Completed
Push — master ( 50d717...c5c8fe )
by Olivier
03:32
created

MonitoredItemService._make_monitored_item_common()   A

Complexity

Conditions 1

Size

Total Lines 16

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 12
CRAP Score 1

Importance

Changes 2
Bugs 1 Features 0
Metric Value
cc 1
c 2
b 1
f 0
dl 0
loc 16
ccs 12
cts 12
cp 1
crap 1
rs 9.4285
1
"""
2
server side implementation of a subscription object
3
"""
4
5 1
from threading import RLock
6 1
import logging
7 1
import copy
8
9 1
from opcua import ua
10
11
12 1
class MonitoredItemData(object):
13
14 1
    def __init__(self):
15 1
        self.client_handle = None
16 1
        self.callback_handle = None
17 1
        self.monitored_item_id = None
18 1
        self.mode = None
19 1
        self.filter = None
20 1
        self.mvalue = MonitoredItemValues()
21
        self.where_clause_evaluator = None
22
        self.queue_size = 0
23 1
24
25
class MonitoredItemValues(object):
26
27
    def __init__(self):
28
        self.current_value = None
29 1
        self.old_value = None
30 1
31 1
    def set_current_value(self, cur_val):
32 1
        self.old_value = self.current_value
33 1
        self.current_value = cur_val
34 1
35 1
    def get_current_value(self):
36 1
        return self.current_value
37 1
38
    def get_old_value(self):
39 1
        return self.old_value
40 1
41
42 1
class MonitoredItemService(object):
43 1
44 1
    """
45 1
    implement monitoreditem service for 1 subscription
46 1
    """
47
48 1
    def __init__(self, isub, aspace):
49
        self.logger = logging.getLogger(__name__ + "." + str(isub.data.SubscriptionId))
50
        self.isub = isub
51
        self.aspace = aspace
52
        self._lock = RLock()
53
        self._monitored_items = {}
54 1
        self._monitored_events = {}
55 1
        self._monitored_datachange = {}
56 1
        self._monitored_item_counter = 111
57 1
58
    def delete_all_monitored_items(self):
59 1
        self.delete_monitored_items([mdata.monitored_item_id for mdata in self._monitored_items.values()])
60
61
    def create_monitored_items(self, params):
62
        results = []
63
        for item in params.ItemsToCreate:
64
            with self._lock:
65
                if item.ItemToMonitor.AttributeId == ua.AttributeIds.EventNotifier:
66
                    result = self._create_events_monitored_item(item)
67
                else:
68
                    result = self._create_data_change_monitored_item(item)
69
            results.append(result)
70
        return results
71
72
    def modify_monitored_items(self, params):
73
        results = []
74 1
        for item in params.ItemsToModify:
75 1
            results.append(self._modify_monitored_item(item))
76 1
        return results
77 1
78 1
    def trigger_datachange(self, handle, nodeid, attr):
79 1
        self.logger.debug("triggering datachange for handle %s, nodeid %s, and attribute %s", handle, nodeid, attr)
80 1
        variant = self.aspace.get_attribute_value(nodeid, attr)
81 1
        self.datachange_callback(handle, variant)
82
83 1
    def _modify_monitored_item(self, params):
84 1
        with self._lock:
85 1
            for mdata in self._monitored_items.values():
86 1
                result = ua.MonitoredItemModifyResult()
87 1
                if mdata.monitored_item_id == params.MonitoredItemId:
88 1
                    result.RevisedSamplingInterval = params.RequestedParameters.SamplingInterval
89
                    result.RevisedQueueSize = params.RequestedParameters.QueueSize
90 1
                    if params.RequestedParameters.Filter is not None:
91
                        mdata.filter = params.RequestedParameters.Filter
92 1
                    mdata.queue_size = params.RequestedParameters.QueueSize
93 1
                    return result
94 1
            result = ua.MonitoredItemModifyResult()
95 1
            result.StatusCode(ua.StatusCodes.BadMonitoredItemIdInvalid)
96 1
            return result
97 1
98
    def _commit_monitored_item(self, result, mdata):
99 1
        if result.StatusCode.is_good():
100 1
            self._monitored_items[result.MonitoredItemId] = mdata
101 1
            self._monitored_item_counter += 1
102 1
103
    def _make_monitored_item_common(self, params):
104 1
        result = ua.MonitoredItemCreateResult()
105
        result.RevisedSamplingInterval = self.isub.data.RevisedPublishingInterval
106 1
        result.RevisedQueueSize = params.RequestedParameters.QueueSize
107 1
        self._monitored_item_counter += 1
108 1
        result.MonitoredItemId = self._monitored_item_counter
109 1
        self.logger.debug("Creating MonitoredItem with id %s", result.MonitoredItemId)
110 1
111 1
        mdata = MonitoredItemData()
112 1
        mdata.mode = params.MonitoringMode
113
        mdata.client_handle = params.RequestedParameters.ClientHandle
114 1
        mdata.monitored_item_id = result.MonitoredItemId
115
        mdata.queue_size = params.RequestedParameters.QueueSize
116 1
        mdata.filter = params.RequestedParameters.Filter
117 1
118 1
        return result, mdata
119
120 1
