From: Michael Tremer <michael.tremer@ipfire.org>
Date: Wed, 10 Oct 2018 11:14:57 +0000 (+0100)
Subject: Add decorators
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=de9dc7164f7c0b0548d4e91bfce3b42f0a9fc9c5;p=ipfire.org.git

Add decorators

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/Makefile.am b/Makefile.am
index 7b043ab6..678cdff2 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -53,6 +53,7 @@ backend_PYTHON = \
 	src/backend/blog.py \
 	src/backend/countries.py \
 	src/backend/database.py \
+	src/backend/decorators.py \
 	src/backend/fireinfo.py \
 	src/backend/geoip.py \
 	src/backend/iuse.py \
diff --git a/src/backend/decorators.py b/src/backend/decorators.py
new file mode 100644
index 00000000..f271daf2
--- /dev/null
+++ b/src/backend/decorators.py
@@ -0,0 +1,33 @@
+#!/usr/bin/python3
+
+class Missing(object):
+	pass
+
+_missing = Missing()
+
+class lazy_property(property):
+	"""
+		The property is only computed once and then being
+		cached until the end of the lifetime of the object.
+	"""
+	def __init__(self, fget, fset=None, fdel=None, doc=None, name=None):
+		property.__init__(self, fget=fget, fset=fset, fdel=fdel, doc=doc)
+
+		self.__name__   = name or fget.__name__
+		self.__module__ = fget.__module__
+
+	def __get__(self, obj, type=None):
+		if object is None:
+			return self
+
+		value = obj.__dict__.get(self.__name__, _missing)
+		if value is _missing:
+			obj.__dict__[self.__name__] = value = self.fget(obj)
+
+		return value
+
+	def __set__(self, obj, value):
+		if self.fset:
+			self.fset(obj, value)
+
+		obj.__dict__[self.__name__] = value