109 lines
3.2 KiB
Python
109 lines
3.2 KiB
Python
"""
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POST /api/chat_callback — 自定义 LLM 回调（SSE 流式响应）
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"""
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import json
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from fastapi import APIRouter, Request
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from fastapi.responses import StreamingResponse
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from services.local_llm_service import local_llm_service
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from services.scene_service import ensure_custom_llm_authorized, get_custom_llm_callback_settings
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from utils.responses import custom_llm_error_response
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router = APIRouter()
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@router.post("/api/chat_callback")
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async def chat_callback(request: Request):
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try:
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settings = get_custom_llm_callback_settings()
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ensure_custom_llm_authorized(request, settings["api_key"])
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payload = await request.json()
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except PermissionError as exc:
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return custom_llm_error_response(
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str(exc),
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code="AuthenticationError",
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status_code=401,
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)
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except json.JSONDecodeError:
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return custom_llm_error_response(
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"请求体必须是合法的 JSON",
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code="BadRequest",
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status_code=400,
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)
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except ValueError as exc:
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return custom_llm_error_response(str(exc))
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except Exception as exc:
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return custom_llm_error_response(
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f"解析请求失败: {exc}",
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code="InternalError",
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status_code=500,
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)
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messages = payload.get("messages")
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if not isinstance(messages, list) or not messages:
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return custom_llm_error_response(
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"messages 不能为空",
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code="BadRequest",
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status_code=400,
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)
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last_message = messages[-1]
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if last_message.get("role") != "user":
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return custom_llm_error_response(
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"最后一条消息必须是用户消息",
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code="BadRequest",
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status_code=400,
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)
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try:
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stream_iterator = local_llm_service.chat_stream(
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history_messages=messages,
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request_options={
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"temperature": payload.get("temperature"),
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"max_tokens": payload.get("max_tokens"),
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"top_p": payload.get("top_p"),
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},
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)
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except Exception as exc:
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return custom_llm_error_response(
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f"初始化本地 LLM 流式调用失败: {exc}",
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code="InternalError",
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status_code=500,
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)
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def generate_sse():
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has_error = False
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try:
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for chunk in stream_iterator:
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if chunk is None:
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continue
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if hasattr(chunk, "model_dump_json"):
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chunk_json = chunk.model_dump_json()
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else:
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chunk_json = json.dumps(chunk, ensure_ascii=False)
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yield f"data: {chunk_json}\n\n"
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except GeneratorExit:
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raise
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except Exception as exc:
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has_error = True
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print(f"❌ /api/chat_callback 流式输出失败: {exc}")
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if has_error:
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print("⚠️ 已提前结束当前 SSE 流")
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yield "data: [DONE]\n\n"
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return StreamingResponse(
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generate_sse(),
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status_code=200,
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media_type="text/event-stream",
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headers={
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"Cache-Control": "no-cache",
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"Connection": "keep-alive",
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"Access-Control-Allow-Origin": "*",
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},
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)
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