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 _GenericMessageIterator(object._SharedObject, _MessageIterator):
  40     def __init__(self, ptr):
  41         self._current_msgs = []
  42         self._at = 0
  43         super().__init__(ptr)
  44
  45     def __next__(self):
  46         if len(self._current_msgs) == self._at:
  47             status, msgs = self._get_msg_range(self._ptr)
  48             utils._handle_func_status(
  49                 status, 'unexpected error: cannot advance the message iterator'
  50             )
  51             self._current_msgs = msgs
  52             self._at = 0
  53
  54         msg_ptr = self._current_msgs[self._at]
  55         self._at += 1
  56
  57         return bt2_message._create_from_ptr(msg_ptr)
  58
  59     @property
  60     def can_seek_beginning(self):
  61         res = self._can_seek_beginning(self._ptr)
  62         return res != 0
  63
  64     def seek_beginning(self):
  65         # Forget about buffered messages, they won't be valid after seeking..
  66         self._current_msgs.clear()
  67         self._at = 0
  68
  69         status = self._seek_beginning(self._ptr)
  70         utils._handle_func_status(status, 'cannot seek message iterator beginning')
  71
  72
  73 # This is created when a component wants to iterate on one of its input ports.
  74 class _UserComponentInputPortMessageIterator(_GenericMessageIterator):
  75     _get_msg_range = staticmethod(native_bt.bt2_self_component_port_input_get_msg_range)
  76     _get_ref = staticmethod(
  77         native_bt.self_component_port_input_message_iterator_get_ref
  78     )
  79     _put_ref = staticmethod(
  80         native_bt.self_component_port_input_message_iterator_put_ref
  81     )
  82     _can_seek_beginning = staticmethod(
  83         native_bt.self_component_port_input_message_iterator_can_seek_beginning
  84     )
  85     _seek_beginning = staticmethod(
  86         native_bt.self_component_port_input_message_iterator_seek_beginning
  87     )
  88
  89
  90 # This is extended by the user to implement component classes in Python.  It
  91 # is created for a given output port when an input port message iterator is
  92 # created on the input port on the other side of the connection.  It is also
  93 # created when an output port message iterator is created on this output port.
  94 #
  95 # Its purpose is to feed the messages that should go out through this output
  96 # port.
  97 class _UserMessageIterator(_MessageIterator):
  98     def __new__(cls, ptr):
  99         # User iterator objects are always created by the native side,
 100         # that is, never instantiated directly by Python code.
 101         #
 102         # The native code calls this, then manually calls
 103         # self.__init__() without the `ptr` argument. The user has
 104         # access to self.component during this call, thanks to this
 105         # self._bt_ptr argument being set.
 106         #
 107         # self._bt_ptr is NOT owned by this object here, so there's nothing
 108         # to do in __del__().
 109         self = super().__new__(cls)
 110         self._bt_ptr = ptr
 111         return self
 112
 113     def _bt_init_from_native(self, self_output_port_ptr):
 114         self_output_port = bt2_port._create_self_from_ptr_and_get_ref(
 115             self_output_port_ptr, native_bt.PORT_TYPE_OUTPUT
 116         )
 117         self.__init__(self_output_port)
 118
 119     def __init__(self, output_port):
 120         pass
 121
 122     @property
 123     def _component(self):
 124         return native_bt.bt2_get_user_component_from_user_msg_iter(self._bt_ptr)
 125
 126     @property
 127     def addr(self):
 128         return int(self._bt_ptr)
 129
 130     @property
 131     def _is_interrupted(self):
 132         return bool(native_bt.self_message_iterator_is_interrupted(self._bt_ptr))
 133
 134     def _user_finalize(self):
 135         pass
 136
 137     def __next__(self):
 138         raise bt2.Stop
 139
 140     def _bt_next_from_native(self):
 141         # this can raise anything: it's catched by the native part
 142         try:
 143             msg = next(self)
 144         except StopIteration:
 145             raise bt2.Stop
 146         except Exception:
 147             raise
 148
 149         utils._check_type(msg, bt2_message._Message)
 150
 151         # The reference we return will be given to the message array.
 152         # However, the `msg` Python object may stay alive, if the user has kept
 153         # a reference to it.  Acquire a new reference to account for that.
 154         msg._get_ref(msg._ptr)
 155         return int(msg._ptr)
 156
 157     @property
 158     def _bt_can_seek_beginning_from_native(self):
 159         # Here, we mimic the behavior of the C API:
 160         #
 161         # - If the iterator has a _user_can_seek_beginning attribute,
 162         #   read it and use that result.
