Completed
Push — master ( c5c8fe...3620aa )
by Olivier
02:15
created

MonitoredItemService.trigger_event()   A

Complexity

Conditions 4

Size

Total Lines 11

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 9
CRAP Score 4.016

Importance

Changes 3
Bugs 1 Features 0
Metric Value
cc 4
dl 0
loc 11
ccs 9
cts 10
cp 0.9
crap 4.016
rs 9.2
c 3
b 1
f 0
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
import traceback
9 1
10
from opcua import ua
11
12 1
13
class MonitoredItemData(object):
14 1
15 1
    def __init__(self):
16 1
        self.client_handle = None
17 1
        self.callback_handle = None
18 1
        self.monitored_item_id = None
19 1
        self.mode = None
20 1
        self.filter = None
21
        self.mvalue = MonitoredItemValues()
22
        self.where_clause_evaluator = None
23 1
        self.queue_size = 0
24
25
26
class MonitoredItemValues(object):
27
28
    def __init__(self):
29 1
        self.current_value = None
30 1
        self.old_value = None
31 1
32 1
    def set_current_value(self, cur_val):
33 1
        self.old_value = self.current_value
34 1
        self.current_value = cur_val
35 1
36 1
    def get_current_value(self):
37 1
        return self.current_value
38
39 1
    def get_old_value(self):
40 1
        return self.old_value
41
42 1
43 1
class MonitoredItemService(object):
44 1
45 1
    """
46 1
    implement monitoreditem service for 1 subscription
47
    """
48 1
49
    def __init__(self, isub, aspace):
50
        self.logger = logging.getLogger(__name__ + "." + str(isub.data.SubscriptionId))
51
        self.isub = isub
52
        self.aspace = aspace
53
        self._lock = RLock()
54 1
        self._monitored_items = {}
55 1
        self._monitored_events = {}
56 1
        self._monitored_datachange = {}
57 1
        self._monitored_item_counter = 111
58
59 1
    def delete_all_monitored_items(self):
60
        self.delete_monitored_items([mdata.monitored_item_id for mdata in self._monitored_items.values()])
61
62
    def create_monitored_items(self, params):
63
        results = []
64
        for item in params.ItemsToCreate:
65
            with self._lock:
66
                if item.ItemToMonitor.AttributeId == ua.AttributeIds.EventNotifier:
67
                    result = self._create_events_monitored_item(item)
68
                else:
69
                    result = self._create_data_change_monitored_item(item)
70
            results.append(result)
71
        return results
72
73
    def modify_monitored_items(self, params):
74 1
        results = []
75 1
        for item in params.ItemsToModify:
76 1
            results.append(self._modify_monitored_item(item))
77 1
        return results
78 1
79 1
    def trigger_datachange(self, handle, nodeid, attr):
80 1
        self.logger.debug("triggering datachange for handle %s, nodeid %s, and attribute %s", handle, nodeid, attr)
81 1
        variant = self.aspace.get_attribute_value(nodeid, attr)
82
        self.datachange_callback(handle, variant)
83 1
84 1
    def _modify_monitored_item(self, params):
85 1
        with self._lock:
86 1
            for mdata in self._monitored_items.values():
87 1
                result = ua.MonitoredItemModifyResult()
88 1
                if mdata.monitored_item_id == params.MonitoredItemId:
89
                    result.RevisedSamplingInterval = params.RequestedParameters.SamplingInterval
90 1
                    result.RevisedQueueSize = params.RequestedParameters.QueueSize
91
                    if params.RequestedParameters.Filter is not None:
92 1
                        mdata.filter = params.RequestedParameters.Filter
93 1
                    mdata.queue_size = params.RequestedParameters.QueueSize
94 1
                    return result
95 1
            result = ua.MonitoredItemModifyResult()
96 1
            result.StatusCode(ua.StatusCodes.BadMonitoredItemIdInvalid)
97 1
            return result
98
99 1
    def _commit_monitored_item(self, result, mdata):
100 1
        if result.StatusCode.is_good():
101 1
            self._monitored_items[result.MonitoredItemId] = mdata
102 1
            self._monitored_item_counter += 1
103
104 1
    def _make_monitored_item_common(self, params):
105
        result = ua.MonitoredItemCreateResult()
106 1
        result.RevisedSamplingInterval = self.isub.data.RevisedPublishingInterval
107 1
        result.RevisedQueueSize = params.RequestedParameters.QueueSize
108 1
        self._monitored_item_counter += 1
109 1
        result.MonitoredItemId = self._monitored_item_counter
110 1
        self.logger.debug("Creating MonitoredItem with id %s", result.MonitoredItemId)
111 1
112 1
        mdata = MonitoredItemData()
113
        mdata.mode = params.MonitoringMode
114 1
        mdata.client_handle = params.RequestedParameters.ClientHandle
115
