backends: Introduce a Backend base class

diff --git a/tasklib/backends.py b/tasklib/backends.py
new file mode 100644 (file)
index 0000000..1bebafd
--- /dev/null
+++ b/tasklib/backends.py
@@ -0,0 +1,29 @@
+import abc
+
+class Backend(object):
+
+    @abc.abstractmethod
+    def filter_tasks(self, filter_obj):
+        """Returns a list of Task objects matching the given filter"""
+        pass
+
+    @abc.abstractmethod
+    def save_task(self, task):
+        pass
+
+    @abc.abstractmethod
+    def delete_task(self, task):
+        pass
+
+    @abc.abstractmethod
+    def start_task(self, task):
+        pass
+
+    @abc.abstractmethod
+    def stop_task(self, task):
+        pass
+
+    @abc.abstractmethod
+    def sync(self):
+        """Syncs the backend database with the taskd server"""
+        pass