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(
  41         native_bt.self_component_port_input_message_iterator_get_ref
  42     )
  43     _put_ref = staticmethod(
  44         native_bt.self_component_port_input_message_iterator_put_ref
  45     )
  46
  47     def __init__(self, ptr):
  48         self._current_msgs = []
  49         self._at = 0
  50         super().__init__(ptr)
  51
  52     def __next__(self):
  53         if len(self._current_msgs) == self._at:
  54             status, msgs = native_bt.bt2_self_component_port_input_get_msg_range(
  55                 self._ptr
  56             )
  57             utils._handle_func_status(
  58                 status, 'unexpected error: cannot advance the message iterator'
  59             )
  60             self._current_msgs = msgs
  61             self._at = 0
  62
  63         msg_ptr = self._current_msgs[self._at]
  64         self._at += 1
  65
  66         return bt2_message._create_from_ptr(msg_ptr)
  67
  68     def can_seek_beginning(self):
  69         (
  70             status,
  71             res,
  72         ) = native_bt.self_component_port_input_message_iterator_can_seek_beginning(
  73             self._ptr
  74         )
  75         utils._handle_func_status(
  76             status,
  77             'cannot check whether or not message iterator can seek its beginning',
  78         )
  79         return res != 0
  80
  81     def seek_beginning(self):
  82         # Forget about buffered messages, they won't be valid after seeking.
  83         self._current_msgs.clear()
  84         self._at = 0
  85
  86         status = native_bt.self_component_port_input_message_iterator_seek_beginning(
  87             self._ptr
  88         )
  89         utils._handle_func_status(status, 'cannot seek message iterator beginning')
  90
  91     def can_seek_ns_from_origin(self, ns_from_origin):
  92         utils._check_int64(ns_from_origin)
  93         (
  94             status,
  95             res,
  96         ) = native_bt.self_component_port_input_message_iterator_can_seek_ns_from_origin(
  97             self._ptr, ns_from_origin
  98         )
  99         utils._handle_func_status(
 100             status,
 101             'cannot check whether or not message iterator can seek given ns from origin',
 102         )
 103         return res != 0
 104
 105     def seek_ns_from_origin(self, ns_from_origin):
 106         utils._check_int64(ns_from_origin)
 107
 108         # Forget about buffered messages, they won't be valid after seeking.
 109         self._current_msgs.clear()
 110         self._at = 0
 111
 112         status = native_bt.self_component_port_input_message_iterator_seek_ns_from_origin(
 113             self._ptr, ns_from_origin
 114         )
 115         utils._handle_func_status(
 116             status, 'message iterator cannot seek given ns from origin'
 117         )
 118
 119     @property
 120     def can_seek_forward(self):
 121         return native_bt.self_component_port_input_message_iterator_can_seek_forward(
 122             self._ptr
 123         )
 124
 125
 126 class _MessageIteratorConfiguration:
 127     def __init__(self, ptr):
 128         self._ptr = ptr
 129
 130     def can_seek_forward(self, value):
 131         utils._check_bool(value)
 132         native_bt.self_message_iterator_configuration_set_can_seek_forward(
 133             self._ptr, value
 134         )
 135
 136     can_seek_forward = property(fset=can_seek_forward)
 137
 138
 139 # This is extended by the user to implement component classes in Python.  It
 140 # is created for a given output port when an input port message iterator is
 141 # created on the input port on the other side of the connection.  It is also
 142 # created when an output port message iterator is created on this output port.
 143 #
 144 # Its purpose is to feed the messages that should go out through this output
 145 # port.
 146 class _UserMessageIterator(_MessageIterator):
 147     def __new__(cls, ptr):
 148         # User iterator objects are always created by the native side,
 149         # that is, never instantiated directly by Python code.
 150         #
 151         # The native code calls this, then manually calls
 152         # self.__init__() without the `ptr` argument. The user has
 153         # access to self.component during this call, thanks to this
 154         # self._bt_ptr argument being set.
 155         #
 156         # self._bt_ptr is NOT owned by this object here, so there's nothing
 157         # to do in __del__().
