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