Files
my-v0-server/app/services/agent.py
T
2026-09-29 16:41:52 +08:00

136 lines
5.4 KiB
Python

"""异步执行与恢复大屏任务,当前使用单进程内存检查点"""
from contextlib import aclosing
from uuid import uuid4
from langgraph.types import Command
from loguru import logger
from app.core.exceptions import BizException
from app.observability.tracing import astream_screen
from app.schemas.agent import AgentResult, ResumeRequest
from app.schemas.request import DesignRequest
class AgentService:
def __init__(self, graph):
self.graph = graph
self._active: set[str] = set()
def _prepare_run(self, request: DesignRequest):
# 新请求始终独立建任务,不用 conversation_id 充当检查点 ID
thread_id = str(uuid4())
# 暂无会话创建接口,未传会话 ID 时先分配标识,不创建数据库记录
conversation_id = request.context.conversation_id or str(uuid4())
payload = request.model_dump(mode="json")
payload["context"]["conversation_id"] = conversation_id
return (
thread_id,
{
"request": payload,
"conversation_id": conversation_id,
"thread_id": thread_id,
"message_id": str(uuid4()),
},
conversation_id,
)
def stream_run(self, request: DesignRequest):
execution = self._prepare_run(request)
self._claim(execution[0])
return execution
async def prepare_resume(self, request: ResumeRequest):
# 在发送流响应头之前完成校验并占用任务
thread_id = str(request.thread_id)
# 检查和占用之间没有 await,同一事件循环内不会重复进入
self._claim(thread_id)
try:
snapshot = await self.graph.aget_state(
{"configurable": {"thread_id": thread_id}}
)
if not snapshot.values:
raise BizException(404, "任务不存在或已过期")
if not any(task.interrupts for task in snapshot.tasks):
raise BizException(409, "任务当前未等待用户补充")
# 恢复前校验选项,避免无效回答消耗一次 interrupt 恢复
clarification = snapshot.values["clarification"]
reply = request.reply
if (
not reply.cancel
and reply.option_id is not None
and reply.option_id not in {item.id for item in clarification.options}
):
raise BizException(422, "请选择当前问题的有效选项")
conversation_id = snapshot.values["conversation_id"]
# 恢复同一任务不能切换会话,补充编辑上下文时也保留原会话标识
if reply.context is not None:
if reply.context.conversation_id not in (None, conversation_id):
raise BizException(422, "恢复任务时不能切换会话")
reply = reply.model_copy(
update={
"context": reply.context.model_copy(
update={"conversation_id": conversation_id}
)
}
)
# 每次有效补充或取消生成新的输入 ID,任务和会话保持不变
return (
thread_id,
Command(
resume=reply.model_dump(mode="json"),
update={"message_id": str(uuid4())},
),
conversation_id,
)
except BaseException:
self.release(thread_id)
raise
def release(self, thread_id):
self._active.discard(thread_id)
def _claim(self, thread_id: str) -> None:
if thread_id in self._active:
raise BizException(409, "任务正在执行,请勿重复提交")
self._active.add(thread_id)
@staticmethod
def _result(state, thread_id):
waiting = bool(state.get("__interrupt__"))
# 只交付校验通过的完整动作批次,失败草稿留在后端
return AgentResult(
conversation_id=state["conversation_id"],
thread_id=thread_id,
message_id=state["message_id"],
status="waiting_for_input" if waiting else state["status"],
actions=state.get("actions") or []
if state.get("validation_passed") is True and state["status"] == "completed"
else [],
answer=state.get("answer"),
clarification=state.get("clarification") if waiting else None,
failure_reason=state.get("failure_reason"),
)
async def stream(self, thread_id, payload, session_id):
"""消费图事件,完整状态只用于整理最终结果,不直接暴露给客户端"""
state = None
with logger.contextualize(thread_id=thread_id):
async with aclosing(
astream_screen(
self.graph, payload, thread_id=thread_id, session_id=session_id
)
) as events:
async for mode, data in events:
if mode == "values":
state = data
elif data.get("type") == "node_progress" and data.get("label"):
yield "progress", data
if state is None:
raise RuntimeError("图未返回状态")
yield "final", self._result(state, thread_id).model_dump(mode="json")