feat: allow to configure media cache (for JS and CSS files) (#946)

src/django_components/cache.py

@@ -0,0 +1,46 @@
+from typing import Optional
+
+from django.core.cache import BaseCache, caches
+from django.core.cache.backends.locmem import LocMemCache
+
+from django_components.app_settings import app_settings
+from django_components.util.cache import LRUCache
+
+# This stores the parsed Templates. This is strictly local for now, as it stores instances.
+# NOTE: Lazily initialized so it can be configured based on user-defined settings.
+#
+# TODO: Once we handle whole template parsing ourselves, this could store just
+#       the parsed template AST (+metadata) instead of Template instances. In that case
+#       we could open this up to be stored non-locally and shared across processes.
+#       This would also allow us to remove our custom `LRUCache` implementation.
+template_cache: Optional[LRUCache] = None
+
+# This stores the inlined component JS and CSS files (e.g. `Component.js` and `Component.css`).
+# We also store here the generated JS and CSS scripts that inject JS / CSS variables into the page.
+component_media_cache: Optional[BaseCache] = None
+
+
+def get_template_cache() -> LRUCache:
+    global template_cache
+    if template_cache is None:
+        template_cache = LRUCache(maxsize=app_settings.TEMPLATE_CACHE_SIZE)
+
+    return template_cache
+
+
+def get_component_media_cache() -> BaseCache:
+    global component_media_cache
+    if component_media_cache is None:
+        if app_settings.CACHE is not None:
+            component_media_cache = caches[app_settings.CACHE]
+        else:
+            component_media_cache = LocMemCache(
+                "django-components-media",
+                {
+                    "TIMEOUT": None,  # No timeout
+                    "MAX_ENTRIES": None,  # No max size
+                    "CULL_FREQUENCY": 3,
+                },
+            )
+
+    return component_media_cache