From 88837172f69eabc408ae3945d82e0270b8e07440 Mon Sep 17 00:00:00 2001 From: Benjamin Drung Date: Sat, 10 Jun 2023 10:55:33 +0200 Subject: Adding upstream version 2.2.1. Signed-off-by: Benjamin Drung --- staslib/singleton.py | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) create mode 100644 staslib/singleton.py (limited to 'staslib/singleton.py') diff --git a/staslib/singleton.py b/staslib/singleton.py new file mode 100644 index 0000000..2171186 --- /dev/null +++ b/staslib/singleton.py @@ -0,0 +1,23 @@ +# Copyright (c) 2022, Dell Inc. or its subsidiaries. All rights reserved. +# SPDX-License-Identifier: Apache-2.0 +# See the LICENSE file for details. +# +# This file is part of NVMe STorage Appliance Services (nvme-stas). +# +# Authors: Martin Belanger +# +'''Implementation of a singleton pattern''' + + +class Singleton(type): + '''metaclass implementation of a singleton pattern''' + + _instances = {} + + def __call__(cls, *args, **kwargs): + if cls not in cls._instances: + # This variable declaration is required to force a + # strong reference on the instance. + instance = super(Singleton, cls).__call__(*args, **kwargs) + cls._instances[cls] = instance + return cls._instances[cls] -- cgit v1.2.3