 163         # - Otherwise, the presence or absence of a `_seek_beginning`
 164         #   method indicates whether the iterator can seek beginning.
 165         if hasattr(self, '_user_can_seek_beginning'):
 166             can_seek_beginning = self._user_can_seek_beginning
 167             utils._check_bool(can_seek_beginning)
 168             return can_seek_beginning
 169         else:
 170             return hasattr(self, '_user_seek_beginning')
 171
 172     def _bt_seek_beginning_from_native(self):
 173         self._user_seek_beginning()
 174
 175     def _create_input_port_message_iterator(self, input_port):
 176         utils._check_type(input_port, bt2_port._UserComponentInputPort)
 177
 178         status, msg_iter_ptr = native_bt.bt2_self_component_port_input_message_iterator_create_from_message_iterator(
 179             self._bt_ptr, input_port._ptr
 180         )
 181         utils._handle_func_status(status, 'cannot create message iterator object')
 182         assert msg_iter_ptr is not None
 183
 184         return _UserComponentInputPortMessageIterator(msg_iter_ptr)
 185
 186     def _create_event_message(self, event_class, parent, default_clock_snapshot=None):
 187         utils._check_type(event_class, bt2_event_class._EventClass)
 188
 189         if event_class.stream_class.supports_packets:
 190             utils._check_type(parent, bt2_packet._Packet)
 191         else:
 192             utils._check_type(parent, bt2_stream._Stream)
 193
 194         if default_clock_snapshot is not None:
 195             if event_class.stream_class.default_clock_class is None:
 196                 raise ValueError(
 197                     'event messages in this stream must not have a default clock snapshot'
 198                 )
 199
 200             utils._check_uint64(default_clock_snapshot)
 201
 202             if event_class.stream_class.supports_packets:
 203                 ptr = native_bt.message_event_create_with_packet_and_default_clock_snapshot(
 204                     self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
 205                 )
 206             else:
 207                 ptr = native_bt.message_event_create_with_default_clock_snapshot(
 208                     self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
 209                 )
 210         else:
 211             if event_class.stream_class.default_clock_class is not None:
 212                 raise ValueError(
 213                     'event messages in this stream must have a default clock snapshot'
 214                 )
 215
 216             if event_class.stream_class.supports_packets:
 217                 ptr = native_bt.message_event_create_with_packet(
 218                     self._bt_ptr, event_class._ptr, parent._ptr
 219                 )
 220             else:
 221                 ptr = native_bt.message_event_create(
 222                     self._bt_ptr, event_class._ptr, parent._ptr
 223                 )
 224
 225         if ptr is None:
 226             raise bt2._MemoryError('cannot create event message object')
 227
 228         return bt2_message._EventMessage(ptr)
 229
 230     def _create_message_iterator_inactivity_message(self, clock_class, clock_snapshot):
 231         utils._check_type(clock_class, bt2_clock_class._ClockClass)
 232         ptr = native_bt.message_message_iterator_inactivity_create(
 233             self._bt_ptr, clock_class._ptr, clock_snapshot
 234         )
 235
 236         if ptr is None:
 237             raise bt2._MemoryError('cannot create inactivity message object')
 238
 239         return bt2_message._MessageIteratorInactivityMessage(ptr)
 240
 241     def _create_stream_beginning_message(self, stream, default_clock_snapshot=None):
 242         utils._check_type(stream, bt2_stream._Stream)
 243
 244         ptr = native_bt.message_stream_beginning_create(self._bt_ptr, stream._ptr)
 245         if ptr is None:
 246             raise bt2._MemoryError('cannot create stream beginning message object')
 247
 248         msg = bt2_message._StreamBeginningMessage(ptr)
 249
 250         if default_clock_snapshot is not None:
 251             msg._default_clock_snapshot = default_clock_snapshot
 252
 253         return msg
 254
 255     def _create_stream_end_message(self, stream, default_clock_snapshot=None):
 256         utils._check_type(stream, bt2_stream._Stream)
 257
 258         ptr = native_bt.message_stream_end_create(self._bt_ptr, stream._ptr)
 259         if ptr is None:
 260             raise bt2._MemoryError('cannot create stream end message object')
 261
 262         msg = bt2_message._StreamEndMessage(ptr)
 263
 264         if default_clock_snapshot is not None:
 265             msg._default_clock_snapshot = default_clock_snapshot
 266
 267         return msg
 268
 269     def _create_packet_beginning_message(self, packet, default_clock_snapshot=None):
 270         utils._check_type(packet, bt2_packet._Packet)
 271
 272         if packet.stream.cls.packets_have_beginning_default_clock_snapshot:
 273             if default_clock_snapshot is None:
 274                 raise ValueError(
 275                     "packet beginning messages in this stream must have a default clock snapshot"
 276                 )
 277
 278             utils._check_uint64(default_clock_snapshot)
 279             ptr = native_bt.message_packet_beginning_create_with_default_clock_snapshot(
 280                 self._bt_ptr, packet._ptr, default_clock_snapshot
 281             )
 282         else:
 283             if default_clock_snapshot is not None:
 284                 raise ValueError(
 285                     "packet beginning messages in this stream must not have a default clock snapshot"
 286                 )
 287
 288             ptr = native_bt.message_packet_beginning_create(self._bt_ptr, packet._ptr)
 289
 290         if ptr is None:
 291             raise bt2._MemoryError('cannot create packet beginning message object')
 292
 293         return bt2_message._PacketBeginningMessage(ptr)
 294
 295     def _create_packet_end_message(self, packet, default_clock_snapshot=None):
 296         utils._check_type(packet, bt2_packet._Packet)
 297
 298         if packet.stream.cls.packets_have_end_default_clock_snapshot:
 299             if default_clock_snapshot is None:
 300                 raise ValueError(
 301                     "packet end messages in this stream must have a default clock snapshot"
 302                 )
 303
 304             utils._check_uint64(default_clock_snapshot)
 305             ptr = native_bt.message_packet_end_create_with_default_clock_snapshot(
 306                 self._bt_ptr, packet._ptr, default_clock_snapshot
 307             )
 308         else:
 309             if default_clock_snapshot is not None:
 310                 raise ValueError(
 311                     "packet end messages in this stream must not have a default clock snapshot"
 312                 )
 313
 314             ptr = native_bt.message_packet_end_create(self._bt_ptr, packet._ptr)
 315
 316         if ptr is None:
 317             raise bt2._MemoryError('cannot create packet end message object')
 318
 319         return bt2_message._PacketEndMessage(ptr)
 320
 321     def _create_discarded_events_message(
 322         self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
 323     ):
 324         utils._check_type(stream, bt2_stream._Stream)
 325
 326         if not stream.cls.supports_discarded_events:
 327             raise ValueError('stream class does not support discarded events')
 328
 329         if stream.cls.discarded_events_have_default_clock_snapshots:
 330             if beg_clock_snapshot is None or end_clock_snapshot is None:
 331                 raise ValueError(
 332                     'discarded events have default clock snapshots for this stream class'
 333                 )
 334
 335             utils._check_uint64(beg_clock_snapshot)
 336             utils._check_uint64(end_clock_snapshot)
 337             ptr = native_bt.message_discarded_events_create_with_default_clock_snapshots(
 338                 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
 339             )
 340         else:
 341             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 342                 raise ValueError(
 343                     'discarded events have no default clock snapshots for this stream class'
 344                 )
 345
 346             ptr = native_bt.message_discarded_events_create(self._bt_ptr, stream._ptr)
 347
 348         if ptr is None:
 349             raise bt2._MemoryError('cannot discarded events message object')
 350
 351         msg = bt2_message._DiscardedEventsMessage(ptr)
 352
 353         if count is not None:
 354             msg._count = count
 355
 356         return msg
 357
 358     def _create_discarded_packets_message(
 359         self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
 360     ):
 361         utils._check_type(stream, bt2_stream._Stream)
 362
 363         if not stream.cls.supports_discarded_packets:
 364             raise ValueError('stream class does not support discarded packets')
 365
 366         if stream.cls.discarded_packets_have_default_clock_snapshots:
 367             if beg_clock_snapshot is None or end_clock_snapshot is None:
 368                 raise ValueError(
 369                     'discarded packets have default clock snapshots for this stream class'
 370                 )
 371
 372             utils._check_uint64(beg_clock_snapshot)
 373             utils._check_uint64(end_clock_snapshot)
 374             ptr = native_bt.message_discarded_packets_create_with_default_clock_snapshots(
 375                 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
 376             )
 377         else:
 378             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 379                 raise ValueError(
 380                     'discarded packets have no default clock snapshots for this stream class'
 381                 )
 382
 383             ptr = native_bt.message_discarded_packets_create(self._bt_ptr, stream._ptr)
 384
 385         if ptr is None:
 386             raise bt2._MemoryError('cannot discarded packets message object')
 387
 388         msg = bt2_message._DiscardedPacketsMessage(ptr)
 389
 390         if count is not None:
 391             msg._count = count
 392
 393         return msg