Move _emerge.SlotObject to portage.util.

1 files changed, 51 insertions, 0 deletions

diff --git a/pym/portage/util/SlotObject.py b/pym/portage/util/SlotObject.py
new file mode 100644
index 000000000..a59dfc199
--- /dev/null
+++ b/pym/portage/util/SlotObject.py
@@ -0,0 +1,51 @@
+# 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__))
+				setattr(self, myattr, myvalue)
+
+		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
+