python/adapters/extensions/omci/database/alarm_db_ext.py - voltha-go - Gitiles

 #
 # Copyright 2018 the original author or authors.
 #
 # 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 mib_db_api import *
 from voltha.protos.omci_alarm_db_pb2 import AlarmInstanceData, AlarmClassData, \
     AlarmDeviceData, AlarmAttributeData


 class AlarmDbExternal(MibDbApi):
     """
     A persistent external OpenOMCI Alarm Database
     """
     CURRENT_VERSION = 1                       # VOLTHA v1.3.0 release
     ALARM_BITMAP_KEY = 'alarm_bit_map'

     _TIME_FORMAT = '%Y%m%d-%H%M%S.%f'

     # Paths from root proxy
     ALARM_PATH = '/omci_alarms'
     DEVICE_PATH = ALARM_PATH + '/{}'            # .format(device_id)

     # Classes, Instances, and Attributes as lists from root proxy
     CLASSES_PATH = DEVICE_PATH + '/classes'                                # .format(device_id)
     INSTANCES_PATH = DEVICE_PATH + '/classes/{}/instances'                 # .format(device_id, class_id)
     ATTRIBUTES_PATH = DEVICE_PATH + '/classes/{}/instances/{}/attributes'  # .format(device_id, class_id, instance_id)

     # Single Class, Instance, and Attribute as objects from device proxy
     CLASS_PATH = '/classes/{}'                                 # .format(class_id)
     INSTANCE_PATH = '/classes/{}/instances/{}'                 # .format(class_id, instance_id)
     ATTRIBUTE_PATH = '/classes/{}/instances/{}/attributes/{}'  # .format(class_id, instance_id
                                                                #         attribute_name)

     def __init__(self, omci_agent):
         """
         Class initializer
         :param omci_agent: (OpenOMCIAgent) OpenOMCI Agent
         """
         super(AlarmDbExternal, self).__init__(omci_agent)
         self._core = omci_agent.core

     def start(self):
         """
         Start up/restore the database
         """
         self.log.debug('start')

         if not self._started:
             super(AlarmDbExternal, self).start()
             root_proxy = self._core.get_proxy('/')

             try:
                 base = root_proxy.get(AlarmDbExternal.ALARM_PATH)
                 self.log.info('db-exists', num_devices=len(base))

             except Exception as e:
                 self.log.exception('start-failure', e=e)
                 raise

     def stop(self):
         """
         Start up the database
         """
         self.log.debug('stop')

         if self._started:
             super(AlarmDbExternal, self).stop()
             # TODO: Delete this method if nothing else is done except calling the base class

     def _time_to_string(self, time):
         return time.strftime(AlarmDbExternal._TIME_FORMAT) if time is not None else ''

     def _string_to_time(self, time):
         return datetime.strptime(time, AlarmDbExternal._TIME_FORMAT) if len(time) else None

     def _attribute_to_string(self, value):
         """
         Convert an ME's attribute value to string representation

         :param value: (long) Alarm bitmaps are always a Long
         :return: (str) String representation of the value
         """
         return str(value)

     def _string_to_attribute(self, str_value):
         """
         Convert an ME's attribute value-string to its Scapy decode equivalent

         :param device_id: (str) ONU Device ID
         :param class_id: (int) Class ID
         :param attr_name: (str) Attribute Name (see EntityClasses)
         :param str_value: (str) Attribute Value in string form

         :return: (various) String representation of the value
         :raises KeyError: Device, Class ID, or Attribute does not exist
         """
         # Alarms are always a bitmap which is a long
         return long(str_value) if len(str_value) else 0L

     def add(self, device_id, overwrite=False):
         """
         Add a new ONU to database

         :param device_id: (str) Device ID of ONU to add
         :param overwrite: (bool) Overwrite existing entry if found.

         :raises KeyError: If device already exists and 'overwrite' is False
         """
         self.log.debug('add-device', device_id=device_id, overwrite=overwrite)

         now = datetime.utcnow()
         found = False
         root_proxy = self._core.get_proxy('/')

         data = AlarmDeviceData(device_id=device_id,
                                created=self._time_to_string(now),
                                version=AlarmDbExternal.CURRENT_VERSION,
                                last_alarm_sequence=0)
         try:
             dev_proxy = self._device_proxy(device_id)
             found = True

             if not overwrite:
                 # Device already exists
                 raise KeyError('Device with ID {} already exists in Alarm database'.
                                format(device_id))

             # Overwrite with new data
             data = dev_proxy.get('/', depth=0)
             self._root_proxy.update(AlarmDbExternal.DEVICE_PATH.format(device_id), data)
             self._modified = now

         except KeyError:
             if found:
                 raise
             # Did not exist, add it now
             root_proxy.add(AlarmDbExternal.ALARM_PATH, data)
             self._created = now
             self._modified = now

     def remove(self, device_id):
         """
         Remove an ONU from the database

         :param device_id: (str) Device ID of ONU to remove from database
         """
         self.log.debug('remove-device', device_id=device_id)

         if not self._started:
             raise DatabaseStateError('The Database is not currently active')

         if not isinstance(device_id, basestring):
             raise TypeError('Device ID should be an string')

         try:
             # self._root_proxy.get(AlarmDbExternal.DEVICE_PATH.format(device_id))
             self._root_proxy.remove(AlarmDbExternal.DEVICE_PATH.format(device_id))
             self._modified = datetime.utcnow()

         except KeyError:
             # Did not exists, which is not a failure
             pass

         except Exception as e:
             self.log.exception('remove-exception', device_id=device_id, e=e)
             raise

