Fix interface compatibility by inheriting from Response

HISTORY.md

@@ -2,7 +2,8 @@
 
 # Unreleased
 
-- Fix `CachedResponse.is_expired` check to consider any errors as "expired"
+- Fixed `CachedResponse.is_expired` check to consider any errors as "expired". (!252)
+- Now `CachedResponse` inherits from the `aiohttp.ClientResponse`. (#251)
 
 ## 0.11.1
 

aiohttp_client_cache/backends/base.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from copy import deepcopy
 import inspect
 import pickle
 from abc import ABCMeta, abstractmethod
@@ -8,17 +9,16 @@
 from logging import getLogger
 from typing import Any, AsyncIterable, Awaitable, Callable, Iterable, Union
 
-from aiohttp import ClientResponse
 from aiohttp.typedefs import StrOrURL
 
 from aiohttp_client_cache.cache_control import CacheActions, ExpirationPatterns, ExpirationTime
 from aiohttp_client_cache.cache_keys import create_key
-from aiohttp_client_cache.response import AnyResponse, CachedResponse
+from aiohttp_client_cache.response import CachedResponse
 
 ResponseOrKey = Union[CachedResponse, bytes, str, None]
 _FilterFn = Union[
-    Callable[[AnyResponse], bool],
-    Callable[[AnyResponse], Awaitable[bool]],
+    Callable[[CachedResponse], bool],
+    Callable[[CachedResponse], Awaitable[bool]],
 ]
 
 logger = getLogger(__name__)
@@ -84,7 +84,7 @@ def __init__(
         self.ignored_params = set(ignored_params or [])
 
     async def is_cacheable(
-        self, response: AnyResponse | None, actions: CacheActions | None = None
+        self, response: CachedResponse | None, actions: CacheActions | None = None
     ) -> bool:
         """Perform all checks needed to determine if the given response should be cached"""
         if not response:
@@ -155,12 +155,12 @@ async def get_response(self, key: str) -> CachedResponse | None:
         logger.debug(f'Attempting to get cached response for key: {key}')
         try:
             response = await self.responses.read(key) or await self._get_redirect_response(str(key))
-            # Catch "quiet" deserialization errors due to upgrading attrs
+            # Catch "quiet" deserialization errors due to upgrading attrs  # TODO: Remove?
             if response is not None:
                 assert response.method  # type: ignore
-        except (AssertionError, AttributeError, KeyError, TypeError, pickle.PickleError):
+        except (AssertionError, AttributeError, KeyError, TypeError, pickle.PickleError) as e:
+            logger.debug(repr(e))
             response = None
-
         if not response:
             logger.debug('No cached response found')
         # If the item is expired or filtered out, delete it from the cache
@@ -181,7 +181,7 @@ async def _get_redirect_response(self, key: str) -> CachedResponse | None:
 
     async def save_response(
         self,
-        response: ClientResponse,
+        response: CachedResponse,
         cache_key: str | None = None,
         expires: datetime | None = None,
     ):
@@ -193,7 +193,7 @@ async def save_response(
             expires: Expiration time to set for the response
         """
         cache_key = cache_key or self.create_key(response.method, response.url)
-        cached_response = await CachedResponse.from_client_response(response, expires)
+        cached_response = await response.postprocess(expires)
         await self.responses.write(cache_key, cached_response)
 
         # Alias any redirect requests to the same cache key
@@ -305,9 +305,14 @@ def serialize(self, item: ResponseOrKey = None) -> bytes | None:
 
     def deserialize(self, item: ResponseOrKey) -> CachedResponse | str | None:
         """Deserialize a cached URL or response"""
-        if isinstance(item, (CachedResponse, str)):
+        if not item:
+            return None
+        if isinstance(item, CachedResponse):
+            item.from_cache = True
             return item
-        return self._serializer.loads(item) if item else None
+        if isinstance(item, str):
+            return item
+        return self._serializer.loads(item)
 
     @staticmethod
     def _get_serializer(secret_key, salt):
@@ -409,6 +414,8 @@ async def read(self, key: str) -> CachedResponse | str | None:
             item.reset()
         except AttributeError:
             pass
+        else:
+            item.from_cache = True
         return item
 
     async def size(self) -> int:
@@ -419,4 +426,7 @@ async def values(self) -> AsyncIterable[ResponseOrKey]:  # type: ignore
             yield value
 
     async def write(self, key: str, item: ResponseOrKey):
-        self.data[key] = item
+        # Keep a copy, as any change to the response will also change the cached value.
+        # While this should not be a problem for any use case I can imagine, we need to
+        # be consistent with other backends such as MongoDB, Redis, etc.
+        self.data[key] = deepcopy(item)

aiohttp_client_cache/cache_control.py

@@ -9,13 +9,15 @@
 from functools import singledispatch
 from itertools import chain
 from logging import getLogger
-from typing import Any, Dict, Mapping, NoReturn, Tuple, Union
+from typing import Any, Dict, Mapping, NoReturn, Tuple, Union, TYPE_CHECKING
 
-from aiohttp import ClientResponse
 from aiohttp.typedefs import StrOrURL
 from attr import define, field
 from multidict import CIMultiDict
 
+if TYPE_CHECKING:
+    from aiohttp_client_cache.response import CachedResponse
+
 # Value that may be set by either Cache-Control headers or CacheBackend params to disable caching
 DO_NOT_CACHE = 0
 
@@ -129,7 +131,7 @@ def expires(self) -> datetime | None:
         """Convert the user/header-provided expiration value to a datetime"""
         return get_expiration_datetime(self.expire_after)
 
-    def update_from_response(self, response: ClientResponse):
+    def update_from_response(self, response: CachedResponse):
         """Update expiration + actions based on response headers, if not previously set by request"""
         if not self.cache_control:
             return