feat(phase3): Task1 embedding链路验证 - embo-01(1536维)+pgvector检索打通

This commit is contained in:
simonkoson
2026-05-26 10:33:25 +08:00
parent d40d46a434
commit 1325807257
6 changed files with 390 additions and 0 deletions
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"""
Embedding 调用服务 — 封装 MiniMax embo-01
请求格式(确认自探路脚本):
POST /v1/embeddings
Body: {"model": "embo-01", "texts": [...], "type": "db"|"query"}
响应格式:
{"vectors": [[...1536 floats...]], "total_tokens": N, "base_resp": {"status_code": 0, "status_msg": "success"}}
"""
import httpx
from typing import List
from app.core.config import settings
class EmbeddingService:
"""MiniMax embo-01 embedding 调用封装"""
def __init__(self):
self.api_key = settings.MINIMAX_EMBED_API_KEY
self.group_id = settings.MINIMAX_GROUP_ID
self.endpoint = "https://api.minimax.chat/v1/embeddings"
def embed(self, texts: List[str], embed_type: str = "db") -> List[List[float]]:
"""
调用 embo-01 将文本列表转为向量
Args:
texts: 文本列表(支持批量)
embed_type: "db" = 存入库,"query" = 查询
Returns:
List[List[float]],每个元素是一组 1536 维向量
"""
if not self.api_key or self.api_key == "your_api_key_here":
raise RuntimeError("MINIMAX_EMBED_API_KEY not configured in .env")
if not self.group_id or self.group_id == "your_group_id_here":
raise RuntimeError("MINIMAX_GROUP_ID not configured in .env")
headers = {
"Authorization": f"Bearer {self.api_key}",
"GroupId": self.group_id,
"Content-Type": "application/json",
}
payload = {
"model": "embo-01",
"texts": texts,
"type": embed_type,
}
resp = httpx.post(self.endpoint, headers=headers, json=payload, timeout=60.0)
resp.raise_for_status()
data = resp.json()
# 检查业务错误
base_resp = data.get("base_resp", {})
if base_resp.get("status_code", 0) != 0:
raise RuntimeError(f"Embedding API error: {base_resp.get('status_msg', 'unknown')}")
vectors = data.get("vectors", [])
if not vectors:
raise RuntimeError("No vectors returned from embedding API")
return vectors
def embed_single(self, text: str, embed_type: str = "db") -> List[float]:
"""单文本 embedding,返回 1536 维向量列表(Python list"""
vectors = self.embed([text], embed_type=embed_type)
return vectors[0]
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"""
知识库服务 — 写入向量 + 语义检索
使用 pgvector 原生 SQL 向量检索(<=> 余弦距离算子),不在 Python 侧计算
"""
from typing import Optional
from sqlalchemy import text
from sqlmodel import Session, select
from pgvector.sqlalchemy import Vector
from app.models.knowledge import KnowledgeItem, KnowledgeEmbedding
from app.services.embedding_service import EmbeddingService
from app.db.session import engine
class KnowledgeService:
"""知识库 CRUD + 语义检索"""
def __init__(self):
self.embedder = EmbeddingService()
def store_md_file(
self,
title: str,
content_md: str,
source_file_name: Optional[str] = None,
source_type: str = "manual",
author: Optional[str] = None,
) -> KnowledgeItem:
"""
读取一篇 md 内容,调用 embo-01 拿到向量,写入 knowledge_items + knowledge_embeddings
"""
# 调用 embeddingtype="db" 表示存入知识库)
embedding_list = self.embedder.embed_single(content_md, embed_type="db")
with Session(engine) as session:
# 写入 knowledge_items
item = KnowledgeItem(
title=title,
content_md=content_md,
source_type=source_type,
source_file_name=source_file_name,
author=author,
)
session.add(item)
session.flush() # 拿到 id
# 写入 knowledge_embeddings(单 chunkchunk_index=0
# 直接传 listpgvector.sqlalchemy.Vector 会自动处理转换
emb = KnowledgeEmbedding(
knowledge_id=item.id,
chunk_index=0,
chunk_text=content_md,
embedding=embedding_list,
)
session.add(emb)
session.commit()
session.refresh(item)
return item
def search_similar(self, query_text: str, top_k: int = 5) -> list[dict]:
"""
语义检索:查询句转为向量,用 SQL 余弦距离(<=>)在数据库层检索
返回 top_k 条相似笔记,含相似度分数
"""
# 查询向量(type="query"
query_vector = self.embedder.embed_single(query_text, embed_type="query")
# 将向量列表转为 pgvector SQL 字符串格式
vec_str = "[" + ",".join(str(v) for v in query_vector) + "]"
with Session(engine) as session:
# pgvector 原生 SQL<=> 是余弦距离,1 - 距离 = 相似度
# 用字符串插注向量,避免 psycopg2 参数化问题
sql = f"""
SELECT
ki.id,
ki.title,
ki.source_type,
1 - (ke.embedding <=> '{vec_str}'::vector) AS similarity
FROM knowledge_embeddings ke
JOIN knowledge_items ki ON ke.knowledge_id = ki.id
WHERE ke.chunk_index = 0
ORDER BY ke.embedding <=> '{vec_str}'::vector
LIMIT {top_k}
"""
stmt = text(sql)
rows = session.execute(stmt).all()
results = []
for row in rows:
results.append({
"id": row.id,
"title": row.title,
"source_type": row.source_type,
"similarity": round(row.similarity, 4),
})
return results
def get_item_count(self) -> int:
"""返回 knowledge_items 表行数"""
with Session(engine) as session:
count = session.exec(select(KnowledgeItem)).all()
return len(count)
def get_embedding_count(self) -> int:
"""返回 knowledge_embeddings 表行数"""
with Session(engine) as session:
count = session.exec(select(KnowledgeEmbedding)).all()
return len(count)