Calipso initial release for OPNFV

Change-Id: I7210c244b0c10fa80bfa8c77cb86c9d6ddf8bc88
Signed-off-by: Yaron Yogev <yaronyogev@gmail.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/app/utils/singleton.py b/app/utils/singleton.py
new file mode 100644
index 0000000..fc1147f
--- /dev/null
+++ b/app/utils/singleton.py
@@ -0,0 +1,16 @@
+###############################################################################
+# Copyright (c) 2017 Koren Lev (Cisco Systems), Yaron Yogev (Cisco Systems)   #
+# and others                                                                  #
+#                                                                             #
+# All rights reserved. This program and the accompanying materials            #
+# are made available under the terms of the Apache License, Version 2.0       #
+# which accompanies this distribution, and is available at                    #
+# http://www.apache.org/licenses/LICENSE-2.0                                  #
+###############################################################################
+class Singleton(type):
+    _instances = {}
+
+    def __call__(cls, *args, **kwargs):
+        if cls not in cls._instances:
+            cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
+        return cls._instances[cls]