synapse/tests/util/caches/test_ttlcache.py

# -*- 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)