 158         self = super().__new__(cls)
 159         self._bt_ptr = ptr
 160         return self
 161
 162     def _bt_init_from_native(self, config_ptr, self_output_port_ptr):
 163         self_output_port = bt2_port._create_self_from_ptr_and_get_ref(
 164             self_output_port_ptr, native_bt.PORT_TYPE_OUTPUT
 165         )
 166         config = _MessageIteratorConfiguration(config_ptr)
 167         self.__init__(config, self_output_port)
 168
 169     def __init__(self, config, self_output_port):
 170         pass
 171
 172     @property
 173     def _component(self):
 174         return native_bt.bt2_get_user_component_from_user_msg_iter(self._bt_ptr)
 175
 176     @property
 177     def _port(self):
 178         port_ptr = native_bt.self_message_iterator_borrow_port(self._bt_ptr)
 179         assert port_ptr is not None
 180         return bt2_port._create_self_from_ptr_and_get_ref(
 181             port_ptr, native_bt.PORT_TYPE_OUTPUT
 182         )
 183
 184     @property
 185     def addr(self):
 186         return int(self._bt_ptr)
 187
 188     @property
 189     def _is_interrupted(self):
 190         return bool(native_bt.self_message_iterator_is_interrupted(self._bt_ptr))
 191
 192     def _user_finalize(self):
 193         pass
 194
 195     def __next__(self):
 196         raise bt2.Stop
 197
 198     def _bt_next_from_native(self):
 199         # this can raise anything: it's catched by the native part
 200         try:
 201             msg = next(self)
 202         except StopIteration:
 203             raise bt2.Stop
 204         except Exception:
 205             raise
 206
 207         utils._check_type(msg, bt2_message._MessageConst)
 208
 209         # The reference we return will be given to the message array.
 210         # However, the `msg` Python object may stay alive, if the user has kept
 211         # a reference to it.  Acquire a new reference to account for that.
 212         msg._get_ref(msg._ptr)
 213         return int(msg._ptr)
 214
 215     def _bt_can_seek_beginning_from_native(self):
 216         # Here, we mimic the behavior of the C API:
 217         #
 218         # - If the iterator has a _user_can_seek_beginning method,
 219         #   read it and use that result.
 220         # - Otherwise, the presence or absence of a `_user_seek_beginning`
 221         #   method indicates whether the iterator can seek beginning.
 222         if hasattr(self, '_user_can_seek_beginning'):
 223             can_seek_beginning = self._user_can_seek_beginning()
 224             utils._check_bool(can_seek_beginning)
 225             return can_seek_beginning
 226         else:
 227             return hasattr(self, '_user_seek_beginning')
 228
 229     def _bt_seek_beginning_from_native(self):
 230         self._user_seek_beginning()
 231
 232     def _bt_can_seek_ns_from_origin_from_native(self, ns_from_origin):
 233         # Return whether the iterator can seek ns from origin using the
 234         # user-implemented seek_ns_from_origin method.  We mimic the behavior
 235         # of the C API:
 236         #
 237         # - If the iterator has a _user_can_seek_ns_from_origin method,
 238         #   call it and use its return value.
 239         # - Otherwise, if there is a `_user_seek_ns_from_origin` method,
 240         #   we presume it's possible.
