Completed
Push — master ( eb5e78...c75f71 )
by Olivier
04:30
created

InternalSubscription.__init__()   A

Complexity

Conditions 1

Size

Total Lines 18

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 11
CRAP Score 1.0305

Importance

Changes 0
Metric Value
cc 1
dl 0
loc 18
ccs 11
cts 16
cp 0.6875
crap 1.0305
rs 9.4285
c 0
b 0
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(
128 1
            params.ItemToMonitor.NodeId, ua.AttributeIds.EventNotifier).Value.Value
129
130 1
        if ev_notify_byte is None or not ua.test_bit(ev_notify_byte, ua.EventNotifier.SubscribeToEvents):
131 1
            result.StatusCode = ua.StatusCode(ua.StatusCodes.BadServiceUnsupported)
132 1
            return result
133 1
        # result.FilterResult = ua.EventFilterResult()  # spec says we can ignore if not error
134 1
        mdata.where_clause_evaluator = WhereClauseEvaluator(self.logger, self.aspace, mdata.filter.WhereClause)
135 1
        self._commit_monitored_item(result, mdata)
136 1
        if params.ItemToMonitor.NodeId not in self._monitored_events:
137 1
            self._monitored_events[params.ItemToMonitor.NodeId] = []
138 1
        self._monitored_events[params.ItemToMonitor.NodeId].append(result.MonitoredItemId)
139 1
        return result
140 1
141 1
    def _create_data_change_monitored_item(self, params):
142 1
        self.logger.info("request to subscribe to datachange for node %s and attribute %s",
143 1
                         params.ItemToMonitor.NodeId,
144
                         params.ItemToMonitor.AttributeId)
145 1
146 1
        result, mdata = self._make_monitored_item_common(params)
147
        result.FilterResult = params.RequestedParameters.Filter
148
        result.StatusCode, handle = self.aspace.add_datachange_callback(
149
            params.ItemToMonitor.NodeId, params.ItemToMonitor.AttributeId, self.datachange_callback)
150 1
151 1
        self.logger.debug("adding callback return status %s and handle %s", result.StatusCode, handle)
152 1
        mdata.callback_handle = handle
153 1
        self._commit_monitored_item(result, mdata)
154 1
        if result.StatusCode.is_good():
155 1
            self._monitored_datachange[handle] = result.MonitoredItemId
156 1
            # force data change event generation
157 1
            self.trigger_datachange(handle, params.ItemToMonitor.NodeId, params.ItemToMonitor.AttributeId)
158
        return result
159 1
160 1
    def delete_monitored_items(self, ids):
161 1
        self.logger.debug("delete monitored items %s", ids)
162 1
        with self._lock:
163 1
            results = []
164 1
            for mid in ids:
165 1
                results.append(self._delete_monitored_items(mid))
166 1
            return results
167
168
    def _delete_monitored_items(self, mid):
169 1
        if mid not in self._monitored_items:
170 1
            return ua.StatusCode(ua.StatusCodes.BadMonitoredItemIdInvalid)
171 1
        for k, v in self._monitored_events.items():
172 1
            if mid in v:
173 1
                v.remove(mid)
174 1
                if not v:
175
                    self._monitored_events.pop(k)
176 1
                break
177 1
        for k, v in self._monitored_datachange.items():
178 1
            if v == mid:
179 1
                self.aspace.delete_datachange_callback(k)
180 1
                self._monitored_datachange.pop(k)
181
                break
182
        self._monitored_items.pop(mid)
183
        return ua.StatusCode()
184
185
    def datachange_callback(self, handle, value, error=None):
186 1
        if error:
187 1
            self.logger.info("subscription %s: datachange callback called with handle '%s' and erorr '%s'", self,
188 1
                             handle, error)
189 1
            self.trigger_statuschange(error)
190
        else:
191
            self.logger.info("subscription %s: datachange callback called with handle '%s' and value '%s'", self,
192 1
                             handle, value.Value)
193
            event = ua.MonitoredItemNotification()
194 1
            with self._lock:
195
                mid = self._monitored_datachange[handle]
196
                mdata = self._monitored_items[mid]
197
                mdata.mvalue.set_current_value(value.Value.Value)
198 1
                if mdata.filter is not None:
199
                    deadband_flag_pass = self.deadband_callback(mdata.mvalue, mdata.filter)
200 1
                else:
201 1
                    deadband_flag_pass = True
202 1
                if deadband_flag_pass:
203 1
                    event.ClientHandle = mdata.client_handle
