https://github.com/konradmalik/hlcpy

Hybrid Logical Clock implementation in Python as a small library
https://github.com/konradmalik/hlcpy

crdt distributed hlc hybrid-logical-clocks python

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Hybrid Logical Clock implementation in Python as a small library

• Host: GitHub
• URL: https://github.com/konradmalik/hlcpy
• Owner: konradmalik
• License: mit
• Created: 2020-11-22T20:44:48.000Z (almost 4 years ago)
• Default Branch: master
• Last Pushed: 2021-04-24T19:12:48.000Z (over 3 years ago)
• Last Synced: 2024-08-09T01:06:17.096Z (3 months ago)
• Topics: crdt, distributed, hlc, hybrid-logical-clocks, python
• Language: Python
• Homepage:
• Size: 23.4 KB
• Stars: 4
• Watchers: 3
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

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README

        
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# Hybrid Logical Clock

Python implementation of Hybrid Logical Clock.

Requires Python version >= 3.7.

You can install this package from [PyPI](https://pypi.org/project/hlcpy/):

```bash

$ pip install hlcpy

```

## Exemplary usage

```python

import hlcpy

# BASIC USAGE

# Instantiate HLC

c = hlcpy.HLC()

# specify starting nanos and logical time

c = hlcpy.HLC(nanos=123, logical=0)

# create from current time

c = hlcpy.HLC.from_now()

# create from iso8601 time

c = hlcpy.HLC.from_str('2020-01-01T00:00:00Z')

# string representation of HLC

print(str(c))

#>>> 2020-01-01T00:00:00.000000000Z_0

# create from string representation

c1 = hlcpy.HLC.from_str(str(c))

# refresh the clock

c.sync()

# supports comparison

print(c > c1)

#>>> True

# merge two events

c.merge(c1)

print(c)

#>>> 2021-04-24T18:42:47.001864924Z_0

# merge event that occured in the future to see the logical tick

import time

future = hlcpy.HLC(nanos=int(time.time_ns() + 3e9))

c.merge(future)

print(c)

#>>> 2021-04-24T18:42:50.001891328Z_1

# More examples - see tests/unit/test_hlc.py

```

## Credits

Based on:

https://www.cse.buffalo.edu/tech-reports/2014-04.pdf

Inspired by:

- https://www.youtube.com/watch?v=iEFcmfmdh2w

- https://github.com/adsharma/hlcpy (based on but heavily rewritten)

- https://bartoszsypytkowski.com/hybrid-logical-clocks/