Completed
Pull Request — master (#133)
by Denis
02:49
created

AddressSpace.generate_nodeid()   A

Complexity

Conditions 2

Size

Total Lines 5

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 5
CRAP Score 2
Metric Value
cc 2
dl 0
loc 5
rs 9.4285
ccs 5
cts 5
cp 1
crap 2
1 1
from threading import RLock
2 1
import logging
3 1
from datetime import datetime
4 1
try:
5 1
    import cPickle as pickle
6 1
except:
7 1
    import pickle
8
9 1
from opcua import ua
10 1
from opcua.server.users import User
11
12
13 1
class AttributeValue(object):
14
15 1
    def __init__(self, value):
16 1
        self.value = value
17 1
        self.value_callback = None
18 1
        self.datachange_callbacks = {}
19
20 1
    def __str__(self):
21
        return "AttributeValue({})".format(self.value)
22 1
    __repr__ = __str__
23
24
25 1
class NodeData(object):
26
27 1
    def __init__(self, nodeid):
28 1
        self.nodeid = nodeid
29 1
        self.attributes = {}
30 1
        self.references = []
31 1
        self.call = None
32
33 1
    def __str__(self):
34
        return "NodeData(id:{}, attrs:{}, refs:{})".format(self.nodeid, self.attributes, self.references)
35 1
    __repr__ = __str__
36
37
38 1
class AttributeService(object):
39
40 1
    def __init__(self, aspace):
41 1
        self.logger = logging.getLogger(__name__)
42 1
        self._aspace = aspace
43
44 1
    def read(self, params):
45 1
        self.logger.debug("read %s", params)
46 1
        res = []
47 1
        for readvalue in params.NodesToRead:
48 1
            res.append(self._aspace.get_attribute_value(readvalue.NodeId, readvalue.AttributeId))
49 1
        return res
50
51 1
    def write(self, params, user=User.Admin):
52 1
        self.logger.debug("write %s as user %s", params, user)
53 1
        res = []
54 1
        for writevalue in params.NodesToWrite:
55 1
            if user != User.Admin:
56 1
                if writevalue.AttributeId != ua.AttributeIds.Value:
57 1
                    res.append(ua.StatusCode(ua.StatusCodes.BadUserAccessDenied))
58 1
                    continue
59 1
                al = self._aspace.get_attribute_value(writevalue.NodeId, ua.AttributeIds.AccessLevel)
60 1
                ual = self._aspace.get_attribute_value(writevalue.NodeId, ua.AttributeIds.UserAccessLevel)
61 1
                if not ua.test_bit(al.Value.Value, ua.AccessLevel.CurrentWrite) or not ua.test_bit(ual.Value.Value, ua.AccessLevel.CurrentWrite):
62 1
                    res.append(ua.StatusCode(ua.StatusCodes.BadUserAccessDenied))
63 1
                    continue
64 1
            res.append(self._aspace.set_attribute_value(writevalue.NodeId, writevalue.AttributeId, writevalue.Value))
65 1
        return res
66
67
68 1
class ViewService(object):
69
70 1
    def __init__(self, aspace):
71 1
        self.logger = logging.getLogger(__name__)
72 1
        self._aspace = aspace
73
74 1
    def browse(self, params):
75 1
        self.logger.debug("browse %s", params)
76 1
        res = []
77 1
        for desc in params.NodesToBrowse:
78 1
            res.append(self._browse(desc))
79 1
        return res
80
81 1
    def _browse(self, desc):
82 1
        res = ua.BrowseResult()
83 1
        if desc.NodeId not in self._aspace:
84
            res.StatusCode = ua.StatusCode(ua.StatusCodes.BadNodeIdInvalid)
85
            return res
86 1
        node = self._aspace[desc.NodeId]
87 1
        for ref in node.references:
88 1
            if not self._is_suitable_ref(desc, ref):
89 1
                continue
90 1
            res.References.append(ref)
91 1
        return res
92
93 1
    def _is_suitable_ref(self, desc, ref):
94 1
        if not self._suitable_direction(desc.BrowseDirection, ref.IsForward):
95
            self.logger.debug("%s is not suitable due to direction", ref)
96
            return False
97 1
        if not self._suitable_reftype(desc.ReferenceTypeId, ref.ReferenceTypeId, desc.IncludeSubtypes):
98 1
            self.logger.debug("%s is not suitable due to type", ref)
99 1
            return False
100 1
        if desc.NodeClassMask and ((desc.NodeClassMask & ref.NodeClass) == 0):
101 1
            self.logger.debug("%s is not suitable due to class", ref)
