Policy Module first commit

[osm/MON.git] / policy_module / osm_policy_module / core / singleton.py

diff --git a/policy_module/osm_policy_module/core/singleton.py b/policy_module/osm_policy_module/core/singleton.py
new file mode 100644 (file)
index 0000000..12cd5a9
--- /dev/null
+++ b/policy_module/osm_policy_module/core/singleton.py
@@ -0,0 +1,19 @@
+"""Simple singleton class."""
+
+from __future__ import unicode_literals
+
+
+class Singleton(object):
+    """Simple singleton class."""
+
+    def __init__(self, decorated):
+        """Initialize singleton instance."""
+        self._decorated = decorated
+
+    def instance(self):
+        """Return singleton instance."""
+        try:
+            return self._instance
+        except AttributeError:
+            self._instance = self._decorated()
+            return self._instance