port part of settings to database (#54)

src/ahriman/core/database/operations/operations.py

@@ -0,0 +1,71 @@
+#
+# Copyright (c) 2021 ahriman team.
+#
+# This file is part of ahriman
+# (see https://github.com/arcan1s/ahriman).
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+import logging
+import sqlite3
+
+from pathlib import Path
+from sqlite3 import Connection, Cursor
+from typing import Any, Dict, Tuple, TypeVar, Callable
+
+
+T = TypeVar("T")
+
+
+class Operations:
+    """
+    base operation class
+    :ivar logger: class logger
+    :ivar path: path to the database file
+    """
+
+    def __init__(self, path: Path) -> None:
+        """
+        default constructor
+        :param path: path to the database file
+        """
+        self.path = path
+        self.logger = logging.getLogger("database")
+
+    @staticmethod
+    def factory(cursor: Cursor, row: Tuple[Any, ...]) -> Dict[str, Any]:
+        """
+        dictionary factory based on official documentation
+        :param cursor: cursor descriptor
+        :param row: fetched row
+        :return: row converted to dictionary
+        """
+        result = {}
+        for index, column in enumerate(cursor.description):
+            result[column[0]] = row[index]
+        return result
+
+    def with_connection(self, query: Callable[[Connection], T], commit: bool = False) -> T:
+        """
+        perform operation in connection
+        :param query: function to be called with connection
+        :param commit: if True commit() will be called on success
+        :return: result of the `query` call
+        """
+        with sqlite3.connect(self.path, detect_types=sqlite3.PARSE_DECLTYPES) as connection:
+            connection.row_factory = self.factory
+            result = query(connection)
+            if commit:
+                connection.commit()
+        return result