Merge pull request #8 from NextThought/jython

In WeakSet, use the `valuerefs` method from Python 2.5 instead of accessing the internal `data` implementation detail.

CHANGES.rst

@@ -4,6 +4,9 @@ Changes
 1.4.4 (unreleased)
 ------------------
 
+- Use the standard ``valuerefs()`` method rather than relying on
+  implementation details of ``WeakValueDictionary`` in ``WeakSet``.
+
 - Add support for PyPy3.
 
 - Require 100% branch coverage (in addition to 100% statement coverage).

tox.ini

 [tox]
+# Jython 2.7rc2+ does work, but unfortunately has an issue running
+# with Tox 1.9.2 (see https://github.com/pypa/virtualenv/pull/746)
 envlist =
-# Jython support pending 2.7 support, due 2012-07-15 or so.  See:
-# http://fwierzbicki.blogspot.com/2012/03/adconion-to-fund-jython-27.html
-#    py26,py27,py32,pypy,jython,coverage
     py26,py27,pypy,py32,py33,py34,pypy3,coverage,docs
 
 [testenv]
@@ -10,10 +9,6 @@ commands =
     python setup.py test -q
 deps = transaction
 
-[testenv:jython]
-commands = 
-   jython setup.py test -q
-
 [testenv:coverage]
 basepython =
     python2.6

transaction/_compat.py

@@ -2,6 +2,7 @@ import sys
 import types
 
 PY3 = sys.version_info[0] == 3
+JYTHON = sys.platform.startswith('java')
 
 if PY3: # pragma: no cover
     string_types = str,
@@ -87,4 +88,3 @@ if PY3:
 else:
     def func_name(func): #pragma NO COVER
         return func.func_name
- 

transaction/tests/test_weakset.py

@@ -12,7 +12,7 @@
 #
 ##############################################################################
 import unittest
-
+from transaction._compat import JYTHON
 
 class WeakSetTests(unittest.TestCase):
     def test_contains(self):
@@ -35,6 +35,8 @@ class WeakSetTests(unittest.TestCase):
         self.assertEqual(len(w), 2)
         del d1
         gc.collect()
+        if not JYTHON:
+            # The Jython GC is non deterministic
             self.assertEqual(len(w), 1)
 
     def test_remove(self):

transaction/weakset.py

@@ -13,6 +13,7 @@
 ############################################################################
 
 import weakref
+from ._compat import PY3
 
 # A simple implementation of weak sets, supplying just enough of Python's
 # sets.Set interface for our needs.
@@ -62,7 +63,6 @@ class WeakSet(object):
     # underlying dict may change size during iteration, due to gc or
     # activity from other threads).  as_weakef_list() is safe.
     #
-    # Something like this should really be a method of Python's weak dicts.
     # If we invoke self.data.values() instead, we get back a list of live
     # objects instead of weakrefs.  If gc occurs while this list is alive,
     # all the objects move to an older generation (because they're strongly
@@ -75,9 +75,12 @@ class WeakSet(object):
     # elements are actually trash.  By returning a list of weakrefs instead,
     # we avoid that, although the decision to use weakrefs is now very
     # visible to our clients.
-    def as_weakref_list(self):
-        # We're cheating by breaking into the internals of Python's
-        # WeakValueDictionary here (accessing its .data attribute).
-        # Python 3: be sure to freeze the list, to avoid RuntimeError:
+    if PY3: #pragma: no cover (coverage tests run under 2.7)
+        # Python 3: be sure to freeze the iterator, to avoid RuntimeError:
         # dictionary changed size during iteration.
-        return list(self.data.data.values())
+        def as_weakref_list(self):
+            return list(self.data.valuerefs())
+    else:
+        # On Python2 we already get a list, no need to copy
+        def as_weakref_list(self):
+            return self.data.valuerefs()