Completed
Pull Request — master (#149)
by Denis
02:39
created

opcua.server.AddressSpace.generate_nodeid()   A

Complexity

Conditions 2

Size

Total Lines 5

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 4
CRAP Score 2.032
Metric Value
cc 2
dl 0
loc 5
ccs 4
cts 5
cp 0.8
crap 2.032
rs 9.4285
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 al.Value.Value & ua.AccessLevelMask.CurrentWrite or not ual.Value.Value & ua.AccessLevelMask.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
        # Check if the null NodeId is given
184 1
        if item.RequestedNewNodeId.is_null():
185 1
            self.logger.debug("RequestedNewNodeId is null")
186 1
            if item.BrowseName.NamespaceIndex:
187 1
                idx = item.BrowseName.NamespaceIndex
188
            else:
189 1
                idx = item.ParentNodeId.NamespaceIndex
190 1
            nodedata = NodeData(self._aspace.generate_nodeid(idx))
191 1
            item.BrowseName = ua.QualifiedName(item.BrowseName.Name, nodedata.nodeid.NamespaceIndex)
192
        else:
193 1
            nodedata = NodeData(item.RequestedNewNodeId)
194
195 1
        if nodedata.nodeid in self._aspace:
196 1
            self.logger.warning("AddNodesItem: node already exists")
197 1
            result.StatusCode = ua.StatusCode(ua.StatusCodes.BadNodeIdExists)
198 1
            return result
199
200 1
        if item.ParentNodeId.is_null():
201
            #self.logger.warning("add_node: creating node %s without parent", nodedata.nodeid)
202 1
            pass
203 1
        elif item.ParentNodeId not in self._aspace:
204
            #self.logger.warning("add_node: while adding node %s, requested parent node %s does not exists", nodedata.nodeid, item.ParentNodeId)
205 1
            result.StatusCode = ua.StatusCode(ua.StatusCodes.BadParentNodeIdInvalid)
206 1
            return result
207
208 1
        if not user == User.Admin:
209 1
            result.StatusCode = ua.StatusCode(ua.StatusCodes.BadUserAccessDenied)
210 1
            return result
211
212
        # add common attrs
213 1
        nodedata.attributes[ua.AttributeIds.NodeId] = AttributeValue(ua.DataValue(ua.Variant(nodedata.nodeid, ua.VariantType.NodeId)))
214 1
        nodedata.attributes[ua.AttributeIds.BrowseName] = AttributeValue(ua.DataValue(ua.Variant(item.BrowseName, ua.VariantType.QualifiedName)))
215 1
        nodedata.attributes[ua.AttributeIds.NodeClass] = AttributeValue(ua.DataValue(ua.Variant(item.NodeClass, ua.VariantType.Int32)))
216
        # add requested attrs
217 1
        self._add_nodeattributes(item.NodeAttributes, nodedata)
218
219 1
        if not item.ParentNodeId.is_null():
220 1
            desc = ua.ReferenceDescription()
221 1
            desc.ReferenceTypeId = item.ReferenceTypeId
222 1
            desc.NodeId = nodedata.nodeid
223 1
            desc.NodeClass = item.NodeClass
224 1
            desc.BrowseName = item.BrowseName
225 1
            desc.DisplayName = ua.LocalizedText(item.BrowseName.Name)
226 1
            desc.TypeDefinition = item.TypeDefinition
227 1
            desc.IsForward = True
228 1
            self._aspace[item.ParentNodeId].references.append(desc)
229
230
        # now add our node to db
231 1
        self._aspace[nodedata.nodeid] = nodedata
232
233
        # add type definition
234 1
        if item.TypeDefinition != ua.NodeId():
235 1
            addref = ua.AddReferencesItem()
236 1
            addref.SourceNodeId = nodedata.nodeid
237 1
            addref.IsForward = True
238 1
            addref.ReferenceTypeId = ua.NodeId(ua.ObjectIds.HasTypeDefinition)
239 1
            addref.TargetNodeId = item.TypeDefinition
240 1
            addref.TargetNodeClass = ua.NodeClass.DataType
241 1
            self._add_reference(addref, user)
242
243 1
        result.StatusCode = ua.StatusCode()
244 1
        result.AddedNodeId = nodedata.nodeid
245
246 1
        return result
247
248 1
    def delete_nodes(self, deletenodeitems, user=User.Admin):
249 1
        results = []
250 1
        for item in deletenodeitems:
251 1
            results.append(self._delete_node(item, user))
252 1
        return results
253
254 1
    def _delete_node(self, item, user):
255 1
