Add a unit test for the snapshot cache

This commit is contained in:
Mark Haines 2015-12-23 11:48:03 +00:00
parent 517fb9a023
commit 7fa71e3267
2 changed files with 62 additions and 2 deletions

View File

@ -28,14 +28,14 @@ class SnapshotCache(object):
def rotate(self, time_now_ms): def rotate(self, time_now_ms):
# Rotate once if the cache duration has passed since the last rotation. # Rotate once if the cache duration has passed since the last rotation.
if time_now_ms - self.time_last_rotated_ms > self.DURATION_MS: if time_now_ms - self.time_last_rotated_ms >= self.DURATION_MS:
self.prev_result_cache = self.next_result_cache self.prev_result_cache = self.next_result_cache
self.next_result_cache = {} self.next_result_cache = {}
self.time_last_rotated_ms += self.DURATION_MS self.time_last_rotated_ms += self.DURATION_MS
# Rotate again if the cache duration has passed twice since the last # Rotate again if the cache duration has passed twice since the last
# rotation. # rotation.
if time_now_ms - self.time_last_rotated_ms > self.DURATION_MS: if time_now_ms - self.time_last_rotated_ms >= self.DURATION_MS:
self.prev_result_cache = self.next_result_cache self.prev_result_cache = self.next_result_cache
self.next_result_cache = {} self.next_result_cache = {}
self.time_last_rotated_ms = time_now_ms self.time_last_rotated_ms = time_now_ms

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@ -0,0 +1,60 @@
# -*- coding: utf-8 -*-
# Copyright 2015 OpenMarket 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 .. import unittest
from synapse.util.caches.snapshot_cache import SnapshotCache
from twisted.internet.defer import Deferred
class SnapshotCacheTestCase(unittest.TestCase):
def setUp(self):
self.cache = SnapshotCache()
self.cache.DURATION_MS = 1
def test_get_set(self):
# Check that getting a missing key returns None
self.assertEquals(self.cache.get(0, "key"), None)
# Check that setting a key with a deferred returns
# a deferred that resolves when the initial deferred does
d = Deferred()
set_result = self.cache.set(0, "key", d)
self.assertIsNotNone(set_result)
self.assertFalse(set_result.called)
# Check that getting the key before the deferred has resolved
# returns a deferred that resolves when the initial deferred does.
get_result_at_10 = self.cache.get(10, "key")
self.assertIsNotNone(get_result_at_10)
self.assertFalse(get_result_at_10.called)
# Check that the returned deferreds resolve when the initial deferred
# does.
d.callback("v")
self.assertTrue(set_result.called)
self.assertTrue(get_result_at_10.called)
# Check that getting the key after the deferred has resolved
# before the cache expires returns a resolved deferred.
get_result_at_11 = self.cache.get(11, "key")
self.assertIsNotNone(get_result_at_11)
self.assertTrue(get_result_at_11.called)
# Check that getting the key after the deferred has resolved
# after the cache expires returns None
get_result_at_12 = self.cache.get(12, "key")
self.assertIsNone(get_result_at_12)