204 1
                    event.Value = value
205 1
                    self.isub.enqueue_datachange_event(mid, event, mdata.queue_size)
206 1
207 1
    def deadband_callback(self, values, flt):
208 1
        if (values.get_old_value() is not None) or \
209 1
                ((abs(values.get_current_value() - values.get_old_value())) > flt.DeadbandValue):
210 1
            return True
211 1
        else:
212 1
            return False
213 1
214 1
    def trigger_event(self, event):
215 1
        with self._lock:
216 1
            if event.SourceNode not in self._monitored_events:
217 1
                self.logger.debug("%s has no subscription for events %s from node: %s",
218
                                  self, event, event.SourceNode)
219 1
                return False
220
            self.logger.debug("%s has subscription for events %s from node: %s",
221
                              self, event, event.SourceNode)
222 1
            mids = self._monitored_events[event.SourceNode]
223 1
            for mid in mids:
224 1
                self._trigger_event(event, mid)
225
226 1
    def _trigger_event(self, event, mid):
227 1
        if mid not in self._monitored_items:
228 1
            self.logger.debug("Could not find monitored items for id %s for event %s in subscription %s",
229 1
                              mid, event, self)
230
            return
231 1
        mdata = self._monitored_items[mid]
232
        if not mdata.where_clause_evaluator.eval(event):
233 1
            self.logger.info("%s, %s, Event %s does not fit WhereClause, not generating event", self, mid, event)
234 1
            return
235
        fieldlist = ua.EventFieldList()
236 1
        fieldlist.ClientHandle = mdata.client_handle
237 1
        fieldlist.EventFields = event.to_event_fields(mdata.filter.SelectClauses)
238 1
        self.isub.enqueue_event(mid, fieldlist, mdata.queue_size)
239 1
240 1
    def trigger_statuschange(self, code):
241
        self.isub.enqueue_statuschange(code)
242 1
243 1
244 1
class InternalSubscription(object):
245 1
246 1
    def __init__(self, subservice, data, addressspace, callback):
247
        self.logger = logging.getLogger(__name__)
248
        self.aspace = addressspace
249 1
        self.subservice = subservice
250 1
        self.data = data
251
        self.callback = callback
252 1
        self.monitored_item_srv = MonitoredItemService(self, addressspace)
253 1
        self.task = None
254
        self._lock = RLock()
255
        self._triggered_datachanges = {}
256
        self._triggered_events = {}
257
        self._triggered_statuschanges = []
258 1
        self._notification_seq = 1
259 1
        self._not_acknowledged_results = {}
260 1
        self._startup = True
261 1
        self._keep_alive_count = 0
262 1
        self._publish_cycles_count = 0
263 1
        self._stopev = False
264 1
265
    def __str__(self):
266 1
        return "Subscription(id:{})".format(self.data.SubscriptionId)
267 1
268 1
    def start(self):
269 1
        self.logger.debug("starting subscription %s", self.data.SubscriptionId)
270 1
        self._subscription_loop()
271 1
272 1
    def stop(self):
273 1
        self.logger.debug("stopping subscription %s", self.data.SubscriptionId)
274 1
        self._stopev = True
275 1
        self.monitored_item_srv.delete_all_monitored_items()
276 1
277 1
    def _subscription_loop(self):
278 1
        if not self._stopev:
279 1
            self.subservice.loop.call_later(self.data.RevisedPublishingInterval / 1000.0, self._sub_loop)
280 1
281
    def _sub_loop(self):
282 1
        if self._stopev:
283 1
            return
284 1
        self.publish_results()
285 1
        self._subscription_loop()
286 1
287 1
    def has_published_results(self):
288 1
        with self._lock:
289
            if self._startup or self._triggered_datachanges or self._triggered_events:
290 1
                return True
291 1
            if self._keep_alive_count > self.data.RevisedMaxKeepAliveCount:
292 1
                self.logger.debug("keep alive count %s is > than max keep alive count %s, sending publish event",
293 1
                                  self._keep_alive_count, self.data.RevisedMaxKeepAliveCount)
294 1
                return True
295 1
            self._keep_alive_count += 1
296 1
            return False
297
298 1
    def publish_results(self):
299 1
        if self._publish_cycles_count > self.data.RevisedLifetimeCount:
300
            self.logger.warning("Subscription %s has expired, publish cycle count(%s) > lifetime count (%s)",
301
