refactor(agents): 移除graph缓存并优化连接和检查点缓存

移除所有agent子类中graph的缓存逻辑，改为每次都重新构建
在BaseAgent中添加_async_conn缓存并优化checkpointer缓存逻辑

src/agents/chatbot/graph.py

@@ -18,9 +18,6 @@ class ChatbotAgent(BaseAgent):
 
     async def get_graph(self, **kwargs):
         """构建图"""
-        if self.graph:
-            return self.graph
-
         # 获取上下文配置
         context = self.context_schema.from_file(module_name=self.module_name)
 
@@ -36,7 +33,6 @@ class ChatbotAgent(BaseAgent):
             checkpointer=await self._get_checkpointer(),
         )
 
-        self.graph = graph
         return graph
 
 

src/agents/common/base.py

@@ -28,6 +28,7 @@ class BaseAgent:
     def __init__(self, **kwargs):
         self.graph = None  # will be covered by get_graph
         self.checkpointer = None
+        self._async_conn = None
         self.workdir = Path(sys_config.save_dir) / "agents" / self.module_name
         self.workdir.mkdir(parents=True, exist_ok=True)
         self._metadata_cache = None  # Cache for metadata to avoid repeated file reads
@@ -147,6 +148,9 @@ class BaseAgent:
         pass
 
     async def _get_checkpointer(self):
+        if self.checkpointer is not None:
+            return self.checkpointer
+
         # 创建数据库连接并确保设置 checkpointer
         checkpointer = None
 
@@ -157,15 +161,20 @@ class BaseAgent:
             logger.error(f"构建 Graph 设置 checkpointer 时出错: {e}, 尝试使用内存存储")
             checkpointer = InMemorySaver()
 
-        return checkpointer
+        self.checkpointer = checkpointer
+        return self.checkpointer
 
     async def get_async_conn(self) -> aiosqlite.Connection:
         """获取异步数据库连接"""
+        if self._async_conn is not None:
+            return self._async_conn
+
         conn = await aiosqlite.connect(os.path.join(self.workdir, "aio_history.db"))
         # Patch: langgraph's AsyncSqliteSaver expects is_alive() method which aiosqlite may not have
         if not hasattr(conn, "is_alive"):
             conn.is_alive = lambda: True
-        return conn
+        self._async_conn = conn
+        return self._async_conn
 
     async def get_aio_memory(self) -> AsyncSqliteSaver:
         """获取异步存储实例"""

src/agents/deep_agent/graph.py

@@ -88,9 +88,6 @@ class DeepAgent(BaseAgent):
 
     async def get_graph(self, **kwargs):
         """构建 Deep Agent 的图"""
-        if self.graph:
-            return self.graph
-
         # 获取上下文配置
         context = self.context_schema.from_file(module_name=self.module_name)
 
@@ -139,5 +136,4 @@ class DeepAgent(BaseAgent):
             checkpointer=await self._get_checkpointer(),
         )
 
-        self.graph = graph
         return graph

src/agents/mini_agent/graph.py

@@ -12,9 +12,6 @@ class MiniAgent(BaseAgent):
         super().__init__(**kwargs)
 
     async def get_graph(self, **kwargs):
-        if self.graph:
-            return self.graph
-
         context = self.context_schema.from_file(module_name=self.module_name)
 
         # 创建 MiniAgent
@@ -25,5 +22,4 @@ class MiniAgent(BaseAgent):
             checkpointer=await self._get_checkpointer(),
         )
 
-        self.graph = graph
         return graph

src/agents/reporter/graph.py

@@ -35,9 +35,6 @@ class SqlReporterAgent(BaseAgent):
         super().__init__(**kwargs)
 
     async def get_graph(self, **kwargs):
-        if self.graph:
-            return self.graph
-
         context = self.context_schema.from_file(module_name=self.module_name)
 
         # 创建 SqlReporterAgent
@@ -48,6 +45,5 @@ class SqlReporterAgent(BaseAgent):
             checkpointer=await self._get_checkpointer(),
         )
 
-        self.graph = graph
         logger.info("SqlReporterAgent 构建成功")
         return graph