spakky-redis 6.4.0

Redis cache backend plugin for Spakky Framework

Spakky Redis

Redis cache backend plugin for Spakky Framework.

Installation

pip install spakky-redis

Features

• Shared cache backend: RedisCache[T] stores values in Redis so multiple process instances can observe the same entries.
• Core contract compatibility: Implements spakky-cache sync and async ICache[T] paths.
• TTL semantics: Positive TTL values are translated into Redis millisecond expiry; missing and expired keys return CacheMiss.
• Loud failures: Redis connection/configuration failures and serialization failures are raised as Spakky cache errors.
• Scoped clear: clear removes keys under the configured prefix instead of flushing the Redis database.

Quick Start

from datetime import timedelta

from spakky.cache import CacheHit
from spakky.plugins.redis import RedisCache

cache = RedisCache[str]()
cache.set("profile:42", "Ada", ttl=timedelta(minutes=5))

result = cache.get("profile:42")
if isinstance(result, CacheHit):
    print(result.value)

Configuration

RedisCacheConfig follows the standard Spakky @Configuration pattern and reads environment variables with the SPAKKY_REDIS__ prefix.

Environment variable	Default
SPAKKY_REDIS__HOST	localhost
SPAKKY_REDIS__PORT	6379
SPAKKY_REDIS__DB	0
SPAKKY_REDIS__USERNAME	unset
SPAKKY_REDIS__PASSWORD	unset
SPAKKY_REDIS__USE_SSL	false
SPAKKY_REDIS__KEY_PREFIX	spakky:cache:
SPAKKY_REDIS__SOCKET_TIMEOUT	5.0

Async Usage

from spakky.cache import CacheHit
from spakky.plugins.redis import RedisCache

cache = RedisCache[int]()
await cache.set_async("answer", 42)

result = await cache.get_async("answer")
if isinstance(result, CacheHit):
    assert result.value == 42

Contract Notes

RedisCache is a backend implementation of the spakky-cache application data cache contract. Business code should depend on ICache[T] and can switch between InMemoryCache and RedisCache without changing cache hit/miss handling.

Values are serialized with pickle and stored under SPAKKY_REDIS__KEY_PREFIX. clear() and clear_async() delete only keys under that prefix. Redis failures, unexpected response types, and serialization failures are raised as Spakky cache errors instead of being treated as cache misses.

This plugin does not add distributed locks, cache stampede protection, tag invalidation, write-through/write-behind policies, or metrics exporters.

License

MIT License