rtc-voice-chat/backend/services/rag_service.py

118 lines
4.0 KiB
Python

from __future__ import annotations
import json
from pathlib import Path
import httpx
from security.signer import Signer
from utils.env import env_bool, env_int, env_str
_KB_API_PATH = "/api/knowledge/collection/search_knowledge"
_KB_SERVICE = "air"
_KB_REGION = "cn-beijing"
def _build_rag_context(result_list: list, with_attachment: bool) -> str:
parts = []
for i, chunk in enumerate(result_list, start=1):
title = chunk.get("chunk_title") or ""
content = chunk.get("content") or ""
header = f"[{i}] {title}" if title else f"[{i}]"
block = f"{header}\n{content}"
if with_attachment:
attachments = chunk.get("chunk_attachment") or []
image_links = [a["link"] for a in attachments if a.get("link")]
if image_links:
block += "\n" + "\n".join(f"![图片]({link})" for link in image_links)
parts.append(block)
return "\n\n".join(parts)
async def _retrieve_from_kb(query: str) -> str:
access_key = env_str("CUSTOM_ACCESS_KEY_ID")
secret_key = env_str("CUSTOM_SECRET_KEY")
if not access_key or not secret_key:
print("⚠️ RAG: CUSTOM_ACCESS_KEY_ID / CUSTOM_SECRET_KEY 未配置,跳过知识库检索")
return ""
endpoint = env_str("VOLC_KB_ENDPOINT", "https://api-knowledgebase.mlp.cn-beijing.volces.com")
top_k = env_int("VOLC_KB_TOP_K", 5)
rerank = env_bool("VOLC_KB_RERANK", False)
attachment_link = env_bool("VOLC_KB_ATTACHMENT_LINK", False)
body: dict = {"query": query, "limit": top_k}
kb_name = env_str("VOLC_KB_NAME")
kb_resource_id = env_str("VOLC_KB_RESOURCE_ID")
kb_project = env_str("VOLC_KB_PROJECT", "default")
if kb_resource_id:
body["resource_id"] = kb_resource_id
elif kb_name:
body["name"] = kb_name
body["project"] = kb_project
else:
print("⚠️ RAG: VOLC_KB_NAME 或 VOLC_KB_RESOURCE_ID 未配置,跳过知识库检索")
return ""
post_processing: dict = {}
if rerank:
post_processing["rerank_switch"] = True
if attachment_link:
post_processing["get_attachment_link"] = True
if post_processing:
body["post_processing"] = post_processing
headers = {"Content-Type": "application/json"}
signer = Signer(
request_data={
"region": _KB_REGION,
"method": "POST",
"path": _KB_API_PATH,
"headers": headers,
"body": body,
},
service=_KB_SERVICE,
)
signer.add_authorization({"accessKeyId": access_key, "secretKey": secret_key})
# 签名与发送必须用完全相同的序列化(紧凑无空格)
body_bytes = json.dumps(body, separators=(",", ":"), ensure_ascii=False).encode("utf-8")
url = endpoint.rstrip("/") + _KB_API_PATH
async with httpx.AsyncClient(timeout=30) as client:
resp = await client.post(url, headers=headers, content=body_bytes)
resp_data = resp.json()
if resp_data.get("code") != 0:
print(f"⚠️ RAG: 知识库检索失败 code={resp_data.get('code')} message={resp_data.get('message')}")
return ""
result_list = resp_data.get("data", {}).get("result_list", [])
print(f"✅ RAG: 检索到 {len(result_list)} 条知识片段")
return _build_rag_context(result_list, with_attachment=attachment_link)
class RagService:
async def retrieve(self, query: str) -> str:
if env_bool("VOLC_KB_ENABLED", False):
try:
return await _retrieve_from_kb(query)
except Exception as exc:
print(f"⚠️ RAG: 知识库检索异常,已降级: {exc}")
return ""
# 旧逻辑:静态上下文
context_file = env_str("RAG_CONTEXT_FILE")
if context_file:
path = Path(context_file).expanduser()
if path.exists() and path.is_file():
return path.read_text(encoding="utf-8")
return env_str("RAG_STATIC_CONTEXT") or ""
rag_service = RagService()