                                self, self._publish_cycles_count, self.data.RevisedLifetimeCount)
302
            # FIXME this will never be send since we do not have publish request anyway
303
            self.monitored_item_srv.trigger_statuschange(ua.StatusCode(ua.StatusCodes.BadTimeout))
304
            self._stopev = True
305 1
        result = None
306 1
        with self._lock:
307 1
            if self.has_published_results():  
308 1
                # FIXME: should we pop a publish request here? or we do not care?
309 1
                self._publish_cycles_count += 1
310 1
                result = self._pop_publish_result()
311 1
        if result is not None:
312
            self.callback(result)
313 1
314
    def _pop_publish_result(self):
315
        result = ua.PublishResult()
316
        result.SubscriptionId = self.data.SubscriptionId
317
        self._pop_triggered_datachanges(result)
318
        self._pop_triggered_events(result)
319
        self._pop_triggered_statuschanges(result)
320
        self._keep_alive_count = 0
321
        self._startup = False
322
        result.NotificationMessage.SequenceNumber = self._notification_seq
323 1
        if len(result.NotificationMessage.NotificationData) != 0:
324 1
            self._notification_seq += 1
325
            self._not_acknowledged_results[result.NotificationMessage.SequenceNumber] = result
326 1
        result.MoreNotifications = False
327 1
        result.AvailableSequenceNumbers = list(self._not_acknowledged_results.keys())
328
        return result
329 1
330
    def _pop_triggered_datachanges(self, result):
331
        if self._triggered_datachanges:
332 1
            notif = ua.DataChangeNotification()
333 1
            notif.MonitoredItems = [item for sublist in self._triggered_datachanges.values() for item in sublist]
334 1
            self._triggered_datachanges = {}
335 1
            self.logger.debug("sending datachanges notification with %s events", len(notif.MonitoredItems))
336 1
            result.NotificationMessage.NotificationData.append(notif)
337
338
    def _pop_triggered_events(self, result):
339 1
        if self._triggered_events:
340
            notif = ua.EventNotificationList()
341
            notif.Events = [item for sublist in self._triggered_events.values() for item in sublist]
342
            self._triggered_events = {}
343
            result.NotificationMessage.NotificationData.append(notif)
344
            self.logger.debug("sending event notification with %s events", len(notif.Events))
345
346
    def _pop_triggered_statuschanges(self, result):
347
        if self._triggered_statuschanges:
348
            notif = ua.StatusChangeNotification()
349
            notif.Status = self._triggered_statuschanges.pop(0)
350
            result.NotificationMessage.NotificationData.append(notif)
351
            self.logger.debug("sending event notification %s", notif.Status)
352
353
    def publish(self, acks):
354
        self.logger.info("publish request with acks %s", acks)
355
        with self._lock:
356
            self._publish_cycles_count = 0
357
            for nb in acks:
358
                if nb in self._not_acknowledged_results:
359
                    self._not_acknowledged_results.pop(nb)
360
361
    def republish(self, nb):
362
        self.logger.info("re-publish request for ack %s in subscription %s", nb, self)
363
        with self._lock:
364
            if nb in self._not_acknowledged_results:
365
                self.logger.info("re-publishing ack %s in subscription %s", nb, self)
366
                return self._not_acknowledged_results[nb].NotificationMessage
367
            else:
368
                self.logger.info("Error request to re-published non existing ack %s in subscription %s", nb, self)
369
                return ua.NotificationMessage()
370
371
    def enqueue_datachange_event(self, mid, eventdata, maxsize):
372
        self._enqueue_event(mid, eventdata, maxsize, self._triggered_datachanges)
373
374
    def enqueue_event(self, mid, eventdata, maxsize):
375
        self._enqueue_event(mid, eventdata, maxsize, self._triggered_events)
376
377
    def enqueue_statuschange(self, code):
378
        self._triggered_statuschanges.append(code)
379
380
    def _enqueue_event(self, mid, eventdata, size, queue):
381
        if mid not in queue:
382
            queue[mid] = [eventdata]
383
            return
384
        if size != 0:
385
            if len(queue[mid]) >= size:
386
                queue[mid].pop(0)
387
        queue[mid].append(eventdata)
388
389
390
class WhereClauseEvaluator(object):
391