    def _create_events_monitored_item(self, params):
121
        self.logger.info("request to subscribe to events for node %s and attribute %s",
122 1
                         params.ItemToMonitor.NodeId,
123 1
                         params.ItemToMonitor.AttributeId)
124 1
125 1
        result, mdata = self._make_monitored_item_common(params)
126 1
        ev_notify_byte = self.aspace.get_attribute_value(params.ItemToMonitor.NodeId, ua.AttributeIds.EventNotifier).Value.Value
127 1
        if ev_notify_byte is None or ev_notify_byte & 1 == 0:
128 1
            result.StatusCode = ua.StatusCode(ua.StatusCodes.BadServiceUnsupported)
129
            return result
130 1
        # result.FilterResult = ua.EventFilterResult()  # spec says we can ignore if not error
131 1
        mdata.where_clause_evaluator = WhereClauseEvaluator(self.logger, self.aspace, mdata.filter.WhereClause)
132 1
        self._commit_monitored_item(result, mdata)
133 1
        if params.ItemToMonitor.NodeId not in self._monitored_events:
134 1
            self._monitored_events[params.ItemToMonitor.NodeId] = []
135 1
        self._monitored_events[params.ItemToMonitor.NodeId].append(result.MonitoredItemId)
136 1
        return result
137 1
138 1
    def _create_data_change_monitored_item(self, params):
139 1
        self.logger.info("request to subscribe to datachange for node %s and attribute %s",
140 1
                         params.ItemToMonitor.NodeId,
141 1
                         params.ItemToMonitor.AttributeId)
142 1
143 1
        result, mdata = self._make_monitored_item_common(params)
144
        result.FilterResult = params.RequestedParameters.Filter
145 1
        result.StatusCode, handle = self.aspace.add_datachange_callback(params.ItemToMonitor.NodeId, params.ItemToMonitor.AttributeId, self.datachange_callback)
146 1
        self.logger.debug("adding callback return status %s and handle %s", result.StatusCode, handle)
147
        mdata.callback_handle = handle
148
        self._commit_monitored_item(result, mdata)
149
        if result.StatusCode.is_good():
150 1
            self._monitored_datachange[handle] = result.MonitoredItemId
151 1
            # force data change event generation
152 1
            self.trigger_datachange(handle, params.ItemToMonitor.NodeId, params.ItemToMonitor.AttributeId)
153 1
        return result
154 1
155 1
    def delete_monitored_items(self, ids):
156 1
        self.logger.debug("delete monitored items %s", ids)
157 1
        with self._lock:
158
            results = []
159 1
            for mid in ids:
160 1
                results.append(self._delete_monitored_items(mid))
161 1
            return results
162 1
163 1
    def _delete_monitored_items(self, mid):
164 1
        if mid not in self._monitored_items:
165 1
            return ua.StatusCode(ua.StatusCodes.BadMonitoredItemIdInvalid)
166 1
        for k, v in self._monitored_events.items():
167
            if mid in v:
168
                v.remove(mid)
169 1
                if not v:
170 1
                    self._monitored_events.pop(k)
171 1
                break
172 1
        for k, v in self._monitored_datachange.items():
173 1
            if v == mid:
174 1
                self.aspace.delete_datachange_callback(k)
175
                self._monitored_datachange.pop(k)
176 1
                break
177 1
        self._monitored_items.pop(mid)
178 1
        return ua.StatusCode()
179 1
180 1
    def datachange_callback(self, handle, value, error=None):
181
        if error:
182
            self.logger.info("subscription %s: datachange callback called with handle '%s' and erorr '%s'", self,
183
                             handle, error)
184
            self.trigger_statuschange(error)
185
        else:
186 1
            self.logger.info("subscription %s: datachange callback called with handle '%s' and value '%s'", self,
187 1
                             handle, value.Value)
188 1
            event = ua.MonitoredItemNotification()
189 1
            with self._lock:
190
                mid = self._monitored_datachange[handle]
191
                mdata = self._monitored_items[mid]
192 1
                mdata.mvalue.set_current_value(value.Value.Value)
193
                if mdata.filter is not None:
194 1
                    deadband_flag_pass = self.deadband_callback(mdata.mvalue, mdata.filter)
195
                else:
196
                    deadband_flag_pass = True
197
                if deadband_flag_pass:
198 1
                    event.ClientHandle = mdata.client_handle
199
                    event.Value = value
200 1
                    self.isub.enqueue_datachange_event(mid, event, mdata.queue_size)
201 1
202 1
    def deadband_callback(self, values, flt):
203 1
        if (values.get_old_value() is not None) or \
204 1
                ((abs(values.get_current_value() - values.get_old_value())) > flt.DeadbandValue):
205 1
            return True
206 1
        else:
207 1
            return False
208 1
209 1
    def trigger_event(self, event):
210 1
        with self._lock:
211 1
            if event.SourceNode not in self._monitored_events:
