Пример #1
0
    def __init__(self, shelffile=None, user_manager=None, session_cls=None):
        self.logger = logging.getLogger(__name__)

        self.server_callback_dispatcher = CallbackDispatcher()

        self.endpoints = []
        self._channel_id_counter = 5
        self.disabled_clock = False  # for debugging we may want to disable clock that writes too much in log
        self._local_discovery_service = None # lazy-loading

        self.aspace = AddressSpace()
        self.attribute_service = AttributeService(self.aspace)
        self.view_service = ViewService(self.aspace)
        self.method_service = MethodService(self.aspace)
        self.node_mgt_service = NodeManagementService(self.aspace)

        self.load_standard_address_space(shelffile)

        self.loop = None
        self.asyncio_transports = []
        self.subscription_service = SubscriptionService(self.aspace)

        self.history_manager = HistoryManager(self)
        self.user_manager = user_manager

        # create a session to use on server side
        self.session_cls = session_cls or InternalSession
        self.isession = self.session_cls(self, self.aspace, \
          self.subscription_service, "Internal", user=UserManager.User.Admin)

        self.current_time_node = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_ServerStatus_CurrentTime))
        self._address_space_fixes()
        self.setup_nodes()
Пример #2
0
    def __init__(self):
        self.logger = logging.getLogger(__name__)
        self.endpoints = []
        self._channel_id_counter = 5
        self.allow_remote_admin = True
        self.disabled_clock = False  # for debugging we may want to disable clock that writes too much in log
        self._known_servers = {}  # used if we are a discovery server

        self.aspace = AddressSpace()
        self.attribute_service = AttributeService(self.aspace)
        self.view_service = ViewService(self.aspace)
        self.method_service = MethodService(self.aspace)
        self.node_mgt_service = NodeManagementService(self.aspace)
        # import address space from code generated from xml
        standard_address_space.fill_address_space(self.node_mgt_service)  
        # import address space from save db to disc
        #standard_address_space.fill_address_space_from_disk(self.aspace)  

        # import address space directly from xml, this has preformance impact so disabled
        #importer = xmlimporter.XmlImporter(self.node_mgt_service)
        #importer.import_xml("/home/olivier/python-opcua/schemas/Opc.Ua.NodeSet2.xml")

        self.loop = utils.ThreadLoop()
        self.subscription_service = SubscriptionService(self.loop, self.aspace)

        # create a session to use on server side
        self.isession = InternalSession(self, self.aspace, self.subscription_service, "Internal", user=User.Admin)
        self.current_time_node = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_ServerStatus_CurrentTime))
        uries = ["http://opcfoundation.org/UA/"]
        ns_node = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_NamespaceArray))
        ns_node.set_value(uries)
Пример #3
0
    def __init__(self, shelffile=None, parent=None):
        self.logger = logging.getLogger(__name__)

        self._parent = parent
        self.server_callback_dispatcher = CallbackDispatcher()

        self.endpoints = []
        self._channel_id_counter = 5
        self.disabled_clock = False  # for debugging we may want to disable clock that writes too much in log
        self._local_discovery_service = None # lazy-loading

        self.aspace = AddressSpace()
        self.attribute_service = AttributeService(self.aspace)
        self.view_service = ViewService(self.aspace)
        self.method_service = MethodService(self.aspace)
        self.node_mgt_service = NodeManagementService(self.aspace)

        self.load_standard_address_space(shelffile)

        self.loop = None
        self.asyncio_transports = []
        self.subscription_service = SubscriptionService(self.aspace)

        self.history_manager = HistoryManager(self)

        # create a session to use on server side
        self.isession = InternalSession(self, self.aspace, \
          self.subscription_service, "Internal", user=UserManager.User.Admin)

        self.current_time_node = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_ServerStatus_CurrentTime))
        self._address_space_fixes()
        self.setup_nodes()
Пример #4
0
    def __init__(self, cacheFile=None):
        self.logger = logging.getLogger(__name__)

        self.server_callback_dispatcher = CallbackDispatcher()

        self.endpoints = []
        self._channel_id_counter = 5
        self.allow_remote_admin = True
        self.disabled_clock = False  # for debugging we may want to disable clock that writes too much in log
        self._known_servers = {}  # used if we are a discovery server

        self.aspace = AddressSpace()
        self.attribute_service = AttributeService(self.aspace)
        self.view_service = ViewService(self.aspace)
        self.method_service = MethodService(self.aspace)
        self.node_mgt_service = NodeManagementService(self.aspace)

        self.load_standard_address_space(cacheFile)

        self.loop = utils.ThreadLoop()
        self.asyncio_transports = []
        self.subscription_service = SubscriptionService(self.loop, self.aspace)

        self.history_manager = HistoryManager(self)

