openstack/oslo.cache
Code Issues Proposed changes

Added NO_VALUE to core file

Browse Source 
Using oslo_cache lib the only way to compare some cached_value with NO_VALUE is
to add bad import like 'from oslo_cache.backends.dictionary import NO_VALUE'.

NO_VALUE is now added to core.py file and the improved import
'oslo_cache.core import NO_VALUE' will look much better in other projects.

NO_VALUE is now public, it is added to __all__ and is used everywhere from core
instead of dogpile.cache.api.NO_VALUE.

Co-Authored-By: Sergey Nikitin <snikitin@mirantis.com>

Change-Id: I8fea4a9eb088089289ba1dd35377fb10465c313a
This commit is contained in:
Pavel Kholkin 2015-07-16 15:19:33 +03:00
parent a267390505
commit 5881ad7cb1
7 changed files with 57 additions and 33 deletions
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14
oslo_cache/backends/dictionary.py
View File

@ -15,15 +15,14 @@
"""dogpile.cache backend that uses dictionary for storage"""
from dogpile.cache import api
from oslo_cache import core
from oslo_utils import timeutils
__all__ = [
'DictCacheBackend'
]
# Value for nonexistent and expired keys
NO_VALUE = api.NO_VALUE
_NO_VALUE = core.NO_VALUE
class DictCacheBackend(api.CacheBackend):
@ -43,15 +42,16 @@ class DictCacheBackend(api.CacheBackend):
self.cache = {}
def get(self, key):
"""Retrieves the value for a key or NO_VALUE for nonexistent and
expired keys.
"""Retrieves the value for a key.
:param key: dictionary key
:returns: value for a key or :data:`oslo_cache.core.NO_VALUE`
for nonexistent or expired keys.
"""
(value, timeout) = self.cache.get(key, (NO_VALUE, 0))
(value, timeout) = self.cache.get(key, (_NO_VALUE, 0))
if self.expiration_time > 0 and timeutils.utcnow_ts() >= timeout:
self.cache.pop(key, None)
return NO_VALUE
return _NO_VALUE
return value

19
oslo_cache/backends/mongo.py
View File

@ -17,6 +17,7 @@ import datetime
from dogpile.cache import api
from dogpile.cache import util as dp_util
from oslo_cache import core
from oslo_log import log
from oslo_utils import importutils
from oslo_utils import timeutils
@ -30,7 +31,7 @@ __all__ = [
'MongoCacheBackend'
]
NO_VALUE = api.NO_VALUE
_NO_VALUE = core.NO_VALUE
LOG = log.getLogger(__name__)
@ -173,16 +174,28 @@ class MongoCacheBackend(api.CacheBackend):
return self.api
def get(self, key):
"""Retrieves the value for a key.
:param key: key to be retrieved.
:returns: value for a key or :data:`oslo_cache.core.NO_VALUE`
for nonexistent or expired keys.
"""
value = self.client.get(key)
if value is None:
return NO_VALUE
return _NO_VALUE
else:
return value
def get_multi(self, keys):
"""Return multiple values from the cache, based on the given keys.
:param keys: sequence of keys to be retrieved.
:returns: returns values (or :data:`oslo_cache.core.NO_VALUE`)
as a list matching the keys given.
"""
values = self.client.get_multi(keys)
return [
NO_VALUE if key not in values
_NO_VALUE if key not in values
else values[key] for key in keys
]

7
oslo_cache/backends/noop.py
View File

@ -13,13 +13,14 @@
# under the License.
from dogpile.cache import api
from oslo_cache import core
__all__ = [
'NoopCacheBackend'
]
NO_VALUE = api.NO_VALUE
_NO_VALUE = core.NO_VALUE
class NoopCacheBackend(api.CacheBackend):
@ -35,10 +36,10 @@ class NoopCacheBackend(api.CacheBackend):
return
def get(self, key):
return NO_VALUE
return _NO_VALUE
def get_multi(self, keys):
return [NO_VALUE for x in keys]
return [_NO_VALUE for x in keys]
def set(self, key, value):
return