212 1
                self.logger.debug("%s has no subscription for events %s from node: %s",
213 1
                                  self, event, event.SourceNode)
214 1
                return False
215 1
            self.logger.debug("%s has subscription for events %s from node: %s",
216 1
                              self, event, event.SourceNode)
217 1
            mids = self._monitored_events[event.SourceNode]
218
            for mid in mids:
219 1
                self._trigger_event(event, mid)
220
221
    def _trigger_event(self, event, mid):
222 1
        if mid not in self._monitored_items:
223 1
            self.logger.debug("Could not find monitored items for id %s for event %s in subscription %s", mid, event, self)
224 1
            return
225
        mdata = self._monitored_items[mid]
226 1
        if not mdata.where_clause_evaluator.eval(event):
227 1
            self.logger.info("%s, %s, Event %s does not fit WhereClause, not generating event", self, mid, event)
228 1
            return
229 1
        fieldlist = ua.EventFieldList()
230
        fieldlist.ClientHandle = mdata.client_handle
231 1
        fieldlist.EventFields = self._get_event_fields(mdata.filter, event)
232
        self.isub.enqueue_event(mid, fieldlist, mdata.queue_size)
233 1
234 1
    def _get_event_fields(self, evfilter, event):
235
        fields = []
236 1
        for sattr in evfilter.SelectClauses:
237 1
            try:
238 1
                if not sattr.BrowsePath:
239 1
                    val = getattr(event, sattr.Attribute.name)
240 1
                    val = copy.deepcopy(val)
241
                    fields.append(ua.Variant(val))
242 1
                else:
243 1
                    name = sattr.BrowsePath[0].Name
244 1
                    val = getattr(event, name)
245 1
                    val = copy.deepcopy(val)
246 1
                    fields.append(ua.Variant(val))
247
            except AttributeError:
248
                fields.append(ua.Variant())
249 1
        return fields
250 1
251
    def trigger_statuschange(self, code):
252 1
        self.isub.enqueue_statuschange(code)
253 1
254
255
class InternalSubscription(object):
256
257
    def __init__(self, subservice, data, addressspace, callback):
258 1
        self.logger = logging.getLogger(__name__)
259 1
        self.aspace = addressspace
260 1
        self.subservice = subservice
261 1
        self.data = data
262 1
        self.callback = callback
263 1
        self.monitored_item_srv = MonitoredItemService(self, addressspace)
264 1
        self.task = None
265
        self._lock = RLock()
266 1
        self._triggered_datachanges = {}
267 1
        self._triggered_events = {}
268 1
        self._triggered_statuschanges = []
269 1
        self._notification_seq = 1
270 1
        self._not_acknowledged_results = {}
271 1
        self._startup = True
272 1
        self._keep_alive_count = 0
273 1
        self._publish_cycles_count = 0
274 1
        self._stopev = False
275 1
276 1
    def __str__(self):
277 1
        return "Subscription(id:{})".format(self.data.SubscriptionId)
278 1
279 1
    def start(self):
280 1
        self.logger.debug("starting subscription %s", self.data.SubscriptionId)
281
        self._subscription_loop()
282 1
283 1
    def stop(self):
284 1
        self.logger.debug("stopping subscription %s", self.data.SubscriptionId)
285 1
        self._stopev = True
286 1
        self.monitored_item_srv.delete_all_monitored_items()
287 1
288 1
    def _subscription_loop(self):
289
        if not self._stopev:
290 1
            self.subservice.loop.call_later(self.data.RevisedPublishingInterval / 1000.0, self._sub_loop)
291 1
292 1
    def _sub_loop(self):
293 1
        if self._stopev:
294 1
            return
295 1
        self.publish_results()
296 1
        self._subscription_loop()
297
298 1
    def has_published_results(self):
299 1
        with self._lock:
300
            if self._startup or self._triggered_datachanges or self._triggered_events:
301
                return True
302
            if self._keep_alive_count > self.data.RevisedMaxKeepAliveCount:
303
                self.logger.debug("keep alive count %s is > than max keep alive count %s, sending publish event", self._keep_alive_count, self.data.RevisedMaxKeepAliveCount)
304
                return True
305 1
            self._keep_alive_count += 1
306 1
            return False
307 1
308 1
    def publish_results(self):
309 1
        if self._publish_cycles_count > self.data.RevisedLifetimeCount:
310 1
            self.logger.warning("Subscription %s has expired, publish cycle count(%s) > lifetime count (%s)", self, self._publish_cycles_count, self.data.RevisedLifetimeCount)
311 1
            # FIXME this will never be send since we do not have publish request anyway
312
            self.monitored_item_srv.trigger_statuschange(ua.StatusCode(ua.StatusCodes.BadTimeout))
313 1
            self._stopev = True
314
        result = None
315
        with self._lock:
316
            if self.has_published_results():  # FIXME: should we pop a publish request here? or we do not care?
