🐛 fix single_session bug

nonebot/plugins/single_session.py

@@ -1,34 +1,33 @@
-from typing import Dict
-
+from typing import Generator, Dict
 from nonebot.adapters import Event
 from nonebot.message import (
     IgnoredException,
-    run_preprocessor,
-    run_postprocessor,
+    event_preprocessor
 )
+from nonebot.params import Depends
 
 _running_matcher: Dict[str, int] = {}
 
 
-@run_preprocessor
-async def preprocess(event: Event):
+async def matcher_mutex(event: Event) -> Generator[bool, None, None]:
+    result = False
     try:
         session_id = event.get_session_id()
     except Exception:
-        return
-    current_event_id = id(event)
-    event_id = _running_matcher.get(session_id, None)
-    if event_id and event_id != current_event_id:
+        yield result
+    else:
+        current_event_id = id(event)
+        event_id = _running_matcher.get(session_id, None)
+        if event_id :
+            result = event_id != current_event_id
+        else:
+            _running_matcher[session_id] = current_event_id
+        yield result
+        if result:
+            del _running_matcher[session_id]
+
+@event_preprocessor
+async def preprocess(mutex: bool = Depends(matcher_mutex)):
+    if mutex:
         raise IgnoredException("Another matcher running")
 
-    _running_matcher[session_id] = current_event_id
-
-
-@run_postprocessor
-async def postprocess(event: Event):
-    try:
-        session_id = event.get_session_id()
-    except Exception:
-        return
-    if session_id in _running_matcher:
-        del _running_matcher[session_id]