     @property
     def _root_proxy(self):
         return self._core.get_proxy('/')

     def _device_proxy(self, device_id):
         """
         Return a config proxy to the OMCI Alarm_DB leaf for a given device

         :param device_id: (str) ONU Device ID
         :return: (ConfigProxy) Configuration proxy rooted at OMCI Alarm DB
         :raises KeyError: If the device does not exist in the database
         """
         if not isinstance(device_id, basestring):
             raise TypeError('Device ID should be an string')

         if not self._started:
             raise DatabaseStateError('The Database is not currently active')

         return self._core.get_proxy(AlarmDbExternal.DEVICE_PATH.format(device_id))

     def _class_proxy(self, device_id, class_id, create=False):
         """
         Get a config proxy to a specific managed entity class
         :param device_id: (str) ONU Device ID
         :param class_id: (int) Class ID
         :param create: (bool) If true, create default instance (and class)
         :return: (ConfigProxy) Class configuration proxy

         :raises DatabaseStateError: If database is not started
         :raises KeyError: If Instance does not exist and 'create' is False
         """
         if not self._started:
             raise DatabaseStateError('The Database is not currently active')

         if not 0 <= class_id <= 0xFFFF:
             raise ValueError('class-id is 0..0xFFFF')

         fmt = AlarmDbExternal.DEVICE_PATH + AlarmDbExternal.CLASS_PATH
         path = fmt.format(device_id, class_id)

         try:
             return self._core.get_proxy(path)

         except KeyError:
             if not create:
                 self.log.error('class-proxy-does-not-exist', device_id=device_id,
                                class_id=class_id)
                 raise

         # Create class
         data = AlarmClassData(class_id=class_id)
         root_path = AlarmDbExternal.CLASSES_PATH.format(device_id)
         self._root_proxy.add(root_path, data)

         return self._core.get_proxy(path)

     def _instance_proxy(self, device_id, class_id, instance_id, create=False):
         """
         Get a config proxy to a specific managed entity instance
         :param device_id: (str) ONU Device ID
         :param class_id: (int) Class ID
         :param instance_id: (int) Instance ID
         :param create: (bool) If true, create default instance (and class)
         :return: (ConfigProxy) Instance configuration proxy

         :raises DatabaseStateError: If database is not started
         :raises KeyError: If Instance does not exist and 'create' is False
         """
         if not self._started:
             raise DatabaseStateError('The Database is not currently active')

         if not isinstance(device_id, basestring):
             raise TypeError('Device ID is a string')

         if not 0 <= class_id <= 0xFFFF:
             raise ValueError('class-id is 0..0xFFFF')

         if not 0 <= instance_id <= 0xFFFF:
             raise ValueError('instance-id is 0..0xFFFF')

         fmt = AlarmDbExternal.DEVICE_PATH + AlarmDbExternal.INSTANCE_PATH
         path = fmt.format(device_id, class_id, instance_id)

         try:
             return self._core.get_proxy(path)

         except KeyError:
             if not create:
                 self.log.error('instance-proxy-does-not-exist', device_id=device_id,
                                class_id=class_id, instance_id=instance_id)
                 raise

         # Create instance, first make sure class exists
         self._class_proxy(device_id, class_id, create=True)

         now = self._time_to_string(datetime.utcnow())
         data = AlarmInstanceData(instance_id=instance_id, created=now, modified=now)
         root_path = AlarmDbExternal.INSTANCES_PATH.format(device_id, class_id)
         self._root_proxy.add(root_path, data)

         return self._core.get_proxy(path)

     def save_last_sync_time(self, device_id, value):
         """
         Save the Last Sync time to the database in an easy location to access

         :param device_id: (str) ONU Device ID
         :param value: (DateTime) Value to save
         """
         self.log.debug('save-last-sync-time', device_id=device_id, time=str(value))

         try:
             if not isinstance(value, datetime):
                 raise TypeError('Expected a datetime object, got {}'.
                                 format(type(datetime)))

             device_proxy = self._device_proxy(device_id)
             data = device_proxy.get(depth=0)

             now = datetime.utcnow()
             data.last_sync_time = self._time_to_string(value)

             # Update
             self._root_proxy.update(AlarmDbExternal.DEVICE_PATH.format(device_id),
                                     data)
             self._modified = now
             self.log.debug('save-sync-time-complete', device_id=device_id)

         except Exception as e:
             self.log.exception('save-last-sync-exception', device_id=device_id, e=e)
             raise

     def get_last_sync_time(self, device_id):
         """
         Get the Last Sync Time saved to the database for a device

         :param device_id: (str) ONU Device ID
         :return: (int) The Value or None if not found
         """
         self.log.debug('get-last-sync-time', device_id=device_id)

         try:
             device_proxy = self._device_proxy(device_id)
             data = device_proxy.get(depth=0)
             return self._string_to_time(data.last_sync_time)

         except KeyError:
             return None     # OMCI MIB_DB entry has not yet been created

         except Exception as e:
             self.log.exception('get-last-sync-time-exception', e=e)
             raise

     def save_alarm_last_sync(self, device_id, value):
         """
         Save the Last Alarm Sequence value to the database in an easy location to access

         :param device_id: (str) ONU Device ID
         :param value: (int) Value to save
         """
         self.log.debug('save-last-sync', device_id=device_id, seq=str(value))

         try:
             if not isinstance(value, int):
                 raise TypeError('Expected a integer, got {}'.format(type(value)))

             device_proxy = self._device_proxy(device_id)
             data = device_proxy.get(depth=0)

             now = datetime.utcnow()
             data.last_alarm_sequence = int(value)