        # create a session to use on server side
        self.isession = InternalSession(self, self.aspace, self.subscription_service, "Internal", user=User.Admin)

        self.current_time_node = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_ServerStatus_CurrentTime))
        self.setup_nodes()
Пример #5
0
class InternalServer(object):

    def __init__(self, shelffile=None, user_manager=None, session_cls=None):
        self.logger = logging.getLogger(__name__)

        self.server_callback_dispatcher = CallbackDispatcher()

        self.endpoints = []
        self._channel_id_counter = 5
        self.disabled_clock = False  # for debugging we may want to disable clock that writes too much in log
        self._local_discovery_service = None # lazy-loading

        self.aspace = AddressSpace()
        self.attribute_service = AttributeService(self.aspace)
        self.view_service = ViewService(self.aspace)
        self.method_service = MethodService(self.aspace)
        self.node_mgt_service = NodeManagementService(self.aspace)

        self.load_standard_address_space(shelffile)

        self.loop = None
        self.asyncio_transports = []
        self.subscription_service = SubscriptionService(self.aspace)

        self.history_manager = HistoryManager(self)
        self.user_manager = user_manager

        # create a session to use on server side
        self.session_cls = session_cls or InternalSession
        self.isession = self.session_cls(self, self.aspace, \
          self.subscription_service, "Internal", user=UserManager.User.Admin)

        self.current_time_node = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_ServerStatus_CurrentTime))
        self._address_space_fixes()
        self.setup_nodes()

    @property
    def thread_loop(self):
        if self.loop is None:
            raise Exception("InternalServer stopped: async threadloop is not running.")
        return self.loop

    @property
    def local_discovery_service(self):
        if self._local_discovery_service is None:
            self._local_discovery_service = LocalDiscoveryService(parent = self)
            for edp in self.endpoints:
                srvDesc = LocalDiscoveryService.ServerDescription(edp.Server)
                self._local_discovery_service.add_server_description(srvDesc)
        return self._local_discovery_service

    def setup_nodes(self):
        """
        Set up some nodes as defined by spec
        """
        uries = ["http://opcfoundation.org/UA/"]
        ns_node = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_NamespaceArray))
        ns_node.set_value(uries)

    def load_standard_address_space(self, shelffile=None):
        if (shelffile is not None) and (os.path.isfile(shelffile) or os.path.isfile(shelffile+".db")):
            # import address space from shelf
            self.aspace.load_aspace_shelf(shelffile)
        else:
            # import address space from code generated from xml
            standard_address_space.fill_address_space(self.node_mgt_service)
            # import address space directly from xml, this has performance impact so disabled
            # importer = xmlimporter.XmlImporter(self.node_mgt_service)
            # importer.import_xml("/path/to/python-opcua/schemas/Opc.Ua.NodeSet2.xml", self)

            # if a cache file was supplied a shelve of the standard address space can now be built for next start up
            if shelffile:
                self.aspace.make_aspace_shelf(shelffile)

    def _address_space_fixes(self):
        """
        Looks like the xml definition of address space has some error. This is a good place to fix them
        """

        it = ua.AddReferencesItem()
        it.SourceNodeId = ua.NodeId(ua.ObjectIds.BaseObjectType)
        it.ReferenceTypeId = ua.NodeId(ua.ObjectIds.Organizes)
        it.IsForward = False
        it.TargetNodeId = ua.NodeId(ua.ObjectIds.ObjectTypesFolder)
        it.TargetNodeClass = ua.NodeClass.Object

        it2 = ua.AddReferencesItem()
        it2.SourceNodeId = ua.NodeId(ua.ObjectIds.BaseDataType)
        it2.ReferenceTypeId = ua.NodeId(ua.ObjectIds.Organizes)
        it2.IsForward = False
        it2.TargetNodeId = ua.NodeId(ua.ObjectIds.DataTypesFolder)
        it2.TargetNodeClass = ua.NodeClass.Object

        results = self.isession.add_references([it, it2])