        mdata.monitored_item_id = result.MonitoredItemId
116 1
        mdata.queue_size = params.RequestedParameters.QueueSize
117 1
        mdata.filter = params.RequestedParameters.Filter
118 1
119
        return result, mdata
120 1
121
    def _create_events_monitored_item(self, params):
122 1
        self.logger.info("request to subscribe to events for node %s and attribute %s",
123 1
                         params.ItemToMonitor.NodeId,
124 1
                         params.ItemToMonitor.AttributeId)
125 1
126 1
        result, mdata = self._make_monitored_item_common(params)
127 1
        ev_notify_byte = self.aspace.get_attribute_value(params.ItemToMonitor.NodeId, ua.AttributeIds.EventNotifier).Value.Value
128 1
        if ev_notify_byte is None or ev_notify_byte & 1 == 0:
129
            result.StatusCode = ua.StatusCode(ua.StatusCodes.BadServiceUnsupported)
130 1
            return result
131 1
        # result.FilterResult = ua.EventFilterResult()  # spec says we can ignore if not error
132 1
        mdata.where_clause_evaluator = WhereClauseEvaluator(self.logger, self.aspace, mdata.filter.WhereClause)
133 1
        self._commit_monitored_item(result, mdata)
134 1
        if params.ItemToMonitor.NodeId not in self._monitored_events:
135 1
            self._monitored_events[params.ItemToMonitor.NodeId] = []
136 1
        self._monitored_events[params.ItemToMonitor.NodeId].append(result.MonitoredItemId)
137 1
        return result
138 1
139 1
    def _create_data_change_monitored_item(self, params):
140 1
        self.logger.info("request to subscribe to datachange for node %s and attribute %s",
141 1
                         params.ItemToMonitor.NodeId,
142 1
                         params.ItemToMonitor.AttributeId)
143 1
144
        result, mdata = self._make_monitored_item_common(params)
145 1
        result.FilterResult = params.RequestedParameters.Filter
146 1
        result.StatusCode, handle = self.aspace.add_datachange_callback(params.ItemToMonitor.NodeId, params.ItemToMonitor.AttributeId, self.datachange_callback)
147
        self.logger.debug("adding callback return status %s and handle %s", result.StatusCode, handle)
148
        mdata.callback_handle = handle
149
        self._commit_monitored_item(result, mdata)
150 1
        if result.StatusCode.is_good():
151 1
            self._monitored_datachange[handle] = result.MonitoredItemId
152 1
            # force data change event generation
153 1
            self.trigger_datachange(handle, params.ItemToMonitor.NodeId, params.ItemToMonitor.AttributeId)
154 1
        return result
155 1
156 1
    def delete_monitored_items(self, ids):
157 1
        self.logger.debug("delete monitored items %s", ids)
158
        with self._lock:
159 1
            results = []
160 1
            for mid in ids:
161 1
                results.append(self._delete_monitored_items(mid))
162 1
            return results
163 1
164 1
    def _delete_monitored_items(self, mid):
165 1
        if mid not in self._monitored_items:
166 1
            return ua.StatusCode(ua.StatusCodes.BadMonitoredItemIdInvalid)
167
        for k, v in self._monitored_events.items():
168
            if mid in v:
169 1
                v.remove(mid)
170 1
                if not v:
171 1
                    self._monitored_events.pop(k)
172 1
                break
173 1
        for k, v in self._monitored_datachange.items():
174 1
            if v == mid:
175
                self.aspace.delete_datachange_callback(k)
176 1
                self._monitored_datachange.pop(k)
177 1
                break
178 1
        self._monitored_items.pop(mid)
179 1
        return ua.StatusCode()
180 1
181
    def datachange_callback(self, handle, value, error=None):
182
        if error:
183
            self.logger.info("subscription %s: datachange callback called with handle '%s' and erorr '%s'", self,
184
                             handle, error)
185
            self.trigger_statuschange(error)
186 1
        else:
187 1
            self.logger.info("subscription %s: datachange callback called with handle '%s' and value '%s'", self,
188 1
                             handle, value.Value)
189 1
            event = ua.MonitoredItemNotification()
190
            with self._lock:
191
                mid = self._monitored_datachange[handle]
192 1
                mdata = self._monitored_items[mid]
193
                mdata.mvalue.set_current_value(value.Value.Value)
194 1
                if mdata.filter is not None:
195
                    deadband_flag_pass = self.deadband_callback(mdata.mvalue, mdata.filter)
196
                else:
197
                    deadband_flag_pass = True
198 1
                if deadband_flag_pass:
199
                    event.ClientHandle = mdata.client_handle
200 1
                    event.Value = value
201 1
