Reuse aiosqlite connection pool for crypto db

Otherwise stopping bridges gets stuck because the crypto pool isn't closed.
asyncpg was already reusing the pool.

Author: tulir

mautrix/bridge/bridge.py

@@ -262,8 +262,11 @@ async def start(self) -> None:
 
     async def system_exit(self) -> None:
         if hasattr(self, "db") and isinstance(self.db, Database):
-            self.log.trace("Stopping database due to SystemExit")
+            self.log.debug("Stopping database due to SystemExit")
             await self.db.stop()
+            self.log.debug("Database stopped")
+        elif getattr(self, "db", None):
+            self.log.trace("Database not started at SystemExit")
 
     async def stop(self) -> None:
         if self.manhole:

mautrix/util/async_db/aiosqlite.py

@@ -5,7 +5,7 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 from __future__ import annotations
 
-from typing import Any
+from typing import Any, AsyncContextManager
 from contextlib import asynccontextmanager
 import asyncio
 import logging
@@ -81,6 +81,7 @@ async def fetchval(
 
 class SQLiteDatabase(Database):
     scheme = Scheme.SQLITE
+    _parent: SQLiteDatabase | None
     _pool: asyncio.Queue[TxnConnection]
     _stopped: bool
     _conns: int
@@ -103,6 +104,7 @@ def __init__(
             owner_name=owner_name,
             ignore_foreign_tables=ignore_foreign_tables,
         )
+        self._parent = None
         self._path = url.path
         if self._path.startswith("/"):
             self._path = self._path[1:]
@@ -134,7 +136,14 @@ def _add_missing_pragmas(init_commands: list[str]) -> list[str]:
             init_commands.append("PRAGMA busy_timeout = 5000")
         return init_commands
 
+    def override_pool(self, db: Database) -> None:
+        assert isinstance(db, SQLiteDatabase)
+        self._parent = db
+
     async def start(self) -> None:
+        if self._parent:
+            await super().start()
+            return
         if self._conns:
             raise RuntimeError("database pool has already been started")
         elif self._stopped:
@@ -155,14 +164,21 @@ async def start(self) -> None:
         await super().start()
 
     async def stop(self) -> None:
+        if self._parent:
+            return
         self._stopped = True
         while self._conns > 0:
             conn = await self._pool.get()
             self._conns -= 1
             await conn.close()
 
+    def acquire(self) -> AsyncContextManager[LoggingConnection]:
+        if self._parent:
+            return self._parent.acquire()
+        return self._acquire()
+
     @asynccontextmanager
-    async def acquire(self) -> LoggingConnection:
+    async def _acquire(self) -> LoggingConnection:
         if self._stopped:
             raise RuntimeError("database pool has been stopped")
         conn = await self._pool.get()