长期记忆
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构建并部署 AI Agent 服务 / deploy (push) Successful in 33s

This commit is contained in:
2026-04-14 20:39:58 +08:00
parent 8dd94c6c19
commit de68916c5a
2 changed files with 130 additions and 54 deletions

View File

@@ -91,13 +91,6 @@ class AIAgentService:
try:
info(f"🔄 正在初始化模型 '{model_name}'...")
llm = llm_creator()
# 测试 LLM 连接(可选,用于调试)
if model_name == "local":
debug(f" 测试 vLLM 连接: {os.getenv('VLLM_BASE_URL', '未设置')}")
elif model_name == "deepseek":
debug(f" 测试 DeepSeek API 连接: https://api.deepseek.com")
builder = GraphBuilder(llm, AVAILABLE_TOOLS, TOOLS_BY_NAME).build()
graph = builder.compile(checkpointer=self.checkpointer, store=self.store)
self.graphs[model_name] = graph

View File

@@ -5,21 +5,27 @@ LangGraph 状态图构建模块 - 完全面向对象风格,无嵌套函数
import operator
import asyncio
import time
import os
from typing import Literal, Annotated, Any
from langchain_core.language_models import BaseLLM
from langchain_core.messages import AnyMessage, AIMessage, ToolMessage, SystemMessage
from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
from langchain_core.runnables import RunnableLambda
from langgraph.graph import StateGraph, START, END
from typing_extensions import TypedDict
from langgraph.store.postgres.aio import AsyncPostgresStore
from langgraph.runtime import Runtime
from dataclasses import dataclass
import uuid
from langchain_core.prompt_values import ChatPromptValue
# 本地模块
from app.logger import debug, info, warning, error
# 是否启用 Graph 流转追踪(通过环境变量控制)
ENABLE_GRAPH_TRACE = os.getenv("ENABLE_GRAPH_TRACE", "true").lower() == "true"
class MessagesState(TypedDict):
"""对话状态类型定义"""
messages: Annotated[list[AnyMessage], operator.add]
@@ -33,6 +39,53 @@ class GraphContext:
user_id: str
# 可扩展更多上下文信息
def _log_state_change(node_name: str, state: MessagesState, prefix: str = "进入"):
"""
通用辅助函数:打印节点状态变化
Args:
node_name: 节点名称
state: 当前状态
prefix: 前缀("进入""离开"
"""
if not ENABLE_GRAPH_TRACE:
return
messages = state.get("messages", [])
msg_count = len(messages)
last_msg = messages[-1] if messages else None
last_info = ""
if last_msg:
content_preview = str(last_msg.content)[:100].replace("\n", " ")
last_info = f"{last_msg.type.upper()}: {content_preview}"
info(f"🔄 [{node_name}] {prefix} | 消息数:{msg_count} | 最后一条:{last_info}")
def _print_llm_input(prompt_value: ChatPromptValue) -> ChatPromptValue:
"""
RunnableLambda 回调函数:打印格式化后发送给 LLM 的完整消息
Args:
prompt_value: ChatPromptValue 对象,包含格式化后的消息列表
Returns:
原样返回 prompt_value不影响链式调用
"""
if not ENABLE_GRAPH_TRACE:
return prompt_value
messages = prompt_value.messages # ChatPromptValue 提供 .messages 属性
debug("\n" + "=" * 80)
debug("📤 [LLM输入] 格式化后发送给大模型的完整消息:")
debug(f" 总消息数: {len(messages)}")
debug("-" * 80)
for i, msg in enumerate(messages):
content_preview = str(msg.content) # 完整输出
debug(f" [{i}] {msg.type.upper():10s}: {content_preview}")
debug( "\n"+"=" * 80 + "\n")
return prompt_value
class GraphBuilder:
"""LangGraph 状态图构建器 - 所有节点均为类方法"""
@@ -50,13 +103,16 @@ class GraphBuilder:
self.tools_by_name = tools_by_name
self._llm_with_tools = llm.bind_tools(tools)
