refactor: 修复database单例多次初始化的问题，改变instance默认返回实例的类型，缩短db相关函数调用时的object名

src/plugins/memory_system/draw_memory.py

@@ -96,7 +96,7 @@ class Memory_graph:
             dot_data = {
                 "concept": node
             }
-            self.db.db.store_memory_dots.insert_one(dot_data)
+            self.db.store_memory_dots.insert_one(dot_data)
 
     @property
     def dots(self):
@@ -106,7 +106,7 @@ class Memory_graph:
     def get_random_chat_from_db(self, length: int, timestamp: str):
         # 从数据库中根据时间戳获取离其最近的聊天记录
         chat_text = ''
-        closest_record = self.db.db.messages.find_one({"time": {"$lte": timestamp}}, sort=[('time', -1)])  # 调试输出
+        closest_record = self.db.messages.find_one({"time": {"$lte": timestamp}}, sort=[('time', -1)])  # 调试输出
         logger.info(
             f"距离time最近的消息时间: {time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(int(closest_record['time'])))}")
 
@@ -115,7 +115,7 @@ class Memory_graph:
             group_id = closest_record['group_id']  # 获取groupid
             # 获取该时间戳之后的length条消息，且groupid相同
             chat_record = list(
-                self.db.db.messages.find({"time": {"$gt": closest_time}, "group_id": group_id}).sort('time', 1).limit(
+                self.db.messages.find({"time": {"$gt": closest_time}, "group_id": group_id}).sort('time', 1).limit(
                     length))
             for record in chat_record:
                 time_str = time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(int(record['time'])))
@@ -130,34 +130,34 @@ class Memory_graph:
 
     def save_graph_to_db(self):
         # 清空现有的图数据
-        self.db.db.graph_data.delete_many({})
+        self.db.graph_data.delete_many({})
         # 保存节点
         for node in self.G.nodes(data=True):
             node_data = {
                 'concept': node[0],
                 'memory_items': node[1].get('memory_items', [])  # 默认为空列表
             }
-            self.db.db.graph_data.nodes.insert_one(node_data)
+            self.db.graph_data.nodes.insert_one(node_data)
         # 保存边
         for edge in self.G.edges():
             edge_data = {
                 'source': edge[0],
                 'target': edge[1]
             }
-            self.db.db.graph_data.edges.insert_one(edge_data)
+            self.db.graph_data.edges.insert_one(edge_data)
 
     def load_graph_from_db(self):
         # 清空当前图
         self.G.clear()
         # 加载节点
-        nodes = self.db.db.graph_data.nodes.find()
+        nodes = self.db.graph_data.nodes.find()
         for node in nodes:
             memory_items = node.get('memory_items', [])
             if not isinstance(memory_items, list):
                 memory_items = [memory_items] if memory_items else []
             self.G.add_node(node['concept'], memory_items=memory_items)
         # 加载边
-        edges = self.db.db.graph_data.edges.find()
+        edges = self.db.graph_data.edges.find()
         for edge in edges:
             self.G.add_edge(edge['source'], edge['target'])
 

src/plugins/memory_system/memory.py

@@ -887,15 +887,6 @@ config = driver.config
 
 start_time = time.time()
 
-Database.initialize(
-    uri=os.getenv("MONGODB_URI"),
-    host=os.getenv("MONGODB_HOST", "127.0.0.1"),
-    port=int(os.getenv("MONGODB_PORT", "27017")),
-    db_name=os.getenv("DATABASE_NAME", "MegBot"),
-    username=os.getenv("MONGODB_USERNAME"),
-    password=os.getenv("MONGODB_PASSWORD"),
-    auth_source=os.getenv("MONGODB_AUTH_SOURCE"),
-)
 # 创建记忆图
 memory_graph = Memory_graph()
 # 创建海马体