             # Update
             self._root_proxy.update(AlarmDbExternal.DEVICE_PATH.format(device_id),
                                     data)
             self._modified = now
             self.log.debug('save-sequence-complete', device_id=device_id)

         except Exception as e:
             self.log.exception('save-last-sync-exception', device_id=device_id, e=e)
             raise

     def get_alarm_last_sync(self, device_id):
         """
         Get the Last Sync Time saved to the database for a device

         :param device_id: (str) ONU Device ID
         :return: (int) The Value or None if not found
         """
         self.log.debug('get-last-sync', device_id=device_id)

         try:
             device_proxy = self._device_proxy(device_id)
             data = device_proxy.get(depth=0)
             return int(data.last_alarm_sequence)

         except KeyError:
             return None     # OMCI ALARM_DB entry has not yet been created

         except Exception as e:
             self.log.exception('get-last-alarm-exception', e=e)
             raise

     def _add_new_class(self, device_id, class_id, instance_id, attributes):
         """
         Create an entry for a new class in the external database

         :param device_id: (str) ONU Device ID
         :param class_id: (int) ME Class ID
         :param instance_id: (int) ME Entity ID
         :param attributes: (dict) Attribute dictionary

         :returns: (bool) True if the value was saved to the database. False if the
                          value was identical to the current instance
         """
         self.log.debug('add', device_id=device_id, class_id=class_id,
                        instance_id=instance_id, attributes=attributes)

         now = self._time_to_string(datetime.utcnow())
         attrs = [AlarmAttributeData(name=k,
                                     value=self._attribute_to_string(v)) for k, v in attributes.items()]
         class_data = AlarmClassData(class_id=class_id,
                                     instances=[AlarmInstanceData(instance_id=instance_id,
                                                                  created=now,
                                                                  modified=now,
                                                                  attributes=attrs)])

         self._root_proxy.add(AlarmDbExternal.CLASSES_PATH.format(device_id), class_data)
         self.log.debug('set-complete', device_id=device_id, class_id=class_id,
                        entity_id=instance_id, attributes=attributes)
         return True

     def _add_new_instance(self,  device_id, class_id, instance_id, attributes):
         """
         Create an entry for a instance of an existing class in the external database

         :param device_id: (str) ONU Device ID
         :param class_id: (int) ME Class ID
         :param instance_id: (int) ME Entity ID
         :param attributes: (dict) Attribute dictionary

         :returns: (bool) True if the value was saved to the database. False if the
                          value was identical to the current instance
         """
         self.log.debug('add', device_id=device_id, class_id=class_id,
                        instance_id=instance_id, attributes=attributes)

         now = self._time_to_string(datetime.utcnow())
         attrs = [AlarmAttributeData(name=k,
                                     value=self._attribute_to_string(v)) for k, v in attributes.items()]
         instance_data = AlarmInstanceData(instance_id=instance_id,
                                           created=now,
                                           modified=now,
                                           attributes=attrs)

         self._root_proxy.add(AlarmDbExternal.INSTANCES_PATH.format(device_id, class_id),
                              instance_data)

         self.log.debug('set-complete', device_id=device_id, class_id=class_id,
                        entity_id=instance_id, attributes=attributes)
         return True

     def set(self, device_id, class_id, instance_id, attributes):
         """
         Set a database value.  This should only be called by the Alarm synchronizer
         and its related tasks

         :param device_id: (str) ONU Device ID
         :param class_id: (int) ME Class ID
         :param instance_id: (int) ME Entity ID
         :param attributes: (dict) Attribute dictionary

         :returns: (bool) True if the value was saved to the database. False if the
                          value was identical to the current instance

         :raises KeyError: If device does not exist
         :raises DatabaseStateError: If the database is not enabled
         """
         self.log.debug('set', device_id=device_id, class_id=class_id,
                        instance_id=instance_id, attributes=attributes)
         try:
             if not isinstance(device_id, basestring):
                 raise TypeError('Device ID should be a string')

             if not 0 <= class_id <= 0xFFFF:
                 raise ValueError("Invalid Class ID: {}, should be 0..65535".format(class_id))

             if not 0 <= instance_id <= 0xFFFF:
                 raise ValueError("Invalid Instance ID: {}, should be 0..65535".format(instance_id))

             if not isinstance(attributes, dict):
                 raise TypeError("Attributes should be a dictionary")

             if not self._started:
                 raise DatabaseStateError('The Database is not currently active')

             # Determine the best strategy to add the information
             dev_proxy = self._device_proxy(device_id)

             try:
                 class_data = dev_proxy.get(AlarmDbExternal.CLASS_PATH.format(class_id), deep=True)

                 inst_data = next((inst for inst in class_data.instances
                                  if inst.instance_id == instance_id), None)

                 if inst_data is None:
                     return self._add_new_instance(device_id, class_id, instance_id, attributes)

                 # Possibly adding to or updating an existing instance
                 # Get instance proxy, creating it if needed

                 exist_attr_indexes = dict()
                 attr_len = len(inst_data.attributes)

                 for index in xrange(0, attr_len):
                     exist_attr_indexes[inst_data.attributes[index].name] = index

                 modified = False
                 str_value = ''
                 new_attributes = []

                 for k, v in attributes.items():
                     try:
                         str_value = self._attribute_to_string(v)
                         new_attributes.append(AlarmAttributeData(name=k, value=str_value))

                     except Exception as e:
                         self.log.exception('save-error', e=e, class_id=class_id,
                                            attr=k, value_type=type(v))

                     if k not in exist_attr_indexes or \
                             inst_data.attributes[exist_attr_indexes[k]].value != str_value:
                         modified = True