102 1
            return False
103 1
        self.logger.debug("%s is a suitable ref for desc %s", ref, desc)
104 1
        return True
105
106 1
    def _suitable_reftype(self, ref1, ref2, subtypes):
107
        """
108
        """
109 1
        if ref1.Identifier == ref2.Identifier:
110 1
            return True
111 1
        if not subtypes and ref2.Identifier == ua.ObjectIds.HasSubtype:
112
            return False
113 1
        oktypes = self._get_sub_ref(ref1)
114 1
        return ref2 in oktypes
115
116 1
    def _get_sub_ref(self, ref):
117 1
        res = []
118 1
        nodedata = self._aspace[ref]
119 1
        for ref in nodedata.references:
120 1
            if ref.ReferenceTypeId.Identifier == ua.ObjectIds.HasSubtype:
121 1
                res.append(ref.NodeId)
122 1
                res += self._get_sub_ref(ref.NodeId)
123 1
        return res
124
125 1
    def _suitable_direction(self, desc, isforward):
126 1
        if desc == ua.BrowseDirection.Both:
127
            return True
128 1
        if desc == ua.BrowseDirection.Forward and isforward:
129 1
            return True
130
        return False
131
132 1
    def translate_browsepaths_to_nodeids(self, browsepaths):
133 1
        self.logger.debug("translate browsepath: %s", browsepaths)
134 1
        results = []
135 1
        for path in browsepaths:
136 1
            results.append(self._translate_browsepath_to_nodeid(path))
137 1
        return results
138
139 1
    def _translate_browsepath_to_nodeid(self, path):
140 1
        self.logger.debug("looking at path: %s", path)
141 1
        res = ua.BrowsePathResult()
142 1
        if path.StartingNode not in self._aspace:
143 1
            res.StatusCode = ua.StatusCode(ua.StatusCodes.BadNodeIdInvalid)
144 1
            return res
145 1
        current = path.StartingNode
146 1
        for el in path.RelativePath.Elements:
147 1
            nodeid = self._find_element_in_node(el, current)
148 1
            if not nodeid:
149 1
                res.StatusCode = ua.StatusCode(ua.StatusCodes.BadNoMatch)
150 1
                return res
151 1
            current = nodeid
152 1
        target = ua.BrowsePathTarget()
153 1
        target.TargetId = current
154 1
        target.RemainingPathIndex = 4294967295
155 1
        res.Targets = [target]
156 1
        return res
157
158 1
    def _find_element_in_node(self, el, nodeid):
159 1
        nodedata = self._aspace[nodeid]
160 1
        for ref in nodedata.references:
161
            # FIXME: here we should check other arguments!!
162 1
            if ref.BrowseName == el.TargetName:
163 1
                return ref.NodeId
164 1
        self.logger.info("element %s was not found in node %s", el, nodeid)
165 1
        return None
166
167
168 1
class NodeManagementService(object):
169
170 1
    def __init__(self, aspace):
171 1
        self.logger = logging.getLogger(__name__)
172 1
        self._aspace = aspace
173
174 1
    def add_nodes(self, addnodeitems, user=User.Admin):
175 1
        results = []
176 1
        for item in addnodeitems:
177 1
            results.append(self._add_node(item, user))
178 1
        return results
179
180 1
    def _add_node(self, item, user):
181 1
        result = ua.AddNodesResult()
182
183
        # If Identifier of requested NodeId is null we generate a new NodeId using
184
        # the namespace of the nodeid, this is an extention of the spec to allow
185
        # to requests the server to generate a new nodeid in a specified namespace
186 1
        if item.RequestedNewNodeId.has_null_identifier():
187 1
            self.logger.debug("RequestedNewNodeId has null identifier, generating Identifier")
188 1
            nodedata = NodeData(self._aspace.generate_nodeid(item.RequestedNewNodeId.NamespaceIndex))
189
        else:
190 1
            nodedata = NodeData(item.RequestedNewNodeId)
191
192 1
        if nodedata.nodeid in self._aspace:
193 1
            self.logger.warning("AddNodesItem: node already exists")
194 1
            result.StatusCode = ua.StatusCode(ua.StatusCodes.BadNodeIdExists)
195 1
            return result
196
197 1
        if item.ParentNodeId.is_null():
