Timeflake is a 128-bit, roughly-ordered, URL-safe UUID. Inspired by Twitter's Snowflake, Instagram's ID and Firebase's PushID.
- Fast. Roughly ordered (K-sortable), incremental timestamp in most significant bits enables faster indexing and less fragmentation on database indices (vs UUID v1/v4).
- Safe. With 1.2e+24 unique timeflakes per millisecond, even if you're creating 50 million of them per millisecond the chance of a collision is still 1 in a billion. You're likely to see a collision when creating 1.3e+12 (one trillion three hundred billion) timeflakes per millisecond.
- Efficient. 128 bits are used to encode a timestamp in milliseconds (48 bits) and a cryptographically generated random number (80 bits).
- Flexible. Out of the box encodings in 128-bit unsigned int, hex, URL-safe base62 and raw bytes. Fully compatible with uuid.UUID.
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')The timeflake 02i2XhN7hAuaFh3MwztcMd (base62) encodes the following:
# Milliseconds since unix epoch
timestamp = 1579275030563
# Cryptographically generated random number
random = 851298578153087956398315
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
This could be useful to you, if you're looking for a UUID with the following properties:
- You want to have UUIDs in URLs that are not predictable (vs auto-increment integers).
- They should be random, but roughly-ordered over time so that your MySQL/Postgres indices stay fast and efficient as the dataset grows.
- And simple to use across multiple machines (no coordination or centralized system required).
- It would be nice if they were compatible with standard 128-bit UUID representations (many libraries in Python handle uuid.UUID, but no third-party types).
Some existing alternatives which I considered:
- UUIDv1 but the timestamp bytes are not sequential and gives away network information.
- UUIDv4 but they're mostly random, and can mess up the performance on clustered indices.
- ULID but approach to incrementing the sequence during same millisecond makes it more predictable.
- KSUID but it's 160-bit, so unfortunately not compatible with standard 128-bit UUIDs.
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()
# ...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).
Right now the codebase is only tested with Python 3.7+.
No dependencies other than the standard library.
Want to hack on the project? Any kind of contribution is welcome! Simply follow the next steps:
- Fork the project.
- Create a new branch.
- Make your changes and write tests when practical.
- Commit your changes to the new branch.
- Send a pull request, it will be reviewed shortly.
- In case you want to add a feature, please create a new issue and briefly explain what the feature would consist of. For bugs or requests, before creating an issue please check if one has already been created for it.
Please see the CHANGELOG for more details.
This project is licensed under the MIT license. Please read the LICENSE file for more details.