Rename pym→lib, for better distutils-r1 interoperability

Closes: https://github.com/gentoo/portage/pull/343

1 files changed, 57 insertions, 0 deletions

diff --git a/lib/portage/util/SlotObject.py b/lib/portage/util/SlotObject.py
new file mode 100644
index 000000000..ba6215874
--- /dev/null
+++ b/lib/portage/util/SlotObject.py
@@ -0,0 +1,57 @@
+# Copyright 1999-2012 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+class SlotObject(object):
+	__slots__ = ("__weakref__",)
+
+	def __init__(self, **kwargs):
+		classes = [self.__class__]
+		while classes:
+			c = classes.pop()
+			if c is SlotObject:
+				continue
+			classes.extend(c.__bases__)
+			slots = getattr(c, "__slots__", None)
+			if not slots:
+				continue
+			for myattr in slots:
+				myvalue = kwargs.pop(myattr, None)
+				if myvalue is None and getattr(self, myattr, None) is not None:
+					raise AssertionError(
+						"class '%s' duplicates '%s' value in __slots__ of base class '%s'" %
+						(self.__class__.__name__, myattr, c.__name__))
+				try:
+					setattr(self, myattr, myvalue)
+				except AttributeError:
+					# Allow a property to override a __slots__ value, but raise an
+					# error if the intended value is something other than None.
+					if not (myvalue is None and
+						isinstance(getattr(type(self), myattr, None), property)):
+						raise
+
+		if kwargs:
+			raise TypeError(
+				"'%s' is an invalid keyword argument for this constructor" %
+				(next(iter(kwargs)),))
+
+	def copy(self):
+		"""
+		Create a new instance and copy all attributes
+		defined from __slots__ (including those from
+		inherited classes).
+		"""
+		obj = self.__class__()
+
+		classes = [self.__class__]
+		while classes:
+			c = classes.pop()
+			if c is SlotObject:
+				continue
+			classes.extend(c.__bases__)
+			slots = getattr(c, "__slots__", None)
+			if not slots:
+				continue
+			for myattr in slots:
+				setattr(obj, myattr, getattr(self, myattr))
+
+		return obj