        params = ua.WriteParameters()
        for nodeid in (ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerRead,
                     ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerHistoryReadData,
                     ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerHistoryReadEvents,
                     ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerWrite,
                     ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerHistoryUpdateData,
                     ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerHistoryUpdateEvents,
                     ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerMethodCall,
                     ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerBrowse,
                     ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerRegisterNodes,
                     ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerTranslateBrowsePathsToNodeIds,
                     ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxNodesPerNodeManagement,
                     ua.ObjectIds.Server_ServerCapabilities_OperationLimits_MaxMonitoredItemsPerCall):
            attr = ua.WriteValue()
            attr.NodeId = ua.NodeId(nodeid)
            attr.AttributeId = ua.AttributeIds.Value
            attr.Value = ua.DataValue(ua.Variant(10000, ua.VariantType.UInt32), ua.StatusCode(ua.StatusCodes.Good))
            attr.Value.ServerTimestamp = datetime.utcnow()
            params.NodesToWrite.append(attr)
        result = self.isession.write(params)
        result[0].check()


    def load_address_space(self, path):
        """
        Load address space from path
        """
        self.aspace.load(path)

    def dump_address_space(self, path):
        """
        Dump current address space to path
        """
        self.aspace.dump(path)

    def start(self):
        self.logger.info("starting internal server")
        self.loop = utils.ThreadLoop()
        self.loop.start()
        self.subscription_service.set_loop(self.loop)
        serverState = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_ServerStatus_State))
        serverState.set_value(ua.uaprotocol_auto.ServerState.Running, ua.VariantType.Int32)
        Node(self.isession, ua.NodeId(ua.ObjectIds.Server_ServerStatus_StartTime)).set_value(datetime.utcnow())
        if not self.disabled_clock:
            self._set_current_time()

    def stop(self):
        self.logger.info("stopping internal server")
        self.isession.close_session()
        self.subscription_service.set_loop(None)
        self.history_manager.stop()
        if self.loop:
            self.loop.stop()
            # wait for ThreadLoop to finish before proceeding
            self.loop.join()
            self.loop.close()
            self.loop = None

    def is_running(self):
        return self.loop is not None

    def _set_current_time(self):
        self.current_time_node.set_value(datetime.utcnow())
        self.loop.call_later(1, self._set_current_time)

    def get_new_channel_id(self):
        self._channel_id_counter += 1
        return self._channel_id_counter

    def add_endpoint(self, endpoint):
        self.endpoints.append(endpoint)

    def get_endpoints(self, params=None, sockname=None):
        self.logger.info("get endpoint")
        if sockname:
            # return to client the ip address it has access to
            edps = []
            for edp in self.endpoints:
                edp1 = copy(edp)
                url = urlparse(edp1.EndpointUrl)
                url = url._replace(netloc=sockname[0] + ":" + str(sockname[1]))
                edp1.EndpointUrl = url.geturl()
                edps.append(edp1)
            return edps
        return self.endpoints[:]

    def create_session(self, name, user=UserManager.User.Anonymous):
        return self.session_cls(self, self.aspace, self.subscription_service, name, user=user)

    def enable_history_data_change(self, node, period=timedelta(days=7), count=0):
        """
        Set attribute Historizing of node to True and start storing data for history
        """
        node.set_attribute(ua.AttributeIds.Historizing, ua.DataValue(True))
        node.set_attr_bit(ua.AttributeIds.AccessLevel, ua.AccessLevel.HistoryRead)
        node.set_attr_bit(ua.AttributeIds.UserAccessLevel, ua.AccessLevel.HistoryRead)
        self.history_manager.historize_data_change(node, period, count)

    def disable_history_data_change(self, node):
        """
        Set attribute Historizing of node to False and stop storing data for history
        """
        node.set_attribute(ua.AttributeIds.Historizing, ua.DataValue(False))
        node.unset_attr_bit(ua.AttributeIds.AccessLevel, ua.AccessLevel.HistoryRead)
        node.unset_attr_bit(ua.AttributeIds.UserAccessLevel, ua.AccessLevel.HistoryRead)
        self.history_manager.dehistorize(node)

    def enable_history_event(self, source, period=timedelta(days=7), count=0):
        """
        Set attribute History Read of object events to True and start storing data for history
        """
        event_notifier = source.get_event_notifier()
        if ua.EventNotifier.SubscribeToEvents not in event_notifier:
            raise ua.UaError("Node does not generate events", event_notifier)

        if ua.EventNotifier.HistoryRead not in event_notifier:
            event_notifier.add(ua.EventNotifier.HistoryRead)
            source.set_event_notifier(event_notifier)