10
oslo_cache/core.py
View File

@ -28,9 +28,15 @@ This library's configuration options must be registered in your application's
:class:`oslo_config.cfg.ConfigOpts` instance. Do this by passing the ConfigOpts
instance to :func:`configure`.
The library has special public value for nonexistent or expired keys called
:data:`NO_VALUE`. To use this value you should import it from oslo_cache.core::
from oslo_cache import core
NO_VALUE = core.NO_VALUE
"""
import dogpile.cache
from dogpile.cache import api
from dogpile.cache import proxy
from dogpile.cache import util
from oslo_log import log
@ -46,8 +52,12 @@ __all__ = [
'configure_cache_region',
'create_region',
'get_memoization_decorator',
'NO_VALUE',
]
NO_VALUE = api.NO_VALUE
"""Value returned for nonexistent or expired keys."""
_LOG = log.getLogger(__name__)
_BACKENDS = [

3
oslo_cache/tests/test_cache.py
View File

@ -17,7 +17,6 @@ import copy
import time
import uuid
from dogpile.cache import api
from dogpile.cache import proxy
import mock
from oslo_config import cfg
@ -28,7 +27,7 @@ from oslo_cache import exception
from oslo_config import fixture as config_fixture
NO_VALUE = api.NO_VALUE
NO_VALUE = cache.NO_VALUE
TEST_GROUP = uuid.uuid4().hex
TEST_GROUP2 = uuid.uuid4().hex