198
            # self.logger.warning("add_node: creating node %s without parent", nodedata.nodeid)
199
            # We should return Error here, but the standard namespace seems to define many nodes
200
            # without parents, so ignore...
201 1
            pass
202 1
        elif item.ParentNodeId not in self._aspace:
203 1
            self.logger.warning("add_node: while adding node %s, requested parent node %s does not exists", nodedata.nodeid, item.ParentNodeId)
204 1
            result.StatusCode = ua.StatusCode(ua.StatusCodes.BadParentNodeIdInvalid)
205 1
            return result
206
207 1
        if not user == User.Admin:
208 1
            result.StatusCode = ua.StatusCode(ua.StatusCodes.BadUserAccessDenied)
209 1
            return result
210
211
        # add common attrs
212 1
        nodedata.attributes[ua.AttributeIds.NodeId] = AttributeValue(ua.DataValue(ua.Variant(nodedata.nodeid, ua.VariantType.NodeId)))
213 1
        nodedata.attributes[ua.AttributeIds.BrowseName] = AttributeValue(ua.DataValue(ua.Variant(item.BrowseName, ua.VariantType.QualifiedName)))
214 1
        nodedata.attributes[ua.AttributeIds.NodeClass] = AttributeValue(ua.DataValue(ua.Variant(item.NodeClass, ua.VariantType.Int32)))
215
        # add requested attrs
216 1
        self._add_nodeattributes(item.NodeAttributes, nodedata)
217
218 1
        if not item.ParentNodeId.is_null():
219 1
            desc = ua.ReferenceDescription()
220 1
            desc.ReferenceTypeId = item.ReferenceTypeId
221 1
            desc.NodeId = nodedata.nodeid
222 1
            desc.NodeClass = item.NodeClass
223 1
            desc.BrowseName = item.BrowseName
224 1
            desc.DisplayName = ua.LocalizedText(item.BrowseName.Name)
225 1
            desc.TypeDefinition = item.TypeDefinition
226 1
            desc.IsForward = True
227 1
            self._aspace[item.ParentNodeId].references.append(desc)
228
229
        # now add our node to db
230 1
        self._aspace[nodedata.nodeid] = nodedata
231
232
        # add type definition
233 1
        if item.TypeDefinition != ua.NodeId():
234 1
            addref = ua.AddReferencesItem()
235 1
            addref.SourceNodeId = nodedata.nodeid
236 1
            addref.IsForward = True
237 1
            addref.ReferenceTypeId = ua.NodeId(ua.ObjectIds.HasTypeDefinition)
238 1
            addref.TargetNodeId = item.TypeDefinition
239 1
            addref.TargetNodeClass = ua.NodeClass.DataType
240 1
            self._add_reference(addref, user)
241
242 1
        result.StatusCode = ua.StatusCode()
243 1
        result.AddedNodeId = nodedata.nodeid
244
245 1
        return result
246
247 1
    def delete_nodes(self, deletenodeitems, user=User.Admin):
248 1
        results = []
249 1
        for item in deletenodeitems:
250 1
            results.append(self._delete_node(item, user))
251 1
        return results
252
253 1
    def _delete_node(self, item, user):
254 1
        if user != User.Admin:
255
            return ua.StatusCode(ua.StatusCodes.BadUserAccessDenied)
256
257 1
        if item.NodeId not in self._aspace:
258
            self.logger.warning("DeleteNodesItem: node does not exists")
259
            return ua.StatusCode(ua.StatusCodes.BadNodeIdUnknown)
260
261 1
        if item.DeleteTargetReferences:
262 1
            for elem in self._aspace.keys():
263 1
                for rdesc in self._aspace[elem].references:
264 1
                    if rdesc.NodeId == item.NodeId:
265 1
                        self._aspace[elem].references.remove(rdesc)
266
267 1
        self._delete_node_callbacks(self._aspace[item.NodeId])
268
269 1
        del(self._aspace[item.NodeId])
270
271 1
        return ua.StatusCode()
272
273 1
    def _delete_node_callbacks(self, nodedata):
274 1