317
                self._publish_cycles_count += 1
318
                result = self._pop_publish_result()
319
        if result is not None:
320
            self.callback(result)
321
322
    def _pop_publish_result(self):
323 1
        result = ua.PublishResult()
324 1
        result.SubscriptionId = self.data.SubscriptionId
325
        self._pop_triggered_datachanges(result)
326 1
        self._pop_triggered_events(result)
327 1
        self._pop_triggered_statuschanges(result)
328
        self._keep_alive_count = 0
329 1
        self._startup = False
330
        result.NotificationMessage.SequenceNumber = self._notification_seq
331
        if len(result.NotificationMessage.NotificationData) != 0:
332 1
            self._notification_seq += 1
333 1
            self._not_acknowledged_results[result.NotificationMessage.SequenceNumber] = result
334 1
        result.MoreNotifications = False
335 1
        result.AvailableSequenceNumbers = list(self._not_acknowledged_results.keys())
336 1
        return result
337
338
    def _pop_triggered_datachanges(self, result):
339 1
        if self._triggered_datachanges:
340
            notif = ua.DataChangeNotification()
341
            notif.MonitoredItems = [item for sublist in self._triggered_datachanges.values() for item in sublist]
342
            self._triggered_datachanges = {}
343
            self.logger.debug("sending datachanges notification with %s events", len(notif.MonitoredItems))
344
            result.NotificationMessage.NotificationData.append(notif)
345
346
    def _pop_triggered_events(self, result):
347
        if self._triggered_events:
348
            notif = ua.EventNotificationList()
349
            notif.Events = [item for sublist in self._triggered_events.values() for item in sublist]
350
            self._triggered_events = {}
351
            result.NotificationMessage.NotificationData.append(notif)
352
            self.logger.debug("sending event notification with %s events", len(notif.Events))
353
354
    def _pop_triggered_statuschanges(self, result):
355
        if self._triggered_statuschanges:
356
            notif = ua.StatusChangeNotification()
357
            notif.Status = self._triggered_statuschanges.pop(0)
358
            result.NotificationMessage.NotificationData.append(notif)
359
            self.logger.debug("sending event notification %s", notif.Status)
360
361
    def publish(self, acks):
362
        self.logger.info("publish request with acks %s", acks)
363
        with self._lock:
364
            self._publish_cycles_count = 0
365
            for nb in acks:
366
                if nb in self._not_acknowledged_results:
367
                    self._not_acknowledged_results.pop(nb)
368
369
    def republish(self, nb):
370
        self.logger.info("re-publish request for ack %s in subscription %s", nb, self)
371
        with self._lock:
372
            if nb in self._not_acknowledged_results:
373
                self.logger.info("re-publishing ack %s in subscription %s", nb, self)
374
                return self._not_acknowledged_results[nb].NotificationMessage
375
            else:
376
                self.logger.info("Error request to re-published non existing ack %s in subscription %s", nb, self)
377
                return ua.NotificationMessage()
378
379
    def enqueue_datachange_event(self, mid, eventdata, maxsize):
380
        self._enqueue_event(mid, eventdata, maxsize, self._triggered_datachanges)
381
382
    def enqueue_event(self, mid, eventdata, maxsize):
383
        self._enqueue_event(mid, eventdata, maxsize, self._triggered_events)
384
385
    def enqueue_statuschange(self, code):
386
        self._triggered_statuschanges.append(code)
387
388
    def _enqueue_event(self, mid, eventdata, size, queue):
389
        if mid not in queue:
390
            queue[mid] = [eventdata]
391
            return
392
        if size != 0:
393
            if len(queue[mid]) >= size:
394
                queue[mid].pop(0)
395
        queue[mid].append(eventdata)
396
397
398
class WhereClauseEvaluator(object):
399
    def __init__(self, logger, aspace, whereclause):
400
        self.logger = logger
401
        self.elements = whereclause.Elements
402
        self._aspace = aspace
403
404
    def eval(self, event):
405
        if not self.elements:
406
            return True