        self.history_manager.historize_event(source, period, count)

    def disable_history_event(self, source):
        """
        Set attribute History Read of node to False and stop storing data for history
        """
        source.unset_attr_bit(ua.AttributeIds.EventNotifier, ua.EventNotifier.HistoryRead)
        self.history_manager.dehistorize(source)

    def subscribe_server_callback(self, event, handle):
        """
        Create a subscription from event to handle
        """
        self.server_callback_dispatcher.addListener(event, handle)

    def unsubscribe_server_callback(self, event, handle):
        """
        Remove a subscription from event to handle
        """
        self.server_callback_dispatcher.removeListener(event, handle)

    def set_attribute_value(self, nodeid, datavalue, attr=ua.AttributeIds.Value):
        """
        directly write datavalue to the Attribute, bypasing some checks and structure creation
        so it is a little faster
        """
        self.aspace.set_attribute_value(nodeid, ua.AttributeIds.Value, datavalue)
Пример #6
0
class InternalServer(object):
    def __init__(self, shelffile=None):
        self.logger = logging.getLogger(__name__)

        self.server_callback_dispatcher = CallbackDispatcher()

        self.endpoints = []
        self._channel_id_counter = 5
        self.allow_remote_admin = True
        self.disabled_clock = False  # for debugging we may want to disable clock that writes too much in log
        self._known_servers = {}  # used if we are a discovery server

        self.aspace = AddressSpace()
        self.attribute_service = AttributeService(self.aspace)
        self.view_service = ViewService(self.aspace)
        self.method_service = MethodService(self.aspace)
        self.node_mgt_service = NodeManagementService(self.aspace)

        self.load_standard_address_space(shelffile)

        self.loop = None
        self.asyncio_transports = []
        self.subscription_service = SubscriptionService(self.aspace)

        self.history_manager = HistoryManager(self)

        # create a session to use on server side
        self.isession = InternalSession(self,
                                        self.aspace,
                                        self.subscription_service,
                                        "Internal",
                                        user=User.Admin)

        self.current_time_node = Node(
            self.isession,
            ua.NodeId(ua.ObjectIds.Server_ServerStatus_CurrentTime))
        self._address_space_fixes()
        self.setup_nodes()

    def setup_nodes(self):
        """
        Set up some nodes as defined by spec
        """
        uries = ["http://opcfoundation.org/UA/"]
        ns_node = Node(self.isession,
                       ua.NodeId(ua.ObjectIds.Server_NamespaceArray))
        ns_node.set_value(uries)

    def load_standard_address_space(self, shelffile=None):
        if (shelffile is not None) and (os.path.isfile(shelffile)
                                        or os.path.isfile(shelffile + ".db")):
            # import address space from shelf
            self.aspace.load_aspace_shelf(shelffile)
        else:
            # import address space from code generated from xml
            standard_address_space.fill_address_space(self.node_mgt_service)
            # import address space directly from xml, this has performance impact so disabled
            # importer = xmlimporter.XmlImporter(self.node_mgt_service)
            # importer.import_xml("/path/to/python-opcua/schemas/Opc.Ua.NodeSet2.xml", self)

            # if a cache file was supplied a shelve of the standard address space can now be built for next start up
            if shelffile:
                self.aspace.make_aspace_shelf(shelffile)

    def _address_space_fixes(self):
        """
        Looks like the xml definition of address space has some error. This is a good place to fix them
        """

        it = ua.AddReferencesItem()
        it.SourceNodeId = ua.NodeId(ua.ObjectIds.BaseObjectType)
        it.ReferenceTypeId = ua.NodeId(ua.ObjectIds.Organizes)
        it.IsForward = False
        it.TargetNodeId = ua.NodeId(ua.ObjectIds.ObjectTypesFolder)
        it.TargetNodeClass = ua.NodeClass.Object

        results = self.isession.add_references([it])

    def load_address_space(self, path):
        """
        Load address space from path
        """
        self.aspace.load(path)

    def dump_address_space(self, path):
        """
        Dump current address space to path
        """
        self.aspace.dump(path)