        if ua.AttributeIds.Value in nodedata.attributes:
275 1
            for handle, callback in nodedata.attributes[ua.AttributeIds.Value].datachange_callbacks.items():
276
                try:
277
                    callback(handle, None, ua.StatusCode(ua.StatusCodes.BadNodeIdUnknown))
278
                    self._aspace.delete_datachange_callback(handle)
279
                except Exception as ex:
280
                    self.logger.exception("Error calling delete node callback callback %s, %s, %s", nodedata, ua.AttributeIds.Value, ex)
281
282 1
    def add_references(self, refs, user=User.Admin):
283 1
        result = []
284 1
        for ref in refs:
285 1
            result.append(self._add_reference(ref, user))
286 1
        return result
287
288 1
    def _add_reference(self, addref, user):
289 1
        if addref.SourceNodeId not in self._aspace:
290
            return ua.StatusCode(ua.StatusCodes.BadSourceNodeIdInvalid)
291 1
        if addref.TargetNodeId not in self._aspace:
292 1
            return ua.StatusCode(ua.StatusCodes.BadTargetNodeIdInvalid)
293 1
        if user != User.Admin:
294
            return ua.StatusCode(ua.StatusCodes.BadUserAccessDenied)
295 1
        rdesc = ua.ReferenceDescription()
296 1
        rdesc.ReferenceTypeId = addref.ReferenceTypeId
297 1
        rdesc.IsForward = addref.IsForward
298 1
        rdesc.NodeId = addref.TargetNodeId
299 1
        rdesc.NodeClass = addref.TargetNodeClass
300 1
        bname = self._aspace.get_attribute_value(addref.TargetNodeId, ua.AttributeIds.BrowseName).Value.Value
301 1
        if bname:
302 1
            rdesc.BrowseName = bname
303 1
        dname = self._aspace.get_attribute_value(addref.TargetNodeId, ua.AttributeIds.DisplayName).Value.Value
304 1
        if dname:
305 1
            rdesc.DisplayName = dname
306 1
        self._aspace[addref.SourceNodeId].references.append(rdesc)
307 1
        return ua.StatusCode()
308
309 1
    def delete_references(self, refs, user=User.Admin):
310
        result = []
311
        for ref in refs:
312
            result.append(self._delete_reference(ref, user))
313
        return result
314
315 1
    def _delete_reference(self, item, user):
316
        if item.SourceNodeId not in self._aspace:
317
            return ua.StatusCode(ua.StatusCodes.BadSourceNodeIdInvalid)
318
        if item.TargetNodeId not in self._aspace:
319
            return ua.StatusCode(ua.StatusCodes.BadTargetNodeIdInvalid)
320
        if user != User.Admin:
321
            return ua.StatusCode(ua.StatusCodes.BadUserAccessDenied)
322
323
        for rdesc in self._aspace[item.SourceNodeId].references:
324
            if rdesc.NodeId is item.TargetNodeId:
325
                if rdesc.RefrenceTypeId != item.RefrenceTypeId:
326
                    return ua.StatusCode(ua.StatusCodes.BadReferenceTypeIdInvalid)
327
                if rdesc.IsForward == item.IsForward or item.DeleteBidirectional:
328
                    self._aspace[item.SourceNodeId].references.remove(rdesc)
329
330
        for rdesc in self._aspace[item.TargetNodeId].references:
331
            if rdesc.NodeId is item.SourceNodeId:
332
                if rdesc.RefrenceTypeId != item.RefrenceTypeId:
333
                    return ua.StatusCode(ua.StatusCodes.BadReferenceTypeIdInvalid)
334
                if rdesc.IsForward == item.IsForward or item.DeleteBidirectional:
335
                    self._aspace[item.SourceNodeId].references.remove(rdesc)
336
337
        return ua.StatusCode()
338
339 1
    def _add_node_attr(self, item, nodedata, name, vtype=None):
340 1
        if item.SpecifiedAttributes & getattr(ua.NodeAttributesMask, name):
341 1
            dv = ua.DataValue(ua.Variant(getattr(item, name), vtype))
342 1
            dv.ServerTimestamp = datetime.utcnow()
