perf(workflow): Adjust graph construction timing, adopting a lazy strategy for constructing cyclic subgraphs within nodes

api/app/core/workflow/engine/graph_builder.py

@@ -61,21 +61,11 @@ class GraphBuilder:
         else:
             self.variable_pool = VariablePool()
 
-        self.graph = StateGraph(WorkflowState)
-        self.add_nodes()
-        self.reachable_nodes = WorkflowValidator.get_reachable_nodes(self.start_node_id, self.edges)
-        self.end_nodes = [
-            node
-            for node in self.nodes
-            if node.get("type") == "end" and node.get("id") in self.reachable_nodes
-        ]
-        self._reverse_adj: dict[str, list[dict]] = defaultdict(list)
-        self._adj: dict[str, list[str]] = defaultdict(list)
-        self._build_reverse_adj()
-        self.add_edges()
-        # EDGES MUST BE ADDED AFTER NODES ARE ADDED.
-
-        self._analyze_end_node_output()
+        self.graph: StateGraph | None = None
+        self.reachable_nodes: set[str] | None = None
+        self.end_nodes: list[dict] = []
+        self._reverse_adj: dict[str, list[dict]] | None = defaultdict(list)
+        self._adj: dict[str, list[str]] | None = defaultdict(list)
 
     @property
     def nodes(self) -> list[dict[str, Any]]:
@@ -109,7 +99,7 @@ class GraphBuilder:
             result[node[0]].append(node[1])
         return result
 
-    def _build_reverse_adj(self):
+    def _build_adj(self):
         for edge in self.edges:
             if edge["source"] not in self.reachable_nodes:
                 continue
@@ -513,6 +503,21 @@ class GraphBuilder:
         return
 
     def build(self) -> CompiledStateGraph:
+        self.graph = StateGraph(WorkflowState)
+        self.add_nodes()
+        self.reachable_nodes = WorkflowValidator.get_reachable_nodes(self.start_node_id, self.edges)
+        self.end_nodes = [
+            node
+            for node in self.nodes
+            if node.get("type") == "end" and node.get("id") in self.reachable_nodes
+        ]
+        self._reverse_adj: dict[str, list[dict]] = defaultdict(list)
+        self._adj: dict[str, list[str]] = defaultdict(list)
+        self._build_adj()
+        self.add_edges()
+        # EDGES MUST BE ADDED AFTER NODES ARE ADDED.
+
+        self._analyze_end_node_output()
         checkpointer = InMemorySaver()
-        self.graph = self.graph.compile(checkpointer=checkpointer)
-        return self.graph
+        return self.graph.compile(checkpointer=checkpointer)
+

api/app/core/workflow/executor.py

@@ -88,9 +88,10 @@ class WorkflowExecutor:
             self.workflow_config,
             stream=stream,
         )
+
+        self.graph = builder.build()
         self.start_node_id = builder.start_node_id
         self.variable_pool = builder.variable_pool
-        self.graph = builder.build()
 
         self.stream_coordinator.initialize_end_outputs(builder.end_node_map)
         self.event_handler = EventStreamHandler(

api/app/core/workflow/nodes/cycle_graph/node.py

@@ -32,15 +32,11 @@ class CycleGraphNode(BaseNode):
 
     def __init__(self, node_config: dict[str, Any], workflow_config: dict[str, Any]):
         super().__init__(node_config, workflow_config)
-
-        self.cycle_nodes = list()  # Nodes belonging to this cycle
-        self.cycle_edges = list()  # Edges connecting nodes within the cycle
+        self.cycle_nodes, self.cycle_edges = self.pure_cycle_graph()
         self.start_node_id = None  # ID of the start node within the cycle
 
         self.graph: StateGraph | CompiledStateGraph | None = None
         self.child_variable_pool: VariablePool | None = None
-        self.build_graph()
-        self.iteration_flag = True
 
     def _output_types(self) -> dict[str, VariableType]:
         outputs = {"__child_state": VariableType.ARRAY_OBJECT}
@@ -137,7 +133,7 @@ class CycleGraphNode(BaseNode):
         3. Compile the graph for runtime execution
         """
         from app.core.workflow.engine.graph_builder import GraphBuilder
-        self.cycle_nodes, self.cycle_edges = self.pure_cycle_graph()
+
         self.child_variable_pool = VariablePool()
         builder = GraphBuilder(
             {
@@ -147,8 +143,8 @@ class CycleGraphNode(BaseNode):
             subgraph=True,
             variable_pool=self.child_variable_pool
         )
-        self.start_node_id = builder.start_node_id
         self.graph = builder.build()
+        self.start_node_id = builder.start_node_id
         self.child_variable_pool = builder.variable_pool
 
     async def execute(self, state: WorkflowState, variable_pool: VariablePool) -> Any:
@@ -169,6 +165,7 @@ class CycleGraphNode(BaseNode):
         Raises:
             RuntimeError: If the node type is unsupported.
         """
+        self.build_graph()
         if self.node_type == NodeType.LOOP:
             return await LoopRuntime(
                 start_id=self.start_node_id,
@@ -194,6 +191,7 @@ class CycleGraphNode(BaseNode):
         raise RuntimeError("Unknown cycle node type")
 
     async def execute_stream(self, state: WorkflowState, variable_pool: VariablePool):
+        self.build_graph()
         if self.node_type == NodeType.LOOP:
             yield {
                 "__final__": True,

api/app/core/workflow/validator.py

@@ -183,7 +183,7 @@ class WorkflowValidator:
                 has_cycle, cycle_path = WorkflowValidator._has_cycle(nodes, edges)
                 if has_cycle:
                     errors.append(
-                        f"工作流存在循环依赖（请使用 loop 节点实现循环）: {' -> '.join(cycle_path)}"
+                        f"工作流存在循环依赖（请使用 loop/iteration 节点实现循环）: {' -> '.join(cycle_path)}"
                     )
 
             # 8. 验证变量名
@@ -229,10 +229,6 @@ class WorkflowValidator:
         Returns:
             (has_cycle, cycle_path): 是否有循环和循环路径
         """
-        # 排除 loop 类型的节点
-        loop_nodes = {n["id"] for n in nodes if n.get("type") == "loop"}
-
-        # 构建邻接表（排除 loop 节点的边和错误边）
         graph: dict[str, list[str]] = {}
         for edge in edges:
             source = edge.get("source")
@@ -243,10 +239,6 @@ class WorkflowValidator:
             if edge_type == "error":
                 continue
 
-            # 如果涉及 loop 节点，跳过
-            if source in loop_nodes or target in loop_nodes:
-                continue
-
             if source and target:
                 if source not in graph:
                     graph[source] = []