114 lines
3.6 KiB
Python
114 lines
3.6 KiB
Python
"""
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Tools 节点 - 负责执行 tool_calls
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"""
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from typing import Dict, Any, Optional, List
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from langchain_core.runnables.config import RunnableConfig
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from langchain_core.messages import AIMessage, ToolMessage
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from backend.app.main_graph.state import AgentState
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from backend.app.logger import info, error, debug
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from backend.app.tools import ALL_TOOLS
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from backend.app.agent.stream_context import get_stream_queue
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async def tools_node(state: AgentState, config: Optional[RunnableConfig] = None) -> Dict[str, Any]:
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"""
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Tools 节点：执行 AIMessage.tool_calls，返回 ToolMessage 列表
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职责：
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1. 获取最后一条 AIMessage 的 tool_calls
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2. 遍历执行每个工具
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3. 记录历史（tool_call_history, tool_result_history）
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4. 更新步数 current_step += 1
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5. 发送工具开始/结束事件
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"""
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queue = get_stream_queue()
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is_streaming = queue is not None
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# 获取最后一条 AIMessage
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last_message = state.messages[-1]
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if not isinstance(last_message, AIMessage) or not last_message.tool_calls:
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info("[Tools] 没有工具调用，跳过")
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return {}
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tool_calls = last_message.tool_calls
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info(f"[Tools] 执行 {len(tool_calls)} 个工具调用")
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# 获取历史记录
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tool_call_history: List[dict] = list(getattr(state, "tool_call_history", []))
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tool_result_history: List[str] = list(getattr(state, "tool_result_history", []))
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tools_used: List[str] = list(getattr(state, "tools_used", []))
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tool_messages = []
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for tc in tool_calls:
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tool_name = tc["name"]
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tool_args = tc["args"]
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tool_id = tc["id"]
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tools_used.append(tool_name)
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# 发送工具开始事件
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if is_streaming:
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await queue.put({
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"type": "custom",
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"data": {
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"type": "tool_start",
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"tool": tool_name,
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"args": tool_args,
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"id": tool_id
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}
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})
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# 查找并执行工具
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tool_result = ""
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tool_found = False
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for tool in ALL_TOOLS:
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if tool.name == tool_name:
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tool_found = True
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try:
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tool_result = await tool.ainvoke(tool_args)
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debug(f"[Tools] 工具 {tool_name} 执行成功")
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except Exception as e:
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tool_result = f"工具调用出错: {str(e)}"
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error(f"[Tools] 工具 {tool_name} 调用出错: {e}")
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break
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if not tool_found:
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tool_result = f"未找到工具: {tool_name}"
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error(f"[Tools] 未找到工具: {tool_name}")
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# 发送工具结束事件
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if is_streaming:
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await queue.put({
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"type": "custom",
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"data": {
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"type": "tool_end",
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"tool": tool_name,
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"id": tool_id,
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"result": str(tool_result)
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}
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})
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# 记录历史
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tool_call_history.append({"name": tool_name, "args": tool_args})
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tool_result_history.append(str(tool_result))
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# 创建 ToolMessage
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tool_messages.append(
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ToolMessage(content=str(tool_result), tool_call_id=tool_id, name=tool_name)
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)
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# 更新步数
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current_step = getattr(state, "current_step", 0) + 1
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return {
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"messages": tool_messages,
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"current_step": current_step,
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"tool_call_history": tool_call_history,
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"tool_result_history": tool_result_history,
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"tools_used": tools_used,
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}
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