343 1
            dv.SourceTimestamp = datetime.utcnow()
344 1
            nodedata.attributes[getattr(ua.AttributeIds, name)] = AttributeValue(dv)
345
346 1
    def _add_nodeattributes(self, item, nodedata):
347 1
        self._add_node_attr(item, nodedata, "AccessLevel", ua.VariantType.Byte)
348 1
        self._add_node_attr(item, nodedata, "ArrayDimensions", ua.VariantType.Int32)
349 1
        self._add_node_attr(item, nodedata, "BrowseName", ua.VariantType.QualifiedName)
350 1
        self._add_node_attr(item, nodedata, "ContainsNoLoops", ua.VariantType.Boolean)
351 1
        self._add_node_attr(item, nodedata, "DataType", ua.VariantType.NodeId)
352 1
        self._add_node_attr(item, nodedata, "Description", ua.VariantType.LocalizedText)
353 1
        self._add_node_attr(item, nodedata, "DisplayName", ua.VariantType.LocalizedText)
354 1
        self._add_node_attr(item, nodedata, "EventNotifier", ua.VariantType.Byte)
355 1
        self._add_node_attr(item, nodedata, "Executable", ua.VariantType.Boolean)
356 1
        self._add_node_attr(item, nodedata, "Historizing", ua.VariantType.Boolean)
357 1
        self._add_node_attr(item, nodedata, "InverseName", ua.VariantType.LocalizedText)
358 1
        self._add_node_attr(item, nodedata, "IsAbstract", ua.VariantType.Boolean)
359 1
        self._add_node_attr(item, nodedata, "MinimumSamplingInterval", ua.VariantType.Double)
360 1
        self._add_node_attr(item, nodedata, "NodeClass", ua.VariantType.UInt32)
361 1
        self._add_node_attr(item, nodedata, "NodeId", ua.VariantType.NodeId)
362 1
        self._add_node_attr(item, nodedata, "Symmetric", ua.VariantType.Boolean)
363 1
        self._add_node_attr(item, nodedata, "UserAccessLevel", ua.VariantType.Byte)
364 1
        self._add_node_attr(item, nodedata, "UserExecutable", ua.VariantType.Byte)
365 1
        self._add_node_attr(item, nodedata, "UserWriteMask", ua.VariantType.Byte)
366 1
        self._add_node_attr(item, nodedata, "ValueRank", ua.VariantType.Int32)
367 1
        self._add_node_attr(item, nodedata, "WriteMask", ua.VariantType.Byte)
368 1
        self._add_node_attr(item, nodedata, "UserWriteMask", ua.VariantType.Byte)
369 1
        self._add_node_attr(item, nodedata, "Value")
370
371
372 1
class MethodService(object):
373
374 1
    def __init__(self, aspace):
375 1
        self.logger = logging.getLogger(__name__)
376 1
        self._aspace = aspace
377
378 1
    def call(self, methods):
379 1
        results = []
380 1
        for method in methods:
381 1
            results.append(self._call(method))
382 1
        return results
383
384 1
    def _call(self, method):
385 1
        res = ua.CallMethodResult()
386 1
        if method.ObjectId not in self._aspace or method.MethodId not in self._aspace:
387 1
            res.StatusCode = ua.StatusCode(ua.StatusCodes.BadNodeIdInvalid)
388
        else:
389 1
            node = self._aspace[method.MethodId]
390 1
            if node.call is None:
391
                res.StatusCode = ua.StatusCode(ua.StatusCodes.BadNothingToDo)
392
            else:
393 1
                try:
394 1
                    res.OutputArguments = node.call(method.ObjectId, *method.InputArguments)
395 1
                    for _ in method.InputArguments:
396 1
                        res.InputArgumentResults.append(ua.StatusCode())
397 1
                except Exception:
398 1
                    self.logger.exception("Error executing method call %s, an exception was raised: ", method)
399 1
                    res.StatusCode = ua.StatusCode(ua.StatusCodes.BadUnexpectedError)
400 1
        return res
401
402
403 1
class AddressSpace(object):
404
405
    """
406
    The address space object stores all the nodes og the OPC-UA server
407
    and helper methods.
