create MemoryGameBoardStore Class and rework Building of Game Board Storage

server/game_board_stats/MemoryGameBoardStore.py

@@ -0,0 +1,17 @@
+from server.GameBoard import GameBoard
+
+class MemoryGameBoardStore:
+  def __init__(self, **kwargs):
+    self._state:dict[str, object] = {}
+
+  async def save(self, game_id:str, game_board:GameBoard) -> None:
+    self._state[game_id] = game_board
+
+  async def load(self, game_id:str):
+    return self._state.get(game_id)
+
+  async def delete(self, game_id:str) -> None:
+    self._state.pop(game_id, None)
+
+  async def close(self) -> None:
+    return None

server/game_board_stats/RedisGameBoardStore.py

@@ -0,0 +1,53 @@
+from server.GameBoard import GameBoard
+import pickle
+
+class RedisGameBoardStore:
+  def __init__(self, redis_url:str="redis://localhost:6379/0", key_prefix:str="snake:gameboard", ttl_seconds:int=900, **kwargs):
+    self.redis_url = redis_url
+    self.key_prefix = key_prefix
+    self.ttl_seconds = max(60, int(ttl_seconds))
+    self._redis = None
+
+  async def _get_redis(self):
+    if self._redis is not None:
+      return self._redis
+
+    try:
+      import aioredis  # type: ignore[import-not-found]
+    except ImportError as error:  # pragma: no cover
+      raise RuntimeError("Redis backend selected but 'aioredis' package is not installed") from error
+
+    self._redis = aioredis.from_url(self.redis_url)
+    return self._redis
+
+  def _key(self, game_id:str) -> str:
+    return f"{self.key_prefix}:{game_id}"
+
+  async def save(self, game_id:str, game_board:GameBoard) -> None:
+    redis = await self._get_redis()
+    payload = pickle.dumps(game_board, protocol=pickle.HIGHEST_PROTOCOL)
+    await redis.set(self._key(game_id), payload, ex=self.ttl_seconds)
+
+  async def load(self, game_id:str):
+    redis = await self._get_redis()
+    payload = await redis.get(self._key(game_id))
+    if payload is None:
+      return None
+    return pickle.loads(payload)
+
+  async def delete(self, game_id:str) -> None:
+    redis = await self._get_redis()
+    await redis.delete(self._key(game_id))
+
+  async def close(self) -> None:
+    if self._redis is None:
+      return
+
+    if hasattr(self._redis, "aclose"):
+      await self._redis.aclose()
+    elif hasattr(self._redis, "close"):
+      close_result = self._redis.close()
+      if close_result is not None:
+        await close_result
+
+    self._redis = None

server/game_board_stats/__init__.py

@@ -0,0 +1,10 @@
+from server.game_board_stats.MemoryGameBoardStore import MemoryGameBoardStore
+from server.game_board_stats.RedisGameBoardStore import RedisGameBoardStore
+
+class GameBoardStoreBuilder:
+  @classmethod
+  def build(self, backend:str="memory", **kwargs) -> MemoryGameBoardStore|RedisGameBoardStore:
+    selected = (backend or "memory").strip().lower()
+    if selected == "redis":
+      return RedisGameBoardStore(**kwargs)
+    return MemoryGameBoardStore(**kwargs)