93595693e6f57962b40ccc6415bdd6a8e967ba12
[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 import bt2.message
25 import collections.abc
26 import bt2.component
27 import bt2
28
29
30 class _MessageIterator(collections.abc.Iterator):
31 def __next__(self):
32 raise NotImplementedError
33
34
35 class _GenericMessageIterator(object._SharedObject, _MessageIterator):
36 def __init__(self, ptr):
37 self._current_msgs = []
38 self._at = 0
39 super().__init__(ptr)
40
41 def __next__(self):
42 if len(self._current_msgs) == self._at:
43 status, msgs = self._get_msg_range(self._ptr)
44 utils._handle_func_status(
45 status, 'unexpected error: cannot advance the message iterator'
46 )
47 self._current_msgs = msgs
48 self._at = 0
49
50 msg_ptr = self._current_msgs[self._at]
51 self._at += 1
52
53 return bt2.message._create_from_ptr(msg_ptr)
54
55 @property
56 def can_seek_beginning(self):
57 res = self._can_seek_beginning(self._ptr)
58 return res != 0
59
60 def seek_beginning(self):
61 # Forget about buffered messages, they won't be valid after seeking..
62 self._current_msgs.clear()
63 self._at = 0
64
65 status = self._seek_beginning(self._ptr)
66 utils._handle_func_status(status, 'cannot seek message iterator beginning')
67
68
69 # This is created when a component wants to iterate on one of its input ports.
70 class _UserComponentInputPortMessageIterator(_GenericMessageIterator):
71 _get_msg_range = staticmethod(native_bt.bt2_self_component_port_input_get_msg_range)
72 _get_ref = staticmethod(
73 native_bt.self_component_port_input_message_iterator_get_ref
74 )
75 _put_ref = staticmethod(
76 native_bt.self_component_port_input_message_iterator_put_ref
77 )
78 _can_seek_beginning = staticmethod(
79 native_bt.self_component_port_input_message_iterator_can_seek_beginning
80 )
81 _seek_beginning = staticmethod(
82 native_bt.self_component_port_input_message_iterator_seek_beginning
83 )
84
85
86 # This is created when the user wants to iterate on a component's output port,
87 # from outside the graph.
88 class _OutputPortMessageIterator(_GenericMessageIterator):
89 _get_msg_range = staticmethod(native_bt.bt2_port_output_get_msg_range)
90 _get_ref = staticmethod(native_bt.port_output_message_iterator_get_ref)
91 _put_ref = staticmethod(native_bt.port_output_message_iterator_put_ref)
92 _can_seek_beginning = staticmethod(
93 native_bt.port_output_message_iterator_can_seek_beginning
94 )
95 _seek_beginning = staticmethod(
96 native_bt.port_output_message_iterator_seek_beginning
97 )
98
99
100 # This is extended by the user to implement component classes in Python. It
101 # is created for a given output port when an input port message iterator is
102 # created on the input port on the other side of the connection. It is also
103 # created when an output port message iterator is created on this output port.
104 #
105 # Its purpose is to feed the messages that should go out through this output
106 # port.
107 class _UserMessageIterator(_MessageIterator):
108 def __new__(cls, ptr):
109 # User iterator objects are always created by the native side,
110 # that is, never instantiated directly by Python code.
111 #
112 # The native code calls this, then manually calls
113 # self.__init__() without the `ptr` argument. The user has
114 # access to self.component during this call, thanks to this
115 # self._bt_ptr argument being set.
116 #
117 # self._bt_ptr is NOT owned by this object here, so there's nothing
118 # to do in __del__().
119 self = super().__new__(cls)
120 self._bt_ptr = ptr
121 return self
122
123 def _bt_init_from_native(self, self_output_port_ptr):
124 self_output_port = bt2.port._create_self_from_ptr_and_get_ref(
125 self_output_port_ptr, native_bt.PORT_TYPE_OUTPUT
126 )
127 self.__init__(self_output_port)
128
129 def __init__(self, output_port):
130 pass
131
132 @property
133 def _component(self):
134 return native_bt.bt2_get_user_component_from_user_msg_iter(self._bt_ptr)
135
136 @property
137 def addr(self):
138 return int(self._bt_ptr)
139
140 def _finalize(self):
141 pass
142
143 def __next__(self):
144 raise bt2.Stop
145
146 def _bt_next_from_native(self):
147 # this can raise anything: it's catched by the native part
148 try:
149 msg = next(self)
150 except StopIteration:
151 raise bt2.Stop
152 except:
153 raise
154
155 utils._check_type(msg, bt2.message._Message)
156
157 # The reference we return will be given to the message array.