        if user != User.Admin:
256
            return ua.StatusCode(ua.StatusCodes.BadUserAccessDenied)
257
258 1
        if item.NodeId not in self._aspace:
259
            self.logger.warning("DeleteNodesItem: node does not exists")
260
            return ua.StatusCode(ua.StatusCodes.BadNodeIdUnknown)
261
262 1
        if item.DeleteTargetReferences:
263 1
            for elem in self._aspace.keys():
264 1
                for rdesc in self._aspace[elem].references:
265 1
                    if rdesc.NodeId == item.NodeId:
266 1
                        self._aspace[elem].references.remove(rdesc)
267
268 1
        self._delete_node_callbacks(self._aspace[item.NodeId])
269
270 1
        del(self._aspace[item.NodeId])
271
272 1
        return ua.StatusCode()
273
274 1
    def _delete_node_callbacks(self, nodedata):
275 1
        if ua.AttributeIds.Value in nodedata.attributes:
276 1
            for handle, callback in nodedata.attributes[ua.AttributeIds.Value].datachange_callbacks.items():
277
                try:
278
                    callback(handle, None, ua.StatusCode(ua.StatusCodes.BadNodeIdUnknown))
279
                    self._aspace.delete_datachange_callback(handle)
280
                except Exception as ex:
281
                    self.logger.exception("Error calling delete node callback callback %s, %s, %s", nodedata, ua.AttributeIds.Value, ex)
282
283 1
    def add_references(self, refs, user=User.Admin):
284 1
        result = []
285 1
        for ref in refs:
286 1
            result.append(self._add_reference(ref, user))
287 1
        return result
288
289 1
    def _add_reference(self, addref, user):
290 1
        if addref.SourceNodeId not in self._aspace:
291
            return ua.StatusCode(ua.StatusCodes.BadSourceNodeIdInvalid)
292 1
        if addref.TargetNodeId not in self._aspace:
293 1
            return ua.StatusCode(ua.StatusCodes.BadTargetNodeIdInvalid)
294 1
        if user != User.Admin:
295
            return ua.StatusCode(ua.StatusCodes.BadUserAccessDenied)
296 1
        rdesc = ua.ReferenceDescription()
297 1
        rdesc.ReferenceTypeId = addref.ReferenceTypeId
298 1
        rdesc.IsForward = addref.IsForward
299 1
        rdesc.NodeId = addref.TargetNodeId
300 1
        rdesc.NodeClass = addref.TargetNodeClass
301 1
        bname = self._aspace.get_attribute_value(addref.TargetNodeId, ua.AttributeIds.BrowseName).Value.Value
302 1
        if bname:
303 1
            rdesc.BrowseName = bname
304 1
        dname = self._aspace.get_attribute_value(addref.TargetNodeId, ua.AttributeIds.DisplayName).Value.Value
305 1
        if dname:
306 1
            rdesc.DisplayName = dname
307 1
        self._aspace[addref.SourceNodeId].references.append(rdesc)
308 1
        return ua.StatusCode()
309
310 1
    def delete_references(self, refs, user=User.Admin):
311
        result = []
312
        for ref in refs:
313
            result.append(self._delete_reference(ref, user))
314
        return result
315
316 1
    def _delete_reference(self, item, user):
317
        if item.SourceNodeId not in self._aspace:
318
            return ua.StatusCode(ua.StatusCodes.BadSourceNodeIdInvalid)
319
        if item.TargetNodeId not in self._aspace:
320
            return ua.StatusCode(ua.StatusCodes.BadTargetNodeIdInvalid)
321
        if user != User.Admin:
322
            return ua.StatusCode(ua.StatusCodes.BadUserAccessDenied)
323
324
        for rdesc in self._aspace[item.SourceNodeId].references:
325
            if rdesc.NodeId is item.TargetNodeId:
326
                if rdesc.RefrenceTypeId != item.RefrenceTypeId:
327
                    return ua.StatusCode(ua.StatusCodes.BadReferenceTypeIdInvalid)
328
                if rdesc.IsForward == item.IsForward or item.DeleteBidirectional:
329
                    self._aspace[item.SourceNodeId].references.remove(rdesc)
330
331
        for rdesc in self._aspace[item.TargetNodeId].references:
332
            if rdesc.NodeId is item.SourceNodeId:
333
                if rdesc.RefrenceTypeId != item.RefrenceTypeId:
334
                    return ua.StatusCode(ua.StatusCodes.BadReferenceTypeIdInvalid)
335
                if rdesc.IsForward == item.IsForward or item.DeleteBidirectional:
