fix invalidation

synapse/util/caches/descriptors.py

@@ -528,7 +528,7 @@ class CacheListDescriptor(_CacheDescriptorBase):
                     deferreds_map[arg] = deferred
                     key = arg_to_cache_key(arg)
                     observable = ObservableDeferred(deferred)
-                    cache.set(key, observable)
+                    cache.set(key, observable, callback=invalidate_callback)
 
                 def complete_all(res):
                     # the wrapped function has completed. It returns a

tests/util/caches/test_descriptors.py

@@ -275,7 +275,6 @@ class DescriptorTestCase(unittest.TestCase):
         obj.mock.assert_not_called()
 
 
-@unittest.DEBUG
 class CachedListDescriptorTestCase(unittest.TestCase):
     @defer.inlineCallbacks
     def test_cache(self):
@@ -334,3 +333,44 @@ class CachedListDescriptorTestCase(unittest.TestCase):
             r = yield obj.list_fn([10, 20, 30], 2)
             obj.mock.assert_not_called()
             self.assertEqual(r, {10: 'fish', 20: 'chips', 30: 'peas'})
+
+    @defer.inlineCallbacks
+    def test_invalidate(self):
+        """Make sure that invalidation callbacks are called."""
+        class Cls(object):
+            def __init__(self):
+                self.mock = mock.Mock()
+
+            @descriptors.cached()
+            def fn(self, arg1, arg2):
+                pass
+
+            @descriptors.cachedList("fn", "args1", inlineCallbacks=True)
+            def list_fn(self, args1, arg2):
+                # we want this to behave like an asynchronous function
+                yield run_on_reactor()
+                defer.returnValue(self.mock(args1, arg2))
+
+        obj = Cls()
+        invalidate0 = mock.Mock()
+        invalidate1 = mock.Mock()
+
+        # cache miss
+        obj.mock.return_value = {10: 'fish', 20: 'chips'}
+        r1 = yield obj.list_fn([10, 20], 2, on_invalidate=invalidate0)
+        obj.mock.assert_called_once_with([10, 20], 2)
+        self.assertEqual(r1, {10: 'fish', 20: 'chips'})
+        obj.mock.reset_mock()
+
+        # cache hit
+        r2 = yield obj.list_fn([10, 20], 2, on_invalidate=invalidate1)
+        obj.mock.assert_not_called()
+        self.assertEqual(r2, {10: 'fish', 20: 'chips'})
+
+        invalidate0.assert_not_called()
+        invalidate1.assert_not_called()
+
+        # now if we invalidate the keys, both invalidations should get called
+        obj.fn.invalidate((10, 2))
+        invalidate0.assert_called_once()
+        invalidate1.assert_called_once()