33
oslo_cache/tests/test_cache_backend_mongo.py
View File

@ -17,12 +17,12 @@ import copy
import functools
import uuid
from dogpile.cache import api
from dogpile.cache import region as dp_region
import six
from six.moves import range
from oslo_cache.backends import mongo
from oslo_cache import core
from oslo_cache import exception
from oslo_cache.tests import test_cache
@ -61,6 +61,7 @@ ks_cache = {
COLLECTIONS = {}
SON_MANIPULATOR = None
NO_VALUE = core.NO_VALUE
class MockCursor(object):
@ -463,7 +464,7 @@ class MongoCache(test_cache.BaseTestCase):
random_key = uuid.uuid4().hex
# should return NO_VALUE as key does not exist in cache
self.assertEqual(api.NO_VALUE, region.get(random_key))
self.assertEqual(NO_VALUE, region.get(random_key))
def test_backend_set_data(self):
@ -551,7 +552,7 @@ class MongoCache(test_cache.BaseTestCase):
random_key3: 'dummyValue3'}
region.set_multi(mapping)
# should return NO_VALUE as key does not exist in cache
self.assertEqual(api.NO_VALUE, region.get(random_key))
self.assertEqual(NO_VALUE, region.get(random_key))
self.assertFalse(region.get(random_key))
self.assertEqual("dummyValue1", region.get(random_key1))
self.assertEqual("dummyValue2", region.get(random_key2))
@ -575,7 +576,7 @@ class MongoCache(test_cache.BaseTestCase):
keys = [random_key, random_key1, random_key2, random_key3]
results = region.get_multi(keys)
# should return NO_VALUE as key does not exist in cache
self.assertEqual(api.NO_VALUE, results[0])
self.assertEqual(NO_VALUE, results[0])
self.assertEqual("dummyValue1", results[1])
self.assertEqual("", results[2])
self.assertEqual("dummyValue3", results[3])
@ -595,7 +596,7 @@ class MongoCache(test_cache.BaseTestCase):
random_key3: 'dummyValue3'}
region.set_multi(mapping)
# should return NO_VALUE as key does not exist in cache
self.assertEqual(api.NO_VALUE, region.get(random_key))
self.assertEqual(NO_VALUE, region.get(random_key))
self.assertEqual("dummyValue1", region.get(random_key1))
self.assertEqual("dummyValue2", region.get(random_key2))
self.assertEqual("dummyValue3", region.get(random_key3))
@ -603,7 +604,7 @@ class MongoCache(test_cache.BaseTestCase):
mapping = {random_key1: 'dummyValue4',
random_key2: 'dummyValue5'}
region.set_multi(mapping)
self.assertEqual(api.NO_VALUE, region.get(random_key))
self.assertEqual(NO_VALUE, region.get(random_key))
self.assertEqual("dummyValue4", region.get(random_key1))
self.assertEqual("dummyValue5", region.get(random_key2))
self.assertEqual("dummyValue3", region.get(random_key3))
@ -625,7 +626,7 @@ class MongoCache(test_cache.BaseTestCase):
random_key4: 'dummyValue4'}
region.set_multi(mapping)
# should return NO_VALUE as key does not exist in cache
self.assertEqual(api.NO_VALUE, region.get(random_key))
self.assertEqual(NO_VALUE, region.get(random_key))
self.assertEqual("dummyValue1", region.get(random_key1))
self.assertIsNone(region.get(random_key2))
self.assertEqual("", region.get(random_key3))
@ -635,7 +636,7 @@ class MongoCache(test_cache.BaseTestCase):
results = region.get_multi(keys)
# should return NO_VALUE as key does not exist in cache
self.assertEqual(api.NO_VALUE, results[0])
self.assertEqual(NO_VALUE, results[0])
self.assertEqual("dummyValue1", results[1])
self.assertIsNone(results[2])
self.assertEqual("", results[3])
@ -644,7 +645,7 @@ class MongoCache(test_cache.BaseTestCase):
mapping = {random_key1: 'dummyValue5',
random_key2: 'dummyValue6'}
region.set_multi(mapping)
self.assertEqual(api.NO_VALUE, region.get(random_key))
self.assertEqual(NO_VALUE, region.get(random_key))
self.assertEqual("dummyValue5", region.get(random_key1))
self.assertEqual("dummyValue6", region.get(random_key2))
self.assertEqual("", region.get(random_key3))
@ -662,7 +663,7 @@ class MongoCache(test_cache.BaseTestCase):
region.delete(random_key)
# should return NO_VALUE as key no longer exists in cache
self.assertEqual(api.NO_VALUE, region.get(random_key))
self.assertEqual(NO_VALUE, region.get(random_key))
def test_backend_multi_delete_data(self):
@ -679,21 +680,21 @@ class MongoCache(test_cache.BaseTestCase):
random_key3: 'dummyValue3'}
region.set_multi(mapping)
# should return NO_VALUE as key does not exist in cache
self.assertEqual(api.NO_VALUE, region.get(random_key))
self.assertEqual(NO_VALUE, region.get(random_key))
self.assertEqual("dummyValue1", region.get(random_key1))
self.assertEqual("dummyValue2", region.get(random_key2))
self.assertEqual("dummyValue3", region.get(random_key3))
self.assertEqual(api.NO_VALUE, region.get("InvalidKey"))
self.assertEqual(NO_VALUE, region.get("InvalidKey"))
keys = mapping.keys()
region.delete_multi(keys)
self.assertEqual(api.NO_VALUE, region.get("InvalidKey"))
self.assertEqual(NO_VALUE, region.get("InvalidKey"))
# should return NO_VALUE as keys no longer exist in cache
self.assertEqual(api.NO_VALUE, region.get(random_key1))
self.assertEqual(api.NO_VALUE, region.get(random_key2))
self.assertEqual(api.NO_VALUE, region.get(random_key3))
self.assertEqual(NO_VALUE, region.get(random_key1))
self.assertEqual(NO_VALUE, region.get(random_key2))
self.assertEqual(NO_VALUE, region.get(random_key3))
def test_additional_crud_method_arguments_support(self):
"""Additional arguments should works across find/insert/update."""

4
oslo_cache/tests/test_dict_backend.py
View File

@ -12,15 +12,15 @@
# License for the specific language governing permissions and limitations
# under the License.
from dogpile.cache import api
from dogpile.cache import region as dp_region
from oslo_cache import core
from oslo_cache.tests import test_cache
from oslo_config import fixture as config_fixture
from oslo_utils import fixture as time_fixture
NO_VALUE = api.NO_VALUE
NO_VALUE = core.NO_VALUE
KEY = 'test_key'
VALUE = 'test_value'