336
                    self._aspace[item.SourceNodeId].references.remove(rdesc)
337
338
        return ua.StatusCode()
339
340 1
    def _add_node_attr(self, item, nodedata, name, vtype=None):
341 1
        if item.SpecifiedAttributes & getattr(ua.NodeAttributesMask, name):
342 1
            dv = ua.DataValue(ua.Variant(getattr(item, name), vtype))
343 1
            dv.ServerTimestamp = datetime.utcnow()
344 1
            dv.SourceTimestamp = datetime.utcnow()
345 1
            nodedata.attributes[getattr(ua.AttributeIds, name)] = AttributeValue(dv)
346
347 1
    def _add_nodeattributes(self, item, nodedata):
348 1
        self._add_node_attr(item, nodedata, "AccessLevel", ua.VariantType.Byte)
349 1
        self._add_node_attr(item, nodedata, "ArrayDimensions", ua.VariantType.Int32)
350 1
        self._add_node_attr(item, nodedata, "BrowseName", ua.VariantType.QualifiedName)
351 1
        self._add_node_attr(item, nodedata, "ContainsNoLoops", ua.VariantType.Boolean)
352 1
        self._add_node_attr(item, nodedata, "DataType", ua.VariantType.NodeId)
353 1
        self._add_node_attr(item, nodedata, "Description", ua.VariantType.LocalizedText)
354 1
        self._add_node_attr(item, nodedata, "DisplayName", ua.VariantType.LocalizedText)
355 1
        self._add_node_attr(item, nodedata, "EventNotifier", ua.VariantType.Byte)
356 1
        self._add_node_attr(item, nodedata, "Executable", ua.VariantType.Boolean)
357 1
        self._add_node_attr(item, nodedata, "Historizing", ua.VariantType.Boolean)
358 1
        self._add_node_attr(item, nodedata, "InverseName", ua.VariantType.LocalizedText)
359 1
        self._add_node_attr(item, nodedata, "IsAbstract", ua.VariantType.Boolean)
360 1
        self._add_node_attr(item, nodedata, "MinimumSamplingInterval", ua.VariantType.Double)
361 1
        self._add_node_attr(item, nodedata, "NodeClass", ua.VariantType.UInt32)
362 1
        self._add_node_attr(item, nodedata, "NodeId", ua.VariantType.NodeId)
363 1
        self._add_node_attr(item, nodedata, "Symmetric", ua.VariantType.Boolean)
364 1
        self._add_node_attr(item, nodedata, "UserAccessLevel", ua.VariantType.Byte)
365 1
        self._add_node_attr(item, nodedata, "UserExecutable", ua.VariantType.Byte)
366 1
        self._add_node_attr(item, nodedata, "UserWriteMask", ua.VariantType.Byte)
367 1
        self._add_node_attr(item, nodedata, "ValueRank", ua.VariantType.Int32)
368 1
        self._add_node_attr(item, nodedata, "WriteMask", ua.VariantType.Byte)
369 1
        self._add_node_attr(item, nodedata, "UserWriteMask", ua.VariantType.Byte)
370 1
        self._add_node_attr(item, nodedata, "Value")
371
372
373 1
class MethodService(object):
374
375 1
    def __init__(self, aspace):
376 1
        self.logger = logging.getLogger(__name__)
377 1
        self._aspace = aspace
378
379 1
    def call(self, methods):
380 1
        results = []
381 1
        for method in methods:
382 1
            results.append(self._call(method))
383 1
        return results
384
385 1
    def _call(self, method):
386 1
        res = ua.CallMethodResult()
387 1
        if method.ObjectId not in self._aspace or method.MethodId not in self._aspace:
388 1
            res.StatusCode = ua.StatusCode(ua.StatusCodes.BadNodeIdInvalid)
389
        else:
390 1
            node = self._aspace[method.MethodId]
391 1
            if node.call is None:
392
                res.StatusCode = ua.StatusCode(ua.StatusCodes.BadNothingToDo)
393
            else:
394 1
                try:
395 1
                    res.OutputArguments = node.call(method.ObjectId, *method.InputArguments)
396 1
                    for _ in method.InputArguments:
397 1
                        res.InputArgumentResults.append(ua.StatusCode())
398 1
                except Exception:
399 1
                    self.logger.exception("Error executing method call %s, an exception was raised: ", method)
400 1
                    res.StatusCode = ua.StatusCode(ua.StatusCodes.BadUnexpectedError)
401 1
        return res
402
403
404 1
class AddressSpace(object):
405
406
    """
407
    The address space object stores all the nodes og the OPC-UA server
408
    and helper methods.
