Copy cache package from oslo-incubator
Related-Bug: #1276440 Change-Id: I7aaf8ae2eb909816d85092baa5c111f00e60d2c7
This commit is contained in:
Jakub Libosvar
parent
fa9098529f
commit
494a0f844d
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@ -0,0 +1,165 @@
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# Copyright 2013 Red Hat, Inc.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import collections
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from neutron.openstack.common.cache import backends
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from neutron.openstack.common import lockutils
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from neutron.openstack.common import timeutils
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class MemoryBackend(backends.BaseCache):
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def __init__(self, parsed_url, options=None):
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super(MemoryBackend, self).__init__(parsed_url, options)
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self._clear()
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def _set_unlocked(self, key, value, ttl=0):
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expires_at = 0
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if ttl != 0:
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expires_at = timeutils.utcnow_ts() + ttl
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self._cache[key] = (expires_at, value)
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if expires_at:
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self._keys_expires[expires_at].add(key)
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def _set(self, key, value, ttl=0, not_exists=False):
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with lockutils.lock(key):
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# NOTE(flaper87): This is needed just in `set`
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# calls, hence it's not in `_set_unlocked`
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if not_exists and self._exists_unlocked(key):
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return False
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self._set_unlocked(key, value, ttl)
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return True
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def _get_unlocked(self, key, default=None):
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now = timeutils.utcnow_ts()
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try:
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timeout, value = self._cache[key]
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except KeyError:
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return (0, default)
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if timeout and now >= timeout:
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# NOTE(flaper87): Record expired,
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# remove it from the cache but catch
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# KeyError and ValueError in case
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# _purge_expired removed this key already.
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try:
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del self._cache[key]
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except KeyError:
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pass
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try:
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# NOTE(flaper87): Keys with ttl == 0
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# don't exist in the _keys_expires dict
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self._keys_expires[timeout].remove(key)
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except (KeyError, ValueError):
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pass
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return (0, default)
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return (timeout, value)
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def _get(self, key, default=None):
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with lockutils.lock(key):
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return self._get_unlocked(key, default)[1]
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def _exists_unlocked(self, key):
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now = timeutils.utcnow_ts()
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try:
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timeout = self._cache[key][0]
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return not timeout or now <= timeout
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except KeyError:
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return False
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def __contains__(self, key):
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with lockutils.lock(key):
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return self._exists_unlocked(key)
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def _incr_append(self, key, other):
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with lockutils.lock(key):
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timeout, value = self._get_unlocked(key)
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if value is None:
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return None
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ttl = timeutils.utcnow_ts() - timeout
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new_value = value + other
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self._set_unlocked(key, new_value, ttl)
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return new_value
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def _incr(self, key, delta):
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if not isinstance(delta, int):
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raise TypeError('delta must be an int instance')
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return self._incr_append(key, delta)
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def _append_tail(self, key, tail):
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return self._incr_append(key, tail)
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def _purge_expired(self):
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"""Removes expired keys from the cache."""
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now = timeutils.utcnow_ts()
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for timeout in sorted(self._keys_expires.keys()):
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# NOTE(flaper87): If timeout is greater
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# than `now`, stop the iteration, remaining
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# keys have not expired.
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if now < timeout:
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break
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# NOTE(flaper87): Unset every key in
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# this set from the cache if its timeout
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# is equal to `timeout`. (The key might
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# have been updated)
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for subkey in self._keys_expires.pop(timeout):
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try:
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if self._cache[subkey][0] == timeout:
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del self._cache[subkey]
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except KeyError:
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continue
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def __delitem__(self, key):
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self._purge_expired()
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# NOTE(flaper87): Delete the key. Using pop
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# since it could have been deleted already
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value = self._cache.pop(key, None)
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if value:
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try:
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# NOTE(flaper87): Keys with ttl == 0
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# don't exist in the _keys_expires dict
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self._keys_expires[value[0]].remove(value[1])
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except (KeyError, ValueError):
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pass
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def _clear(self):
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self._cache = {}
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self._keys_expires = collections.defaultdict(set)
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def _get_many(self, keys, default):
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return super(MemoryBackend, self)._get_many(keys, default)
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def _set_many(self, data, ttl=0):
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return super(MemoryBackend, self)._set_many(data, ttl)
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def _unset_many(self, keys):
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return super(MemoryBackend, self)._unset_many(keys)
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@ -0,0 +1,263 @@
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# Copyright 2013 Red Hat, Inc.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import abc
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import six
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NOTSET = object()
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@six.add_metaclass(abc.ABCMeta)
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class BaseCache(object):
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"""Base Cache Abstraction
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:params parsed_url: Parsed url object.
