Add a caching layer to .well-known responses (#4516)

tests/util/caches/test_ttlcache.py

@@ -0,0 +1,83 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 New Vector Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from mock import Mock
+
+from synapse.util.caches.ttlcache import TTLCache
+
+from tests import unittest
+
+
+class CacheTestCase(unittest.TestCase):
+    def setUp(self):
+        self.mock_timer = Mock(side_effect=lambda: 100.0)
+        self.cache = TTLCache("test_cache", self.mock_timer)
+
+    def test_get(self):
+        """simple set/get tests"""
+        self.cache.set('one', '1', 10)
+        self.cache.set('two', '2', 20)
+        self.cache.set('three', '3', 30)
+
+        self.assertEqual(len(self.cache), 3)
+
+        self.assertTrue('one' in self.cache)
+        self.assertEqual(self.cache.get('one'), '1')
+        self.assertEqual(self.cache['one'], '1')
+        self.assertEqual(self.cache.get_with_expiry('one'), ('1', 110))
+        self.assertEqual(self.cache._metrics.hits, 3)
+        self.assertEqual(self.cache._metrics.misses, 0)
+
+        self.cache.set('two', '2.5', 20)
+        self.assertEqual(self.cache['two'], '2.5')
+        self.assertEqual(self.cache._metrics.hits, 4)
+
+        # non-existent-item tests
+        self.assertEqual(self.cache.get('four', '4'), '4')
+        self.assertIs(self.cache.get('four', None), None)
+
+        with self.assertRaises(KeyError):
+            self.cache['four']
+
+        with self.assertRaises(KeyError):
+            self.cache.get('four')
+
+        with self.assertRaises(KeyError):
+            self.cache.get_with_expiry('four')
+
+        self.assertEqual(self.cache._metrics.hits, 4)
+        self.assertEqual(self.cache._metrics.misses, 5)
+
+    def test_expiry(self):
+        self.cache.set('one', '1', 10)
+        self.cache.set('two', '2', 20)
+        self.cache.set('three', '3', 30)
+
+        self.assertEqual(len(self.cache), 3)
+        self.assertEqual(self.cache['one'], '1')
+        self.assertEqual(self.cache['two'], '2')
+
+        # enough for the first entry to expire, but not the rest
+        self.mock_timer.side_effect = lambda: 110.0
+
+        self.assertEqual(len(self.cache), 2)
+        self.assertFalse('one' in self.cache)
+        self.assertEqual(self.cache['two'], '2')
+        self.assertEqual(self.cache['three'], '3')
+
+        self.assertEqual(self.cache.get_with_expiry('two'), ('2', 120))
+
+        self.assertEqual(self.cache._metrics.hits, 5)
+        self.assertEqual(self.cache._metrics.misses, 0)