Files
SlabUploader/backend/db/__init__.py
T
Ty a0032ddd2d fix(db): schema_version drift detection + rebuild for pre-M3 volumes
- Add schema_version table; init_db detects a pre-M3/unknown DB (no version
  row, or settings table missing the value column) and rebuilds to the clean
  M3 schema, then stamps version 1
- _has_schema_version checks for a real row (empty table != versioned)
- _reset_for_tests checkpoints WAL before close (Windows handle release)
- TDD: test_schema_drift seeds the M2 settings shape, asserts rebuild + version

Fixes live 500 'no such column: value' on the UAT host (stale M2 slab_db volume).
Gates: check_requirements + check_coverage exit 0; pytest 14 passed.
2026-09-19 16:05:40 -07:00

130 lines
4.0 KiB
Python

"""S0 db factory package: stdlib sqlite3 ONLY. ... (same as before)"""
from __future__ import annotations
import os
import sqlite3
import threading
import logging
from pathlib import Path
from typing import Any
DB_PATH_ENV = "SLAB_DB_PATH"
IMAGES_DIR_ENV = "SLAB_IMAGES_DIR"
SCHEMA_FILE = "schema.sql"
_lock = threading.Lock()
_conn: sqlite3.Connection | None = None
_current_path: str | None = None
def _get_schema_path() -> Path:
# backend/db/__init__.py -> backend/db/schema.sql
return Path(__file__).parent / SCHEMA_FILE
def get_connection(db_path: str | None = None) -> sqlite3.Connection:
global _conn, _current_path
if db_path is None:
db_path = os.environ.get(DB_PATH_ENV)
if not db_path:
raise RuntimeError(f"{DB_PATH_ENV} env var is required")
db_path = str(Path(db_path).resolve())
with _lock:
if _conn is None or _current_path != db_path:
if _conn is not None:
_conn.close()
_conn = sqlite3.connect(db_path, check_same_thread=False)
_conn.row_factory = sqlite3.Row
_conn.execute("PRAGMA journal_mode=WAL")
_conn.execute("PRAGMA foreign_keys=ON")
_conn.execute("PRAGMA busy_timeout=5000")
_conn.execute("PRAGMA synchronous=NORMAL")
_current_path = db_path
return _conn
def _has_schema_version(conn: sqlite3.Connection) -> bool:
try:
return conn.execute("SELECT 1 FROM schema_version LIMIT 1").fetchone() is not None
except sqlite3.OperationalError:
return False
def _has_settings_value_column(conn: sqlite3.Connection) -> bool:
try:
info = conn.execute("PRAGMA table_info(settings)").fetchall()
columns = {row[1]: row[2] for row in info}
return 'value' in columns
except sqlite3.OperationalError:
return False
def init_db(db_path: str | None = None) -> sqlite3.Connection:
conn = get_connection(db_path)
schema_path = _get_schema_path()
if not schema_path.exists():
raise FileNotFoundError(f"Schema not found: {schema_path}")
with open(schema_path, "r", encoding="utf-8") as f:
schema = f.read()
with _lock:
conn.executescript(schema)
conn.commit()
if not _has_schema_version(conn):
if not _has_settings_value_column(conn):
logger = logging.getLogger("slab.db")
logger.info("Detected pre-M3 DB, rebuilding schema")
conn.executescript("DROP TABLE IF EXISTS settings")
conn.executescript(schema)
conn.execute("INSERT OR REPLACE INTO schema_version (version) VALUES (1)")
else:
# M3-era tables present but no version stamped; stamp it.
conn.execute("INSERT OR REPLACE INTO schema_version (version) VALUES (1)")
conn.commit()
return conn
def get_images_dir() -> Path:
img = os.environ.get(IMAGES_DIR_ENV)
if not img:
raise RuntimeError(f"{IMAGES_DIR_ENV} env var is required")
return Path(img).resolve()
def probe_writable(conn: sqlite3.Connection | None = None) -> bool:
try:
c = conn or get_connection()
c.execute("SELECT 1").fetchone()
return True
except Exception:
return False
def probe_images_writable() -> bool:
try:
img_dir = get_images_dir()
if not img_dir.exists():
img_dir.mkdir(parents=True, exist_ok=True)
probe = img_dir / ".health-probe"
probe.write_text("ok", encoding="utf-8")
probe.unlink(missing_ok=True)
return True
except Exception:
return False
def _reset_for_tests() -> None:
"""Close global conn so temp dirs can be cleaned on Windows (test only)."""
global _conn, _current_path
with _lock:
if _conn is not None:
try:
_conn.execute("PRAGMA wal_checkpoint(TRUNCATE)")
except Exception:
pass
try:
_conn.close()
except Exception:
pass
_conn = None
_current_path = None