158 # However, the `msg` Python object may stay alive, if the user has kept
159 # a reference to it. Acquire a new reference to account for that.
160 msg._get_ref(msg._ptr)
161 return int(msg._ptr)
162
163 @property
164 def _bt_can_seek_beginning_from_native(self):
165 # Here, we mimic the behavior of the C API:
166 #
167 # - If the iterator has a _can_seek_beginning attribute, read it and use
168 # that result.
169 # - Otherwise, the presence or absence of a `_seek_beginning`
170 # method indicates whether the iterator can seek beginning.
171 if hasattr(self, '_can_seek_beginning'):
172 can_seek_beginning = self._can_seek_beginning
173 utils._check_bool(can_seek_beginning)
174 return can_seek_beginning
175 else:
176 return hasattr(self, '_seek_beginning')
177
178 def _bt_seek_beginning_from_native(self):
179 self._seek_beginning()
180
181 def _create_event_message(
182 self, event_class, parent=None, default_clock_snapshot=None
183 ):
184 utils._check_type(event_class, bt2.event_class._EventClass)
185
186 if event_class.stream_class.supports_packets:
187 utils._check_type(parent, bt2.packet._Packet)
188 else:
189 utils._check_type(parent, bt2.stream._Stream)
190
191 if default_clock_snapshot is not None:
192 if event_class.stream_class.default_clock_class is None:
193 raise ValueError(
194 'event messages in this stream must not have a default clock snapshot'
195 )
196
197 utils._check_uint64(default_clock_snapshot)
198
199 if event_class.stream_class.supports_packets:
200 ptr = native_bt.message_event_create_with_packet_and_default_clock_snapshot(
201 self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
202 )
203 else:
204 ptr = native_bt.message_event_create_with_default_clock_snapshot(
205 self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
206 )
207 else:
208 if event_class.stream_class.default_clock_class is not None:
209 raise ValueError(
210 'event messages in this stream must have a default clock snapshot'
211 )
212
213 if event_class.stream_class.supports_packets:
214 ptr = native_bt.message_event_create_with_packet(
215 self._bt_ptr, event_class._ptr, parent._ptr
216 )
217 else:
218 ptr = native_bt.message_event_create(
219 self._bt_ptr, event_class._ptr, parent._ptr
220 )
221
222 if ptr is None:
223 raise bt2._MemoryError('cannot create event message object')
224
225 return bt2.message._EventMessage(ptr)
226
227 def _create_message_iterator_inactivity_message(self, clock_class, clock_snapshot):
228 utils._check_type(clock_class, bt2.clock_class._ClockClass)
229 ptr = native_bt.message_message_iterator_inactivity_create(
230 self._bt_ptr, clock_class._ptr, clock_snapshot
231 )
232
233 if ptr is None:
234 raise bt2._MemoryError('cannot create inactivity message object')
235
236 return bt2.message._MessageIteratorInactivityMessage(ptr)
237
238 def _create_stream_beginning_message(self, stream, default_clock_snapshot=None):
239 utils._check_type(stream, bt2.stream._Stream)
240
241 ptr = native_bt.message_stream_beginning_create(self._bt_ptr, stream._ptr)
242 if ptr is None:
243 raise bt2._MemoryError('cannot create stream beginning message object')
244
245 msg = bt2.message._StreamBeginningMessage(ptr)
246
247 if default_clock_snapshot is not None:
248 msg._default_clock_snapshot = default_clock_snapshot
249
250 return msg
251
252 def _create_stream_end_message(self, stream, default_clock_snapshot=None):
253 utils._check_type(stream, bt2.stream._Stream)
254
255 ptr = native_bt.message_stream_end_create(self._bt_ptr, stream._ptr)
256 if ptr is None:
257 raise bt2._MemoryError('cannot create stream end message object')
258
259 msg = bt2.message._StreamEndMessage(ptr)
260
261 if default_clock_snapshot is not None:
262 msg._default_clock_snapshot = default_clock_snapshot
263
264 return msg
265
266 def _create_packet_beginning_message(self, packet, default_clock_snapshot=None):
267 utils._check_type(packet, bt2.packet._Packet)
268
269 if packet.stream.cls.packets_have_beginning_default_clock_snapshot:
270 if default_clock_snapshot is None:
271 raise ValueError(
272 "packet beginning messages in this stream must have a default clock snapshot"
