add abstract classes for db readers/writers

1 files changed, 25 insertions, 0 deletions

diff --git a/vk/tracking/db/meta.py b/vk/tracking/db/meta.py
new file mode 100644
index 0000000..024d9d8
--- /dev/null
+++ b/vk/tracking/db/meta.py
@@ -0,0 +1,25 @@
+# Copyright (c) 2017 Egor Tensin <Egor.Tensin@gmail.com>
+# This file is part of the "VK scripts" project.
+# For details, see https://github.com/egor-tensin/vk-scripts.
+# Distributed under the MIT License.
+
+import abc
+from collections.abc import Iterable
+
+class Writer(metaclass=abc.ABCMeta):
+    @abc.abstractmethod
+    def on_initial_status(self, user):
+        pass
+
+    @abc.abstractmethod
+    def on_status_update(self, user):
+        pass
+
+    @abc.abstractmethod
+    def on_connection_error(self, e):
+        pass
+
+class Reader(Iterable, metaclass=abc.ABCMeta):
+    @abc.abstractmethod
+    def __iter__(self):
+        pass