neutron/neutron/tests/unit/common/test_cache_utils.py
Ihar Hrachyshka d034532d37 cache_utils: fixed cache misses for the new (oslo.cache) configuration
When the new (oslo.cache) way of configuring the cache is used, cache is
never hit, because self._cache.get() consistently raises exceptions:

TypeError: 'sha1() argument 1 must be string or buffer, not tuple'

It occurs because the key passed into the oslo.cache region does not
conform to oslo.cache requirements. The library enforces the key to be
compatible with sha1_mangle_key() function:

http://git.openstack.org/cgit/openstack/oslo.cache/tree/oslo_cache/core.py?id=8b8a718507b30a4a2fd36e6c14d1071bd6cca878#n140

With this patch, we transform the key to a string, to conform to the
requirements.

The bug sneaked into the tree unnoticed because of two reasons:

- there were no unit tests to validate the new way of cache
  configuration.
- the 'legacy' code path was configuring the cache in a slightly
  different way, omitting some oslo.cache code.

For the former, new unit tests were introduced that cover the cache on
par with the legacy mode.

For the latter, the legacy code path was modified to rely on the same
configuration path as for the new way.

Closes-Bug: #1593342
Change-Id: I2724aa21f66f0fb69147407bfcf3184585d7d5cd
2016-06-16 23:07:40 +02:00

131 lines
5.0 KiB
Python

# 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.
import mock
from oslo_config import cfg
from oslo_config import fixture as config_fixture
from neutron.common import cache_utils as cache
from neutron.tests import base
class CacheConfFixture(config_fixture.Config):
def setUp(self):
super(CacheConfFixture, self).setUp()
cache.register_oslo_configs(self.conf)
self.config(enabled=True, group='cache')
class TestOsloCache(base.BaseTestCase):
def setUp(self):
super(TestOsloCache, self).setUp()
self.memory_conf = cfg.ConfigOpts()
memory_conf_fixture = CacheConfFixture(self.memory_conf)
self.useFixture(memory_conf_fixture)
memory_conf_fixture.config(cache_url='memory://?default_ttl=5')
self.dict_conf = cfg.ConfigOpts()
dict_conf_fixture = CacheConfFixture(self.dict_conf)
self.useFixture(dict_conf_fixture)
dict_conf_fixture.config(expiration_time=60,
backend='oslo_cache.dict', group='cache')
self.null_cache_conf = cfg.ConfigOpts()
null_conf_fixture = CacheConfFixture(self.null_cache_conf)
self.useFixture(null_conf_fixture)
null_conf_fixture.config(expiration_time=600,
backend='dogpile.cache.null', group='cache')
def _test_get_cache_region_helper(self, conf):
region = cache._get_cache_region(conf)
self.assertIsNotNone(region)
def test_get_cache_region(self):
self._test_get_cache_region_helper(self.dict_conf)
self._test_get_cache_region_helper(self.null_cache_conf)
def test_get_cache_region_for_legacy(self):
region = cache._get_cache_region_for_legacy("memory://?default_ttl=10")
self.assertIsNotNone(region)
self.assertEqual(10, region.expiration_time)
@mock.patch('neutron.common.cache_utils._get_cache_region_for_legacy')
@mock.patch('neutron.common.cache_utils._get_cache_region')
def test_get_cache(self, mock_get_cache_region,
mock_get_cache_region_for_legacy):
self.assertIsNotNone(cache.get_cache(self.memory_conf))
self.assertIsNotNone(cache.get_cache(self.dict_conf))
self.assertIsNotNone(cache.get_cache(self.null_cache_conf))
mock_get_cache_region.assert_has_calls(
[mock.call(self.dict_conf),
mock.call(self.null_cache_conf)]
)
mock_get_cache_region_for_legacy.assert_has_calls(
[mock.call('memory://?default_ttl=5')]
)
class _CachingDecorator(object):
def __init__(self):
self.func_retval = 'bar'
self._cache = mock.Mock()
@cache.cache_method_results
def func(self, *args, **kwargs):
return self.func_retval
class TestCachingDecorator(base.BaseTestCase):
def setUp(self):
super(TestCachingDecorator, self).setUp()
self.decor = _CachingDecorator()
self.func_name = '%(module)s._CachingDecorator.func' % {
'module': self.__module__
}
self.not_cached = self.decor.func.func.__self__._not_cached
def test_cache_miss(self):
expected_key = (self.func_name, 1, 2, ('foo', 'bar'))
args = (1, 2)
kwargs = {'foo': 'bar'}
self.decor._cache.get.return_value = self.not_cached
retval = self.decor.func(*args, **kwargs)
self.decor._cache.set.assert_called_once_with(
str(expected_key), self.decor.func_retval)
self.assertEqual(self.decor.func_retval, retval)
def test_cache_hit(self):
expected_key = (self.func_name, 1, 2, ('foo', 'bar'))
args = (1, 2)
kwargs = {'foo': 'bar'}
retval = self.decor.func(*args, **kwargs)
self.assertFalse(self.decor._cache.set.called)
self.assertEqual(self.decor._cache.get.return_value, retval)
self.decor._cache.get.assert_called_once_with(str(expected_key))
def test_get_unhashable(self):
expected_key = (self.func_name, [1], 2)
self.decor._cache.get.side_effect = TypeError
retval = self.decor.func([1], 2)
self.assertFalse(self.decor._cache.set.called)
self.assertEqual(self.decor.func_retval, retval)
self.decor._cache.get.assert_called_once_with(str(expected_key))
def test_missing_cache(self):
delattr(self.decor, '_cache')
self.assertRaises(NotImplementedError, self.decor.func, (1, 2))
def test_no_cache(self):
self.decor._cache = False
retval = self.decor.func((1, 2))
self.assertEqual(self.decor.func_retval, retval)