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 component as bt2_component
  27 from bt2 import stream as bt2_stream
  28 from bt2 import event_class as bt2_event_class
  29 from bt2 import packet as bt2_packet
  30 from bt2 import port as bt2_port
  31 from bt2 import clock_class as bt2_clock_class
  32 import bt2
  33
  34
  35 class _MessageIterator(collections.abc.Iterator):
  36     def __next__(self):
  37         raise NotImplementedError
  38
  39
  40 class _GenericMessageIterator(object._SharedObject, _MessageIterator):
  41     def __init__(self, ptr):
  42         self._current_msgs = []
  43         self._at = 0
  44         super().__init__(ptr)
  45
  46     def __next__(self):
  47         if len(self._current_msgs) == self._at:
  48             status, msgs = self._get_msg_range(self._ptr)
  49             utils._handle_func_status(
  50                 status, 'unexpected error: cannot advance the message iterator'
  51             )
  52             self._current_msgs = msgs
  53             self._at = 0
  54
  55         msg_ptr = self._current_msgs[self._at]
  56         self._at += 1
  57
  58         return bt2_message._create_from_ptr(msg_ptr)
  59
  60     @property
  61     def can_seek_beginning(self):
  62         res = self._can_seek_beginning(self._ptr)
  63         return res != 0
  64
  65     def seek_beginning(self):
  66         # Forget about buffered messages, they won't be valid after seeking..
  67         self._current_msgs.clear()
  68         self._at = 0
  69
  70         status = self._seek_beginning(self._ptr)
  71         utils._handle_func_status(status, 'cannot seek message iterator beginning')
  72
  73
  74 # This is created when a component wants to iterate on one of its input ports.
  75 class _UserComponentInputPortMessageIterator(_GenericMessageIterator):
  76     _get_msg_range = staticmethod(native_bt.bt2_self_component_port_input_get_msg_range)
  77     _get_ref = staticmethod(
  78         native_bt.self_component_port_input_message_iterator_get_ref
  79     )
  80     _put_ref = staticmethod(
  81         native_bt.self_component_port_input_message_iterator_put_ref
  82     )
  83     _can_seek_beginning = staticmethod(
  84         native_bt.self_component_port_input_message_iterator_can_seek_beginning
  85     )
  86     _seek_beginning = staticmethod(
  87         native_bt.self_component_port_input_message_iterator_seek_beginning
  88     )
  89
  90
  91 # This is extended by the user to implement component classes in Python.  It
  92 # is created for a given output port when an input port message iterator is
  93 # created on the input port on the other side of the connection.  It is also
  94 # created when an output port message iterator is created on this output port.
  95 #
  96 # Its purpose is to feed the messages that should go out through this output
  97 # port.
  98 class _UserMessageIterator(_MessageIterator):
  99     def __new__(cls, ptr):
 100         # User iterator objects are always created by the native side,
 101         # that is, never instantiated directly by Python code.
 102         #
 103         # The native code calls this, then manually calls
 104         # self.__init__() without the `ptr` argument. The user has
 105         # access to self.component during this call, thanks to this
 106         # self._bt_ptr argument being set.
 107         #
 108         # self._bt_ptr is NOT owned by this object here, so there's nothing
 109         # to do in __del__().
 110         self = super().__new__(cls)
 111         self._bt_ptr = ptr
 112         return self
 113
 114     def _bt_init_from_native(self, self_output_port_ptr):
 115         self_output_port = bt2_port._create_self_from_ptr_and_get_ref(
 116             self_output_port_ptr, native_bt.PORT_TYPE_OUTPUT
 117         )
 118         self.__init__(self_output_port)
 119
 120     def __init__(self, output_port):
 121         pass
 122
 123     @property
 124     def _component(self):
 125         return native_bt.bt2_get_user_component_from_user_msg_iter(self._bt_ptr)
 126
 127     @property
 128     def addr(self):
 129         return int(self._bt_ptr)
 130
 131     @property
 132     def _is_interrupted(self):
 133         return bool(native_bt.self_message_iterator_is_interrupted(self._bt_ptr))
 134
 135     def _user_finalize(self):
 136         pass
 137
 138     def __next__(self):
 139         raise bt2.Stop
 140
 141     def _bt_next_from_native(self):
 142         # this can raise anything: it's catched by the native part
 143         try:
 144             msg = next(self)
 145         except StopIteration:
 146             raise bt2.Stop
 147         except:
 148             raise
 149
 150         utils._check_type(msg, bt2_message._Message)
 151
 152         # The reference we return will be given to the message array.
 153         # However, the `msg` Python object may stay alive, if the user has kept
 154         # a reference to it.  Acquire a new reference to account for that.
 155         msg._get_ref(msg._ptr)
 156         return int(msg._ptr)
 157
 158     @property
 159     def _bt_can_seek_beginning_from_native(self):
 160         # Here, we mimic the behavior of the C API:
 161         #
 162         # - If the iterator has a _user_can_seek_beginning attribute,
 163         #   read it and use that result.
 164         # - Otherwise, the presence or absence of a `_seek_beginning`
 165         #   method indicates whether the iterator can seek beginning.
 166         if hasattr(self, '_user_can_seek_beginning'):
 167             can_seek_beginning = self._user_can_seek_beginning
 168             utils._check_bool(can_seek_beginning)
 169             return can_seek_beginning
 170         else:
 171             return hasattr(self, '_user_seek_beginning')
 172
 173     def _bt_seek_beginning_from_native(self):
 174         self._user_seek_beginning()
 175
 176     def _create_input_port_message_iterator(self, input_port):
 177         utils._check_type(input_port, bt2_port._UserComponentInputPort)
 178
 179         msg_iter_ptr = native_bt.self_component_port_input_message_iterator_create_from_message_iterator(
 180             self._bt_ptr, input_port._ptr
 181         )
 182
 183         if msg_iter_ptr is None:
 184             raise bt2.CreationError('cannot create message iterator object')
 185
 186         return _UserComponentInputPortMessageIterator(msg_iter_ptr)
 187
 188     def _create_event_message(
 189         self, event_class, parent=None, default_clock_snapshot=None
 190     ):
 191         utils._check_type(event_class, bt2_event_class._EventClass)
 192
 193         if event_class.stream_class.supports_packets:
 194             utils._check_type(parent, bt2_packet._Packet)
 195         else:
 196             utils._check_type(parent, bt2_stream._Stream)
 197
 198         if default_clock_snapshot is not None:
 199             if event_class.stream_class.default_clock_class is None:
 200                 raise ValueError(
 201                     'event messages in this stream must not have a default clock snapshot'
 202                 )
 203
 204             utils._check_uint64(default_clock_snapshot)
 205
 206             if event_class.stream_class.supports_packets:
 207                 ptr = native_bt.message_event_create_with_packet_and_default_clock_snapshot(
 208                     self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
 209                 )
 210             else:
 211                 ptr = native_bt.message_event_create_with_default_clock_snapshot(
 212                     self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
 213                 )
 214         else:
 215             if event_class.stream_class.default_clock_class is not None:
 216                 raise ValueError(
 217                     'event messages in this stream must have a default clock snapshot'
 218                 )
 219
 220             if event_class.stream_class.supports_packets:
 221                 ptr = native_bt.message_event_create_with_packet(
 222                     self._bt_ptr, event_class._ptr, parent._ptr
 223                 )
 224             else:
 225                 ptr = native_bt.message_event_create(
 226                     self._bt_ptr, event_class._ptr, parent._ptr
 227                 )
 228
 229         if ptr is None:
 230             raise bt2._MemoryError('cannot create event message object')
 231
 232         return bt2_message._EventMessage(ptr)
 233
 234     def _create_message_iterator_inactivity_message(self, clock_class, clock_snapshot):
 235         utils._check_type(clock_class, bt2_clock_class._ClockClass)
 236         ptr = native_bt.message_message_iterator_inactivity_create(
 237             self._bt_ptr, clock_class._ptr, clock_snapshot
 238         )
 239
 240         if ptr is None:
 241             raise bt2._MemoryError('cannot create inactivity message object')
 242
 243         return bt2_message._MessageIteratorInactivityMessage(ptr)
 244
 245     def _create_stream_beginning_message(self, stream, default_clock_snapshot=None):
 246         utils._check_type(stream, bt2_stream._Stream)
 247
 248         ptr = native_bt.message_stream_beginning_create(self._bt_ptr, stream._ptr)
 249         if ptr is None:
 250             raise bt2._MemoryError('cannot create stream beginning message object')
 251
 252         msg = bt2_message._StreamBeginningMessage(ptr)
 253
 254         if default_clock_snapshot is not None:
 255             msg._default_clock_snapshot = default_clock_snapshot
 256
 257         return msg
 258
 259     def _create_stream_end_message(self, stream, default_clock_snapshot=None):
 260         utils._check_type(stream, bt2_stream._Stream)
 261
 262         ptr = native_bt.message_stream_end_create(self._bt_ptr, stream._ptr)
 263         if ptr is None:
 264             raise bt2._MemoryError('cannot create stream end message object')
 265
 266         msg = bt2_message._StreamEndMessage(ptr)
 267
 268         if default_clock_snapshot is not None:
 269             msg._default_clock_snapshot = default_clock_snapshot
 270
 271         return msg
 272
 273     def _create_packet_beginning_message(self, packet, default_clock_snapshot=None):
 274         utils._check_type(packet, bt2_packet._Packet)
 275
 276         if packet.stream.cls.packets_have_beginning_default_clock_snapshot:
 277             if default_clock_snapshot is None:
 278                 raise ValueError(
 279                     "packet beginning messages in this stream must have a default clock snapshot"
 280                 )
 281
 282             utils._check_uint64(default_clock_snapshot)
 283             ptr = native_bt.message_packet_beginning_create_with_default_clock_snapshot(
 284                 self._bt_ptr, packet._ptr, default_clock_snapshot
 285             )
 286         else:
 287             if default_clock_snapshot is not None:
 288                 raise ValueError(
 289                     "packet beginning messages in this stream must not have a default clock snapshot"
 290                 )
 291
 292             ptr = native_bt.message_packet_beginning_create(self._bt_ptr, packet._ptr)
 293
 294         if ptr is None:
 295             raise bt2._MemoryError('cannot create packet beginning message object')
 296
 297         return bt2_message._PacketBeginningMessage(ptr)
 298
 299     def _create_packet_end_message(self, packet, default_clock_snapshot=None):
 300         utils._check_type(packet, bt2_packet._Packet)
 301
 302         if packet.stream.cls.packets_have_end_default_clock_snapshot:
 303             if default_clock_snapshot is None:
 304                 raise ValueError(
 305                     "packet end messages in this stream must have a default clock snapshot"
 306                 )
 307
 308             utils._check_uint64(default_clock_snapshot)
 309             ptr = native_bt.message_packet_end_create_with_default_clock_snapshot(
 310                 self._bt_ptr, packet._ptr, default_clock_snapshot
 311             )
 312         else:
 313             if default_clock_snapshot is not None:
 314                 raise ValueError(
 315                     "packet end messages in this stream must not have a default clock snapshot"
 316                 )
 317
 318             ptr = native_bt.message_packet_end_create(self._bt_ptr, packet._ptr)
 319
 320         if ptr is None:
 321             raise bt2._MemoryError('cannot create packet end message object')
 322
 323         return bt2_message._PacketEndMessage(ptr)
 324
 325     def _create_discarded_events_message(
 326         self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
 327     ):
 328         utils._check_type(stream, bt2_stream._Stream)
 329
 330         if not stream.cls.supports_discarded_events:
 331             raise ValueError('stream class does not support discarded events')
 332
 333         if stream.cls.discarded_events_have_default_clock_snapshots:
 334             if beg_clock_snapshot is None or end_clock_snapshot is None:
 335                 raise ValueError(
 336                     'discarded events have default clock snapshots for this stream class'
 337                 )
 338
 339             utils._check_uint64(beg_clock_snapshot)
 340             utils._check_uint64(end_clock_snapshot)
 341             ptr = native_bt.message_discarded_events_create_with_default_clock_snapshots(
 342                 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
 343             )
 344         else:
 345             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 346                 raise ValueError(
 347                     'discarded events have no default clock snapshots for this stream class'
 348                 )
 349
 350             ptr = native_bt.message_discarded_events_create(self._bt_ptr, stream._ptr)
 351
 352         if ptr is None:
 353             raise bt2._MemoryError('cannot discarded events message object')
 354
 355         msg = bt2_message._DiscardedEventsMessage(ptr)
 356
 357         if count is not None:
 358             msg._count = count
 359
 360         return msg
 361
 362     def _create_discarded_packets_message(
 363         self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
 364     ):
 365         utils._check_type(stream, bt2_stream._Stream)
 366
 367         if not stream.cls.supports_discarded_packets:
 368             raise ValueError('stream class does not support discarded packets')
 369
 370         if stream.cls.discarded_packets_have_default_clock_snapshots:
 371             if beg_clock_snapshot is None or end_clock_snapshot is None:
 372                 raise ValueError(
 373                     'discarded packets have default clock snapshots for this stream class'
 374                 )
 375
 376             utils._check_uint64(beg_clock_snapshot)
 377             utils._check_uint64(end_clock_snapshot)
 378             ptr = native_bt.message_discarded_packets_create_with_default_clock_snapshots(
 379                 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
 380             )
 381         else:
 382             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 383                 raise ValueError(
 384                     'discarded packets have no default clock snapshots for this stream class'
 385                 )
 386
 387             ptr = native_bt.message_discarded_packets_create(self._bt_ptr, stream._ptr)
 388
 389         if ptr is None:
 390             raise bt2._MemoryError('cannot discarded packets message object')
 391
 392         msg = bt2_message._DiscardedPacketsMessage(ptr)
 393
 394         if count is not None:
 395             msg._count = count
 396
 397         return msg