Completed
Pull Request — master (#114)
by Denis
01:56
created

opcua.server.NodeManagementService   B

Complexity

Total Complexity 45

Size/Duplication

Total Lines 182
Duplicated Lines 0 %

Test Coverage

Coverage 96.45%
Metric Value
dl 0
loc 182
ccs 136
cts 141
cp 0.9645
rs 8.3673
wmc 45

11 Methods

Rating   Name   Duplication   Size   Complexity  
A __init__() 0 3 1
B _add_node() 0 55 6
A add_nodes() 0 5 2
B _add_nodeattributes() 0 24 1
A delete_references() 0 5 2
B _add_reference() 0 20 6
A _add_node_attr() 0 6 2
B _delete_node() 0 19 7
F _delete_reference() 0 23 14
A add_references() 0 5 2
A delete_nodes() 0 5 2

How to fix   Complexity   

Complex Class

Complex classes like opcua.server.NodeManagementService often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.

Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.

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