273 )
274
275 utils._check_uint64(default_clock_snapshot)
276 ptr = native_bt.message_packet_beginning_create_with_default_clock_snapshot(
277 self._bt_ptr, packet._ptr, default_clock_snapshot
278 )
279 else:
280 if default_clock_snapshot is not None:
281 raise ValueError(
282 "packet beginning messages in this stream must not have a default clock snapshot"
283 )
284
285 ptr = native_bt.message_packet_beginning_create(self._bt_ptr, packet._ptr)
286
287 if ptr is None:
288 raise bt2._MemoryError('cannot create packet beginning message object')
289
290 return bt2.message._PacketBeginningMessage(ptr)
291
292 def _create_packet_end_message(self, packet, default_clock_snapshot=None):
293 utils._check_type(packet, bt2.packet._Packet)
294
295 if packet.stream.cls.packets_have_end_default_clock_snapshot:
296 if default_clock_snapshot is None:
297 raise ValueError(
298 "packet end messages in this stream must have a default clock snapshot"
299 )
300
301 utils._check_uint64(default_clock_snapshot)
302 ptr = native_bt.message_packet_end_create_with_default_clock_snapshot(
303 self._bt_ptr, packet._ptr, default_clock_snapshot
304 )
305 else:
306 if default_clock_snapshot is not None:
307 raise ValueError(
308 "packet end messages in this stream must not have a default clock snapshot"
309 )
310
311 ptr = native_bt.message_packet_end_create(self._bt_ptr, packet._ptr)
312
313 if ptr is None:
314 raise bt2._MemoryError('cannot create packet end message object')
315
316 return bt2.message._PacketEndMessage(ptr)
317
318 def _create_discarded_events_message(
319 self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
320 ):
321 utils._check_type(stream, bt2.stream._Stream)
322
323 if not stream.cls.supports_discarded_events:
324 raise ValueError('stream class does not support discarded events')
325
326 if stream.cls.discarded_events_have_default_clock_snapshots:
327 if beg_clock_snapshot is None or end_clock_snapshot is None:
328 raise ValueError(
329 'discarded events have default clock snapshots for this stream class'
330 )
331
332 utils._check_uint64(beg_clock_snapshot)
333 utils._check_uint64(end_clock_snapshot)
334 ptr = native_bt.message_discarded_events_create_with_default_clock_snapshots(
335 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
336 )
337 else:
338 if beg_clock_snapshot is not None or end_clock_snapshot is not None:
339 raise ValueError(
340 'discarded events have no default clock snapshots for this stream class'
341 )
342
343 ptr = native_bt.message_discarded_events_create(self._bt_ptr, stream._ptr)
344
345 if ptr is None:
346 raise bt2._MemoryError('cannot discarded events message object')
347
348 msg = bt2.message._DiscardedEventsMessage(ptr)
349
350 if count is not None:
351 msg._count = count
352
353 return msg
354
355 def _create_discarded_packets_message(
356 self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
357 ):
358 utils._check_type(stream, bt2.stream._Stream)
359
360 if not stream.cls.supports_discarded_packets:
361 raise ValueError('stream class does not support discarded packets')
362
363 if stream.cls.discarded_packets_have_default_clock_snapshots:
364 if beg_clock_snapshot is None or end_clock_snapshot is None:
365 raise ValueError(
366 'discarded packets have default clock snapshots for this stream class'
367 )
368
369 utils._check_uint64(beg_clock_snapshot)
370 utils._check_uint64(end_clock_snapshot)
371 ptr = native_bt.message_discarded_packets_create_with_default_clock_snapshots(
372 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
373 )
374 else:
375 if beg_clock_snapshot is not None or end_clock_snapshot is not None:
376 raise ValueError(
377 'discarded packets have no default clock snapshots for this stream class'
378 )
379
380 ptr = native_bt.message_discarded_packets_create(self._bt_ptr, stream._ptr)
381
382 if ptr is None:
383 raise bt2._MemoryError('cannot discarded packets message object')
384
385 msg = bt2.message._DiscardedPacketsMessage(ptr)
386
387 if count is not None:
388 msg._count = count
389
390 return msg
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