src/bindings/python/bt2/bt2/message_iterator.py

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