Home

Awesome

Timeflake

PyPi Latest Version PyPi Downloads License

Timeflake is a 128-bit, roughly-ordered, URL-safe UUID. Inspired by Twitter's Snowflake, Instagram's ID and Firebase's PushID.

Features

* Please consider how the Birthday Paradox might affect your use case. Also read the security note on this readme.

Why?

This could be useful to you, if you're looking for a UUID with the following properties:

Some existing alternatives which I considered:

Usage

import timeflake

# Create a random Timeflake
flake = timeflake.random()
>>> Timeflake(base62='00mx79Rjxvfgr8qat2CeQDs')

# Get the base62, int, hex or bytes representation
flake.base62
>>> '00mx79Rjxvfgr8qat2CeQDs'

flake.hex
>>> '016fa936bff0997a0a3c428548fee8c9'

flake.int
>>> 1909005012028578488143182045514754249

flake.bytes
>>> b'\x01o\xa96\xbf\xf0\x99z\n<B\x85H\xfe\xe8\xc9'

# Convert to the standard library's UUID type
flake.uuid
>>> UUID('016fa936-bff0-997a-0a3c-428548fee8c9')

# Get the timestamp component
flake.timestamp
>>> 1579091935216

# Get the random component
flake.random
>>> 724773312193627487660233

# Parse an existing flake (you can also pass bytes, hex or int representations)
timeflake.parse(from_base62='0002HCZffkHWhKPVdXxs0YH')
>>> Timeflake('0004fbc6872f70fc9e27355a499e8b6d')

# Create from a user defined timestamp or random value:
timeflake.from_values(1579091935216, 724773312193627487660233)
>>> Timeflake('016fa936bff0997a0a3c428548fee8c9')

Spec

128 bits are used to encode:

  1. UNIX-time in milliseconds (48 bits)
  2. Cryptographically generated random number (80 bits)

For example, the timeflake 016fb4209023b444fd07590f81b7b0eb (hex) encodes the following:

016fb4209023  +  b444fd07590f81b7b0eb
      |                   |
      |                   |
  timestamp            random
  [48 bits]           [80 bits]

In Python:

flake = timeflake.parse(from_hex='016fb4209023b444fd07590f81b7b0eb')
flake.timestamp = 1579275030563  # 2020-01-17T15:30:30.563 UTC
flake.random = 851298578153087956398315

Alphabets

A custom base62 alphabet representation is included, modified to preserve lexicographical order when sorting strings using this encoding. The hex representation has a max length of 32 characters, while the base62 will be 22 characters. Padding is required to be able to derive the encoding from the string length.

The following are all valid representations of the same Timeflake:

int    = 1909226360721144613344160656901255403
hex    = 016fb4209023b444fd07590f81b7b0eb
base62 = 02i2XhN7hAuaFh3MwztcMd

You can convert a timeflake to any alphabet using the itoa (integer to ASCII) function:

from timeflake.utils import itoa

flake = timeflake.random()
itoa(flake.int, alphabet=timeflake.flake.HEX, padding=32)

Provided extensions

Django model fields

You can use timeflakes as primary keys for your models. These fields currently support MySQL, Postgres and Sqlite3.

Example usage:

from timeflake.extensions.django import TimeflakePrimaryKeyBinary

class Item(models.Model):
   item_id = TimeflakePrimaryKeyBinary()
   # ...

Peewee ORM

See this gist for an example.

Note on security

Since the timestamp part is predictable, the search space within any given millisecond is 2^80 random numbers, which is meant to avoid collisions, not to secure or hide information. You should not be using timeflakes for password-reset tokens, API keys or for anything which is security sensitive. There are better libraries which are meant for this use case (for example, the standard library's secrets module).

Note on privacy

Please be aware of the privacy implications that time based IDs can have. As Timeflake encodes the precise time in which the ID was created, this could potentially reveal:

Supported versions

Right now the codebase is only tested with Python 3.7+.

Dependencies

No dependencies other than the standard library.

Contribute

Want to hack on the project? Any kind of contribution is welcome! Simply follow the next steps:

Contributors

Thank you for making this project better!

Changelog

Please see the CHANGELOG for more details.

Implementations in other languages

License

This project is licensed under the MIT license. Please read the LICENSE file for more details.

Prior art