                 if modified:
                     now = datetime.utcnow()
                     new_data = AlarmInstanceData(instance_id=instance_id,
                                                  created=inst_data.created,
                                                  modified=self._time_to_string(now),
                                                  attributes=new_attributes)
                     dev_proxy.remove(AlarmDbExternal.INSTANCE_PATH.format(class_id, instance_id))
                     self._root_proxy.add(AlarmDbExternal.INSTANCES_PATH.format(device_id,
                                                                                class_id), new_data)

                 self.log.debug('set-complete', device_id=device_id, class_id=class_id,
                                entity_id=instance_id, attributes=attributes, modified=modified)
                 return modified

             except KeyError:
                 # Here if the class-id does not yet exist in the database
                 return self._add_new_class(device_id, class_id, instance_id,
                                            attributes)
         except Exception as e:
             self.log.exception('set-exception', device_id=device_id, class_id=class_id,
                                instance_id=instance_id, attributes=attributes, e=e)
             raise

     def delete(self, device_id, class_id, entity_id):
         """
         Delete an entity from the database if it exists.  If all instances
         of a class are deleted, the class is deleted as well.

         :param device_id: (str) ONU Device ID
         :param class_id: (int) ME Class ID
         :param entity_id: (int) ME Entity ID

         :returns: (bool) True if the instance was found and deleted. False
                          if it did not exist.

         :raises KeyError: If device does not exist
         :raises DatabaseStateError: If the database is not enabled
         """
         self.log.debug('delete', device_id=device_id, class_id=class_id,
                        entity_id=entity_id)

         if not self._started:
             raise DatabaseStateError('The Database is not currently active')

         if not isinstance(device_id, basestring):
             raise TypeError('Device ID should be an string')

         if not 0 <= class_id <= 0xFFFF:
             raise ValueError('class-id is 0..0xFFFF')

         if not 0 <= entity_id <= 0xFFFF:
             raise ValueError('instance-id is 0..0xFFFF')

         try:
             # Remove instance
             self._instance_proxy(device_id, class_id, entity_id).remove('/')
             now = datetime.utcnow()

             # If resulting class has no instance, remove it as well
             class_proxy = self._class_proxy(device_id, class_id)
             class_data = class_proxy.get('/', depth=1)

             if len(class_data.instances) == 0:
                 class_proxy.remove('/')

             self._modified = now
             return True

         except KeyError:
             return False    # Not found

         except Exception as e:
             self.log.exception('get-last-data-exception', device_id=device_id, e=e)
             raise

     def query(self, device_id, class_id=None, instance_id=None, attributes=None):
         """
         Get database information.

         This method can be used to request information from the database to the detailed
         level requested

         :param device_id: (str) ONU Device ID
         :param class_id:  (int) Managed Entity class ID
         :param instance_id: (int) Managed Entity instance
         :param attributes: (list/set or str) Managed Entity instance's attributes

         :return: (dict) The value(s) requested. If class/inst/attribute is
                         not found, an empty dictionary is returned
         :raises KeyError: If the requested device does not exist
         :raises DatabaseStateError: If the database is not enabled
         """
         self.log.debug('query', device_id=device_id, class_id=class_id,
                        instance_id=instance_id, attributes=attributes)
         try:
             if class_id is None:
                 # Get full device info
                 dev_data = self._device_proxy(device_id).get('/', depth=-1)
                 data = self._device_to_dict(dev_data)

             elif instance_id is None:
                 # Get all instances of the class
                 try:
                     cls_data = self._class_proxy(device_id, class_id).get('/', depth=-1)
                     data = self._class_to_dict(cls_data)

                 except KeyError:
                     data = dict()

             else:
                 # Get all attributes of a specific ME
                 try:
                     inst_data = self._instance_proxy(device_id, class_id, instance_id).\
                         get('/', depth=-1)

                     if attributes is None:
                         # All Attributes
                         data = self._instance_to_dict(inst_data)

                     else:
                         # Specific attribute(s)
                         if isinstance(attributes, basestring):
                             attributes = {attributes}

                         data = {
                             attr.name: self._string_to_attribute(attr.value)
                             for attr in inst_data.attributes if attr.name in attributes}

                 except KeyError:
                     data = dict()

             return data

         except KeyError:
             self.log.warn('query-no-device', device_id=device_id)
             raise

         except Exception as e:
             self.log.exception('get-last-sync-exception', device_id=device_id, e=e)
             raise

     def _instance_to_dict(self, instance):
         if not isinstance(instance, AlarmInstanceData):
             raise TypeError('{} is not of type AlarmInstanceData'.format(type(instance)))

         data = {
             INSTANCE_ID_KEY: instance.instance_id,
             CREATED_KEY: self._string_to_time(instance.created),
             MODIFIED_KEY: self._string_to_time(instance.modified),
             ATTRIBUTES_KEY: dict()
         }
         for attribute in instance.attributes:
             data[ATTRIBUTES_KEY][attribute.name] = self._string_to_attribute(attribute.value)
         return data

     def _class_to_dict(self, val):
         if not isinstance(val, AlarmClassData):
             raise TypeError('{} is not of type AlarmClassData'.format(type(val)))

         data = {
             CLASS_ID_KEY: val.class_id,
         }
         for instance in val.instances:
             data[instance.instance_id] = self._instance_to_dict(instance)
         return data

     def _device_to_dict(self, val):
         if not isinstance(val, AlarmDeviceData):
             raise TypeError('{} is not of type AlarmDeviceData'.format(type(val)))

         data = {
             DEVICE_ID_KEY: val.device_id,
             CREATED_KEY: self._string_to_time(val.created),
             VERSION_KEY: val.version,
             ME_KEY: dict(),
             MSG_TYPE_KEY: set()
         }
         for class_data in val.classes:
             data[class_data.class_id] = self._class_to_dict(class_data)
         for managed_entity in val.managed_entities:
             data[ME_KEY][managed_entity.class_id] = managed_entity.name

         for msg_type in val.message_types:
             data[MSG_TYPE_KEY].add(msg_type.message_type)

         return data
	#
	# Copyright 2018 the original author or authors.
	#
	# 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 mib_db_api import *
	from voltha.protos.omci_alarm_db_pb2 import AlarmInstanceData, AlarmClassData, \
	AlarmDeviceData, AlarmAttributeData


	class AlarmDbExternal(MibDbApi):
	"""
	A persistent external OpenOMCI Alarm Database
	"""
	CURRENT_VERSION = 1 # VOLTHA v1.3.0 release
	ALARM_BITMAP_KEY = 'alarm_bit_map'

