Files
Remote-Terminal-for-MeshCore/app/migrations/__init__.py
2026-04-10 16:28:03 -07:00

67 lines
2.0 KiB
Python

"""
Database migrations using SQLite's user_version pragma.
Migrations run automatically on startup. The user_version pragma tracks
which migrations have been applied (defaults to 0 for existing databases).
Each migration lives in its own file: ``_NNN_description.py``, exposing an
``async def migrate(conn)`` entry point. The runner auto-discovers files by
numeric prefix and executes them in order.
This approach is safe for existing users - their databases have user_version=0,
so all migrations run in order on first startup after upgrade.
"""
import importlib
import logging
import pkgutil
import re
import aiosqlite
logger = logging.getLogger(__name__)
async def get_version(conn: aiosqlite.Connection) -> int:
"""Get current schema version from SQLite user_version pragma."""
cursor = await conn.execute("PRAGMA user_version")
row = await cursor.fetchone()
return row[0] if row else 0
async def set_version(conn: aiosqlite.Connection, version: int) -> None:
"""Set schema version using SQLite user_version pragma."""
await conn.execute(f"PRAGMA user_version = {version}")
async def run_migrations(conn: aiosqlite.Connection) -> int:
"""
Run all pending migrations.
Returns the number of migrations applied.
"""
version = await get_version(conn)
applied = 0
for module_info in sorted(pkgutil.iter_modules(__path__), key=lambda m: m.name):
match = re.match(r"_(\d+)_", module_info.name)
if not match:
continue
num = int(match.group(1))
if num <= version:
continue
logger.info("Applying migration %d: %s", num, module_info.name)
mod = importlib.import_module(f"{__name__}.{module_info.name}")
await mod.migrate(conn)
await set_version(conn, num)
applied += 1
if applied > 0:
logger.info(
"Applied %d migration(s), schema now at version %d", applied, await get_version(conn)
)
else:
logger.debug("Schema up to date at version %d", version)
return applied