self._prompt = self._create_prompt()
self._chain = self._prompt | self._llm_with_tools
self._chain = (
self._prompt
| RunnableLambda(_print_llm_input)
| self._llm_with_tools
)
@staticmethod
def _create_prompt() -> ChatPromptTemplate:
"""创建系统提示模板(静态方法,无需访问实例)"""
return ChatPromptTemplate.from_messages([
SystemMessage(content=(
system_template = (
"你是一个个人生活助手和数据分析助手,请使用中文交流。\n\n"
"【用户背景信息】\n"
"以下是对当前用户的已知信息和长期记忆,你必须优先采纳并在回答中体现:\n"
@@ -73,7 +129,9 @@ class GraphBuilder:
"1. 回答必须简洁、直接,禁止描述任何思考过程或内心活动。\n"
"2. 优先利用已知用户信息进行个性化回复。\n"
"3. 若无信息可依,礼貌询问或提供通用帮助。"
)),
)
return ChatPromptTemplate.from_messages([
("system", system_template),
MessagesPlaceholder(variable_name="messages")
])
@@ -82,26 +140,9 @@ class GraphBuilder:
LLM 调用节点(异步方法)
注意:因为 self._chain.invoke 是同步方法,使用 run_in_executor 避免阻塞事件循环
"""
_log_state_change("llm_call", state, "进入")
memory_context = state.get("memory_context", "暂无用户信息")
# 构建完整的输入消息列表(用于调试打印)
system_prompt = self._prompt.messages[0] # SystemMessage
if isinstance(system_prompt, SystemMessage):
system_content = system_prompt.content.format(memory_context=memory_context)
else:
system_content = str(system_prompt.content)
input_messages = [SystemMessage(content=system_content)] + state["messages"]
# 打印发送给大模型的最终输入
debug("\n" + "="*80)
debug("📤 [LLM输入] 发送给大模型的完整消息:")
debug(f" 总消息数: {len(input_messages)}")
for i, msg in enumerate(input_messages):
content_preview = str(msg.content) # 不截断,完整输出
debug(f" [{i}] {msg.type.upper():10s}: {content_preview}")
debug("="*80 + "\n")
loop = asyncio.get_event_loop()
start_time = time.time()
@@ -155,13 +196,16 @@ class GraphBuilder:
debug(f"{response.content}")
debug("="*80 + "\n")
return {
result = {
"messages": [response],
"llm_calls": state.get('llm_calls', 0) + 1,
"last_token_usage": token_usage,
"last_elapsed_time": elapsed_time
}
_log_state_change("llm_call", {**state, **result}, "离开")
return result
except Exception as e:
elapsed_time = time.time() - start_time
error(f"\n❌ [LLM错误] 调用失败 (耗时: {elapsed_time:.2f}秒)")
@@ -175,33 +219,45 @@ class GraphBuilder:
error_response = AIMessage(
content="抱歉,模型暂时无法响应,可能是网络超时或服务繁忙,请稍后再试。"
)
return {
error_result = {
"messages": [error_response],
"llm_calls": state.get('llm_calls', 0),
"last_token_usage": {},
"last_elapsed_time": elapsed_time
}
_log_state_change("llm_call", state, "离开(异常)")
return error_result
async def call_tools(self, state: MessagesState, runtime: Runtime[GraphContext]) -> dict:
"""
工具执行节点(异步方法)
对于每个工具调用,在线程池中执行同步工具函数
"""
_log_state_change("tool_node", state, "进入")
last_message = state['messages'][-1]
if not isinstance(last_message, AIMessage) or not last_message.tool_calls:
_log_state_change("tool_node", state, "离开(无工具调用)")
return {"messages": []}
results = []
loop = asyncio.get_event_loop()
info(f"🛠️ [工具调用] 准备执行 {len(last_message.tool_calls)} 个工具")
for tool_call in last_message.tool_calls:
tool_name = tool_call["name"]
tool_args = tool_call["args"]
tool_id = tool_call["id"]
tool_func = self.tools_by_name.get(tool_name)
debug(f" ├─ 调用工具: {tool_name} 参数: {tool_args}")
if tool_func is None:
results.append(ToolMessage(content=f"Tool {tool_name} not found", tool_call_id=tool_id))
