Fix: bt2: _trim_docstring(): docstring can have 0 or 1 line
[babeltrace.git] / src / bindings / python / bt2 / bt2 / message_iterator.py
1 # The MIT License (MIT)
2 #
3 # Copyright (c) 2017 Philippe Proulx <pproulx@efficios.com>
4 #
5 # Permission is hereby granted, free of charge, to any person obtaining a copy
6 # of this software and associated documentation files (the "Software"), to deal
7 # in the Software without restriction, including without limitation the rights
8 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 # copies of the Software, and to permit persons to whom the Software is
10 # furnished to do so, subject to the following conditions:
11 #
12 # The above copyright notice and this permission notice shall be included in
13 # all copies or substantial portions of the Software.
14 #
15 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
21 # THE SOFTWARE.
22
23 from bt2 import native_bt, object, utils
24 from bt2 import message as bt2_message
25 import collections.abc
26 from bt2 import stream as bt2_stream
27 from bt2 import event_class as bt2_event_class
28 from bt2 import packet as bt2_packet
29 from bt2 import port as bt2_port
30 from bt2 import clock_class as bt2_clock_class
31 import bt2
32
33
34 class _MessageIterator(collections.abc.Iterator):
35 def __next__(self):
36 raise NotImplementedError
37
38
39 class _UserComponentInputPortMessageIterator(object._SharedObject, _MessageIterator):
40 _get_ref = staticmethod(native_bt.message_iterator_get_ref)
41 _put_ref = staticmethod(native_bt.message_iterator_put_ref)
42
43 def __init__(self, ptr):
44 self._current_msgs = []
45 self._at = 0
46 super().__init__(ptr)
47
48 def __next__(self):
49 if len(self._current_msgs) == self._at:
50 status, msgs = native_bt.bt2_self_component_port_input_get_msg_range(
51 self._ptr
52 )
53 utils._handle_func_status(
54 status, 'unexpected error: cannot advance the message iterator'
55 )
56 self._current_msgs = msgs
57 self._at = 0
58
59 msg_ptr = self._current_msgs[self._at]
60 self._at += 1
61
62 return bt2_message._create_from_ptr(msg_ptr)
63
64 def can_seek_beginning(self):
65 (status, res) = native_bt.message_iterator_can_seek_beginning(self._ptr)
66 utils._handle_func_status(
67 status,
68 'cannot check whether or not message iterator can seek its beginning',
69 )
70 return res != 0
71
72 def seek_beginning(self):
73 # Forget about buffered messages, they won't be valid after seeking.
74 self._current_msgs.clear()
75 self._at = 0
76
77 status = native_bt.message_iterator_seek_beginning(self._ptr)
78 utils._handle_func_status(status, 'cannot seek message iterator beginning')
79
80 def can_seek_ns_from_origin(self, ns_from_origin):
81 utils._check_int64(ns_from_origin)
82 (status, res) = native_bt.message_iterator_can_seek_ns_from_origin(
83 self._ptr, ns_from_origin
84 )
85 utils._handle_func_status(
86 status,
87 'cannot check whether or not message iterator can seek given ns from origin',
88 )
89 return res != 0
90
91 def seek_ns_from_origin(self, ns_from_origin):
92 utils._check_int64(ns_from_origin)
93
94 # Forget about buffered messages, they won't be valid after seeking.
95 self._current_msgs.clear()
96 self._at = 0
97
98 status = native_bt.message_iterator_seek_ns_from_origin(
99 self._ptr, ns_from_origin
100 )
101 utils._handle_func_status(
102 status, 'message iterator cannot seek given ns from origin'
103 )
104
105 @property
106 def can_seek_forward(self):
107 return native_bt.message_iterator_can_seek_forward(self._ptr)
108
109
110 class _MessageIteratorConfiguration:
111 def __init__(self, ptr):
112 self._ptr = ptr
113
114 def can_seek_forward(self, value):
115 utils._check_bool(value)
116 native_bt.self_message_iterator_configuration_set_can_seek_forward(
117 self._ptr, value
118 )
119
120 can_seek_forward = property(fset=can_seek_forward)
121
122
123 # This is extended by the user to implement component classes in Python. It
124 # is created for a given output port when an input port message iterator is
125 # created on the input port on the other side of the connection. It is also
126 # created when an output port message iterator is created on this output port.