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:params options: A dictionary with configuration parameters
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for the cache. For example:
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- default_ttl: An integer defining the default ttl
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for keys.
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"""
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def __init__(self, parsed_url, options=None):
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self._parsed_url = parsed_url
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self._options = options or {}
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self._default_ttl = int(self._options.get('default_ttl', 0))
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@abc.abstractmethod
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def _set(self, key, value, ttl, not_exists=False):
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"""Implementations of this class have to override this method."""
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def set(self, key, value, ttl, not_exists=False):
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"""Sets or updates a cache entry
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NOTE: Thread-safety is required and has to be
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guaranteed by the backend implementation.
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:params key: Item key as string.
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:type key: `unicode string`
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:params value: Value to assign to the key. This
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can be anything that is handled
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by the current backend.
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:params ttl: Key's timeout in seconds. 0 means
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no timeout.
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:type ttl: int
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:params not_exists: If True, the key will be set
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if it doesn't exist. Otherwise,
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it'll always be set.
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:type not_exists: bool
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:returns: True if the operation succeeds, False otherwise.
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"""
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if ttl is None:
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ttl = self._default_ttl
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return self._set(key, value, ttl, not_exists)
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def __setitem__(self, key, value):
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self.set(key, value, self._default_ttl)
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def setdefault(self, key, value):
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"""Sets the key value to `value` if it doesn't exist
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:params key: Item key as string.
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:type key: `unicode string`
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:params value: Value to assign to the key. This
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can be anything that is handled
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by the current backend.
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"""
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try:
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return self[key]
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except KeyError:
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self[key] = value
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return value
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@abc.abstractmethod
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def _get(self, key, default):
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"""Implementations of this class have to override this method."""
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def get(self, key, default=None):
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"""Gets one item from the cache
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NOTE: Thread-safety is required and it has to be
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guaranteed by the backend implementation.
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:params key: Key for the item to retrieve
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from the cache.
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:params default: The default value to return.
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:returns: `key`'s value in the cache if it exists,
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otherwise `default` should be returned.
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"""
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return self._get(key, default)
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def __getitem__(self, key):
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value = self.get(key, NOTSET)
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if value is NOTSET:
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raise KeyError
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return value
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@abc.abstractmethod
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def __delitem__(self, key):
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"""Removes an item from cache.
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NOTE: Thread-safety is required and it has to be
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guaranteed by the backend implementation.
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:params key: The key to remove.
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:returns: The key value if there's one
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"""
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@abc.abstractmethod
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def _clear(self):
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"""Implementations of this class have to override this method."""
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def clear(self):
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"""Removes all items from the cache.
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NOTE: Thread-safety is required and it has to be
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guaranteed by the backend implementation.
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"""
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return self._clear()
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@abc.abstractmethod
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def _incr(self, key, delta):
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"""Implementations of this class have to override this method."""
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def incr(self, key, delta=1):
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"""Increments the value for a key
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:params key: The key for the value to be incremented
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:params delta: Number of units by which to increment
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the value. Pass a negative number to
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decrement the value.
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:returns: The new value
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"""
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return self._incr(key, delta)
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@abc.abstractmethod
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def _append_tail(self, key, tail):
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"""Implementations of this class have to override this method."""
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def append_tail(self, key, tail):
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"""Appends `tail` to `key`'s value.
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:params key: The key of the value to which
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`tail` should be appended.
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:params tail: The list of values to append to the
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original.
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:returns: The new value
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"""
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if not hasattr(tail, "__iter__"):
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raise TypeError('Tail must be an iterable')
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if not isinstance(tail, list):
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# NOTE(flaper87): Make sure we pass a list
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# down to the implementation. Not all drivers
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# have support for generators, sets or other
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# iterables.
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tail = list(tail)
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return self._append_tail(key, tail)
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def append(self, key, value):
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"""Appends `value` to `key`'s value.
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:params key: The key of the value to which
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`tail` should be appended.
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:params value: The value to append to the
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original.
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:returns: The new value
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"""
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return self.append_tail(key, [value])
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@abc.abstractmethod
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def __contains__(self, key):
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"""Verifies that a key exists.
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:params key: The key to verify.
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:returns: True if the key exists,
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otherwise False.
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"""
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@abc.abstractmethod
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def _get_many(self, keys, default):
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"""Implementations of this class have to override this method."""