409
    The methods are threadsafe
410
    """
411
412 1
    def __init__(self):
413 1
        self.logger = logging.getLogger(__name__)
414 1
        self._nodes = {}
415 1
        self._lock = RLock()  # FIXME: should use multiple reader, one writter pattern
416 1
        self._datachange_callback_counter = 200
417 1
        self._handle_to_attribute_map = {}
418 1
        self._default_idx = 2
419 1
        self._nodeid_counter = 2000
420
421 1
    def __getitem__(self, nodeid):
422 1
        with self._lock:
423 1
            return self._nodes.__getitem__(nodeid)
424
425 1
    def __setitem__(self, nodeid, value):
426 1
        with self._lock:
427 1
            return self._nodes.__setitem__(nodeid, value)
428
429 1
    def __contains__(self, nodeid):
430 1
        with self._lock:
431 1
            return self._nodes.__contains__(nodeid)
432
433 1
    def __delitem__(self, nodeid):
434 1
        with self._lock:
435 1
            self._nodes.__delitem__(nodeid)
436
437 1
    def generate_nodeid(self, idx=0):
438 1
        if not idx:
439
            idx = self._default_idx
440 1
        self._nodeid_counter += 1
441 1
        return ua.NodeId(self._nodeid_counter, idx)
442
443 1
    def keys(self):
444 1
        with self._lock:
445 1
            return self._nodes.keys()
446
447 1
    def dump(self, path):
448
        """
449
        dump address space as binary to file
450
        """
451
        with open(path, 'wb') as f:
452
            pickle.dump(self._nodes, f, pickle.HIGHEST_PROTOCOL)
453
454 1
    def load(self, path):
455
        """
456
        load address space from file, overwritting everything current address space
457
        """
458
        with open(path, 'rb') as f:
459
            self._nodes = pickle.load(f)
460
461 1
    def get_attribute_value(self, nodeid, attr):
462 1
        with self._lock:
463
            #self.logger.debug("get attr val: %s %s", nodeid, attr)
464 1
            if nodeid not in self._nodes:
465 1
                dv = ua.DataValue()
466 1
                dv.StatusCode = ua.StatusCode(ua.StatusCodes.BadNodeIdUnknown)
467 1
                return dv
468 1
            node = self._nodes[nodeid]
469 1
            if attr not in node.attributes:
470 1
                dv = ua.DataValue()
471 1
                dv.StatusCode = ua.StatusCode(ua.StatusCodes.BadAttributeIdInvalid)
472 1
                return dv
473 1
            attval = node.attributes[attr]
474 1
            if attval.value_callback:
475
                return attval.value_callback()
476 1
            return attval.value
477
478 1
    def set_attribute_value(self, nodeid, attr, value):
479 1
        with self._lock:
480 1
            self.logger.debug("set attr val: %s %s %s", nodeid, attr, value)
481 1
            if nodeid not in self._nodes:
482 1
                return ua.StatusCode(ua.StatusCodes.BadNodeIdUnknown)
483 1
            node = self._nodes[nodeid]
484 1
            if attr not in node.attributes:
485 1
                return ua.StatusCode(ua.StatusCodes.BadAttributeIdInvalid)
486 1
            if not value.SourceTimestamp:
487 1
                value.SourceTimestamp = datetime.utcnow()
488 1
            if not value.ServerTimestamp:
489 1
                value.ServerTimestamp = datetime.utcnow()
490
491 1
            attval = node.attributes[attr]
492 1
            old = attval.value
493 1
            attval.value = value
494 1
            cbs = []
495 1
            if old.Value != value.Value:  # only send call callback when a value change has happend
496 1
                cbs = list(attval.datachange_callbacks.items())
497
498 1
        for k, v in cbs:
499 1
            try:
500 1
                v(k, value)
501
            except Exception as ex:
502
                self.logger.exception("Error calling datachange callback %s, %s, %s", k, v, ex)
503
504 1
        return ua.StatusCode()
505
506 1
    def add_datachange_callback(self, nodeid, attr, callback):
507 1
        with self._lock:
508 1
            self.logger.debug("set attr callback: %s %s %s", nodeid, attr, callback)
509 1
            if nodeid not in self._nodes:
510
                return ua.StatusCode(ua.StatusCodes.BadNodeIdUnknown), 0
511 1
            node = self._nodes[nodeid]
512 1
            if attr not in node.attributes:
513 1
                return ua.StatusCode(ua.StatusCodes.BadAttributeIdInvalid), 0
514 1
            attval = node.attributes[attr]
515 1
            self._datachange_callback_counter += 1
516 1
            handle = self._datachange_callback_counter
517 1
            attval.datachange_callbacks[handle] = callback
518 1
            self._handle_to_attribute_map[handle] = (nodeid, attr)
519 1
            return ua.StatusCode(), handle
520
521 1
    def delete_datachange_callback(self, handle):
522 1
        with self._lock:
523 1
            nodeid, attr = self._handle_to_attribute_map.pop(handle)
524 1
            self._nodes[nodeid].attributes[attr].datachange_callbacks.pop(handle)
525
526 1
    def add_method_callback(self, methodid, callback):
527 1
        with self._lock:
528 1
            node = self._nodes[methodid]
529
            node.call = callback
530