Merge pull request #134 from mjpieters/backend_coder_bytes

Make backends store bytes instead of strings

README.md

@@ -78,7 +78,7 @@ async def index():
 
 @app.on_event("startup")
 async def startup():
-    redis = aioredis.from_url("redis://localhost", encoding="utf8", decode_responses=True)
+    redis = aioredis.from_url("redis://localhost")
     FastAPICache.init(RedisBackend(redis), prefix="fastapi-cache")
 
 ```
@@ -180,6 +180,13 @@ async def index():
 `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.
 
+
+### RedisBackend
+
+When using the redis backend, please make sure you pass in a redis client that does [_not_ decode responses][redis-decode] (`decode_responses` **must** be `False`, which is the default). Cached data is stored as `bytes` (binary), decoding these i the redis client would break caching.
+
+[redis-decode]: https://redis-py.readthedocs.io/en/latest/examples/connection_examples.html#by-default-Redis-return-binary-responses,-to-decode-them-use-decode_responses=True
+
 ## Tests and coverage
 
 ```shell

fastapi_cache/backends/__init__.py

@@ -4,15 +4,15 @@ from typing import Optional, Tuple
 
 class Backend:
     @abc.abstractmethod
-    async def get_with_ttl(self, key: str) -> Tuple[int, Optional[str]]:
+    async def get_with_ttl(self, key: str) -> Tuple[int, Optional[bytes]]:
         raise NotImplementedError
 
     @abc.abstractmethod
-    async def get(self, key: str) -> Optional[str]:
+    async def get(self, key: str) -> Optional[bytes]:
         raise NotImplementedError
 
     @abc.abstractmethod
-    async def set(self, key: str, value: str, expire: Optional[int] = None) -> None:
+    async def set(self, key: str, value: bytes, expire: Optional[int] = None) -> None:
         raise NotImplementedError
 
     @abc.abstractmethod

fastapi_cache/backends/dynamodb.py

@@ -39,11 +39,11 @@ class DynamoBackend(Backend):
     async def close(self) -> None:
         self.client = await self.client.__aexit__(None, None, None)
 
-    async def get_with_ttl(self, key: str) -> Tuple[int, str]:
+    async def get_with_ttl(self, key: str) -> Tuple[int, Optional[bytes]]:
         response = await self.client.get_item(TableName=self.table_name, Key={"key": {"S": key}})
 
         if "Item" in response:
-            value = response["Item"].get("value", {}).get("S")
+            value = response["Item"].get("value", {}).get("B")
             ttl = response["Item"].get("ttl", {}).get("N")
 
             if not ttl:
@@ -56,12 +56,12 @@ class DynamoBackend(Backend):
 
         return 0, None
 
-    async def get(self, key: str) -> str:
+    async def get(self, key: str) -> Optional[bytes]:
         response = await self.client.get_item(TableName=self.table_name, Key={"key": {"S": key}})
         if "Item" in response:
-            return response["Item"].get("value", {}).get("S")
+            return response["Item"].get("value", {}).get("B")
 
-    async def set(self, key: str, value: str, expire: Optional[int] = None) -> None:
+    async def set(self, key: str, value: bytes, expire: Optional[int] = None) -> None:
         ttl = (
             {
                 "ttl": {
@@ -83,7 +83,7 @@ class DynamoBackend(Backend):
             Item={
                 **{
                     "key": {"S": key},
-                    "value": {"S": value},
+                    "value": {"B": value},
                 },
                 **ttl,
             },

fastapi_cache/backends/inmemory.py

@@ -8,7 +8,7 @@ from fastapi_cache.backends import Backend
 
 @dataclass
 class Value:
-    data: str
+    data: bytes
     ttl_ts: int
 
 
@@ -29,21 +29,21 @@ class InMemoryBackend(Backend):
                 return v
         return None
 