	_TIME_FORMAT = '%Y%m%d-%H%M%S.%f'

	# Paths from root proxy
	ALARM_PATH = '/omci_alarms'
	DEVICE_PATH = ALARM_PATH + '/{}' # .format(device_id)

	# Classes, Instances, and Attributes as lists from root proxy
	CLASSES_PATH = DEVICE_PATH + '/classes' # .format(device_id)
	INSTANCES_PATH = DEVICE_PATH + '/classes/{}/instances' # .format(device_id, class_id)
	ATTRIBUTES_PATH = DEVICE_PATH + '/classes/{}/instances/{}/attributes' # .format(device_id, class_id, instance_id)

	# Single Class, Instance, and Attribute as objects from device proxy
	CLASS_PATH = '/classes/{}' # .format(class_id)
	INSTANCE_PATH = '/classes/{}/instances/{}' # .format(class_id, instance_id)
	ATTRIBUTE_PATH = '/classes/{}/instances/{}/attributes/{}' # .format(class_id, instance_id
	# attribute_name)

	def __init__(self, omci_agent):
	"""
	Class initializer
	:param omci_agent: (OpenOMCIAgent) OpenOMCI Agent
	"""
	super(AlarmDbExternal, self).__init__(omci_agent)
	self._core = omci_agent.core

	def start(self):
	"""
	Start up/restore the database
	"""
	self.log.debug('start')

	if not self._started:
	super(AlarmDbExternal, self).start()
	root_proxy = self._core.get_proxy('/')

	try:
	base = root_proxy.get(AlarmDbExternal.ALARM_PATH)
	self.log.info('db-exists', num_devices=len(base))

	except Exception as e:
	self.log.exception('start-failure', e=e)
	raise

	def stop(self):
	"""
	Start up the database
	"""
	self.log.debug('stop')

	if self._started:
	super(AlarmDbExternal, self).stop()
	# TODO: Delete this method if nothing else is done except calling the base class

	def _time_to_string(self, time):
	return time.strftime(AlarmDbExternal._TIME_FORMAT) if time is not None else ''

	def _string_to_time(self, time):
	return datetime.strptime(time, AlarmDbExternal._TIME_FORMAT) if len(time) else None

	def _attribute_to_string(self, value):
	"""
	Convert an ME's attribute value to string representation

	:param value: (long) Alarm bitmaps are always a Long
	:return: (str) String representation of the value
	"""
	return str(value)

	def _string_to_attribute(self, str_value):
	"""
	Convert an ME's attribute value-string to its Scapy decode equivalent

	:param device_id: (str) ONU Device ID
	:param class_id: (int) Class ID
	:param attr_name: (str) Attribute Name (see EntityClasses)
	:param str_value: (str) Attribute Value in string form

	:return: (various) String representation of the value
	:raises KeyError: Device, Class ID, or Attribute does not exist
	"""
	# Alarms are always a bitmap which is a long
	return long(str_value) if len(str_value) else 0L

	def add(self, device_id, overwrite=False):
	"""
	Add a new ONU to database

	:param device_id: (str) Device ID of ONU to add
	:param overwrite: (bool) Overwrite existing entry if found.

	:raises KeyError: If device already exists and 'overwrite' is False
	"""
	self.log.debug('add-device', device_id=device_id, overwrite=overwrite)

	now = datetime.utcnow()
	found = False
	root_proxy = self._core.get_proxy('/')

	data = AlarmDeviceData(device_id=device_id,
	created=self._time_to_string(now),
	version=AlarmDbExternal.CURRENT_VERSION,
	last_alarm_sequence=0)
	try:
	dev_proxy = self._device_proxy(device_id)
	found = True

	if not overwrite:
	# Device already exists
	raise KeyError('Device with ID {} already exists in Alarm database'.
	format(device_id))

	# Overwrite with new data
	data = dev_proxy.get('/', depth=0)
	self._root_proxy.update(AlarmDbExternal.DEVICE_PATH.format(device_id), data)
	self._modified = now

	except KeyError:
	if found:
	raise
	# Did not exist, add it now
	root_proxy.add(AlarmDbExternal.ALARM_PATH, data)
	self._created = now
	self._modified = now

	def remove(self, device_id):
	"""
	Remove an ONU from the database

	:param device_id: (str) Device ID of ONU to remove from database
	"""
	self.log.debug('remove-device', device_id=device_id)

	if not self._started:
	raise DatabaseStateError('The Database is not currently active')

	if not isinstance(device_id, basestring):
	raise TypeError('Device ID should be an string')

	try:
	# self._root_proxy.get(AlarmDbExternal.DEVICE_PATH.format(device_id))
	self._root_proxy.remove(AlarmDbExternal.DEVICE_PATH.format(device_id))
	self._modified = datetime.utcnow()

	except KeyError:
	# Did not exists, which is not a failure
	pass

	except Exception as e:
	self.log.exception('remove-exception', device_id=device_id, e=e)
	raise

