Hello!

I'm exited to share my first Rust lib for Python — moka-py!

What My Project Does

moka-py is a Python binding for the highly efficient Moka caching library written in Rust. This library allows you to leverage the power of Moka's high-performance, feature-rich cache in your Python projects.

Key Features:

• Synchronous Cache: Supports thread-safe, in-memory caching for Python applications.
• TTL Support: Automatically evicts entries after a configurable time-to-live (TTL).
• TTI Support: Automatically evicts entries after a configurable time-to-idle (TTI).
• Size-based Eviction: Automatically removes items when the cache exceeds its size limit using the TinyLFU policy.
• Concurrency: Optimized for high-performance, concurrent access in multi-threaded environments.
• Fully typed: mypy/pyright friendly. Even decorators

Example (@lru_cache drop-in replacement but with TTL and TTI support):

from time import sleep
from moka_py import cached


@cached(maxsize=1024, ttl=10.0, tti=1.0)
def f(x, y):
    print("hard computations")
    return x + y


f(1, 2)  # calls computations
f(1, 2)  # gets from the cache
sleep(1.1)
f(1, 2)  # calls computations (since TTI has passed)

One more example:

from time import sleep
from moka_py import Moka


# Create a cache with a capacity of 100 entries, with a TTL of 30 seconds
# and a TTI of 5.2 seconds. Entries are always removed after 30 seconds
# and are removed after 5.2 seconds if there are no `get`s happened for this time.
# 
# Both TTL and TTI settings are optional. In the absence of an entry, 
# the corresponding policy will not expire it.
cache: Moka[str, list[int]] = Moka(capacity=100, ttl=30, tti=5.2)

# Insert a value.
cache.set("key", [3, 2, 1])

# Retrieve the value.
assert cache.get("key") == [3, 2, 1]

# Wait for 5.2+ seconds, and the entry will be automatically evicted.
sleep(5.3)
assert cache.get("key") is None

Target Audience

moka-py might be useful for short-term in-memory caching for frequently-asked data

Comparison

• cachetools — Pure Python caching library. 10-50% slower and has no typing

TODO:

• Per-entry expiration
• Choosing between eviction policies (LRU/TinyLFU)
• Size-aware eviction
• Support async functions

Links

• https://github.com/deliro/moka-py
• https://pypi.org/project/moka-py/