-    async def get_with_ttl(self, key: str) -> Tuple[int, Optional[str]]:
+    async def get_with_ttl(self, key: str) -> Tuple[int, Optional[bytes]]:
         async with self._lock:
             v = self._get(key)
             if v:
                 return v.ttl_ts - self._now, v.data
             return 0, None
 
-    async def get(self, key: str) -> Optional[str]:
+    async def get(self, key: str) -> Optional[bytes]:
         async with self._lock:
             v = self._get(key)
             if v:
                 return v.data
             return None
 
-    async def set(self, key: str, value: str, expire: Optional[int] = None) -> None:
+    async def set(self, key: str, value: bytes, expire: Optional[int] = None) -> None:
         async with self._lock:
             self._store[key] = Value(value, self._now + (expire or 0))
 

fastapi_cache/backends/memcached.py

@@ -9,14 +9,14 @@ class MemcachedBackend(Backend):
     def __init__(self, mcache: Client):
         self.mcache = mcache
 
-    async def get_with_ttl(self, key: str) -> Tuple[int, Optional[str]]:
+    async def get_with_ttl(self, key: str) -> Tuple[int, Optional[bytes]]:
-        return 3600, await self.mcache.get(key.encode())
+        return 3600, await self.get(key)
 
-    async def get(self, key: str) -> Optional[str]:
+    async def get(self, key: str) -> Optional[bytes]:
-        return await self.mcache.get(key, key.encode())
+        return await self.mcache.get(key.encode())
 
-    async def set(self, key: str, value: str, expire: Optional[int] = None) -> None:
+    async def set(self, key: str, value: bytes, expire: Optional[int] = None) -> None:
-        await self.mcache.set(key.encode(), value.encode(), exptime=expire or 0)
+        await self.mcache.set(key.encode(), value, exptime=expire or 0)
 
     async def clear(self, namespace: Optional[str] = None, key: Optional[str] = None) -> int:
         raise NotImplementedError

fastapi_cache/backends/redis.py

@@ -1,4 +1,4 @@
-from typing import Optional, Tuple
+from typing import Optional, Tuple, Union
 
 from redis.asyncio.client import Redis
 from redis.asyncio.cluster import RedisCluster
@@ -7,18 +7,18 @@ from fastapi_cache.backends import Backend
 
 
 class RedisBackend(Backend):
-    def __init__(self, redis: Redis[str] | RedisCluster[str]):
+    def __init__(self, redis: Union[Redis[bytes], RedisCluster[bytes]]):
         self.redis = redis
         self.is_cluster: bool = isinstance(redis, RedisCluster)
 
-    async def get_with_ttl(self, key: str) -> Tuple[int, str]:
+    async def get_with_ttl(self, key: str) -> Tuple[int, Optional[bytes]]:
         async with self.redis.pipeline(transaction=not self.is_cluster) as pipe:
             return await pipe.ttl(key).get(key).execute()
 
-    async def get(self, key: str) -> Optional[str]:
+    async def get(self, key: str) -> Optional[bytes]:
         return await self.redis.get(key)
 
-    async def set(self, key: str, value: str, expire: Optional[int] = None) -> None:
+    async def set(self, key: str, value: bytes, expire: Optional[int] = None) -> None:
         return await self.redis.set(key, value, ex=expire)
 
     async def clear(self, namespace: Optional[str] = None, key: Optional[str] = None) -> int:

fastapi_cache/coder.py

@@ -1,9 +1,8 @@
-import codecs
 import datetime
 import json
 import pickle  # nosec:B403
 from decimal import Decimal
-from typing import Any, Callable, ClassVar, Dict, TypeVar, overload
+from typing import Any, Callable, ClassVar, Dict, Optional, TypeVar, Union, overload
 
 import pendulum
 from fastapi.encoders import jsonable_encoder
@@ -46,11 +45,11 @@ def object_hook(obj: Any) -> Any:
 
 class Coder:
     @classmethod
-    def encode(cls, value: Any) -> str:
+    def encode(cls, value: Any) -> bytes:
         raise NotImplementedError
 
     @classmethod
-    def decode(cls, value: str) -> Any:
+    def decode(cls, value: bytes) -> Any:
         raise NotImplementedError
 
     # (Shared) cache for endpoint return types to Pydantic model fields.
@@ -62,16 +61,16 @@ class Coder:
 
     @overload
     @classmethod
-    def decode_as_type(cls, value: str, type_: _T) -> _T:
+    def decode_as_type(cls, value: bytes, *, type_: _T) -> _T:
         ...
 