    def start(self):
        self.logger.info("starting internal server")
        for edp in self.endpoints:
            self._known_servers[edp.Server.ApplicationUri] = ServerDesc(
                edp.Server)
        self.loop = utils.ThreadLoop()
        self.loop.start()
        self.subscription_service.set_loop(self.loop)
        Node(self.isession,
             ua.NodeId(ua.ObjectIds.Server_ServerStatus_State)).set_value(
                 0, ua.VariantType.Int32)
        Node(self.isession,
             ua.NodeId(ua.ObjectIds.Server_ServerStatus_StartTime)).set_value(
                 datetime.utcnow())
        if not self.disabled_clock:
            self._set_current_time()

    def stop(self):
        self.logger.info("stopping internal server")
        self.isession.close_session()
        if self.loop:
            self.loop.stop()
            self.loop = None
        self.subscription_service.set_loop(None)
        self.history_manager.stop()

    def _set_current_time(self):
        self.current_time_node.set_value(datetime.utcnow())
        self.loop.call_later(1, self._set_current_time)

    def get_new_channel_id(self):
        self._channel_id_counter += 1
        return self._channel_id_counter

    def add_endpoint(self, endpoint):
        self.endpoints.append(endpoint)

    def get_endpoints(self, params=None, sockname=None):
        self.logger.info("get endpoint")
        if sockname:
            # return to client the ip address it has access to
            edps = []
            for edp in self.endpoints:
                edp1 = copy(edp)
                url = urlparse(edp1.EndpointUrl)
                url = url._replace(netloc=sockname[0] + ":" + str(sockname[1]))
                edp1.EndpointUrl = url.geturl()
                edps.append(edp1)
            return edps
        return self.endpoints[:]

    def find_servers(self, params):
        if not params.ServerUris:
            return [desc.Server for desc in self._known_servers.values()]
        servers = []
        for serv in self._known_servers.values():
            serv_uri = serv.Server.ApplicationUri.split(":")
            for uri in params.ServerUris:
                uri = uri.split(":")
                if serv_uri[:len(uri)] == uri:
                    servers.append(serv.Server)
                    break
        return servers

    def register_server(self, server, conf=None):
        appdesc = ua.ApplicationDescription()
        appdesc.ApplicationUri = server.ServerUri
        appdesc.ProductUri = server.ProductUri
        # FIXME: select name from client locale
        appdesc.ApplicationName = server.ServerNames[0]
        appdesc.ApplicationType = server.ServerType
        appdesc.DiscoveryUrls = server.DiscoveryUrls
        # FIXME: select discovery uri using reachability from client network
        appdesc.GatewayServerUri = server.GatewayServerUri
        self._known_servers[server.ServerUri] = ServerDesc(appdesc, conf)

    def register_server2(self, params):
        return self.register_server(params.Server,
                                    params.DiscoveryConfiguration)

    def create_session(self, name, user=User.Anonymous, external=False):
        return InternalSession(self,
                               self.aspace,
                               self.subscription_service,
                               name,
                               user=user,
                               external=external)

    def enable_history_data_change(self,
                                   node,
                                   period=timedelta(days=7),
                                   count=0):
        """
        Set attribute Historizing of node to True and start storing data for history
        """
        node.set_attribute(ua.AttributeIds.Historizing, ua.DataValue(True))
        node.set_attr_bit(ua.AttributeIds.AccessLevel,
                          ua.AccessLevel.HistoryRead)
        node.set_attr_bit(ua.AttributeIds.UserAccessLevel,
                          ua.AccessLevel.HistoryRead)
        self.history_manager.historize_data_change(node, period, count)

    def disable_history_data_change(self, node):
        """
        Set attribute Historizing of node to False and stop storing data for history
        """
        node.set_attribute(ua.AttributeIds.Historizing, ua.DataValue(False))
        node.unset_attr_bit(ua.AttributeIds.AccessLevel,
                            ua.AccessLevel.HistoryRead)
        node.unset_attr_bit(ua.AttributeIds.UserAccessLevel,
                            ua.AccessLevel.HistoryRead)
        self.history_manager.dehistorize(node)

    def enable_history_event(self, source, period=timedelta(days=7), count=0):
        """
        Set attribute History Read of object events to True and start storing data for history
        """
        event_notifier = source.get_event_notifier()
        if ua.EventNotifier.SubscribeToEvents not in event_notifier:
            raise ua.UaError("Node does not generate events", event_notifier)

        if ua.EventNotifier.HistoryRead not in event_notifier:
            event_notifier.add(ua.EventNotifier.HistoryRead)
            source.set_event_notifier(event_notifier)

        self.history_manager.historize_event(source, period, count)

