Autogenerated type safety parameterisation of all methods

core/single_object_data_cache.py

@@ -1,18 +1,23 @@
+from __future__ import annotations
+
 import logging
 import threading
+from typing import Generic, TypeVar
 
 import diskcache
 
 logger = logging.getLogger(__name__)
 
+T = TypeVar("T")
 
-class SingleObjectDataCache:
+
+class SingleObjectDataCache(Generic[T]):
     """Cache for status and solar conditions. This uses DiskCache, but unlike the standard DiskCache users like
     activity ref and callsign lookup handlers, status and solar conditions are persisted as a single object. If we
     just load the object from DiskCache and modify it, DiskCache doesn't know that it's been updated and needs
     re-caching, so we provide a store() method that any functions updating the object can call afterwards."""
 
-    def __init__(self, cache_dir, object_if_empty):
+    def __init__(self, cache_dir: str, object_if_empty: T) -> None:
         """Initialize a SingleObjectDataCache. Provide the directory to load the cache from and save it to. If the cache
         is empty, the provided object_if_empty parameter will be used to initialise it."""
 
@@ -22,24 +27,24 @@ class SingleObjectDataCache:
         if "object" not in self._cache:
             self._cache.add("object", object_if_empty)
         try:
-            self._obj = self._cache.get("object")
+            self._obj: T = self._cache.get("object")
         except Exception:  # noqa: BLE001 (If any exceptions we treat the data as junk and start from scratch, it's probably due to a version upgrade having incompatible data structures, fine to not log the exception in this case)
             logger.warning(f"Failed to load cache from {cache_dir}, clearing it.")
             self._cache.clear()
             self._cache.add("object", object_if_empty)
             self._obj = object_if_empty
 
-    def get(self):
+    def get(self) -> T:
         """Get the data object. This can then be manipulated as necessary across multiple threads. Any function
         modifying the object must remember to call store() afterwards."""
         return self._obj
 
-    def store(self):
+    def store(self) -> None:
         """Store the updated object in the cache. Any function modifying the object must remember to call this
         afterwards."""
         with self._lock:
             self._cache.set("object", self._obj)
 
-    def close(self):
+    def close(self) -> None:
         self.store()
         self._cache.close()