                    self.isub.enqueue_datachange_event(mid, event, mdata.queue_size)
202 1
203 1
    def deadband_callback(self, values, flt):
204 1
        if (values.get_old_value() is not None) or \
205 1
                ((abs(values.get_current_value() - values.get_old_value())) > flt.DeadbandValue):
206 1
            return True
207 1
        else:
208 1
            return False
209 1
210 1
    def trigger_event(self, event):
211 1
        with self._lock:
212 1
            if event.SourceNode not in self._monitored_events:
213 1
                self.logger.debug("%s has no subscription for events %s from node: %s",
214 1
                                  self, event, event.SourceNode)
215 1
                return False
216 1
            self.logger.debug("%s has subscription for events %s from node: %s",
217 1
                              self, event, event.SourceNode)
218
            mids = self._monitored_events[event.SourceNode]
219 1
            for mid in mids:
220
                self._trigger_event(event, mid)
221
222 1
    def _trigger_event(self, event, mid):
223 1
        if mid not in self._monitored_items:
224 1
            self.logger.debug("Could not find monitored items for id %s for event %s in subscription %s", mid, event, self)
225
            return
226 1
        mdata = self._monitored_items[mid]
227 1
        if not mdata.where_clause_evaluator.eval(event):
228 1
            self.logger.info("%s, %s, Event %s does not fit WhereClause, not generating event", self, mid, event)
229 1
            return
230
        fieldlist = ua.EventFieldList()
231 1
        fieldlist.ClientHandle = mdata.client_handle
232
        fieldlist.EventFields = event.to_event_fields(mdata.filter.SelectClauses)
233 1
        self.isub.enqueue_event(mid, fieldlist, mdata.queue_size)
234 1
235
    def trigger_statuschange(self, code):
236 1
        self.isub.enqueue_statuschange(code)
237 1
238 1
239 1
class InternalSubscription(object):
240 1
241
    def __init__(self, subservice, data, addressspace, callback):
242 1
        self.logger = logging.getLogger(__name__)
243 1
        self.aspace = addressspace
244 1
        self.subservice = subservice
245 1
        self.data = data
246 1
        self.callback = callback
247
        self.monitored_item_srv = MonitoredItemService(self, addressspace)
248
        self.task = None
249 1
        self._lock = RLock()
250 1
        self._triggered_datachanges = {}
251
        self._triggered_events = {}
252 1
        self._triggered_statuschanges = []
253 1
        self._notification_seq = 1
254
        self._not_acknowledged_results = {}
255
        self._startup = True
256
        self._keep_alive_count = 0
257
        self._publish_cycles_count = 0
258 1
        self._stopev = False
259 1
260 1
    def __str__(self):
261 1
        return "Subscription(id:{})".format(self.data.SubscriptionId)
262 1
263 1
    def start(self):
264 1
        self.logger.debug("starting subscription %s", self.data.SubscriptionId)
265
        self._subscription_loop()
266 1
267 1
    def stop(self):
268 1
        self.logger.debug("stopping subscription %s", self.data.SubscriptionId)
269 1
        self._stopev = True
270 1
        self.monitored_item_srv.delete_all_monitored_items()
271 1
272 1
    def _subscription_loop(self):
273 1
        if not self._stopev:
274 1
            self.subservice.loop.call_later(self.data.RevisedPublishingInterval / 1000.0, self._sub_loop)
275 1
276 1
    def _sub_loop(self):
277 1
        if self._stopev:
278 1
            return
279 1
        self.publish_results()
280 1
        self._subscription_loop()
281
282 1
    def has_published_results(self):
283 1
        with self._lock:
284 1
            if self._startup or self._triggered_datachanges or self._triggered_events:
285 1
                return True
286 1
            if self._keep_alive_count > self.data.RevisedMaxKeepAliveCount:
287 1
                self.logger.debug("keep alive count %s is > than max keep alive count %s, sending publish event", self._keep_alive_count, self.data.RevisedMaxKeepAliveCount)
288 1
                return True
289
            self._keep_alive_count += 1
290 1
            return False
291 1
292 1
    def publish_results(self):
293 1
        if self._publish_cycles_count > self.data.RevisedLifetimeCount:
294 1
            self.logger.warning("Subscription %s has expired, publish cycle count(%s) > lifetime count (%s)", self, self._publish_cycles_count, self.data.RevisedLifetimeCount)
295 1
            # FIXME this will never be send since we do not have publish request anyway
296 1
            self.monitored_item_srv.trigger_statuschange(ua.StatusCode(ua.StatusCodes.BadTimeout))
297
            self._stopev = True
298 1
        result = None
299 1
        with self._lock:
300
            if self.has_published_results():  