 241
 242         if hasattr(self, '_user_can_seek_ns_from_origin'):
 243             can_seek_ns_from_origin = self._user_can_seek_ns_from_origin(ns_from_origin)
 244             utils._check_bool(can_seek_ns_from_origin)
 245             return can_seek_ns_from_origin
 246         else:
 247             return hasattr(self, '_user_seek_ns_from_origin')
 248
 249     def _bt_seek_ns_from_origin_from_native(self, ns_from_origin):
 250         self._user_seek_ns_from_origin(ns_from_origin)
 251
 252     def _create_input_port_message_iterator(self, input_port):
 253         utils._check_type(input_port, bt2_port._UserComponentInputPort)
 254
 255         (
 256             status,
 257             msg_iter_ptr,
 258         ) = native_bt.bt2_self_component_port_input_message_iterator_create_from_message_iterator(
 259             self._bt_ptr, input_port._ptr
 260         )
 261         utils._handle_func_status(status, 'cannot create message iterator object')
 262         assert msg_iter_ptr is not None
 263
 264         return _UserComponentInputPortMessageIterator(msg_iter_ptr)
 265
 266     def _create_event_message(self, event_class, parent, default_clock_snapshot=None):
 267         utils._check_type(event_class, bt2_event_class._EventClass)
 268
 269         if event_class.stream_class.supports_packets:
 270             utils._check_type(parent, bt2_packet._Packet)
 271         else:
 272             utils._check_type(parent, bt2_stream._Stream)
 273
 274         if default_clock_snapshot is not None:
 275             if event_class.stream_class.default_clock_class is None:
 276                 raise ValueError(
 277                     'event messages in this stream must not have a default clock snapshot'
 278                 )
 279
 280             utils._check_uint64(default_clock_snapshot)
 281
 282             if event_class.stream_class.supports_packets:
 283                 ptr = native_bt.message_event_create_with_packet_and_default_clock_snapshot(
 284                     self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
 285                 )
 286             else:
 287                 ptr = native_bt.message_event_create_with_default_clock_snapshot(
 288                     self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
 289                 )
 290         else:
 291             if event_class.stream_class.default_clock_class is not None:
 292                 raise ValueError(
 293                     'event messages in this stream must have a default clock snapshot'
 294                 )
 295
 296             if event_class.stream_class.supports_packets:
 297                 ptr = native_bt.message_event_create_with_packet(
 298                     self._bt_ptr, event_class._ptr, parent._ptr
 299                 )
 300             else:
 301                 ptr = native_bt.message_event_create(
 302                     self._bt_ptr, event_class._ptr, parent._ptr
 303                 )
 304
 305         if ptr is None:
 306             raise bt2._MemoryError('cannot create event message object')
 307
 308         return bt2_message._EventMessage(ptr)
 309
 310     def _create_message_iterator_inactivity_message(self, clock_class, clock_snapshot):
 311         utils._check_type(clock_class, bt2_clock_class._ClockClass)
 312         ptr = native_bt.message_message_iterator_inactivity_create(
 313             self._bt_ptr, clock_class._ptr, clock_snapshot
 314         )
 315
 316         if ptr is None:
 317             raise bt2._MemoryError('cannot create inactivity message object')
 318
 319         return bt2_message._MessageIteratorInactivityMessage(ptr)
 320
 321     def _create_stream_beginning_message(self, stream, default_clock_snapshot=None):
 322         utils._check_type(stream, bt2_stream._Stream)
 323
 324         ptr = native_bt.message_stream_beginning_create(self._bt_ptr, stream._ptr)
 325         if ptr is None:
 326             raise bt2._MemoryError('cannot create stream beginning message object')
 327
 328         msg = bt2_message._StreamBeginningMessage(ptr)
 329
 330         if default_clock_snapshot is not None:
 331             msg._default_clock_snapshot = default_clock_snapshot
 332
 333         return msg
 334
 335     def _create_stream_end_message(self, stream, default_clock_snapshot=None):
 336         utils._check_type(stream, bt2_stream._Stream)
 337
 338         ptr = native_bt.message_stream_end_create(self._bt_ptr, stream._ptr)
 339         if ptr is None:
 340             raise bt2._MemoryError('cannot create stream end message object')
 341
 342         msg = bt2_message._StreamEndMessage(ptr)
 343
 344         if default_clock_snapshot is not None:
 345             msg._default_clock_snapshot = default_clock_snapshot
 346
 347         return msg
 348
 349     def _create_packet_beginning_message(self, packet, default_clock_snapshot=None):
 350         utils._check_type(packet, bt2_packet._Packet)
 351
 352         if packet.stream.cls.packets_have_beginning_default_clock_snapshot:
 353             if default_clock_snapshot is None:
 354                 raise ValueError(
 355                     "packet beginning messages in this stream must have a default clock snapshot"