	@property
	def _root_proxy(self):
	return self._core.get_proxy('/')

	def _device_proxy(self, device_id):
	"""
	Return a config proxy to the OMCI Alarm_DB leaf for a given device

	:param device_id: (str) ONU Device ID
	:return: (ConfigProxy) Configuration proxy rooted at OMCI Alarm DB
	:raises KeyError: If the device does not exist in the database
	"""
	if not isinstance(device_id, basestring):
	raise TypeError('Device ID should be an string')

	if not self._started:
	raise DatabaseStateError('The Database is not currently active')

	return self._core.get_proxy(AlarmDbExternal.DEVICE_PATH.format(device_id))

	def _class_proxy(self, device_id, class_id, create=False):
	"""
	Get a config proxy to a specific managed entity class
	:param device_id: (str) ONU Device ID
	:param class_id: (int) Class ID
	:param create: (bool) If true, create default instance (and class)
	:return: (ConfigProxy) Class configuration proxy

	:raises DatabaseStateError: If database is not started
	:raises KeyError: If Instance does not exist and 'create' is False
	"""
	if not self._started:
	raise DatabaseStateError('The Database is not currently active')

	if not 0 <= class_id <= 0xFFFF:
	raise ValueError('class-id is 0..0xFFFF')

	fmt = AlarmDbExternal.DEVICE_PATH + AlarmDbExternal.CLASS_PATH
	path = fmt.format(device_id, class_id)

	try:
	return self._core.get_proxy(path)

	except KeyError:
	if not create:
	self.log.error('class-proxy-does-not-exist', device_id=device_id,
	class_id=class_id)
	raise

	# Create class
	data = AlarmClassData(class_id=class_id)
	root_path = AlarmDbExternal.CLASSES_PATH.format(device_id)
	self._root_proxy.add(root_path, data)

	return self._core.get_proxy(path)

	def _instance_proxy(self, device_id, class_id, instance_id, create=False):
	"""
	Get a config proxy to a specific managed entity instance
	:param device_id: (str) ONU Device ID
	:param class_id: (int) Class ID
	:param instance_id: (int) Instance ID
	:param create: (bool) If true, create default instance (and class)
	:return: (ConfigProxy) Instance configuration proxy

	:raises DatabaseStateError: If database is not started
	:raises KeyError: If Instance does not exist and 'create' is False
	"""
	if not self._started:
	raise DatabaseStateError('The Database is not currently active')

	if not isinstance(device_id, basestring):
	raise TypeError('Device ID is a string')

	if not 0 <= class_id <= 0xFFFF:
	raise ValueError('class-id is 0..0xFFFF')

	if not 0 <= instance_id <= 0xFFFF:
	raise ValueError('instance-id is 0..0xFFFF')

	fmt = AlarmDbExternal.DEVICE_PATH + AlarmDbExternal.INSTANCE_PATH
	path = fmt.format(device_id, class_id, instance_id)

	try:
	return self._core.get_proxy(path)

	except KeyError:
	if not create:
	self.log.error('instance-proxy-does-not-exist', device_id=device_id,
	class_id=class_id, instance_id=instance_id)
	raise

	# Create instance, first make sure class exists
	self._class_proxy(device_id, class_id, create=True)

	now = self._time_to_string(datetime.utcnow())
	data = AlarmInstanceData(instance_id=instance_id, created=now, modified=now)
	root_path = AlarmDbExternal.INSTANCES_PATH.format(device_id, class_id)
	self._root_proxy.add(root_path, data)

	return self._core.get_proxy(path)

	def save_last_sync_time(self, device_id, value):
	"""
	Save the Last Sync time to the database in an easy location to access

	:param device_id: (str) ONU Device ID
	:param value: (DateTime) Value to save
	"""
	self.log.debug('save-last-sync-time', device_id=device_id, time=str(value))

	try:
	if not isinstance(value, datetime):
	raise TypeError('Expected a datetime object, got {}'.
	format(type(datetime)))

	device_proxy = self._device_proxy(device_id)
	data = device_proxy.get(depth=0)

	now = datetime.utcnow()
	data.last_sync_time = self._time_to_string(value)

	# Update
	self._root_proxy.update(AlarmDbExternal.DEVICE_PATH.format(device_id),
	data)
	self._modified = now
	self.log.debug('save-sync-time-complete', device_id=device_id)

	except Exception as e:
	self.log.exception('save-last-sync-exception', device_id=device_id, e=e)
	raise

	def get_last_sync_time(self, device_id):
	"""
	Get the Last Sync Time saved to the database for a device

	:param device_id: (str) ONU Device ID
	:return: (int) The Value or None if not found
	"""
	self.log.debug('get-last-sync-time', device_id=device_id)

	try:
	device_proxy = self._device_proxy(device_id)
	data = device_proxy.get(depth=0)
	return self._string_to_time(data.last_sync_time)

	except KeyError:
	return None # OMCI MIB_DB entry has not yet been created

	except Exception as e:
	self.log.exception('get-last-sync-time-exception', e=e)
	raise

	def save_alarm_last_sync(self, device_id, value):
	"""
	Save the Last Alarm Sequence value to the database in an easy location to access

	:param device_id: (str) ONU Device ID
	:param value: (int) Value to save
	"""
	self.log.debug('save-last-sync', device_id=device_id, seq=str(value))

	try:
	if not isinstance(value, int):
	raise TypeError('Expected a integer, got {}'.format(type(value)))

	device_proxy = self._device_proxy(device_id)
	data = device_proxy.get(depth=0)

	now = datetime.utcnow()
	data.last_alarm_sequence = int(value)