301
                # FIXME: should we pop a publish request here? or we do not care?
302
                self._publish_cycles_count += 1
303
                result = self._pop_publish_result()
304
        if result is not None:
305 1
            self.callback(result)
306 1
307 1
    def _pop_publish_result(self):
308 1
        result = ua.PublishResult()
309 1
        result.SubscriptionId = self.data.SubscriptionId
310 1
        self._pop_triggered_datachanges(result)
311 1
        self._pop_triggered_events(result)
312
        self._pop_triggered_statuschanges(result)
313 1
        self._keep_alive_count = 0
314
        self._startup = False
315
        result.NotificationMessage.SequenceNumber = self._notification_seq
316
        if len(result.NotificationMessage.NotificationData) != 0:
317
            self._notification_seq += 1
318
            self._not_acknowledged_results[result.NotificationMessage.SequenceNumber] = result
319
        result.MoreNotifications = False
320
        result.AvailableSequenceNumbers = list(self._not_acknowledged_results.keys())
321
        return result
322
323 1
    def _pop_triggered_datachanges(self, result):
324 1
        if self._triggered_datachanges:
325
            notif = ua.DataChangeNotification()
326 1
            notif.MonitoredItems = [item for sublist in self._triggered_datachanges.values() for item in sublist]
327 1
            self._triggered_datachanges = {}
328
            self.logger.debug("sending datachanges notification with %s events", len(notif.MonitoredItems))
329 1
            result.NotificationMessage.NotificationData.append(notif)
330
331
    def _pop_triggered_events(self, result):
332 1
        if self._triggered_events:
333 1
            notif = ua.EventNotificationList()
334 1
            notif.Events = [item for sublist in self._triggered_events.values() for item in sublist]
335 1
            self._triggered_events = {}
336 1
            result.NotificationMessage.NotificationData.append(notif)
337
            self.logger.debug("sending event notification with %s events", len(notif.Events))
338
339 1
    def _pop_triggered_statuschanges(self, result):
340
        if self._triggered_statuschanges:
341
            notif = ua.StatusChangeNotification()
342
            notif.Status = self._triggered_statuschanges.pop(0)
343
            result.NotificationMessage.NotificationData.append(notif)
344
            self.logger.debug("sending event notification %s", notif.Status)
345
346
    def publish(self, acks):
347
        self.logger.info("publish request with acks %s", acks)
348
        with self._lock:
349
            self._publish_cycles_count = 0
350
            for nb in acks:
351
                if nb in self._not_acknowledged_results:
352
                    self._not_acknowledged_results.pop(nb)
353
354
    def republish(self, nb):
355
        self.logger.info("re-publish request for ack %s in subscription %s", nb, self)
356
        with self._lock:
357
            if nb in self._not_acknowledged_results:
358
                self.logger.info("re-publishing ack %s in subscription %s", nb, self)
359
                return self._not_acknowledged_results[nb].NotificationMessage
360
            else:
361
                self.logger.info("Error request to re-published non existing ack %s in subscription %s", nb, self)
362
                return ua.NotificationMessage()
363
364
    def enqueue_datachange_event(self, mid, eventdata, maxsize):
365
        self._enqueue_event(mid, eventdata, maxsize, self._triggered_datachanges)
366
367
    def enqueue_event(self, mid, eventdata, maxsize):
368
        self._enqueue_event(mid, eventdata, maxsize, self._triggered_events)
369
370
    def enqueue_statuschange(self, code):
371
        self._triggered_statuschanges.append(code)
372
373
    def _enqueue_event(self, mid, eventdata, size, queue):
374
        if mid not in queue:
375
            queue[mid] = [eventdata]
376
            return
377
        if size != 0:
378
            if len(queue[mid]) >= size:
379
                queue[mid].pop(0)
380
        queue[mid].append(eventdata)
381
382
383
class WhereClauseEvaluator(object):
384
    def __init__(self, logger, aspace, whereclause):
385
        self.logger = logger
386
        self.elements = whereclause.Elements
387
        self._aspace = aspace
388
389
    def eval(self, event):
390
        if not self.elements:
391
            return True
392
        # spec says we should only evaluate first element, which may use other elements
393
        try:
394
            res = self._eval_el(0, event)
395
        except Exception as ex:
396
            self.logger.exception("Exception while evaluating WhereClause %s for event %s: %s", self.elements, event, ex)
397
            return False
398
        return res
399
400
    def _eval_el(self, index, event):
401
        el = self.elements[index]
402
        #ops = [self._eval_op(op, event) for op in el.FilterOperands]
403
        ops = el.FilterOperands  # just to make code more readable
404
        if el.FilterOperator == ua.FilterOperator.Equals:
405
            return self._eval_op(ops[0], event) == self._eval_el(ops[1], event)
406
        elif el.FilterOperator == ua.FilterOperator.IsNull:
407
            return self._eval_op(ops[0], event) is None  # FIXME: might be too strict
408
        elif el.FilterOperator == ua.FilterOperator.GreaterThan:
409
            return self._eval_op(ops[0], event) > self._eval_el(ops[1], event)
410
        elif el.FilterOperator == ua.FilterOperator.LessThan:
411
            return self._eval_op(ops[0], event) < self._eval_el(ops[1], event)
412
        elif el.FilterOperator == ua.FilterOperator.GreaterThanOrEqual:
413
            return self._eval_op(ops[0], event) >= self._eval_el(ops[1], event)
414
        elif el.FilterOperator == ua.FilterOperator.LessThanOrEqual:
415
            return self._eval_op(ops[0], event) <= self._eval_el(ops[1], event)
416
        elif el.FilterOperator == ua.FilterOperator.Like:
417
            return self._likeoperator(self._eval_op(ops[0], event), self._eval_el(ops[1], event))
418
        elif el.FilterOperator == ua.FilterOperator.Not:
419
            return not self._eval_op(ops[0], event)
420
        elif el.FilterOperator == ua.FilterOperator.Between:
421
            return self._eval_el(ops[2], event) >= self._eval_op(ops[0], event) >= self._eval_el(ops[1], event)
422
        elif el.FilterOperator == ua.FilterOperator.InList:
423
            return self._eval_op(ops[0], event) in [self._eval_op(op, event) for op in ops[1:]]
424
        elif el.FilterOperator == ua.FilterOperator.And:
425
            self.elements(ops[0].Index)
426
            return self._eval_op(ops[0], event) and self._eval_op(ops[1], event)
427
        elif el.FilterOperator == ua.FilterOperator.Or:
428
            return self._eval_op(ops[0], event) or self._eval_el(ops[1], event)
429
        elif el.FilterOperator == ua.FilterOperator.Cast:
430
            self.logger.warn("Cast operand not implemented, assuming True")
431
            return True
432
        elif el.FilterOperator == ua.FilterOperator.OfType:
433
            return event.EventType == self._eval_op(ops[0], event)
434
        else:
435
            # TODO: implement missing operators
436
            self.logger.warning("WhereClause not implemented for element: %s", el)
437
            raise NotImplementedError
438
439
    def _like_operator(self, string, pattern):
440
        raise NotImplementedError
441
442
    def _eval_op(self, op, event):
443
        # seems spec says we should return Null if issues
444
        if type(op) is ua.ElementOperand:
445
            return self._eval_el(op.Index, event)
446
        elif type(op) is ua.AttributeOperand:
447
            if op.BrowsePath:
448
                return getattr(event, op.BrowsePath.Elements[0].TargetName.Name)
449
            else:
450
                return self._aspace.get_attribute_value(event.EventType, op.AttributeId).Value.Value
451
            # FIXME: check, this is probably broken
452
        elif type(op) is ua.SimpleAttributeOperand:
453
            if op.BrowsePath:
454
                # we only support depth of 1
455
                return getattr(event, op.BrowsePath[0].Name)
456
            else:
457
                # TODO: write code for index range.... but doe it make any sense
458
                return self._aspace.get_attribute_value(event.EventType, op.AttributeId).Value.Value
459
        elif type(op) is ua.LiteralOperand:
460
            return op.Value.Value
461
        else:
462
            self.logger.warning("Where clause element % is not of a known type", op)
463
            raise NotImplementedError
464
465
466
467