 356                 )
 357
 358             utils._check_uint64(default_clock_snapshot)
 359             ptr = native_bt.message_packet_beginning_create_with_default_clock_snapshot(
 360                 self._bt_ptr, packet._ptr, default_clock_snapshot
 361             )
 362         else:
 363             if default_clock_snapshot is not None:
 364                 raise ValueError(
 365                     "packet beginning messages in this stream must not have a default clock snapshot"
 366                 )
 367
 368             ptr = native_bt.message_packet_beginning_create(self._bt_ptr, packet._ptr)
 369
 370         if ptr is None:
 371             raise bt2._MemoryError('cannot create packet beginning message object')
 372
 373         return bt2_message._PacketBeginningMessage(ptr)
 374
 375     def _create_packet_end_message(self, packet, default_clock_snapshot=None):
 376         utils._check_type(packet, bt2_packet._Packet)
 377
 378         if packet.stream.cls.packets_have_end_default_clock_snapshot:
 379             if default_clock_snapshot is None:
 380                 raise ValueError(
 381                     "packet end messages in this stream must have a default clock snapshot"
 382                 )
 383
 384             utils._check_uint64(default_clock_snapshot)
 385             ptr = native_bt.message_packet_end_create_with_default_clock_snapshot(
 386                 self._bt_ptr, packet._ptr, default_clock_snapshot
 387             )
 388         else:
 389             if default_clock_snapshot is not None:
 390                 raise ValueError(
 391                     "packet end messages in this stream must not have a default clock snapshot"
 392                 )
 393
 394             ptr = native_bt.message_packet_end_create(self._bt_ptr, packet._ptr)
 395
 396         if ptr is None:
 397             raise bt2._MemoryError('cannot create packet end message object')
 398
 399         return bt2_message._PacketEndMessage(ptr)
 400
 401     def _create_discarded_events_message(
 402         self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
 403     ):
 404         utils._check_type(stream, bt2_stream._Stream)
 405
 406         if not stream.cls.supports_discarded_events:
 407             raise ValueError('stream class does not support discarded events')
 408
 409         if stream.cls.discarded_events_have_default_clock_snapshots:
 410             if beg_clock_snapshot is None or end_clock_snapshot is None:
 411                 raise ValueError(
 412                     'discarded events have default clock snapshots for this stream class'
 413                 )
 414
 415             utils._check_uint64(beg_clock_snapshot)
 416             utils._check_uint64(end_clock_snapshot)
 417             ptr = native_bt.message_discarded_events_create_with_default_clock_snapshots(
 418                 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
 419             )
 420         else:
 421             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 422                 raise ValueError(
 423                     'discarded events have no default clock snapshots for this stream class'
 424                 )
 425
 426             ptr = native_bt.message_discarded_events_create(self._bt_ptr, stream._ptr)
 427
 428         if ptr is None:
 429             raise bt2._MemoryError('cannot discarded events message object')
 430
 431         msg = bt2_message._DiscardedEventsMessage(ptr)
 432
 433         if count is not None:
 434             msg._count = count
 435
 436         return msg
 437
 438     def _create_discarded_packets_message(
 439         self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
 440     ):
 441         utils._check_type(stream, bt2_stream._Stream)
 442
 443         if not stream.cls.supports_discarded_packets:
 444             raise ValueError('stream class does not support discarded packets')
 445
 446         if stream.cls.discarded_packets_have_default_clock_snapshots:
 447             if beg_clock_snapshot is None or end_clock_snapshot is None:
 448                 raise ValueError(
 449                     'discarded packets have default clock snapshots for this stream class'
 450                 )
 451
 452             utils._check_uint64(beg_clock_snapshot)
 453             utils._check_uint64(end_clock_snapshot)
 454             ptr = native_bt.message_discarded_packets_create_with_default_clock_snapshots(
 455                 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
 456             )
 457         else:
 458             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 459                 raise ValueError(
 460                     'discarded packets have no default clock snapshots for this stream class'
 461                 )
 462
 463             ptr = native_bt.message_discarded_packets_create(self._bt_ptr, stream._ptr)
 464
 465         if ptr is None:
 466             raise bt2._MemoryError('cannot discarded packets message object')
 467
 468         msg = bt2_message._DiscardedPacketsMessage(ptr)
 469
 470         if count is not None:
 471             msg._count = count
 472
 473         return msg