127 #
128 # Its purpose is to feed the messages that should go out through this output
129 # port.
130 class _UserMessageIterator(_MessageIterator):
131 def __new__(cls, ptr):
132 # User iterator objects are always created by the native side,
133 # that is, never instantiated directly by Python code.
134 #
135 # The native code calls this, then manually calls
136 # self.__init__() without the `ptr` argument. The user has
137 # access to self.component during this call, thanks to this
138 # self._bt_ptr argument being set.
139 #
140 # self._bt_ptr is NOT owned by this object here, so there's nothing
141 # to do in __del__().
142 self = super().__new__(cls)
143 self._bt_ptr = ptr
144 return self
145
146 def _bt_init_from_native(self, config_ptr, self_output_port_ptr):
147 self_output_port = bt2_port._create_self_from_ptr_and_get_ref(
148 self_output_port_ptr, native_bt.PORT_TYPE_OUTPUT
149 )
150 config = _MessageIteratorConfiguration(config_ptr)
151 self.__init__(config, self_output_port)
152
153 def __init__(self, config, self_output_port):
154 pass
155
156 @property
157 def _component(self):
158 return native_bt.bt2_get_user_component_from_user_msg_iter(self._bt_ptr)
159
160 @property
161 def _port(self):
162 port_ptr = native_bt.self_message_iterator_borrow_port(self._bt_ptr)
163 assert port_ptr is not None
164 return bt2_port._create_self_from_ptr_and_get_ref(
165 port_ptr, native_bt.PORT_TYPE_OUTPUT
166 )
167
168 @property
169 def addr(self):
170 return int(self._bt_ptr)
171
172 @property
173 def _is_interrupted(self):
174 return bool(native_bt.self_message_iterator_is_interrupted(self._bt_ptr))
175
176 def _user_finalize(self):
177 pass
178
179 def __next__(self):
180 raise bt2.Stop
181
182 def _bt_next_from_native(self):
183 # this can raise anything: it's catched by the native part
184 try:
185 msg = next(self)
186 except StopIteration:
187 raise bt2.Stop
188 except Exception:
189 raise
190
191 utils._check_type(msg, bt2_message._MessageConst)
192
193 # The reference we return will be given to the message array.
194 # However, the `msg` Python object may stay alive, if the user has kept
195 # a reference to it. Acquire a new reference to account for that.
196 msg._get_ref(msg._ptr)
197 return int(msg._ptr)
198
199 def _bt_can_seek_beginning_from_native(self):
200 # Here, we mimic the behavior of the C API:
201 #
202 # - If the iterator has a _user_can_seek_beginning method,
203 # read it and use that result.
204 # - Otherwise, the presence or absence of a `_user_seek_beginning`
205 # method indicates whether the iterator can seek beginning.
206 if hasattr(self, '_user_can_seek_beginning'):
207 can_seek_beginning = self._user_can_seek_beginning()
208 utils._check_bool(can_seek_beginning)
209 return can_seek_beginning
210 else:
211 return hasattr(self, '_user_seek_beginning')
212
213 def _bt_seek_beginning_from_native(self):
214 self._user_seek_beginning()
215
216 def _bt_can_seek_ns_from_origin_from_native(self, ns_from_origin):
217 # Return whether the iterator can seek ns from origin using the
218 # user-implemented seek_ns_from_origin method. We mimic the behavior
219 # of the C API:
220 #
221 # - If the iterator has a _user_can_seek_ns_from_origin method,
222 # call it and use its return value.
223 # - Otherwise, if there is a `_user_seek_ns_from_origin` method,
224 # we presume it's possible.
