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 = native_bt.message_discarded_events_create_with_default_clock_snapshots(
 402                 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
 403             )
 404         else:
 405             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 406                 raise ValueError(
 407                     'discarded events have no default clock snapshots for this stream class'
 408                 )
 409
 410             ptr = native_bt.message_discarded_events_create(self._bt_ptr, stream._ptr)
 411
 412         if ptr is None:
 413             raise bt2._MemoryError('cannot discarded events message object')
 414
 415         msg = bt2_message._DiscardedEventsMessage(ptr)
 416
 417         if count is not None:
 418             msg._count = count
 419
 420         return msg
 421
 422     def _create_discarded_packets_message(
 423         self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
 424     ):
 425         utils._check_type(stream, bt2_stream._Stream)
 426
 427         if not stream.cls.supports_discarded_packets:
 428             raise ValueError('stream class does not support discarded packets')
 429
 430         if stream.cls.discarded_packets_have_default_clock_snapshots:
 431             if beg_clock_snapshot is None or end_clock_snapshot is None:
 432                 raise ValueError(
 433                     'discarded packets have default clock snapshots for this stream class'
 434                 )
 435
 436             utils._check_uint64(beg_clock_snapshot)
 437             utils._check_uint64(end_clock_snapshot)
 438             ptr = native_bt.message_discarded_packets_create_with_default_clock_snapshots(
 439                 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
 440             )
 441         else:
 442             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 443                 raise ValueError(
 444                     'discarded packets have no default clock snapshots for this stream class'
 445                 )
 446
 447             ptr = native_bt.message_discarded_packets_create(self._bt_ptr, stream._ptr)
 448
 449         if ptr is None:
 450             raise bt2._MemoryError('cannot discarded packets message object')
 451
 452         msg = bt2_message._DiscardedPacketsMessage(ptr)
 453
 454         if count is not None:
 455             msg._count = count
 456
 457         return msg