feat(db): extract non-stateful logic to class methods

invokeai/app/services/shared/sqlite/sqlite_migrator.py

@@ -112,17 +112,6 @@ class MigrationSet:
         return sorted(self._migrations, key=lambda m: m.to_version)[-1].to_version
 
 
-def get_temp_db_path(original_db_path: Path) -> Path:
-    """Gets the path to the temp database."""
-    return original_db_path.parent / original_db_path.name.replace(".db", ".db.temp")
-
-
-def get_backup_db_path(original_db_path: Path) -> Path:
-    """Gets the path to the final backup database."""
-    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
-    return original_db_path.parent / f"{original_db_path.stem}_backup_{timestamp}.db"
-
-
 class SQLiteMigrator:
     """
     Manages migrations for a SQLite database.
@@ -161,9 +150,9 @@ class SQLiteMigrator:
         self._migration_set = MigrationSet()
 
         # The presence of an temp database file indicates a catastrophic failure of a previous migration.
-        if self._db_path and get_temp_db_path(self._db_path).is_file():
+        if self._db_path and self._get_temp_db_path(self._db_path).is_file():
             self._logger.warning("Previous migration failed! Trying again...")
-            get_temp_db_path(self._db_path).unlink()
+            self._get_temp_db_path(self._db_path).unlink()
 
     def register_migration(self, migration: Migration) -> None:
         """Registers a migration."""
@@ -200,10 +189,11 @@ class SQLiteMigrator:
                 # Close the connections, copy the original database as a backup, and move the temp database to the
                 # original database's path.
                 backup_db_path = self._finalize_migration(
-                    temp_db_conn=temp_db_conn,
                     temp_db_path=temp_db_path,
                     original_db_path=self._db_path,
                 )
+                temp_db_conn.close()
+                self._conn.close()
                 self._logger.info(f"Migration successful. Original DB backed up to {backup_db_path}")
             else:
                 # We are using a memory database. No special backup or special handling needed.
@@ -280,31 +270,46 @@ class SQLiteMigrator:
                 cursor.connection.rollback()
                 raise MigrationError(msg) from e
 
-    def _get_current_version(self, cursor: sqlite3.Cursor) -> int:
+    @classmethod
+    def _get_current_version(cls, cursor: sqlite3.Cursor) -> int:
         """Gets the current version of the database, or 0 if the migrations table does not exist."""
-        with self._lock:
+        try:
-            try:
+            cursor.execute("SELECT MAX(version) FROM migrations;")
-                cursor.execute("SELECT MAX(version) FROM migrations;")
+            version = cursor.fetchone()[0]
-                version = cursor.fetchone()[0]
+            if version is None:
-                if version is None:
+                return 0
-                    return 0
+            return version
-                return version
+        except sqlite3.OperationalError as e:
-            except sqlite3.OperationalError as e:
+            if "no such table" in str(e):
-                if "no such table" in str(e):
+                return 0
-                    return 0
+            raise
-                raise
 
-    def _create_temp_db(self, current_db_path: Path) -> Path:
+    @classmethod
+    def _create_temp_db(cls, original_db_path: Path) -> Path:
         """Copies the current database to a new file for migration."""
-        temp_db_path = get_temp_db_path(current_db_path)
+        temp_db_path = cls._get_temp_db_path(original_db_path)
-        shutil.copy2(current_db_path, temp_db_path)
+        shutil.copy2(original_db_path, temp_db_path)
         return temp_db_path
 
-    def _finalize_migration(self, temp_db_conn: sqlite3.Connection, temp_db_path: Path, original_db_path: Path) -> Path:
+    @classmethod
-        """Closes connections, renames the original database as a backup and renames the migrated database to the original name."""
+    def _finalize_migration(
-        self._conn.close()
+        cls,
-        temp_db_conn.close()
+        temp_db_path: Path,
-        backup_db_path = get_backup_db_path(original_db_path)
+        original_db_path: Path,
+    ) -> Path:
+        """Renames the original database as a backup and renames the migrated database to the original name."""
+        backup_db_path = cls._get_backup_db_path(original_db_path)
         original_db_path.rename(backup_db_path)
         temp_db_path.rename(original_db_path)
         return backup_db_path
+
+    @classmethod
+    def _get_temp_db_path(cls, original_db_path: Path) -> Path:
+        """Gets the path to the temp database."""
+        return original_db_path.parent / original_db_path.name.replace(".db", ".db.temp")
+
+    @classmethod
+    def _get_backup_db_path(cls, original_db_path: Path) -> Path:
+        """Gets the path to the final backup database."""
+        timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+        return original_db_path.parent / f"{original_db_path.stem}_backup_{timestamp}.db"