Ensure thread safety in storage update callbacks

- Added storage lock in index_done_callback
- Fixed potential race conditions

lightrag/kg/faiss_impl.py

@@ -343,6 +343,7 @@ class FaissVectorDBStorage(BaseVectorStorage):
             self._id_to_meta = {}
 
     async def index_done_callback(self) -> None:
+        async with self._storage_lock:
             # Check if storage was updated by another process
             if is_multiprocess and self.storage_updated.value:
                 # Storage was updated by another process, reload data instead of saving

lightrag/kg/nano_vector_db_impl.py

@@ -206,6 +206,7 @@ class NanoVectorDBStorage(BaseVectorStorage):
 
     async def index_done_callback(self) -> bool:
         """Save data to disk"""
+        async with self._storage_lock:
             # Check if storage was updated by another process
             if is_multiprocess and self.storage_updated.value:
                 # Storage was updated by another process, reload data instead of saving

lightrag/kg/networkx_impl.py

@@ -401,6 +401,7 @@ class NetworkXStorage(BaseGraphStorage):
 
     async def index_done_callback(self) -> bool:
         """Save data to disk"""
+        async with self._storage_lock:
             # Check if storage was updated by another process
             if is_multiprocess and self.storage_updated.value:
                 # Storage was updated by another process, reload data instead of saving