Only compute displayed rating if enforcement is enabled

This should significantly reduce calls to rating initialization code

server/games/game.py

@@ -861,17 +861,22 @@ def report_army_stats(self, stats_json):
         self._process_pending_army_stats()
 
     def is_visible_to_player(self, player: Player) -> bool:
+        """
+        Determine if a player should see this game in their games list.
+
+        Note: This is a *hot* function, it can have significant impacts on
+        performance.
+        """
         if self.host is None:
             return False
 
         if player == self.host or player in self._connections:
             return True
 
-        mean, dev = player.ratings[self.rating_type]
-        displayed_rating = mean - 3 * dev
         if (
             self.enforce_rating_range
-            and displayed_rating not in self.displayed_rating_range
+            and player.get_displayed_rating(self.rating_type)
+            not in self.displayed_rating_range
         ):
             return False
 

server/players.py

@@ -88,6 +88,10 @@ def faction(self, value: Union[str, int, Faction]) -> None:
         else:
             self._faction = Faction.from_value(value)
 
+    def get_displayed_rating(self, rating_type: str) -> float:
+        mean, dev = self.ratings[rating_type]
+        return mean - 3 * dev
+
     def power(self) -> int:
         """An artifact of the old permission system. The client still uses this
         number to determine if a player gets a special category in the user list