408
    The methods are threadsafe
409
    """
410
411 1
    def __init__(self):
412 1
        self.logger = logging.getLogger(__name__)
413 1
        self._nodes = {}
414 1
        self._lock = RLock()  # FIXME: should use multiple reader, one writter pattern
415 1
        self._datachange_callback_counter = 200
416 1
        self._handle_to_attribute_map = {}
417 1
        self._default_idx = 2
418 1
        self._nodeid_counter = 2000
419
420 1
    def __getitem__(self, nodeid):
421 1
        with self._lock:
422 1
            return self._nodes.__getitem__(nodeid)
423
424 1
    def __setitem__(self, nodeid, value):
425 1
        with self._lock:
426 1
            return self._nodes.__setitem__(nodeid, value)
427
428 1
    def __contains__(self, nodeid):
429 1
        with self._lock:
430 1
            return self._nodes.__contains__(nodeid)
431
432 1
    def __delitem__(self, nodeid):
433 1
        with self._lock:
434 1
            self._nodes.__delitem__(nodeid)
435
436 1
    def generate_nodeid(self, idx=0):
437 1
        if not idx:
438 1
            idx = self._default_idx
439 1
        self._nodeid_counter += 1
440 1
        return ua.NodeId(self._nodeid_counter, idx)
441
442 1
    def keys(self):
443 1
        with self._lock:
444 1
            return self._nodes.keys()
445
446 1
    def dump(self, path):
447
        """
448
        dump address space as binary to file
449
        """
450
        with open(path, 'wb') as f:
451
            pickle.dump(self._nodes, f, pickle.HIGHEST_PROTOCOL)
452
453 1
    def load(self, path):
454
        """
455
        load address space from file, overwritting everything current address space
456
        """
457
        with open(path, 'rb') as f:
458
            self._nodes = pickle.load(f)
459
460 1
    def get_attribute_value(self, nodeid, attr):
461 1
        with self._lock:
462 1
            self.logger.debug("get attr val: %s %s", nodeid, attr)
463 1
            if nodeid not in self._nodes:
464 1
                dv = ua.DataValue()
465 1
                dv.StatusCode = ua.StatusCode(ua.StatusCodes.BadNodeIdUnknown)
466 1
                return dv
467 1
            node = self._nodes[nodeid]
468 1
            if attr not in node.attributes:
469 1
                dv = ua.DataValue()
470 1
                dv.StatusCode = ua.StatusCode(ua.StatusCodes.BadAttributeIdInvalid)
471 1
                return dv
472 1
            attval = node.attributes[attr]
473 1
            if attval.value_callback:
474
                return attval.value_callback()
475 1
            return attval.value
476
477 1
    def set_attribute_value(self, nodeid, attr, value):
478 1
        with self._lock:
479 1
            self.logger.debug("set attr val: %s %s %s", nodeid, attr, value)
480 1
            if nodeid not in self._nodes:
481 1
                return ua.StatusCode(ua.StatusCodes.BadNodeIdUnknown)
482 1
            node = self._nodes[nodeid]
483 1
            if attr not in node.attributes:
484 1
                return ua.StatusCode(ua.StatusCodes.BadAttributeIdInvalid)
485 1
            if not value.SourceTimestamp:
486 1
                value.SourceTimestamp = datetime.utcnow()
487 1
            if not value.ServerTimestamp:
488 1
                value.ServerTimestamp = datetime.utcnow()
489
490 1
            attval = node.attributes[attr]
491 1
            old = attval.value
492 1
            attval.value = value
493 1
            cbs = []
494 1
            if old.Value != value.Value:  # only send call callback when a value change has happend
495 1
                cbs = list(attval.datachange_callbacks.items())
496
497 1
        for k, v in cbs:
498 1
            try:
499 1
                v(k, value)
500
            except Exception as ex:
501
                self.logger.exception("Error calling datachange callback %s, %s, %s", k, v, ex)
502
503 1
        return ua.StatusCode()
504
505 1
    def add_datachange_callback(self, nodeid, attr, callback):
506 1
        with self._lock:
507 1
            self.logger.debug("set attr callback: %s %s %s", nodeid, attr, callback)
508 1
            if nodeid not in self._nodes:
509
                return ua.StatusCode(ua.StatusCodes.BadNodeIdUnknown), 0
510 1
            node = self._nodes[nodeid]
511 1
            if attr not in node.attributes:
512 1
                return ua.StatusCode(ua.StatusCodes.BadAttributeIdInvalid), 0
513 1
            attval = node.attributes[attr]
514 1
            self._datachange_callback_counter += 1
515 1
            handle = self._datachange_callback_counter
516 1
            attval.datachange_callbacks[handle] = callback
517 1
            self._handle_to_attribute_map[handle] = (nodeid, attr)
518 1
            return ua.StatusCode(), handle
519
520 1
    def delete_datachange_callback(self, handle):
521 1
        with self._lock:
522 1
            nodeid, attr = self._handle_to_attribute_map.pop(handle)
523 1
            self._nodes[nodeid].attributes[attr].datachange_callbacks.pop(handle)
524
525 1
    def add_method_callback(self, methodid, callback):
526 1
        with self._lock:
527 1
            node = self._nodes[methodid]
528
            node.call = callback
529