     @overload
     @classmethod
-    def decode_as_type(cls, value: str, *, type_: None) -> Any:
+    def decode_as_type(cls, value: bytes, *, type_: None) -> Any:
         ...
 
     @classmethod
-    def decode_as_type(cls, value: str, *, type_: _T | None) -> _T | Any:
+    def decode_as_type(cls, value: bytes, *, type_: Optional[_T]) -> Union[_T, Any]:
         """Decode value to the specific given type
 
         The default implementation uses the Pydantic model system to convert the value.
@@ -95,29 +94,32 @@ class Coder:
 
 class JsonCoder(Coder):
     @classmethod
-    def encode(cls, value: Any) -> str:
+    def encode(cls, value: Any) -> bytes:
         if isinstance(value, JSONResponse):
-            return value.body.decode()
+            return value.body
-        return json.dumps(value, cls=JsonEncoder)
+        return json.dumps(value, cls=JsonEncoder).encode()
 
     @classmethod
-    def decode(cls, value: str) -> str:
+    def decode(cls, value: bytes) -> Any:
-        return json.loads(value, object_hook=object_hook)
+        # explicitly decode from UTF-8 bytes first, as otherwise
+        # json.loads() will first have to detect the correct UTF-
+        # encoding used.
+        return json.loads(value.decode(), object_hook=object_hook)
 
 
 class PickleCoder(Coder):
     @classmethod
-    def encode(cls, value: Any) -> str:
+    def encode(cls, value: Any) -> bytes:
         if isinstance(value, TemplateResponse):
             value = value.body
-        return codecs.encode(pickle.dumps(value), "base64").decode()
+        return pickle.dumps(value)
 
     @classmethod
-    def decode(cls, value: str) -> Any:
+    def decode(cls, value: bytes) -> Any:
-        return pickle.loads(codecs.decode(value.encode(), "base64"))  # nosec:B403,B301
+        return pickle.loads(value)  # nosec:B403,B301
 
     @classmethod
-    def decode_as_type(cls, value: str, *, type_: Any) -> Any:
+    def decode_as_type(cls, value: bytes, *, type_: Optional[_T]) -> Any:
         # Pickle already produces the correct type on decoding, no point
         # in paying an extra performance penalty for pydantic to discover
         # the same.

tests/test_codecs.py

@@ -36,7 +36,7 @@ class PDItem(BaseModel):
 )
 def test_pickle_coder(value: Any) -> None:
     encoded_value = PickleCoder.encode(value)
-    assert isinstance(encoded_value, str)
+    assert isinstance(encoded_value, bytes)
     decoded_value = PickleCoder.decode(encoded_value)
     assert decoded_value == value
 
@@ -55,12 +55,12 @@ def test_pickle_coder(value: Any) -> None:
 )
 def test_json_coder(value: Any, return_type) -> None:
     encoded_value = JsonCoder.encode(value)
-    assert isinstance(encoded_value, str)
+    assert isinstance(encoded_value, bytes)
     decoded_value = JsonCoder.decode_as_type(encoded_value, type_=return_type)
     assert decoded_value == value
 
 
 def test_json_coder_validation_error() -> None:
-    invalid = '{"name": "incomplete"}'
+    invalid = b'{"name": "incomplete"}'
     with pytest.raises(ValidationError):
         JsonCoder.decode_as_type(invalid, type_=PDItem)