    def disable_history_event(self, source):
        """
        Set attribute History Read of node to False and stop storing data for history
        """
        source.unset_attr_bit(ua.AttributeIds.EventNotifier,
                              ua.EventNotifier.HistoryRead)
        self.history_manager.dehistorize(source)

    def subscribe_server_callback(self, event, handle):
        """
        Create a subscription from event to handle
        """
        self.server_callback_dispatcher.addListener(event, handle)

    def unsubscribe_server_callback(self, event, handle):
        """
        Remove a subscription from event to handle
        """
        self.server_callback_dispatcher.removeListener(event, handle)
Пример #7
0
class InternalServer(object):

    def __init__(self, shelffile=None, parent=None):
        self.logger = logging.getLogger(__name__)

        self._parent = parent
        self.server_callback_dispatcher = CallbackDispatcher()

        self.endpoints = []
        self._channel_id_counter = 5
        self.disabled_clock = False  # for debugging we may want to disable clock that writes too much in log
        self._local_discovery_service = None # lazy-loading

        self.aspace = AddressSpace()
        self.attribute_service = AttributeService(self.aspace)
        self.view_service = ViewService(self.aspace)
        self.method_service = MethodService(self.aspace)
        self.node_mgt_service = NodeManagementService(self.aspace)

        self.load_standard_address_space(shelffile)

        self.loop = None
        self.asyncio_transports = []
        self.subscription_service = SubscriptionService(self.aspace)

        self.history_manager = HistoryManager(self)

        # create a session to use on server side
        self.isession = InternalSession(self, self.aspace, \
          self.subscription_service, "Internal", user=UserManager.User.Admin)

        self.current_time_node = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_ServerStatus_CurrentTime))
        self._address_space_fixes()
        self.setup_nodes()

    @property
    def user_manager(self):
        return self._parent.user_manager

    @property
    def thread_loop(self):
        if self.loop is None:
            raise Exception("InternalServer stopped: async threadloop is not running.")
        return self.loop

    @property
    def local_discovery_service(self):
        if self._local_discovery_service is None:
            self._local_discovery_service = LocalDiscoveryService(parent = self)
            for edp in self.endpoints:
                srvDesc = LocalDiscoveryService.ServerDescription(edp.Server)
                self._local_discovery_service.add_server_description(srvDesc)
        return self._local_discovery_service

    def setup_nodes(self):
        """
        Set up some nodes as defined by spec
        """
        uries = ["http://opcfoundation.org/UA/"]
        ns_node = Node(self.isession, ua.NodeId(ua.ObjectIds.Server_NamespaceArray))
        ns_node.set_value(uries)

    def load_standard_address_space(self, shelffile=None):
        if (shelffile is not None) and (os.path.isfile(shelffile) or os.path.isfile(shelffile+".db")):
            # import address space from shelf
            self.aspace.load_aspace_shelf(shelffile)
        else:
            # import address space from code generated from xml
            standard_address_space.fill_address_space(self.node_mgt_service)
            # import address space directly from xml, this has performance impact so disabled
            # importer = xmlimporter.XmlImporter(self.node_mgt_service)
            # importer.import_xml("/path/to/python-opcua/schemas/Opc.Ua.NodeSet2.xml", self)

            # if a cache file was supplied a shelve of the standard address space can now be built for next start up
            if shelffile:
                self.aspace.make_aspace_shelf(shelffile)

    def _address_space_fixes(self):
        """
        Looks like the xml definition of address space has some error. This is a good place to fix them
        """

        it = ua.AddReferencesItem()
        it.SourceNodeId = ua.NodeId(ua.ObjectIds.BaseObjectType)
        it.ReferenceTypeId = ua.NodeId(ua.ObjectIds.Organizes)
        it.IsForward = False
        it.TargetNodeId = ua.NodeId(ua.ObjectIds.ObjectTypesFolder)
        it.TargetNodeClass = ua.NodeClass.Object

        it2 = ua.AddReferencesItem()
        it2.SourceNodeId = ua.NodeId(ua.ObjectIds.BaseDataType)
        it2.ReferenceTypeId = ua.NodeId(ua.ObjectIds.Organizes)
        it2.IsForward = False
        it2.TargetNodeId = ua.NodeId(ua.ObjectIds.DataTypesFolder)
        it2.TargetNodeClass = ua.NodeClass.Object

        results = self.isession.add_references([it, it2])
 