err_msg = f"Tool {tool_name} not found"
debug(f" └─ ❌ {err_msg}")
results.append(ToolMessage(content=err_msg, tool_call_id=tool_id))
continue
try:
@@ -214,11 +270,20 @@ class GraphBuilder:
None,
lambda args=tool_args: tool_func.invoke(args) # 默认参数捕获当前值
)
# 字符打印
result_preview = str(observation).replace("\n", " ")
debug(f" └─ ✅ 结果: {result_preview}")
results.append(ToolMessage(content=str(observation), tool_call_id=tool_id))
except Exception as e:
debug(f" └─ ❌ 异常: {e}")
results.append(ToolMessage(content=f"Error: {e}", tool_call_id=tool_id))
return {"messages": results}
info(f"🛠️ [工具调用] 执行完成,返回 {len(results)} 条 ToolMessage")
result = {"messages": results}
_log_state_change("tool_node", {**state, **result}, "离开")
return result
@staticmethod
def should_continue(state: MessagesState) -> Literal['tool_node', 'save_memory', 'END']:
@@ -227,18 +292,26 @@ class GraphBuilder:
# 1. 如果需要调用工具,优先进入工具节点
if isinstance(last_message, AIMessage) and last_message.tool_calls:
if ENABLE_GRAPH_TRACE:
info(f"🔀 [路由决策] 检测到 {len(last_message.tool_calls)} 个工具调用 → 转向 'tool_node'")
return 'tool_node'
# 2. 如果是 AI 的最终回复,可以考虑进入记忆保存节点(可增加判断逻辑)
# 这里简单处理:只要没有工具调用,且是 AI 消息,就尝试保存记忆。
if isinstance(last_message, AIMessage):
if ENABLE_GRAPH_TRACE:
info(f"🔀 [路由决策] 收到 AI 最终回复(无工具调用) → 转向 'save_memory'")
return 'save_memory'
# 3. 其他情况(如只有用户消息)直接结束
if ENABLE_GRAPH_TRACE:
info(f"🔀 [路由决策] 非 AI 消息(如纯用户消息) → 结束流程")
return 'END'
async def retrieve_memory(self, state: MessagesState, runtime: Runtime[GraphContext]) -> dict:
"""搜索并返回长期记忆"""
_log_state_change("retrieve_memory", state, "进入")
user_id = runtime.context.user_id
namespace = ("memories", user_id)
query = str(state["messages"][-1].content)
@@ -260,24 +333,33 @@ class GraphBuilder:
for i, memory in enumerate(memories, 1):
debug(f" [{i}] {memory.value['data']}")
debug(f"{'='*60}\n")
return {"memory_context": memory_text}
result = {"memory_context": memory_text}
_log_state_change("retrieve_memory", {**state, **result}, "离开")
return result
else:
debug(f"⚠️ [记忆检索] 未找到相关记忆")
debug(f"{'='*60}\n")
return {"memory_context": ""}
result = {"memory_context": ""}
_log_state_change("retrieve_memory", {**state, **result}, "离开")
return result
except Exception as e:
error(f"❌ [记忆检索] 检索失败: {e}")
import traceback
traceback.print_exc()
debug(f"{'='*60}\n")
return {"memory_context": ""}
result = {"memory_context": ""}
_log_state_change("retrieve_memory", {**state, **result}, "离开(异常)")
return result
async def save_memory(self, state: MessagesState, runtime: Runtime[GraphContext]) -> dict:
"""尝试从对话中提取并保存长期记忆"""
_log_state_change("save_memory", state, "进入")
# 获取最后一条用户消息(通常是要记住的内容的来源)
user_messages = [msg for msg in state["messages"] if msg.type == "human"]
if not user_messages:
_log_state_change("save_memory", state, "离开(无用户消息)")
return {}
last_user_msg = user_messages[-1].content.lower()
@@ -291,6 +373,7 @@ class GraphBuilder:
await runtime.store.aput(namespace, str(uuid.uuid4()), {"data": memory_content})
info(f"✅ 长期记忆已保存:{memory_content}")
_log_state_change("save_memory", state, "离开")
return {}
def build(self) -> StateGraph: