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