prepare for multiple apps

apps/weblibre/lib/data/database/extensions/database_table_size.dart

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2024-2026 Fabian Freund.
+ *
+ * This file is part of WebLibre
+ * (see https://weblibre.eu).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+import 'package:drift/drift.dart';
+
+extension TableSize on DatabaseConnectionUser {
+  SingleSelectable<double> tableSize(TableInfo table) {
+    return customSelect(
+      'SELECT SUM(pgsize) /(1024.0 * 1024.0)AS pgsize_mb FROM dbstat WHERE name = ?1',
+      variables: [Variable<String>(table.actualTableName)],
+      readsFrom: {table},
+    ).map((QueryRow row) => row.read<double>('pgsize_mb'));
+  }
+}