordered: prefixed with millisecond precision timestamp
- database friendly: fits within a uuid and generally appends to the index
- human friendly: canonically encodes as a case-insensitive Crockford 32 number

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

Additional Instance Properties

$3

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

Additional Factory Methods

$3

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:
- t is 4 bits of time
- r is 4 bits of random

UlidMonotonic

`es6
const { UlidMonotonic } = require('id128');
`

UlidMonotonic is inspired by the specification:
- collision resistant: 15-bits of random seeded clock sequence plus 64-bits of randomness
- total ordered: prefixed with millisecond precision timestamp plus 15-bit clock sequence
- database friendly: fits within a uuid and generally appends to the index
- human friendly: canonically encodes as a case-insensitive Crockford 32 number

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

Additional Instance Properties

$3

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

Additional Factory Methods

$3

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.

$3

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:
- t is 4 bits of time
- c is 4 bits of random-seeded clock sequence
- r is 4 bits of random

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

`es6
const { Uuid1 } = require('id128');
`

Uuid1 implements the RFC 4122 time specification:
- time-based: encodes the current millisecond timestamp
- location-based: encodes the mac address of the machine

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:
- high precision time is unreliable in the browser so this ensures better precision
- the max supported date is now around the year 10502 instead of around 5236
- generating 4096 ids/ms (~4,000,000 ids/s) is wildly unlikely in real world uses
- in the rare hi-res overflow, the count simply spills over to the clock sequence

Additional Instance Properties

$3

Return the clock sequence encoded in the id.

$3

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

$3

Return the MAC address encoded in the id.

$3

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

$3

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

$3

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

Additional Factory Methods

$3

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.

$3

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:
- l is 4 bits of low millisecond time
- n is 4 bits of hi-res time
- m is 4 bits of mid millisecond time
- v is 4 bits of the version
- h is 4 bits of high millisecond time
- t is 2 bits of the variant followed by 2 bits of the clock sequence
- c is 4 bits of the clock sequence
- a is 4 bits of the machine address

Uuid4

`es6
const { Uuid4 } = require('id128');
`

Uuid4 implements the RFC 4122 random uuid specification:

- 122 random bits
- 2 bits reserved for the variant (1)
- 4 bits reserved for the version (4)

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

Additional Instance Properties

$3

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

$3

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

Byte Format

Format rrrr rrrr rrrr vrrr trrr rrrr rrrr rrrr where:
- r is 4 bits of random
- v is 4 bits of the version
- t is 2 bits of the variant followed by 2 bits of random

Uuid6

`es6
const { Uuid6 } = require('id128');
`

Uuid6 implements this controversial blog post:
- time-based: encodes the current millisecond timestamp
- location-based: encodes the mac address of the machine

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

$3

Return the clock sequence encoded in the id.

$3

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

$3

Return the MAC address encoded in the id.

$3

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

$3

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

$3

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

Additional Factory Methods

$3

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.

$3

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:
- m is 4 bits of millisecond time
- v is 4 bits of the version
- n is 4 bits of hi-res time
- t is 2 bits of the variant followed by 2 bits of the clock sequence
- c is 4 bits of the clock sequence
- a is 4 bits of the machine address

UuidNil

`es6
const { UuidNil } = require('id128');
`

UuidNil implements the RFC 4122 nil uuid specification:

- 128 bits of glorious 0

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

Additional Instance Properties

$3

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

$3

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

Byte Format

Format 0000 0000 0000 v000 t000 0000 0000 0000 where:
- 0 is 4 bits of 0
- v is 4 bits of the version (also 0)
- t is 2 bits of the variant (also 0) followed by 2 bits of 0

Uuid

`es6
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

$3

Return the factories of all the supported ids.

Factory Methods

$3

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

$3

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

$3

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

$3

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

$3

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.

$3

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.

$3

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.

$3

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

`es6
const { Exception } = require('id128');
`
All exceptions are namespaced under Exception for clarity.

Id128Error

`es6
const { Exception: { Id128Error } } = require('id128');
`
Base exception class for generic error catching.

ClockSequenceOverflow

`es6
const { Exception: { ClockSequenceOverflow } } = require('id128');
`
Incrementing the clock sequence is impossible. Should not happen unless manually seeding #generate.

InvalidBytes

`es6
const { Exception: { InvalidBytes } } = require('id128');
`
Encoding something other than 16 bytes. Likely to happen when encoding untrusted user input.

InvalidEncoding

`es6
const { Exception: { InvalidEncoding } } = require('id128');
`
Decoding an invalid format or non-string object. Likely to happen when decoding untrusted user input.

InvalidEpoch

`es6
const { Exception: { InvalidEpoch } } = require('id128');
`
Generating an id with an invalid timestamp. Should not happen unless manually seeding #generate.

UnsupportedVersion

`es6
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:
- Random number generation is optimized for memory usage over speed since only a
handful of ids are likely to be generated during a user's session so the overhead
of generating a page of random values has poor amortized cost.
- The browser must have native support for crypto. Math.random is far too
insecure to support as a fallback, especially since the fallback only makes sense
for older browsers with proven security holes. msCrypto is not a supported
fallback due to many of the other required features.
- The browser must support:
* classes
* closures
* const and let
* Uint8Array
* Symbol

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:
- secure: uses cryptographic randomness to ensure general uniqueness
- performant: currently one of the fastest id generators available
- maintainable: heavily tested isolated code with a consistent interface
- extensible: modular design to easily add new ids and new encodings

Tests

To run the tests:
`bash
npm install
npm run test-all
`

Benchmarks

Competitive benchmarks have been moved to benchmark-guid

To run the benchmarks:
`bash
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:

- ksuid: an in-depth exploration of the guid nuances
- ulid: an elegant solution to a persistent problem
- uuid-random: allocating pages of randomness is by far the biggest performance factor

Also, thank you:
- ruleb: researching and patching worker support

Contributing

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

Issues

Please report any issues or bugs through github