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Diffstat (limited to 'openstack/common/plugin/callbackplugin.py')
-rw-r--r-- | openstack/common/plugin/callbackplugin.py | 93 |
1 files changed, 0 insertions, 93 deletions
diff --git a/openstack/common/plugin/callbackplugin.py b/openstack/common/plugin/callbackplugin.py deleted file mode 100644 index 2de7fb0..0000000 --- a/openstack/common/plugin/callbackplugin.py +++ /dev/null @@ -1,93 +0,0 @@ -# Copyright 2012 OpenStack Foundation. -# All Rights Reserved. -# -# 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 openstack.common import log as logging -from openstack.common.plugin import plugin - - -LOG = logging.getLogger(__name__) - - -class _CallbackNotifier(object): - """Manages plugin-defined notification callbacks. - - For each Plugin, a CallbackNotifier will be added to the - notification driver list. Calls to notify() with appropriate - messages will be hooked and prompt callbacks. - - A callback should look like this: - def callback(context, message, user_data) - """ - - def __init__(self): - self._callback_dict = {} - - def _add_callback(self, event_type, callback, user_data): - callback_list = self._callback_dict.get(event_type, []) - callback_list.append({'function': callback, - 'user_data': user_data}) - self._callback_dict[event_type] = callback_list - - def _remove_callback(self, callback): - for callback_list in self._callback_dict.values(): - for entry in callback_list: - if entry['function'] == callback: - callback_list.remove(entry) - - def notify(self, context, message): - if message.get('event_type') not in self._callback_dict: - return - - for entry in self._callback_dict[message.get('event_type')]: - entry['function'](context, message, entry.get('user_data')) - - def callbacks(self): - return self._callback_dict - - -class CallbackPlugin(plugin.Plugin): - """Plugin with a simple callback interface. - - This class is provided as a convenience for producing a simple - plugin that only watches a couple of events. For example, here's - a subclass which prints a line the first time an instance is created. - - class HookInstanceCreation(CallbackPlugin): - - def __init__(self, _service_name): - super(HookInstanceCreation, self).__init__() - self._add_callback(self.magic, 'compute.instance.create.start') - - def magic(self): - print "An instance was created!" - self._remove_callback(self, self.magic) - """ - - def __init__(self, service_name): - super(CallbackPlugin, self).__init__(service_name) - self._callback_notifier = _CallbackNotifier() - self._add_notifier(self._callback_notifier) - - def _add_callback(self, callback, event_type, user_data=None): - """Add callback for a given event notification. - - Subclasses can call this as an alternative to implementing - a fullblown notify notifier. - """ - self._callback_notifier._add_callback(event_type, callback, user_data) - - def _remove_callback(self, callback): - """Remove all notification callbacks to specified function.""" - self._callback_notifier._remove_callback(callback) |