	# Update
	self._root_proxy.update(AlarmDbExternal.DEVICE_PATH.format(device_id),
	data)
	self._modified = now
	self.log.debug('save-sequence-complete', device_id=device_id)

	except Exception as e:
	self.log.exception('save-last-sync-exception', device_id=device_id, e=e)
	raise

	def get_alarm_last_sync(self, device_id):
	"""
	Get the Last Sync Time saved to the database for a device

	:param device_id: (str) ONU Device ID
	:return: (int) The Value or None if not found
	"""
	self.log.debug('get-last-sync', device_id=device_id)

	try:
	device_proxy = self._device_proxy(device_id)
	data = device_proxy.get(depth=0)
	return int(data.last_alarm_sequence)

	except KeyError:
	return None # OMCI ALARM_DB entry has not yet been created

	except Exception as e:
	self.log.exception('get-last-alarm-exception', e=e)
	raise

	def _add_new_class(self, device_id, class_id, instance_id, attributes):
	"""
	Create an entry for a new class in the external database

	:param device_id: (str) ONU Device ID
	:param class_id: (int) ME Class ID
	:param instance_id: (int) ME Entity ID
	:param attributes: (dict) Attribute dictionary

	:returns: (bool) True if the value was saved to the database. False if the
	value was identical to the current instance
	"""
	self.log.debug('add', device_id=device_id, class_id=class_id,
	instance_id=instance_id, attributes=attributes)

	now = self._time_to_string(datetime.utcnow())
	attrs = [AlarmAttributeData(name=k,
	value=self._attribute_to_string(v)) for k, v in attributes.items()]
	class_data = AlarmClassData(class_id=class_id,
	instances=[AlarmInstanceData(instance_id=instance_id,
	created=now,
	modified=now,
	attributes=attrs)])

	self._root_proxy.add(AlarmDbExternal.CLASSES_PATH.format(device_id), class_data)
	self.log.debug('set-complete', device_id=device_id, class_id=class_id,
	entity_id=instance_id, attributes=attributes)
	return True

	def _add_new_instance(self, device_id, class_id, instance_id, attributes):
	"""
	Create an entry for a instance of an existing class in the external database

	:param device_id: (str) ONU Device ID
	:param class_id: (int) ME Class ID
	:param instance_id: (int) ME Entity ID
	:param attributes: (dict) Attribute dictionary

	:returns: (bool) True if the value was saved to the database. False if the
	value was identical to the current instance
	"""
	self.log.debug('add', device_id=device_id, class_id=class_id,
	instance_id=instance_id, attributes=attributes)

	now = self._time_to_string(datetime.utcnow())
	attrs = [AlarmAttributeData(name=k,
	value=self._attribute_to_string(v)) for k, v in attributes.items()]
	instance_data = AlarmInstanceData(instance_id=instance_id,
	created=now,
	modified=now,
	attributes=attrs)

	self._root_proxy.add(AlarmDbExternal.INSTANCES_PATH.format(device_id, class_id),
	instance_data)

	self.log.debug('set-complete', device_id=device_id, class_id=class_id,
	entity_id=instance_id, attributes=attributes)
	return True

	def set(self, device_id, class_id, instance_id, attributes):
	"""
	Set a database value. This should only be called by the Alarm synchronizer
	and its related tasks

	:param device_id: (str) ONU Device ID
	:param class_id: (int) ME Class ID
	:param instance_id: (int) ME Entity ID
	:param attributes: (dict) Attribute dictionary

	:returns: (bool) True if the value was saved to the database. False if the
	value was identical to the current instance

	:raises KeyError: If device does not exist
	:raises DatabaseStateError: If the database is not enabled
	"""
	self.log.debug('set', device_id=device_id, class_id=class_id,
	instance_id=instance_id, attributes=attributes)
	try:
	if not isinstance(device_id, basestring):
	raise TypeError('Device ID should be a string')

	if not 0 <= class_id <= 0xFFFF:
	raise ValueError("Invalid Class ID: {}, should be 0..65535".format(class_id))

	if not 0 <= instance_id <= 0xFFFF:
	raise ValueError("Invalid Instance ID: {}, should be 0..65535".format(instance_id))

	if not isinstance(attributes, dict):
	raise TypeError("Attributes should be a dictionary")

	if not self._started:
	raise DatabaseStateError('The Database is not currently active')

	# Determine the best strategy to add the information
	dev_proxy = self._device_proxy(device_id)

	try:
	class_data = dev_proxy.get(AlarmDbExternal.CLASS_PATH.format(class_id), deep=True)

	inst_data = next((inst for inst in class_data.instances
	if inst.instance_id == instance_id), None)

	if inst_data is None:
	return self._add_new_instance(device_id, class_id, instance_id, attributes)

	# Possibly adding to or updating an existing instance
	# Get instance proxy, creating it if needed

	exist_attr_indexes = dict()
	attr_len = len(inst_data.attributes)

	for index in xrange(0, attr_len):
	exist_attr_indexes[inst_data.attributes[index].name] = index

	modified = False
	str_value = ''
	new_attributes = []

	for k, v in attributes.items():
	try:
	str_value = self._attribute_to_string(v)
	new_attributes.append(AlarmAttributeData(name=k, value=str_value))

	except Exception as e:
	self.log.exception('save-error', e=e, class_id=class_id,
	attr=k, value_type=type(v))

	if k not in exist_attr_indexes or \
	inst_data.attributes[exist_attr_indexes[k]].value != str_value:
	modified = True

	if modified:
	now = datetime.utcnow()
	new_data = AlarmInstanceData(instance_id=instance_id,
	created=inst_data.created,
	modified=self._time_to_string(now),
	attributes=new_attributes)
	dev_proxy.remove(AlarmDbExternal.INSTANCE_PATH.format(class_id, instance_id))
	self._root_proxy.add(AlarmDbExternal.INSTANCES_PATH.format(device_id,
	class_id), new_data)

	self.log.debug('set-complete', device_id=device_id, class_id=class_id,
	entity_id=instance_id, attributes=attributes, modified=modified)
	return modified

	except KeyError:
	# Here if the class-id does not yet exist in the database
	return self._add_new_class(device_id, class_id, instance_id,
	attributes)
	except Exception as e:
	self.log.exception('set-exception', device_id=device_id, class_id=class_id,
	instance_id=instance_id, attributes=attributes, e=e)
	raise

	def delete(self, device_id, class_id, entity_id):
	"""
	Delete an entity from the database if it exists. If all instances
	of a class are deleted, the class is deleted as well.

