fastapi-cache
Introduction
fastapi-cache is a tool to cache fastapi response and function result, with backends support redis, memcache, and dynamodb.
Features
- Support
redis,memcache,dynamodb, andin-memorybackends. - Easily integration with
fastapi. - Support http cache like
ETagandCache-Control.
Requirements
asyncioenvironment.redisif useRedisBackend.memcacheif useMemcacheBackend.aiobotocoreif useDynamoBackend.
Install
> pip install fastapi-cache2
or
> pip install "fastapi-cache2[redis]"
or
> pip install "fastapi-cache2[memcache]"
or
> pip install "fastapi-cache2[dynamodb]"
Usage
Quick Start
import aioredis
from fastapi import FastAPI
from starlette.requests import Request
from starlette.responses import Response
from fastapi_cache import FastAPICache
from fastapi_cache.backends.redis import RedisBackend
from fastapi_cache.decorator import cache
app = FastAPI()
@cache()
async def get_cache():
return 1
@app.get("/")
@cache(expire=60)
async def index(request: Request, response: Response):
return dict(hello="world")
@app.on_event("startup")
async def startup():
redis = aioredis.from_url("redis://localhost", encoding="utf8", decode_responses=True)
FastAPICache.init(RedisBackend(redis), prefix="fastapi-cache")
Initialization
Firstly you must call FastAPICache.init on startup event of fastapi, there are some global config you can pass in.
Use cache decorator
If you want cache fastapi response transparently, you can use cache as decorator between router decorator and view function and must pass request as param of view function.
| Parameter | type, description |
|---|---|
| expire | int, states a caching time in seconds |
| namespace | str, namespace to use to store certain cache items |
| coder | which coder to use, e.g. JsonCoder |
| key_builder | which key builder to use, default to builtin |
And if you want use ETag and Cache-Control features, you must pass response param also.
You can also use cache as decorator like other cache tools to cache common function result.
Custom coder
By default use JsonCoder, you can write custom coder to encode and decode cache result, just need inherit fastapi_cache.coder.Coder.
@app.get("/")
@cache(expire=60,coder=JsonCoder)
async def index(request: Request, response: Response):
return dict(hello="world")
Custom key builder
By default use builtin key builder, if you need, you can override this and pass in cache or FastAPICache.init to take effect globally.
def my_key_builder(
func,
namespace: Optional[str] = "",
request: Request = None,
response: Response = None,
*args,
**kwargs,
):
prefix = FastAPICache.get_prefix()
cache_key = f"{prefix}:{namespace}:{func.__module__}:{func.__name__}:{args}:{kwargs}"
return cache_key
@app.get("/")
@cache(expire=60,coder=JsonCoder,key_builder=my_key_builder)
async def index(request: Request, response: Response):
return dict(hello="world")
InMemoryBackend
InMemoryBackend store cache data in memory and use lazy delete, which mean if you don't access it after cached, it will not delete automatically.
License
This project is licensed under the Apache-2.0 License.