Lazy-load asyncio.Lock in SQLiteBackend to prevent premature initiali…

…zation outside main event loop

HISTORY.md

@@ -1,5 +1,8 @@
 # History
 
+## 0.4.1 (2021-06-TBD)
+* Fix initialziation of `SQLiteBackend` so it can be created outside main event loop
+
 ## 0.4.0 (2021-05-12)
 * Add optional support for the following **request** headers:
     * `Cache-Control: max-age`

aiohttp_client_cache/__init__.py

@@ -1,4 +1,4 @@
-__version__ = '0.4.0'
+__version__ = '0.4.1'
 
 # flake8: noqa: F401, F403
 try:

aiohttp_client_cache/backends/sqlite.py

@@ -61,11 +61,11 @@ def __init__(self, filename: str, table_name: str, use_temp: bool = False, **kwa
         self._bulk_commit = False
         self._initialized = False
         self._connection = None
-        self._lock = asyncio.Lock()
+        self._lock = None
 
     @asynccontextmanager
     async def get_connection(self, autocommit: bool = False) -> AsyncIterator[aiosqlite.Connection]:
-        async with self._lock:
+        async with self.lock:
             db = (
                 self._connection
                 if self._connection
@@ -79,6 +79,12 @@ async def get_connection(self, autocommit: bool = False) -> AsyncIterator[aiosql
                 if not self._bulk_commit:
                     await db.close()
 
+    @property
+    def lock(self):
+        if self._lock is None:
+            self._lock = asyncio.Lock()
+        return self._lock
+
     async def _init_db(self, db: aiosqlite.Connection):
         """Create table if this is the first connection opened, and set fast save if possible"""
         if not self._bulk_commit: