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     @staticmethod
  23     def _get_ref(ptr):
  24         native_bt.message_iterator_get_ref(ptr)
  25
  26     @staticmethod
  27     def _put_ref(ptr):
  28         native_bt.message_iterator_put_ref(ptr)
  29
  30     def __init__(self, ptr):
  31         self._current_msgs = []
  32         self._at = 0
  33         super().__init__(ptr)
  34
  35     def __next__(self):
  36         if len(self._current_msgs) == self._at:
  37             status, msgs = native_bt.bt2_self_component_port_input_get_msg_range(
  38                 self._ptr
  39             )
  40             utils._handle_func_status(
  41                 status, "unexpected error: cannot advance the message iterator"
  42             )
  43             self._current_msgs = msgs
  44             self._at = 0
  45
  46         msg_ptr = self._current_msgs[self._at]
  47         self._at += 1
  48
  49         return bt2_message._create_from_ptr(msg_ptr)
  50
  51     def can_seek_beginning(self):
  52         (status, res) = native_bt.message_iterator_can_seek_beginning(self._ptr)
  53         utils._handle_func_status(
  54             status,
  55             "cannot check whether or not message iterator can seek its beginning",
  56         )
  57         return res != 0
  58
  59     def seek_beginning(self):
  60         # Forget about buffered messages, they won't be valid after seeking.
  61         self._current_msgs.clear()
  62         self._at = 0
  63
  64         status = native_bt.message_iterator_seek_beginning(self._ptr)
  65         utils._handle_func_status(status, "cannot seek message iterator beginning")
  66
  67     def can_seek_ns_from_origin(self, ns_from_origin):
  68         utils._check_int64(ns_from_origin)
  69         (status, res) = native_bt.message_iterator_can_seek_ns_from_origin(
  70             self._ptr, ns_from_origin
  71         )
  72         utils._handle_func_status(
  73             status,
  74             "cannot check whether or not message iterator can seek given ns from origin",
  75         )
  76         return res != 0
  77
  78     def seek_ns_from_origin(self, ns_from_origin):
  79         utils._check_int64(ns_from_origin)
  80
  81         # Forget about buffered messages, they won't be valid after seeking.
  82         self._current_msgs.clear()
  83         self._at = 0
  84
  85         status = native_bt.message_iterator_seek_ns_from_origin(
  86             self._ptr, ns_from_origin
  87         )
  88         utils._handle_func_status(
  89             status, "message iterator cannot seek given ns from origin"
  90         )
  91
  92     @property
  93     def can_seek_forward(self):
  94         return native_bt.message_iterator_can_seek_forward(self._ptr)
  95
  96
  97 class _MessageIteratorConfiguration:
  98     def __init__(self, ptr):
  99         self._ptr = ptr
 100
 101     def can_seek_forward(self, value):
 102         utils._check_bool(value)
 103         native_bt.self_message_iterator_configuration_set_can_seek_forward(
 104             self._ptr, value
 105         )
 106
 107     can_seek_forward = property(fset=can_seek_forward)
 108
 109
 110 # This is extended by the user to implement component classes in Python.  It
 111 # is created for a given output port when an input port message iterator is
 112 # created on the input port on the other side of the connection.
 113 #
 114 # Its purpose is to feed the messages that should go out through this output
 115 # port.
 116 class _UserMessageIterator(_MessageIterator):
 117     def __new__(cls, ptr):
 118         # User iterator objects are always created by the native side,
 119         # that is, never instantiated directly by Python code.
 120         #
 121         # The native code calls this, then manually calls
 122         # self.__init__() without the `ptr` argument. The user has
 123         # access to self.component during this call, thanks to this
 124         # self._bt_ptr argument being set.
 125         #
 126         # self._bt_ptr is NOT owned by this object here, so there's nothing
 127         # to do in __del__().
 128         self = super().__new__(cls)
 129         self._bt_ptr = ptr
 130         return self
 131
 132     def _bt_init_from_native(self, config_ptr, self_output_port_ptr):
 133         self_output_port = bt2_port._create_self_from_ptr_and_get_ref(
 134             self_output_port_ptr, native_bt.PORT_TYPE_OUTPUT
 135         )
 136         config = _MessageIteratorConfiguration(config_ptr)
 137         self.__init__(config, self_output_port)
 138
 139     def __init__(self, config, self_output_port):
 140         pass
 141
 142     @property
 143     def _component(self):
 144         return native_bt.bt2_get_user_component_from_user_msg_iter(self._bt_ptr)
 145
 146     @property
 147     def _port(self):
 148         port_ptr = native_bt.self_message_iterator_borrow_port(self._bt_ptr)
 149         assert port_ptr is not None
 150         return bt2_port._create_self_from_ptr_and_get_ref(
 151             port_ptr, native_bt.PORT_TYPE_OUTPUT
 152         )
 153
 154     @property
 155     def addr(self):
 156         return int(self._bt_ptr)
 157
 158     @property
 159     def _is_interrupted(self):
 160         return bool(native_bt.self_message_iterator_is_interrupted(self._bt_ptr))
 161
 162     def _user_finalize(self):
 163         pass
 164
 165     def __next__(self):
 166         raise bt2.Stop
 167
 168     def _bt_next_from_native(self):
 169         # this can raise anything: it's catched by the native part
 170         try:
 171             msg = next(self)
 172         except StopIteration:
 173             raise bt2.Stop
 174         except Exception:
 175             raise
 176
 177         utils._check_type(msg, bt2_message._MessageConst)
 178
 179         # The reference we return will be given to the message array.
 180         # However, the `msg` Python object may stay alive, if the user has kept
 181         # a reference to it.  Acquire a new reference to account for that.
 182         msg._get_ref(msg._ptr)
 183         return int(msg._ptr)
 184
 185     def _bt_can_seek_beginning_from_native(self):
 186         # Here, we mimic the behavior of the C API:
 187         #
 188         # - If the iterator has a _user_can_seek_beginning method,
 189         #   read it and use that result.
 190         # - Otherwise, the presence or absence of a `_user_seek_beginning`
 191         #   method indicates whether the iterator can seek beginning.
 192         if hasattr(self, "_user_can_seek_beginning"):
 193             can_seek_beginning = self._user_can_seek_beginning()
 194             utils._check_bool(can_seek_beginning)
 195             return can_seek_beginning
 196         else:
 197             return hasattr(self, "_user_seek_beginning")
 198
 199     def _bt_seek_beginning_from_native(self):
 200         self._user_seek_beginning()
 201
 202     def _bt_can_seek_ns_from_origin_from_native(self, ns_from_origin):
 203         # Return whether the iterator can seek ns from origin using the
 204         # user-implemented seek_ns_from_origin method.  We mimic the behavior
 205         # of the C API:
 206         #
 207         # - If the iterator has a _user_can_seek_ns_from_origin method,
 208         #   call it and use its return value.
 209         # - Otherwise, if there is a `_user_seek_ns_from_origin` method,
 210         #   we presume it's possible.
 211
 212         if hasattr(self, "_user_can_seek_ns_from_origin"):
 213             can_seek_ns_from_origin = self._user_can_seek_ns_from_origin(ns_from_origin)
 214             utils._check_bool(can_seek_ns_from_origin)
 215             return can_seek_ns_from_origin
 216         else:
 217             return hasattr(self, "_user_seek_ns_from_origin")
 218
 219     def _bt_seek_ns_from_origin_from_native(self, ns_from_origin):
 220         self._user_seek_ns_from_origin(ns_from_origin)
 221
 222     def _create_message_iterator(self, input_port):
 223         utils._check_type(input_port, bt2_port._UserComponentInputPort)
 224
 225         if not input_port.is_connected:
 226             raise ValueError("input port is not connected")
 227
 228         (
 229             status,
 230             msg_iter_ptr,
 231         ) = native_bt.bt2_message_iterator_create_from_message_iterator(
 232             self._bt_ptr, input_port._ptr
 233         )
 234         utils._handle_func_status(status, "cannot create message iterator object")
 235         assert msg_iter_ptr is not None
 236
 237         return _UserComponentInputPortMessageIterator(msg_iter_ptr)
 238
 239     def _create_event_message(self, event_class, parent, default_clock_snapshot=None):
 240         utils._check_type(event_class, bt2_event_class._EventClass)
 241
 242         if event_class.stream_class.supports_packets:
 243             utils._check_type(parent, bt2_packet._Packet)
 244         else:
 245             utils._check_type(parent, bt2_stream._Stream)
 246
 247         if default_clock_snapshot is not None:
 248             if event_class.stream_class.default_clock_class is None:
 249                 raise ValueError(
 250                     "event messages in this stream must not have a default clock snapshot"
 251                 )
 252
 253             utils._check_uint64(default_clock_snapshot)
 254
 255             if event_class.stream_class.supports_packets:
 256                 ptr = native_bt.message_event_create_with_packet_and_default_clock_snapshot(
 257                     self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
 258                 )
 259             else:
 260                 ptr = native_bt.message_event_create_with_default_clock_snapshot(
 261                     self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
 262                 )
 263         else:
 264             if event_class.stream_class.default_clock_class is not None:
 265                 raise ValueError(
 266                     "event messages in this stream must have a default clock snapshot"
 267                 )
 268
 269             if event_class.stream_class.supports_packets:
 270                 ptr = native_bt.message_event_create_with_packet(
 271                     self._bt_ptr, event_class._ptr, parent._ptr
 272                 )
 273             else:
 274                 ptr = native_bt.message_event_create(
 275                     self._bt_ptr, event_class._ptr, parent._ptr
 276                 )
 277
 278         if ptr is None:
 279             raise bt2._MemoryError("cannot create event message object")
 280
 281         return bt2_message._EventMessage(ptr)
 282
 283     def _create_message_iterator_inactivity_message(self, clock_class, clock_snapshot):
 284         utils._check_type(clock_class, bt2_clock_class._ClockClass)
 285         ptr = native_bt.message_message_iterator_inactivity_create(
 286             self._bt_ptr, clock_class._ptr, clock_snapshot
 287         )
 288
 289         if ptr is None:
 290             raise bt2._MemoryError("cannot create inactivity message object")
 291
 292         return bt2_message._MessageIteratorInactivityMessage(ptr)
 293
 294     def _create_stream_beginning_message(self, stream, default_clock_snapshot=None):
 295         utils._check_type(stream, bt2_stream._Stream)
 296
 297         ptr = native_bt.message_stream_beginning_create(self._bt_ptr, stream._ptr)
 298         if ptr is None:
 299             raise bt2._MemoryError("cannot create stream beginning message object")
 300
 301         msg = bt2_message._StreamBeginningMessage(ptr)
 302
 303         if default_clock_snapshot is not None:
 304             msg._default_clock_snapshot = default_clock_snapshot
 305
 306         return msg
 307
 308     def _create_stream_end_message(self, stream, default_clock_snapshot=None):
 309         utils._check_type(stream, bt2_stream._Stream)
 310
 311         ptr = native_bt.message_stream_end_create(self._bt_ptr, stream._ptr)
 312         if ptr is None:
 313             raise bt2._MemoryError("cannot create stream end message object")
 314
 315         msg = bt2_message._StreamEndMessage(ptr)
 316
 317         if default_clock_snapshot is not None:
 318             msg._default_clock_snapshot = default_clock_snapshot
 319
 320         return msg
 321
 322     def _create_packet_beginning_message(self, packet, default_clock_snapshot=None):
 323         utils._check_type(packet, bt2_packet._Packet)
 324
 325         if packet.stream.cls.packets_have_beginning_default_clock_snapshot:
 326             if default_clock_snapshot is None:
 327                 raise ValueError(
 328                     "packet beginning messages in this stream must have a default clock snapshot"
 329                 )
 330
 331             utils._check_uint64(default_clock_snapshot)
 332             ptr = native_bt.message_packet_beginning_create_with_default_clock_snapshot(
 333                 self._bt_ptr, packet._ptr, default_clock_snapshot
 334             )
 335         else:
 336             if default_clock_snapshot is not None:
 337                 raise ValueError(
 338                     "packet beginning messages in this stream must not have a default clock snapshot"
 339                 )
 340
 341             ptr = native_bt.message_packet_beginning_create(self._bt_ptr, packet._ptr)
 342
 343         if ptr is None:
 344             raise bt2._MemoryError("cannot create packet beginning message object")
 345
 346         return bt2_message._PacketBeginningMessage(ptr)
 347
 348     def _create_packet_end_message(self, packet, default_clock_snapshot=None):
 349         utils._check_type(packet, bt2_packet._Packet)
 350
 351         if packet.stream.cls.packets_have_end_default_clock_snapshot:
 352             if default_clock_snapshot is None:
 353                 raise ValueError(
 354                     "packet end messages in this stream must have a default clock snapshot"
 355                 )
 356
 357             utils._check_uint64(default_clock_snapshot)
 358             ptr = native_bt.message_packet_end_create_with_default_clock_snapshot(
 359                 self._bt_ptr, packet._ptr, default_clock_snapshot
 360             )
 361         else:
 362             if default_clock_snapshot is not None:
 363                 raise ValueError(
 364                     "packet end messages in this stream must not have a default clock snapshot"
 365                 )
 366
 367             ptr = native_bt.message_packet_end_create(self._bt_ptr, packet._ptr)
 368
 369         if ptr is None:
 370             raise bt2._MemoryError("cannot create packet end message object")
 371
 372         return bt2_message._PacketEndMessage(ptr)
 373
 374     def _create_discarded_events_message(
 375         self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
 376     ):
 377         utils._check_type(stream, bt2_stream._Stream)
 378
 379         if not stream.cls.supports_discarded_events:
 380             raise ValueError("stream class does not support discarded events")
 381
 382         if stream.cls.discarded_events_have_default_clock_snapshots:
 383             if beg_clock_snapshot is None or end_clock_snapshot is None:
 384                 raise ValueError(
 385                     "discarded events have default clock snapshots for this stream class"
 386                 )
 387
 388             utils._check_uint64(beg_clock_snapshot)
 389             utils._check_uint64(end_clock_snapshot)
 390
 391             if beg_clock_snapshot > end_clock_snapshot:
 392                 raise ValueError(
 393                     "beginning default clock snapshot value ({}) is greater than end default clock snapshot value ({})".format(
 394                         beg_clock_snapshot, end_clock_snapshot
 395                     )
 396                 )
 397
 398             ptr = (
 399                 native_bt.message_discarded_events_create_with_default_clock_snapshots(
 400                     self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
 401                 )
 402             )
 403         else:
 404             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 405                 raise ValueError(
 406                     "discarded events have no default clock snapshots for this stream class"
 407                 )
 408
 409             ptr = native_bt.message_discarded_events_create(self._bt_ptr, stream._ptr)
 410
 411         if ptr is None:
 412             raise bt2._MemoryError("cannot discarded events message object")
 413
 414         msg = bt2_message._DiscardedEventsMessage(ptr)
 415
 416         if count is not None:
 417             msg._count = count
 418
 419         return msg
 420
 421     def _create_discarded_packets_message(
 422         self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
 423     ):
 424         utils._check_type(stream, bt2_stream._Stream)
 425
 426         if not stream.cls.supports_discarded_packets:
 427             raise ValueError("stream class does not support discarded packets")
 428
 429         if stream.cls.discarded_packets_have_default_clock_snapshots:
 430             if beg_clock_snapshot is None or end_clock_snapshot is None:
 431                 raise ValueError(
 432                     "discarded packets have default clock snapshots for this stream class"
 433                 )
 434
 435             utils._check_uint64(beg_clock_snapshot)
 436             utils._check_uint64(end_clock_snapshot)
 437
 438             if beg_clock_snapshot > end_clock_snapshot:
 439                 raise ValueError(
 440                     "beginning default clock snapshot value ({}) is greater than end default clock snapshot value ({})".format(
 441                         beg_clock_snapshot, end_clock_snapshot
 442                     )
 443                 )
 444
 445             ptr = (
 446                 native_bt.message_discarded_packets_create_with_default_clock_snapshots(
 447                     self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
 448                 )
 449             )
 450         else:
 451             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 452                 raise ValueError(
 453                     "discarded packets have no default clock snapshots for this stream class"
 454                 )
 455
 456             ptr = native_bt.message_discarded_packets_create(self._bt_ptr, stream._ptr)
 457
 458         if ptr is None:
 459             raise bt2._MemoryError("cannot discarded packets message object")
 460
 461         msg = bt2_message._DiscardedPacketsMessage(ptr)
 462
 463         if count is not None:
 464             msg._count = count
 465
 466         return msg