Feature/fix caching middleware conflict with 4.2

fancy_cache/__init__.py

@@ -1,3 +1,3 @@
 from .cache_page import cache_page  # NOQA
 
-__version__ = "1.2.1"
+__version__ = "1.2.1.8"

fancy_cache/memory.py

@@ -41,7 +41,10 @@ def find_urls(
 ) -> typing.Generator[
     typing.Tuple[str, str, typing.Optional[typing.Dict[str, int]]], None, None
 ]:
-    remembered_urls = cache.get(REMEMBERED_URLS_KEY, {})
+    if USE_MEMCACHED_CAS is True:
+        remembered_urls = cache._cache.get(REMEMBERED_URLS_KEY, {})
+    else:
+        remembered_urls = cache.get(REMEMBERED_URLS_KEY, {})
     keys_to_delete = []
     if urls:
         regexes = _urls_to_regexes(urls)
@@ -63,9 +66,15 @@ def find_urls(
             if not cache.get(cache_key):
                 if purge:
                     keys_to_delete.append(url)
+                    if "/clubs/" in url and "/messages/" in url:
+                        LOGGER.info("fancy_cache.memory.find_urls: cache.get not found for messages url %s", url)
                 continue
             if purge:
-                cache.delete(cache_key)
+                result = cache.delete(cache_key)
+                if result:
+                    LOGGER.info("fancy_cache.memory.find_urls: deleted cache entry for url %s", url)
+                if not result and "/clubs/" in url and "/messages/" in url:
+                    LOGGER.exception("fancy_cache.memory.find_urls: cache.delete not found for messages url %s", url)
                 keys_to_delete.append(url)
             misses_cache_key = "%s__misses" % url
             misses_cache_key = md5(misses_cache_key)
@@ -87,6 +96,14 @@ def find_urls(
             deleted = delete_keys_cas(keys_to_delete)
             if deleted is True:
                 return
+            # CAS uses `cache._cache.get/set` so we need to set the
+            # REMEMBERED_URLS dict at that location.
+            # This is because CAS cannot call `BaseCache.make_key` to generate
+            # the key when it tries to get a cache entry set by `cache.get/set`.
+            remembered_urls = cache._cache.get(REMEMBERED_URLS_KEY, {})
+            remembered_urls = delete_keys(keys_to_delete, remembered_urls)
+            cache._cache.set(REMEMBERED_URLS_KEY, remembered_urls, LONG_TIME)
+            return
 
         remembered_urls = cache.get(REMEMBERED_URLS_KEY, {})
         remembered_urls = delete_keys(keys_to_delete, remembered_urls)
@@ -121,7 +138,7 @@ def delete_keys(
     Helper function to delete `keys_to_delete` from the `remembered_urls` dict.
     """
     for url in keys_to_delete:
-        remembered_urls.pop(url)
+        remembered_urls.pop(url, None)
         misses_cache_key = "%s__misses" % url
         hits_cache_key = "%s__hits" % url
         cache.delete(misses_cache_key)

fancy_cache/middleware.py

@@ -179,6 +179,15 @@ def remember_url(self, request, cache_key: str, timeout: int) -> None:
                 # Remembered URLs have been successfully saved
                 # via Memcached CAS.
                 return
+            # CAS uses `cache._cache.get/set` so we need to set the
+            # REMEMBERED_URLS dict at that location.
+            # This is because CAS cannot call `BaseCache.make_key` to generate
+            # the key when it tries to get a cache entry set by `cache.get/set`.
+            remembered_urls = self.cache._cache.get(REMEMBERED_URLS_KEY, {})
+            remembered_urls = filter_remembered_urls(remembered_urls)
+            remembered_urls[url] = (cache_key, expiration_time)
+            self.cache._cache.set(REMEMBERED_URLS_KEY, remembered_urls, LONG_TIME)
+            return
 
         remembered_urls = self.cache.get(REMEMBERED_URLS_KEY, {})
         remembered_urls = filter_remembered_urls(remembered_urls)
@@ -205,8 +214,11 @@ def _remember_url_cas(
 
             if remembered_urls is None:
                 # No cache entry; set the cache using `cache.set`.
+                LOGGER.info("fancy_cache._remember_url_cas: remembered_urls is None")
                 return False
 
+            LOGGER.info("fancy_cache._remember_url_cas: remembered_urls is not None")
+
             remembered_urls = filter_remembered_urls(remembered_urls)
 
             remembered_urls[url] = (cache_key, expiration_time)
@@ -222,6 +234,8 @@ def _remember_url_cas(
                 "Django-fancy-cache failed to save using CAS after %s tries.",
                 tries,
             )
+        if result is True and "/clubs/" in url and "/messages/" in url:
+            LOGGER.info("fancy_cache._remember_url_cas: Successfully cached and remembered URL %s", url)
         return result
 
 
@@ -379,15 +393,6 @@ def __init__(
             if cache_alias is None:
                 cache_alias = DEFAULT_CACHE_ALIAS
             self.cache_alias = cache_alias
-            # TODO: Likely this will cause a conflict with this commit
-            # in Django 4.1+:
-            # https://github.com/django/django/commit/3ff7b15bb79f2ee5b7af245c55ae14546243bb77
-            # The commit uses a @property decorator to set self.cache
-            # instead of setting it directly as we do in the line below.
-            # We can likely solve this by simply removing this line,
-            # but will need to make sure that the library still works for
-            # older versions of Django that use this `self.cache =` method.
-            self.cache = caches[self.cache_alias]
         except KeyError:
             pass
 

fancy_cache/utils.py

@@ -1,8 +1,12 @@
 import hashlib
+import logging
 import time
 import typing
 
 
+LOGGER = logging.getLogger(__name__)
+
+
 def md5(x) -> str:
     return hashlib.md5(x.encode("utf-8")).hexdigest()
 
@@ -22,4 +26,11 @@ def filter_remembered_urls(
         for key, value in remembered_urls.items()
         if isinstance(value, tuple) and value[1] > now
     }
+    filtered_urls = [
+        key
+        for key, value in remembered_urls.items()
+        if "/clubs/" in key and "/messages/" in key and isinstance(value, tuple) and value[1] < now
+    ]
+    LOGGER.info("fancy_cache.filter_remembered_urls: filtering these URLs: %s", filtered_urls)
+
     return remembered_urls