225
226 if hasattr(self, '_user_can_seek_ns_from_origin'):
227 can_seek_ns_from_origin = self._user_can_seek_ns_from_origin(ns_from_origin)
228 utils._check_bool(can_seek_ns_from_origin)
229 return can_seek_ns_from_origin
230 else:
231 return hasattr(self, '_user_seek_ns_from_origin')
232
233 def _bt_seek_ns_from_origin_from_native(self, ns_from_origin):
234 self._user_seek_ns_from_origin(ns_from_origin)
235
236 def _create_message_iterator(self, input_port):
237 utils._check_type(input_port, bt2_port._UserComponentInputPort)
238
239 (
240 status,
241 msg_iter_ptr,
242 ) = native_bt.bt2_message_iterator_create_from_message_iterator(
243 self._bt_ptr, input_port._ptr
244 )
245 utils._handle_func_status(status, 'cannot create message iterator object')
246 assert msg_iter_ptr is not None
247
248 return _UserComponentInputPortMessageIterator(msg_iter_ptr)
249
250 def _create_event_message(self, event_class, parent, default_clock_snapshot=None):
251 utils._check_type(event_class, bt2_event_class._EventClass)
252
253 if event_class.stream_class.supports_packets:
254 utils._check_type(parent, bt2_packet._Packet)
255 else:
256 utils._check_type(parent, bt2_stream._Stream)
257
258 if default_clock_snapshot is not None:
259 if event_class.stream_class.default_clock_class is None:
260 raise ValueError(
261 'event messages in this stream must not have a default clock snapshot'
262 )
263
264 utils._check_uint64(default_clock_snapshot)
265
266 if event_class.stream_class.supports_packets:
267 ptr = native_bt.message_event_create_with_packet_and_default_clock_snapshot(
268 self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
269 )
270 else:
271 ptr = native_bt.message_event_create_with_default_clock_snapshot(
272 self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
273 )
274 else:
275 if event_class.stream_class.default_clock_class is not None:
276 raise ValueError(
277 'event messages in this stream must have a default clock snapshot'
278 )
279
280 if event_class.stream_class.supports_packets:
281 ptr = native_bt.message_event_create_with_packet(
282 self._bt_ptr, event_class._ptr, parent._ptr
283 )
284 else:
285 ptr = native_bt.message_event_create(
286 self._bt_ptr, event_class._ptr, parent._ptr
287 )
288
289 if ptr is None:
290 raise bt2._MemoryError('cannot create event message object')
291
292 return bt2_message._EventMessage(ptr)
293
294 def _create_message_iterator_inactivity_message(self, clock_class, clock_snapshot):
295 utils._check_type(clock_class, bt2_clock_class._ClockClass)
296 ptr = native_bt.message_message_iterator_inactivity_create(
297 self._bt_ptr, clock_class._ptr, clock_snapshot
298 )
299
300 if ptr is None:
301 raise bt2._MemoryError('cannot create inactivity message object')
302
303 return bt2_message._MessageIteratorInactivityMessage(ptr)
304
305 def _create_stream_beginning_message(self, stream, default_clock_snapshot=None):
306 utils._check_type(stream, bt2_stream._Stream)
307
308 ptr = native_bt.message_stream_beginning_create(self._bt_ptr, stream._ptr)
309 if ptr is None:
310 raise bt2._MemoryError('cannot create stream beginning message object')
311
312 msg = bt2_message._StreamBeginningMessage(ptr)
313
314 if default_clock_snapshot is not None:
315 msg._default_clock_snapshot = default_clock_snapshot
316
317 return msg
318
319 def _create_stream_end_message(self, stream, default_clock_snapshot=None):
320 utils._check_type(stream, bt2_stream._Stream)
321
322 ptr = native_bt.message_stream_end_create(self._bt_ptr, stream._ptr)
323 if ptr is None:
324 raise bt2._MemoryError('cannot create stream end message object')
325
326 msg = bt2_message._StreamEndMessage(ptr)
327
328 if default_clock_snapshot is not None:
329 msg._default_clock_snapshot = default_clock_snapshot
330
331 return msg
332
333 def _create_packet_beginning_message(self, packet, default_clock_snapshot=None):
334 utils._check_type(packet, bt2_packet._Packet)
335
336 if packet.stream.cls.packets_have_beginning_default_clock_snapshot:
337 if default_clock_snapshot is None:
338 raise ValueError(
339 "packet beginning messages in this stream must have a default clock snapshot"