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return ((k, self.get(k, default=default)) for k in keys)
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def get_many(self, keys, default=NOTSET):
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"""Gets keys' value from cache
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:params keys: List of keys to retrieve.
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:params default: The default value to return
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for each key that is not in
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the cache.
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:returns: A generator of (key, value)
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"""
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return self._get_many(keys, default)
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@abc.abstractmethod
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def _set_many(self, data, ttl):
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"""Implementations of this class have to override this method."""
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for key, value in data.items():
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self.set(key, value, ttl=ttl)
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def set_many(self, data, ttl=None):
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"""Puts several items into the cache at once
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Depending on the backend, this operation may or may
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not be efficient. The default implementation calls
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set for each (key, value) pair passed, other backends
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support set_many operations as part of their protocols.
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:params data: A dictionary like {key: val} to store
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in the cache.
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:params ttl: Key's timeout in seconds.
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"""
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if ttl is None:
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ttl = self._default_ttl
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self._set_many(data, ttl)
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def update(self, **kwargs):
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"""Sets several (key, value) paris.
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Refer to the `set_many` docstring.
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"""
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self.set_many(kwargs, ttl=self._default_ttl)
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@abc.abstractmethod
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def _unset_many(self, keys):
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"""Implementations of this class have to override this method."""
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for key in keys:
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del self[key]
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def unset_many(self, keys):
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"""Removes several keys from the cache at once
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:params keys: List of keys to unset.
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"""
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self._unset_many(keys)
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@ -0,0 +1,79 @@
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# Copyright 2013 Red Hat, Inc.
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#
|
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# 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.
|
||||
|
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"""Cache library.
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Supported configuration options:
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`default_backend`: Name of the cache backend to use.
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`key_namespace`: Namespace under which keys will be created.
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"""
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from stevedore import driver
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from neutron.openstack.common.py3kcompat import urlutils
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def _get_olso_configs():
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"""Returns the oslo.config options to register."""
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# NOTE(flaper87): Oslo config should be
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# optional. Instead of doing try / except
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# at the top of this file, lets import cfg
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# here and assume that the caller of this
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# function already took care of this dependency.
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from oslo.config import cfg
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return [
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cfg.StrOpt('cache_url', default='memory://',
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help='URL to connect to the cache back end.')
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]
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def register_oslo_configs(conf):
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"""Registers a cache configuration options
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:params conf: Config object.
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:type conf: `cfg.ConfigOptions`
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"""
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conf.register_opts(_get_olso_configs())
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def get_cache(url='memory://'):
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"""Loads the cache backend
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This function loads the cache backend
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specified in the given configuration.
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:param conf: Configuration instance to use
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"""
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parsed = urlutils.urlparse(url)
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backend = parsed.scheme
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query = parsed.query
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# NOTE(flaper87): We need the following hack
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# for python versions < 2.7.5. Previous versions
|
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# of python parsed query params just for 'known'
|
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# schemes. This was changed in this patch:
|
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# http://hg.python.org/cpython/rev/79e6ff3d9afd
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if not query and '?' in parsed.path:
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query = parsed.path.split('?', 1)[-1]
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parameters = urlutils.parse_qsl(query)
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kwargs = {'options': dict(parameters)}
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mgr = driver.DriverManager('neutron.openstack.common.cache.backends', backend,
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invoke_on_load=True,
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invoke_args=[parsed],
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invoke_kwds=kwargs)
|
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return mgr.driver
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|
|
@ -1,5 +1,6 @@
|
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[DEFAULT]
|
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# The list of modules to copy from oslo-incubator.git
|
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module=cache
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module=context
|
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module=db
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module=db.sqlalchemy
|
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|
|
|
|||
|
|
@ -161,6 +161,8 @@ neutron.ml2.mechanism_drivers =
|
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cisco_nexus = neutron.plugins.ml2.drivers.cisco.nexus.mech_cisco_nexus:CiscoNexusMechanismDriver
|
||||
l2population = neutron.plugins.ml2.drivers.l2pop.mech_driver:L2populationMechanismDriver
|
||||
bigswitch = neutron.plugins.ml2.drivers.mech_bigswitch.driver:BigSwitchMechanismDriver
|
||||
neutron.openstack.common.cache.backends =
|
||||
memory = neutron.openstack.common.cache._backends.memory:MemoryBackend
|
||||
|
||||
[build_sphinx]
|
||||
all_files = 1
|
||||
|
|
|
|||
Loading…
Reference in New Issue