    def __init__(self, logger, aspace, whereclause):
392
        self.logger = logger
393
        self.elements = whereclause.Elements
394
        self._aspace = aspace
395
396
    def eval(self, event):
397
        if not self.elements:
398
            return True
399
        # spec says we should only evaluate first element, which may use other elements
400
        try:
401
            res = self._eval_el(0, event)
402
        except Exception as ex:
403
            self.logger.exception("Exception while evaluating WhereClause %s for event %s: %s",
404
                                  self.elements, event, ex)
405
            return False
406
        return res
407
408
    def _eval_el(self, index, event):
409
        el = self.elements[index]
410
        # ops = [self._eval_op(op, event) for op in el.FilterOperands]
411
        ops = el.FilterOperands  # just to make code more readable
412
        if el.FilterOperator == ua.FilterOperator.Equals:
413
            return self._eval_op(ops[0], event) == self._eval_el(ops[1], event)
414
        elif el.FilterOperator == ua.FilterOperator.IsNull:
415
            return self._eval_op(ops[0], event) is None  # FIXME: might be too strict
416
        elif el.FilterOperator == ua.FilterOperator.GreaterThan:
417
            return self._eval_op(ops[0], event) > self._eval_el(ops[1], event)
418
        elif el.FilterOperator == ua.FilterOperator.LessThan:
419
            return self._eval_op(ops[0], event) < self._eval_el(ops[1], event)
420
        elif el.FilterOperator == ua.FilterOperator.GreaterThanOrEqual:
421
            return self._eval_op(ops[0], event) >= self._eval_el(ops[1], event)
422
        elif el.FilterOperator == ua.FilterOperator.LessThanOrEqual:
423
            return self._eval_op(ops[0], event) <= self._eval_el(ops[1], event)
424
        elif el.FilterOperator == ua.FilterOperator.Like:
425
            return self._likeoperator(self._eval_op(ops[0], event), self._eval_el(ops[1], event))
426
        elif el.FilterOperator == ua.FilterOperator.Not:
427
            return not self._eval_op(ops[0], event)
428
        elif el.FilterOperator == ua.FilterOperator.Between:
429
            return self._eval_el(ops[2], event) >= self._eval_op(ops[0], event) >= self._eval_el(ops[1], event)
430
        elif el.FilterOperator == ua.FilterOperator.InList:
431
            return self._eval_op(ops[0], event) in [self._eval_op(op, event) for op in ops[1:]]
432
        elif el.FilterOperator == ua.FilterOperator.And:
433
            self.elements(ops[0].Index)
434
            return self._eval_op(ops[0], event) and self._eval_op(ops[1], event)
435
        elif el.FilterOperator == ua.FilterOperator.Or:
436
            return self._eval_op(ops[0], event) or self._eval_el(ops[1], event)
437
        elif el.FilterOperator == ua.FilterOperator.Cast:
438
            self.logger.warn("Cast operand not implemented, assuming True")
439
            return True
440
        elif el.FilterOperator == ua.FilterOperator.OfType:
441
            return event.EventType == self._eval_op(ops[0], event)
442
        else:
443
            # TODO: implement missing operators
444
            self.logger.warning("WhereClause not implemented for element: %s", el)
445
            raise NotImplementedError
446
447
    def _like_operator(self, string, pattern):
448
        raise NotImplementedError
449
450
    def _eval_op(self, op, event):
451
        # seems spec says we should return Null if issues
452
        if type(op) is ua.ElementOperand:
453
            return self._eval_el(op.Index, event)
454
        elif type(op) is ua.AttributeOperand:
455
            if op.BrowsePath:
456
                return getattr(event, op.BrowsePath.Elements[0].TargetName.Name)
457
            else:
458
                return self._aspace.get_attribute_value(event.EventType, op.AttributeId).Value.Value
459
            # FIXME: check, this is probably broken
460
        elif type(op) is ua.SimpleAttributeOperand:
461
            if op.BrowsePath:
462
                # we only support depth of 1
463
                return getattr(event, op.BrowsePath[0].Name)
464
            else:
465
                # TODO: write code for index range.... but doe it make any sense
466
                return self._aspace.get_attribute_value(event.EventType, op.AttributeId).Value.Value
467
        elif type(op) is ua.LiteralOperand:
468
            return op.Value.Value
469
        else:
470
            self.logger.warning("Where clause element % is not of a known type", op)
471
            raise NotImplementedError
472
473
474
475