340 )
341
342 utils._check_uint64(default_clock_snapshot)
343 ptr = native_bt.message_packet_beginning_create_with_default_clock_snapshot(
344 self._bt_ptr, packet._ptr, default_clock_snapshot
345 )
346 else:
347 if default_clock_snapshot is not None:
348 raise ValueError(
349 "packet beginning messages in this stream must not have a default clock snapshot"
350 )
351
352 ptr = native_bt.message_packet_beginning_create(self._bt_ptr, packet._ptr)
353
354 if ptr is None:
355 raise bt2._MemoryError('cannot create packet beginning message object')
356
357 return bt2_message._PacketBeginningMessage(ptr)
358
359 def _create_packet_end_message(self, packet, default_clock_snapshot=None):
360 utils._check_type(packet, bt2_packet._Packet)
361
362 if packet.stream.cls.packets_have_end_default_clock_snapshot:
363 if default_clock_snapshot is None:
364 raise ValueError(
365 "packet end messages in this stream must have a default clock snapshot"
366 )
367
368 utils._check_uint64(default_clock_snapshot)
369 ptr = native_bt.message_packet_end_create_with_default_clock_snapshot(
370 self._bt_ptr, packet._ptr, default_clock_snapshot
371 )
372 else:
373 if default_clock_snapshot is not None:
374 raise ValueError(
375 "packet end messages in this stream must not have a default clock snapshot"
376 )
377
378 ptr = native_bt.message_packet_end_create(self._bt_ptr, packet._ptr)
379
380 if ptr is None:
381 raise bt2._MemoryError('cannot create packet end message object')
382
383 return bt2_message._PacketEndMessage(ptr)
384
385 def _create_discarded_events_message(
386 self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
387 ):
388 utils._check_type(stream, bt2_stream._Stream)
389
390 if not stream.cls.supports_discarded_events:
391 raise ValueError('stream class does not support discarded events')
392
393 if stream.cls.discarded_events_have_default_clock_snapshots:
394 if beg_clock_snapshot is None or end_clock_snapshot is None:
395 raise ValueError(
396 'discarded events have default clock snapshots for this stream class'
397 )
398
399 utils._check_uint64(beg_clock_snapshot)
400 utils._check_uint64(end_clock_snapshot)
401 ptr = (
402 native_bt.message_discarded_events_create_with_default_clock_snapshots(
403 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
404 )
405 )
406 else:
407 if beg_clock_snapshot is not None or end_clock_snapshot is not None:
408 raise ValueError(
409 'discarded events have no default clock snapshots for this stream class'
410 )
411
412 ptr = native_bt.message_discarded_events_create(self._bt_ptr, stream._ptr)
413
414 if ptr is None:
415 raise bt2._MemoryError('cannot discarded events message object')
416
417 msg = bt2_message._DiscardedEventsMessage(ptr)
418
419 if count is not None:
420 msg._count = count
421
422 return msg
423
424 def _create_discarded_packets_message(
425 self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
426 ):
427 utils._check_type(stream, bt2_stream._Stream)
428
429 if not stream.cls.supports_discarded_packets:
430 raise ValueError('stream class does not support discarded packets')
431
432 if stream.cls.discarded_packets_have_default_clock_snapshots:
433 if beg_clock_snapshot is None or end_clock_snapshot is None:
434 raise ValueError(
435 'discarded packets have default clock snapshots for this stream class'
436 )
437
438 utils._check_uint64(beg_clock_snapshot)
439 utils._check_uint64(end_clock_snapshot)
440 ptr = (
441 native_bt.message_discarded_packets_create_with_default_clock_snapshots(
442 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
443 )
444 )
445 else:
446 if beg_clock_snapshot is not None or end_clock_snapshot is not None:
447 raise ValueError(
448 'discarded packets have no default clock snapshots for this stream class'
449 )
450
451 ptr = native_bt.message_discarded_packets_create(self._bt_ptr, stream._ptr)
452
453 if ptr is None:
454 raise bt2._MemoryError('cannot discarded packets message object')
455
456 msg = bt2_message._DiscardedPacketsMessage(ptr)
457
458 if count is not None:
459 msg._count = count
460
461 return msg
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