268 lines
8.3 KiB
Python
268 lines
8.3 KiB
Python
"""
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生成式大模型服务模块
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本模块提供统一的生成式大模型服务获取接口，支持多种模型：
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1. Local VLLM 服务：本地 gemma-4-E4B-it 模型
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2. Zhipu AI：智谱 glm-5.1 模型
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3. DeepSeek：deepseek-v4-pro 模型
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主要功能：
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- LocalVLLMChatProvider：本地 VLLM 服务提供者
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- ZhipuChatProvider：智谱 API 服务提供者
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- DeepSeekChatProvider：DeepSeek API 服务提供者
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- get_chat_service()：获取默认服务（带自动降级）
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- get_all_chat_services()：获取所有可用模型服务（用于多模型切换）
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"""
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import logging
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from typing import Dict, Callable
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from langchain_core.language_models import BaseChatModel
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from .base import (
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BaseServiceProvider,
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FallbackServiceChain,
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SingletonServiceManager
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)
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from app.config import (
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VLLM_BASE_URL,
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LLM_API_KEY,
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ZHIPUAI_API_KEY,
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DEEPSEEK_API_KEY
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)
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logger = logging.getLogger(__name__)
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class LocalVLLMChatProvider(BaseServiceProvider[BaseChatModel]):
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"""
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本地 VLLM 生成式大模型服务提供者
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"""
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def __init__(self, model: str = "gemma-4-E4B-it"):
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super().__init__("local_vllm_chat")
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self._model = model
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def is_available(self) -> bool:
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"""
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检查本地 VLLM 服务是否可用
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Returns:
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bool: 服务是否可用
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"""
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if not VLLM_BASE_URL:
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logger.warning("VLLM_BASE_URL 未配置")
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return False
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try:
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# 先测试主机名能否解析
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import httpx
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from urllib.parse import urlparse
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parsed_url = urlparse(VLLM_BASE_URL)
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host = parsed_url.hostname
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port = parsed_url.port or (80 if parsed_url.scheme == 'http' else 443)
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# 测试能否建立 TCP 连接（快速失败）
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import socket
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sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
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sock.settimeout(2.0)
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try:
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sock.connect((host, port))
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sock.close()
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except Exception as e:
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logger.warning(f"本地 VLLM 服务无法连接: {host}:{port} - {e}")
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return False
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# 再尝试调用简单的 API（比如 models 接口）
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client = httpx.Client(base_url=VLLM_BASE_URL.rstrip('/'), timeout=5.0)
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headers = {}
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if LLM_API_KEY:
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headers["Authorization"] = f"Bearer {LLM_API_KEY}"
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try:
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response = client.get("/v1/models", headers=headers)
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if response.status_code == 200:
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logger.info(f"本地 VLLM 服务可用: {self._model}")
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return True
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except Exception:
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pass
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# 如果 /v1/models 失败，也认为服务不可用
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logger.warning(f"本地 VLLM 服务响应异常")
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return False
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except Exception as e:
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logger.warning(f"本地 VLLM 服务不可用: {e}")
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return False
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def get_service(self) -> BaseChatModel:
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"""
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获取本地 VLLM 服务
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Returns:
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BaseChatModel: LangChain 兼容的 ChatModel 实例
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"""
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if self._service_instance is None:
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from langchain_openai import ChatOpenAI
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from pydantic import SecretStr
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self._service_instance = ChatOpenAI(
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base_url=VLLM_BASE_URL,
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api_key=SecretStr(LLM_API_KEY) if LLM_API_KEY else SecretStr(""),
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model=self._model,
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timeout=60.0,
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max_retries=2,
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streaming=True,
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)
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return self._service_instance
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class ZhipuChatProvider(BaseServiceProvider[BaseChatModel]):
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"""
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智谱 AI 生成式大模型服务提供者
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"""
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def __init__(self, model: str = "glm-5.1"):
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super().__init__("zhipu_chat")
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self._model = model
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def is_available(self) -> bool:
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"""
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检查智谱 AI 服务是否可用
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Returns:
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bool: 服务是否可用
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"""
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if not ZHIPUAI_API_KEY:
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logger.warning("ZHIPUAI_API_KEY 未配置")
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return False
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try:
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logger.info(f"智谱 AI 服务配置正确，准备使用: {self._model}")
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return True
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except Exception as e:
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logger.warning(f"智谱 AI 服务不可用: {e}")
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return False
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def get_service(self) -> BaseChatModel:
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"""
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获取智谱 AI 服务
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Returns:
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BaseChatModel: LangChain 兼容的 ChatModel 实例
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"""
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if self._service_instance is None:
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from langchain_community.chat_models import ChatZhipuAI
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self._service_instance = ChatZhipuAI(
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model=self._model,
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api_key=ZHIPUAI_API_KEY,
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temperature=0.1,
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max_tokens=4096,
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timeout=120.0,
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max_retries=3,
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streaming=True,
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)
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return self._service_instance
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class DeepSeekChatProvider(BaseServiceProvider[BaseChatModel]):
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"""
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DeepSeek 生成式大模型服务提供者
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"""
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def __init__(self, model: str = "deepseek-v4-pro"):
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super().__init__("deepseek_chat")
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self._model = model
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def is_available(self) -> bool:
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"""
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检查 DeepSeek 服务是否可用
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Returns:
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bool: 服务是否可用
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"""
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if not DEEPSEEK_API_KEY:
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logger.warning("DEEPSEEK_API_KEY 未配置")
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return False
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try:
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logger.info(f"DeepSeek 服务配置正确，准备使用: {self._model}")
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return True
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except Exception as e:
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logger.warning(f"DeepSeek 服务不可用: {e}")
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return False
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def get_service(self) -> BaseChatModel:
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"""
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获取 DeepSeek 服务
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Returns:
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BaseChatModel: LangChain 兼容的 ChatModel 实例
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"""
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if self._service_instance is None:
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from langchain_openai import ChatOpenAI
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from pydantic import SecretStr
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self._service_instance = ChatOpenAI(
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base_url="https://api.deepseek.com",
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api_key=SecretStr(DEEPSEEK_API_KEY),
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model=self._model,
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temperature=0.1,
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max_tokens=4096,
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timeout=60.0,
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max_retries=2,
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streaming=True,
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)
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return self._service_instance
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# 全局服务映射表 - 名称 -> Provider
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CHAT_PROVIDERS: Dict[str, Callable[[], BaseServiceProvider[BaseChatModel]]] = {
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"local": lambda: LocalVLLMChatProvider(),
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"zhipu": lambda: ZhipuChatProvider(),
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"deepseek": lambda: DeepSeekChatProvider(),
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}
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def get_chat_service() -> BaseChatModel:
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"""
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获取默认的生成式大模型服务（带自动降级）
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优先顺序: local -> zhipu -> deepseek
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Returns:
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BaseChatModel: LangChain 兼容的 ChatModel 实例
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"""
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def _create_chain():
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primary = LocalVLLMChatProvider()
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fallbacks = [ZhipuChatProvider(), DeepSeekChatProvider()]
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return FallbackServiceChain(primary, fallbacks)
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chain = SingletonServiceManager.get_or_create("chat_service_chain", _create_chain)
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return chain.get_available_service()
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def get_all_chat_services() -> Dict[str, BaseChatModel]:
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"""
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获取所有可用的生成式大模型服务（用于多模型切换）
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Returns:
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Dict[str, BaseChatModel]: 模型名称 -> ChatModel 实例 的字典
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"""
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services = {}
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for name, provider_factory in CHAT_PROVIDERS.items():
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try:
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provider = provider_factory()
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if provider.is_available():
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logger.info(f"模型 '{name}' 可用")
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services[name] = provider.get_service()
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else:
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logger.warning(f"模型 '{name}' 不可用，跳过")
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except Exception as e:
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logger.warning(f"初始化模型 '{name}' 失败: {e}")
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if not services:
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raise RuntimeError(f"没有可用的生成式大模型，尝试了: {list(CHAT_PROVIDERS.keys())}")
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return services
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