pyrate-limiter 0.1.1

Python Rate-Limiter using Leaky-Bucket Algorimth Family

Request Rate Limiter using Leaky-bucket algorimth

Introduction

This module can be used to apply rate-limit for API request, using leaky-bucket algorimth. User defines window duration and the limit of function calls within such interval.

• To hold the state of the Bucket, you can use LocalBucket as internal bucket.
• To use PyrateLimiter with Redis, redis-py is required to be installed.
• It is also possible to use your own Bucket implementation, by extending AbstractBucket from pyrate_limiter.core

Project coverage

CICD flow is not currently setup since I dont have much time, but FYI, the coverage is decent enought IMO...

tests/test_leaky_bucket.py::test_bucket_overloaded PASSED
tests/test_leaky_bucket.py::test_bucket_cooldown PASSED
tests/test_local_engine.py::test_invalid_initials PASSED
tests/test_local_engine.py::test_leaky_bucket_overloaded PASSED
tests/test_local_engine.py::test_leaky_bucket_cooldown PASSED
tests/test_local_engine.py::test_token_bucket_overloaded PASSED
tests/test_local_engine.py::test_token_bucket_cooldown PASSED
tests/test_redis_engine.py::test_bucket_overloaded PASSED
tests/test_redis_engine.py::test_bucket_cooldown PASSED
tests/test_redis_engine.py::test_normalize_redis_value PASSED
tests/test_redis_engine.py::test_token_bucket_overloaded PASSED
tests/test_redis_engine.py::test_token_bucket_cooldown PASSED
tests/test_token_bucket.py::test_bucket_overloaded PASSED
tests/test_token_bucket.py::test_bucket_cooldown PASSED

---------- coverage: platform darwin, python 3.7.5-final-0 -----------
Name                                Stmts   Miss  Cover
-------------------------------------------------------
pyrate_limiter/__init__.py              1      0   100%
pyrate_limiter/basic_algorimth.py      45      0   100%
pyrate_limiter/core.py                 63      3    95%
pyrate_limiter/engines/local.py        14      0   100%
pyrate_limiter/engines/redis.py        33      1    97%
pyrate_limiter/exceptions.py            5      0   100%
-------------------------------------------------------
TOTAL                                 161      4    98%

Installation

$ pip install pyrate-limiter

Usage

from pyrate_limiter.core import TokenBucketLimiter, LeakyBucketLimiter
from pyrate_limiter.engines.redis import RedisBucket
from pyrate_limiter.engines.local import LocalBucket
from pyrate_limiter.exceptions import BucketFullException

# Init redis bucket
bucket = RedisBucket('redis-url', hash='some-hash', key='some-key')

# Create Limiter using Token-Bucket Algorimth
# Maximum 10 items over 60 seconds
limiter = TokenBucketLimiter(bucket, capacity=10, window=60)
limiter.queue.config(key='change-key')
# Process an item
try:
    limiter.process('some-json-serializable-value')
    print('Item allowed to pass through')
except BucketFullException:
    print('Bucket is full')
    # do something



# Similarly, using Leaky-Bucket Algorimth
limiter = LeakyBucketLimiter(bucket, capacity=5, window=6)
limiter.queue.config(key='change-key')
# Process an item
try:
    # For LeakyBucketLimiter using the similar process method, only
    # different in naming...
    limiter.append('some-json-serializable-value')
    print('Item allowed to pass through')
except BucketFullException:
    print('Bucket is full')
    # do something


# If using LocalBucket, the instantiation is even simpler
bucket = LocalBucket(initial_values=some_list_type_value)

Understanding the Algorimths

View tests/test_leaky_bucket.py and tests/test_token_bucket.py for explaination. Documents are on the way.

License

Copyright 2019 vutr

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.