    def load_address_space(self, path):
        """
        Load address space from path
        """
        self.aspace.load(path)

    def dump_address_space(self, path):
        """
        Dump current address space to path
        """
        self.aspace.dump(path)

    def start(self):
        self.logger.info("starting internal server")
        self.loop = utils.ThreadLoop()
        self.loop.start()
        self.subscription_service.set_loop(self.loop)
        Node(self.isession, ua.NodeId(ua.ObjectIds.Server_ServerStatus_State)).set_value(0, ua.VariantType.Int32)
        Node(self.isession, ua.NodeId(ua.ObjectIds.Server_ServerStatus_StartTime)).set_value(datetime.utcnow())
        if not self.disabled_clock:
            self._set_current_time()

    def stop(self):
        self.logger.info("stopping internal server")
        self.isession.close_session()
        if self.loop:
            self.loop.stop()
            self.loop = None
        self.subscription_service.set_loop(None)
        self.history_manager.stop()

    def is_running(self):
        return self.loop is not None

    def _set_current_time(self):
        self.current_time_node.set_value(datetime.utcnow())
        self.loop.call_later(1, self._set_current_time)

    def get_new_channel_id(self):
        self._channel_id_counter += 1
        return self._channel_id_counter

    def add_endpoint(self, endpoint):
        self.endpoints.append(endpoint)

    def get_endpoints(self, params=None, sockname=None):
        self.logger.info("get endpoint")
        if sockname:
            # return to client the ip address it has access to
            edps = []
            for edp in self.endpoints:
                edp1 = copy(edp)
                url = urlparse(edp1.EndpointUrl)
                url = url._replace(netloc=sockname[0] + ":" + str(sockname[1]))
                edp1.EndpointUrl = url.geturl()
                edps.append(edp1)
            return edps
        return self.endpoints[:]

    def create_session(self, name, user=UserManager.User.Anonymous, external=False):
        return InternalSession(self, self.aspace, self.subscription_service, name, user=user, external=external)

    def enable_history_data_change(self, node, period=timedelta(days=7), count=0):
        """
        Set attribute Historizing of node to True and start storing data for history
        """
        node.set_attribute(ua.AttributeIds.Historizing, ua.DataValue(True))
        node.set_attr_bit(ua.AttributeIds.AccessLevel, ua.AccessLevel.HistoryRead)
        node.set_attr_bit(ua.AttributeIds.UserAccessLevel, ua.AccessLevel.HistoryRead)
        self.history_manager.historize_data_change(node, period, count)

    def disable_history_data_change(self, node):
        """
        Set attribute Historizing of node to False and stop storing data for history
        """
        node.set_attribute(ua.AttributeIds.Historizing, ua.DataValue(False))
        node.unset_attr_bit(ua.AttributeIds.AccessLevel, ua.AccessLevel.HistoryRead)
        node.unset_attr_bit(ua.AttributeIds.UserAccessLevel, ua.AccessLevel.HistoryRead)
        self.history_manager.dehistorize(node)

    def enable_history_event(self, source, period=timedelta(days=7), count=0):
        """
        Set attribute History Read of object events to True and start storing data for history
        """
        event_notifier = source.get_event_notifier()
        if ua.EventNotifier.SubscribeToEvents not in event_notifier:
            raise ua.UaError("Node does not generate events", event_notifier)

        if ua.EventNotifier.HistoryRead not in event_notifier:
            event_notifier.add(ua.EventNotifier.HistoryRead)
            source.set_event_notifier(event_notifier)

        self.history_manager.historize_event(source, period, count)

    def disable_history_event(self, source):
        """
        Set attribute History Read of node to False and stop storing data for history
        """
        source.unset_attr_bit(ua.AttributeIds.EventNotifier, ua.EventNotifier.HistoryRead)
        self.history_manager.dehistorize(source)

    def subscribe_server_callback(self, event, handle):
        """
        Create a subscription from event to handle
        """
        self.server_callback_dispatcher.addListener(event, handle)

    def unsubscribe_server_callback(self, event, handle):
        """
        Remove a subscription from event to handle
        """
        self.server_callback_dispatcher.removeListener(event, handle)

    def set_attribute_value(self, nodeid, datavalue, attr=ua.AttributeIds.Value):
        """
        directly write datavalue to the Attribute, bypasing some checks and structure creation
        so it is a little faster
        """
        self.aspace.set_attribute_value(nodeid, ua.AttributeIds.Value, datavalue)