Support Components subclasses that are not hashable. (#54)

* Support Components subclasses that are not hashable.

Fixes #53.

2 files changed, 31 insertions, 11 deletions

diff --git a/src/zope/interface/registry.py b/src/zope/interface/registry.py
index 2e1b085..c2b588c 100644
--- a/src/zope/interface/registry.py
+++ b/src/zope/interface/registry.py
@@ -14,7 +14,7 @@
 """Basic components support
 """
 from collections import defaultdict
-from weakref import WeakKeyDictionary
+import weakref
 
 try:
     from zope.event import notify
@@ -71,15 +71,18 @@ class _UnhashableComponentCounter(object):
 
 class _UtilityRegistrations(object):
 
-    _regs_for_components = WeakKeyDictionary()
+    _regs_for_components = {}
+    _weakrefs_for_components = {}
 
     @classmethod
     def for_components(cls, components):
         # We manage these utility/subscription registrations as associated
         # objects with a weakref to avoid making any changes to
-        # the pickle format
+        # the pickle format. They are keyed off the id of the component because
+        # Components subclasses are not guaranteed to be hashable.
+        key = id(components)
         try:
-            regs = cls._regs_for_components[components]
+            regs = cls._regs_for_components[key]
         except KeyError:
             regs = None
         else:
@@ -91,7 +94,14 @@ class _UtilityRegistrations(object):
 
         if regs is None:
             regs = cls(components.utilities, components._utility_registrations)
-            cls._regs_for_components[components] = regs
+            cls._regs_for_components[key] = regs
+
+            if key not in cls._weakrefs_for_components:
+                def _cleanup(r):
+                    cls._weakrefs_for_components.pop(key)
+                    cls._regs_for_components.pop(key)
+
+                cls._weakrefs_for_components[key] = weakref.ref(components, _cleanup)
 
         return regs
 
diff --git a/src/zope/interface/tests/test_registry.py b/src/zope/interface/tests/test_registry.py
index c2a940a..852034e 100644
--- a/src/zope/interface/tests/test_registry.py
+++ b/src/zope/interface/tests/test_registry.py
@@ -2133,6 +2133,15 @@ class ComponentsTests(unittest.TestCase):
         self.assertEqual(_called_2, [bar])
 
 
+class UnhashableComponentsTests(ComponentsTests):
+
+    def _getTargetClass(self):
+        # Mimic what pyramid does to create an unhashable
+        # registry
+        class Components(super(UnhashableComponentsTests, self)._getTargetClass(), dict):
+            pass
+        return Components
+
 # Test _getUtilityProvided, _getAdapterProvided, _getAdapterRequired via their
 # callers (Component.registerUtility, Component.registerAdapter).
 
@@ -2646,9 +2655,10 @@ class _Monkey(object):
 
 def test_suite():
     return unittest.TestSuite((
-            unittest.makeSuite(ComponentsTests),
-            unittest.makeSuite(UtilityRegistrationTests),
-            unittest.makeSuite(AdapterRegistrationTests),
-            unittest.makeSuite(SubscriptionRegistrationTests),
-            unittest.makeSuite(AdapterRegistrationTests),
-        ))
+        unittest.makeSuite(ComponentsTests),
+        unittest.makeSuite(UnhashableComponentsTests),
+        unittest.makeSuite(UtilityRegistrationTests),
+        unittest.makeSuite(AdapterRegistrationTests),
+        unittest.makeSuite(SubscriptionRegistrationTests),
+        unittest.makeSuite(AdapterRegistrationTests),
+    ))