SC2: Python 3.11 compatibility (#1821)

Co-authored-by: Salzkorn

worlds/_sc2common/bot/cache.py

@@ -0,0 +1,49 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Callable, Hashable, TypeVar
+
+if TYPE_CHECKING:
+    from .bot_ai import BotAI
+
+T = TypeVar("T")
+
+
+class CacheDict(dict):
+
+    def retrieve_and_set(self, key: Hashable, func: Callable[[], T]) -> T:
+        """ Either return the value at a certain key,
+        or set the return value of a function to that key, then return that value. """
+        if key not in self:
+            self[key] = func()
+        return self[key]
+
+
+class property_cache_once_per_frame(property):
+    """This decorator caches the return value for one game loop,
+    then clears it if it is accessed in a different game loop.
+    Only works on properties of the bot object, because it requires
+    access to self.state.game_loop
+
+    This decorator compared to the above runs a little faster, however you should only use this decorator if you are sure that you do not modify the mutable once it is calculated and cached.
+
+    Copied and modified from https://tedboy.github.io/flask/_modules/werkzeug/utils.html#cached_property
+    # """
+
+    def __init__(self, func: Callable[[BotAI], T], name=None):
+        # pylint: disable=W0231
+        self.__name__ = name or func.__name__
+        self.__frame__ = f"__frame__{self.__name__}"
+        self.func = func
+
+    def __set__(self, obj: BotAI, value: T):
+        obj.cache[self.__name__] = value
+        obj.cache[self.__frame__] = obj.state.game_loop
+
+    def __get__(self, obj: BotAI, _type=None) -> T:
+        value = obj.cache.get(self.__name__, None)
+        bot_frame = obj.state.game_loop
+        if value is None or obj.cache[self.__frame__] < bot_frame:
+            value = self.func(obj)
+            obj.cache[self.__name__] = value
+            obj.cache[self.__frame__] = bot_frame
+        return value