# HG changeset patch
# User Marcin Kuzminski <marcin@python-works.com>
# Date 1362573361 -3600
# Node ID f134d125fb6789ded69d5bcafbf53167203333e0
# Parent  2e703c3ef0b8ea339c7656213ca357c43348eaf0
refactored lazy properties little bit for ThreadecLocal to work better

diff -r 2e703c3ef0b8 -r f134d125fb67 rhodecode/lib/vcs/utils/lazy.py
--- a/rhodecode/lib/vcs/utils/lazy.py	Wed Mar 06 02:03:16 2013 +0100
+++ b/rhodecode/lib/vcs/utils/lazy.py	Wed Mar 06 13:36:01 2013 +0100
@@ -1,3 +1,14 @@
+class _Missing(object):
+
+    def __repr__(self):
+        return 'no value'
+
+    def __reduce__(self):
+        return '_missing'
+
+_missing = _Missing()
+
+
 class LazyProperty(object):
     """
     Decorator for easier creation of ``property`` from potentially expensive to
@@ -24,8 +35,11 @@
     def __get__(self, obj, klass=None):
         if obj is None:
             return self
-        result = obj.__dict__[self.__name__] = self._func(obj)
-        return result
+        value = obj.__dict__.get(self.__name__, _missing)
+        if value is _missing:
+            value = self._func(obj)
+            obj.__dict__[self.__name__] = value
+        return value
 
 import threading
 
@@ -41,5 +55,8 @@
         if not hasattr(obj, '__tl_dict__'):
             obj.__tl_dict__ = threading.local().__dict__
 
-        result = obj.__tl_dict__[self.__name__] = self._func(obj)
-        return result
+        value = obj.__tl_dict__.get(self.__name__, _missing)
+        if value is _missing:
+            value = self._func(obj)
+            obj.__tl_dict__[self.__name__] = value
+        return value