	:param device_id: (str) ONU Device ID
	:param class_id: (int) ME Class ID
	:param entity_id: (int) ME Entity ID

	:returns: (bool) True if the instance was found and deleted. False
	if it did not exist.

	:raises KeyError: If device does not exist
	:raises DatabaseStateError: If the database is not enabled
	"""
	self.log.debug('delete', device_id=device_id, class_id=class_id,
	entity_id=entity_id)

	if not self._started:
	raise DatabaseStateError('The Database is not currently active')

	if not isinstance(device_id, basestring):
	raise TypeError('Device ID should be an string')

	if not 0 <= class_id <= 0xFFFF:
	raise ValueError('class-id is 0..0xFFFF')

	if not 0 <= entity_id <= 0xFFFF:
	raise ValueError('instance-id is 0..0xFFFF')

	try:
	# Remove instance
	self._instance_proxy(device_id, class_id, entity_id).remove('/')
	now = datetime.utcnow()

	# If resulting class has no instance, remove it as well
	class_proxy = self._class_proxy(device_id, class_id)
	class_data = class_proxy.get('/', depth=1)

	if len(class_data.instances) == 0:
	class_proxy.remove('/')

	self._modified = now
	return True

	except KeyError:
	return False # Not found

	except Exception as e:
	self.log.exception('get-last-data-exception', device_id=device_id, e=e)
	raise

	def query(self, device_id, class_id=None, instance_id=None, attributes=None):
	"""
	Get database information.

	This method can be used to request information from the database to the detailed
	level requested

	:param device_id: (str) ONU Device ID
	:param class_id: (int) Managed Entity class ID
	:param instance_id: (int) Managed Entity instance
	:param attributes: (list/set or str) Managed Entity instance's attributes

	:return: (dict) The value(s) requested. If class/inst/attribute is
	not found, an empty dictionary is returned
	:raises KeyError: If the requested device does not exist
	:raises DatabaseStateError: If the database is not enabled
	"""
	self.log.debug('query', device_id=device_id, class_id=class_id,
	instance_id=instance_id, attributes=attributes)
	try:
	if class_id is None:
	# Get full device info
	dev_data = self._device_proxy(device_id).get('/', depth=-1)
	data = self._device_to_dict(dev_data)

	elif instance_id is None:
	# Get all instances of the class
	try:
	cls_data = self._class_proxy(device_id, class_id).get('/', depth=-1)
	data = self._class_to_dict(cls_data)

	except KeyError:
	data = dict()

	else:
	# Get all attributes of a specific ME
	try:
	inst_data = self._instance_proxy(device_id, class_id, instance_id).\
	get('/', depth=-1)

	if attributes is None:
	# All Attributes
	data = self._instance_to_dict(inst_data)

	else:
	# Specific attribute(s)
	if isinstance(attributes, basestring):
	attributes = {attributes}

	data = {
	attr.name: self._string_to_attribute(attr.value)
	for attr in inst_data.attributes if attr.name in attributes}

	except KeyError:
	data = dict()

	return data

	except KeyError:
	self.log.warn('query-no-device', device_id=device_id)
	raise

	except Exception as e:
	self.log.exception('get-last-sync-exception', device_id=device_id, e=e)
	raise

	def _instance_to_dict(self, instance):
	if not isinstance(instance, AlarmInstanceData):
	raise TypeError('{} is not of type AlarmInstanceData'.format(type(instance)))

	data = {
	INSTANCE_ID_KEY: instance.instance_id,
	CREATED_KEY: self._string_to_time(instance.created),
	MODIFIED_KEY: self._string_to_time(instance.modified),
	ATTRIBUTES_KEY: dict()
	}
	for attribute in instance.attributes:
	data[ATTRIBUTES_KEY][attribute.name] = self._string_to_attribute(attribute.value)
	return data

	def _class_to_dict(self, val):
	if not isinstance(val, AlarmClassData):
	raise TypeError('{} is not of type AlarmClassData'.format(type(val)))

	data = {
	CLASS_ID_KEY: val.class_id,
	}
	for instance in val.instances:
	data[instance.instance_id] = self._instance_to_dict(instance)
	return data

	def _device_to_dict(self, val):
	if not isinstance(val, AlarmDeviceData):
	raise TypeError('{} is not of type AlarmDeviceData'.format(type(val)))

	data = {
	DEVICE_ID_KEY: val.device_id,
	CREATED_KEY: self._string_to_time(val.created),
	VERSION_KEY: val.version,
	ME_KEY: dict(),
	MSG_TYPE_KEY: set()
	}
	for class_data in val.classes:
	data[class_data.class_id] = self._class_to_dict(class_data)
	for managed_entity in val.managed_entities:
	data[ME_KEY][managed_entity.class_id] = managed_entity.name

	for msg_type in val.message_types:
	data[MSG_TYPE_KEY].add(msg_type.message_type)

	return data