jerryandClaude Fable 5
1e94de7464
- BFF 薄适配层（FastAPI，8090）：QA 代理/SSE 中继/Neo4j 直连/抽取代理/会话持久化 - Vue3 前端：五相位检索流水线、文献来源与证据链、知识图谱、提取任务四 tab - 四档响应式（桌面/笔记本/平板/手机）、深浅主题 - 81 个 FR 全部实现，测试追溯矩阵 81/81，后端 121 测/前端 156 测 - 真实凭据已脱敏，运行时配置在 backend/.env（不入 git） Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
164 lines
5.0 KiB
Python
164 lines
5.0 KiB
Python
"""db.py —— SQLite 持久层（aiosqlite + WAL，无 ORM）。
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Schema 与 API.md §5 对齐：
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- sessions: id / title / status / meta / created_at / updated_at
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- messages: id / session_id(FK CASCADE) / role / kind / status / blocks(JSON)
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/ raw(JSON) / text / created_at / updated_at
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启动时幂等迁移（CREATE TABLE IF NOT EXISTS）。时间一律 ISO 8601 UTC
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（`2026-08-25T12:34:56Z`），由 BFF 侧统一生成（SQLite 不写 DEFAULT 时间戳）。
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"""
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from __future__ import annotations
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import asyncio
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import json
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import time
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from collections.abc import AsyncIterator, Iterable
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from datetime import datetime, timezone
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from pathlib import Path
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from typing import Any
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import aiosqlite
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from .config import get_settings
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_SCHEMA = """
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CREATE TABLE IF NOT EXISTS sessions (
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id TEXT PRIMARY KEY,
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title TEXT NOT NULL DEFAULT '新会话',
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status TEXT NOT NULL DEFAULT 'idle',
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meta TEXT NOT NULL DEFAULT '{}',
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created_at TEXT NOT NULL,
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updated_at TEXT NOT NULL
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);
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CREATE TABLE IF NOT EXISTS messages (
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id TEXT PRIMARY KEY,
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session_id TEXT NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
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role TEXT NOT NULL,
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kind TEXT NOT NULL DEFAULT 'qa',
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status TEXT NOT NULL DEFAULT 'done',
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blocks TEXT NOT NULL DEFAULT '[]',
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raw TEXT,
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text TEXT,
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created_at TEXT NOT NULL,
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updated_at TEXT NOT NULL
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);
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CREATE INDEX IF NOT EXISTS idx_messages_session ON messages(session_id);
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CREATE INDEX IF NOT EXISTS idx_sessions_updated ON sessions(updated_at);
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"""
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def _now_iso() -> str:
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return datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%SZ")
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def _db_path() -> Path:
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path = Path(get_settings().db_path)
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path.parent.mkdir(parents=True, exist_ok=True)
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return path
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class Database:
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"""aiosqlite 单连接封装。
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SQLite 写并发不高，BFF 用单写连接（WAL 模式下读写不互斥）；
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依赖注入经 get_db() 提供本实例。
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"""
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def __init__(self, path: str | Path | None = None) -> None:
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self._path: Path | None = Path(path) if path is not None else None
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self._conn: aiosqlite.Connection | None = None
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self._lock = asyncio.Lock()
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@property
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def path(self) -> Path:
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if self._path is None:
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self._path = _db_path()
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return self._path
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async def connect(self) -> None:
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self.path.parent.mkdir(parents=True, exist_ok=True)
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self._conn = await aiosqlite.connect(self.path)
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self._conn.row_factory = aiosqlite.Row
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await self._conn.execute("PRAGMA journal_mode=WAL")
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await self._conn.execute("PRAGMA foreign_keys=ON")
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await self._conn.execute("PRAGMA busy_timeout=5000")
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await self._conn.executescript(_SCHEMA)
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await self._conn.commit()
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async def close(self) -> None:
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if self._conn is not None:
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await self._conn.close()
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self._conn = None
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@property
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def conn(self) -> aiosqlite.Connection:
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if self._conn is None:
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raise RuntimeError("Database 未初始化：先 await init_db()")
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return self._conn
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# ---- 通用查询（只读）----
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async def fetchall(self, sql: str, params: Iterable[Any] = ()) -> list[aiosqlite.Row]:
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async with self._conn.execute(sql, tuple(params)) as cursor:
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return list(await cursor.fetchall())
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async def fetchone(self, sql: str, params: Iterable[Any] = ()) -> aiosqlite.Row | None:
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async with self._conn.execute(sql, tuple(params)) as cursor:
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return await cursor.fetchone()
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# ---- 写操作（串行化，提交后返回 lastrowid）----
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async def execute(self, sql: str, params: Iterable[Any] = ()) -> int:
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async with self._lock:
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cur = await self._conn.execute(sql, tuple(params))
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await self._conn.commit()
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return cur.lastrowid
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db = Database()
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async def init_db(path: str | Path | None = None) -> Database:
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"""app 启动钩子：创建并迁移数据库（幂等）。返回全局单例（或指定路径的实例）。"""
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global db
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if path is not None:
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db = Database(path)
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await db.connect()
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return db
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async def get_db() -> AsyncIterator[Database]:
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"""FastAPI 依赖：每个请求交出同一数据库实例。"""
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yield db
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async def close_db() -> None:
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"""app shutdown 钩子。"""
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await db.close()
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# ---- JSON 编解码（落库用；失败时按契约置 null/[] 而不吞请求）----
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def dumps_json(value: Any, default: Any = None) -> str:
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try:
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return json.dumps(value, ensure_ascii=False)
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except (TypeError, ValueError):
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return json.dumps(default, ensure_ascii=False)
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def loads_json(text: str | None, default: Any = None) -> Any:
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if text is None:
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return default
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try:
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return json.loads(text)
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except (TypeError, ValueError):
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return default
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def monotonic() -> float:
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"""测试/内部计时用（time.monotonic 别名，避免各处直接 import time）。"""
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return time.monotonic()
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