# 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`, and `in-memory` backends.
- Easily integration with `fastapi`.
- Support http cache like `ETag` and `Cache-Control`.
## Requirements
- `asyncio` environment.
- `redis` if use `RedisBackend`.
- `memcache` if use `MemcacheBackend`.
- `aiobotocore` if use `DynamoBackend`.
## Install
```shell
> pip install fastapi-cache2
```
or
```shell
> pip install "fastapi-cache2[redis]"
```
or
```shell
> pip install "fastapi-cache2[memcache]"
```
or
```shell
> pip install "fastapi-cache2[dynamodb]"
```
## Usage
### Quick Start
```python
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
from redis import asyncio as aioredis
app = FastAPI()
@cache()
async def get_cache():
return 1
@app.get("/")
@cache(expire=60)
async def index():
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
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`.
```python
@app.get("/")
@cache(expire=60, coder=JsonCoder)
async def index():
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.
```python
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():
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.
## Tests and coverage
```shell
coverage run -m pytest
coverage html
xdg-open htmlcov/index.html
```
## License
This project is licensed under the [Apache-2.0](https://github.com/long2ice/fastapi-cache/blob/master/LICENSE) License.