407
        # spec says we should only evaluate first element, which may use other elements
408
        try:
409
            res = self._eval_el(0, event)
410
        except Exception as ex:
411
            self.logger.warning("Exception while evaluating WhereClause %s for event %s: %s", self.elements, event, ex)
412
            return False
413
        return res
414
415
    def _eval_el(self, index, event):
416
        el = self.elements[index]
417
        #ops = [self._eval_op(op, event) for op in el.FilterOperands]
418
        ops = el.FilterOperands  # just to make code more readable
419
        if el.FilterOperator == ua.FilterOperator.Equals:
420
            return self._eval_op(ops[0], event) == self._eval_el(ops[1], event)
421
        elif el.FilterOperator == ua.FilterOperator.IsNull:
422
            return self._eval_op(ops[0], event) is None  # FIXME: might be too strict
423
        elif el.FilterOperator == ua.FilterOperator.GreaterThan:
424
            return self._eval_op(ops[0], event) > self._eval_el(ops[1], event)
425
        elif el.FilterOperator == ua.FilterOperator.LessThan:
426
            return self._eval_op(ops[0], event) < self._eval_el(ops[1], event)
427
        elif el.FilterOperator == ua.FilterOperator.GreaterThanOrEqual:
428
            return self._eval_op(ops[0], event) >= self._eval_el(ops[1], event)
429
        elif el.FilterOperator == ua.FilterOperator.LessThanOrEqual:
430
            return self._eval_op(ops[0], event) <= self._eval_el(ops[1], event)
431
        elif el.FilterOperator == ua.FilterOperator.Like:
432
            return self._likeoperator(self._eval_op(ops[0], event), self._eval_el(ops[1], event))
433
        elif el.FilterOperator == ua.FilterOperator.Not:
434
            return not self._eval_op(ops[0], event)
435
        elif el.FilterOperator == ua.FilterOperator.Between:
436
            return self._eval_el(ops[2], event) >= self._eval_op(ops[0], event) >= self._eval_el(ops[1], event)
437
        elif el.FilterOperator == ua.FilterOperator.InList:
438
            return self._eval_op(ops[0], event) in [self._eval_op(op, event) for op in ops[1:]]
439
        elif el.FilterOperator == ua.FilterOperator.And:
440
            self.elements(ops[0].Index)
441
            return self._eval_op(ops[0], event) and self._eval_op(ops[1], event)
442
        elif el.FilterOperator == ua.FilterOperator.Or:
443
            return self._eval_op(ops[0], event) or self._eval_el(ops[1], event)
444
        elif el.FilterOperator == ua.FilterOperator.Cast:
445
            self.logger.warn("Cast operand not implemented, assuming True")
446
            return True
447
        elif el.FilterOperator == ua.FilterOperator.OfType:
448
            self.logger.warn("OfType operand not implemented, assuming True")
449
            return True
450
        else:
451
            # TODO: implement missing operators
452
            print("WhereClause not implemented for element: %s", el)
453
            raise NotImplementedError
454
455
    def _like_operator(self, string, pattern):
456
        raise NotImplementedError
457
458
    def _eval_op(self, op, event):
459
        # seems spec says we should return Null if issues
460
        if type(op) is ua.ElementOperand:
461
            return self._eval_el(op.Index, event)
462
        elif type(op) is ua.AttributeOperand:
463
            if op.BrowsePath:
464
                return getattr(event, op.BrowsePath.Elements[0].TargetName.Name)
465
            else:
466
                return self._aspace.get_attribute_value(event.EventType, op.AttributeId).Value.Value
467
            # FIXME: check, this is probably broken
468
        elif type(op) is ua.SimpleAttributeOperand:
469
            if op.BrowsePath:
470
                # we only support depth of 1
471
                return getattr(event, op.BrowsePath[0].Name)
472
            else:
473
                # TODO: write code for index range.... but doe it make any sense
474
                return self._aspace.get_attribute_value(event.EventType, op.AttributeId).Value.Value
475
        elif type(op) is ua.LiteralOperand:
476
            return op.Value.Value
477
        else:
478
            self.logger.warning("Where clause element % is not of a known type", op)
479
            raise NotImplementedError
480
481
482
483