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         msg_iter_ptr = native_bt.self_component_port_input_message_iterator_create_from_message_iterator(
 179             self._bt_ptr, input_port._ptr
 180         )
 181
 182         if msg_iter_ptr is None:
 183             raise bt2._MemoryError('cannot create message iterator object')
 184
 185         return _UserComponentInputPortMessageIterator(msg_iter_ptr)
 186
 187     def _create_event_message(self, event_class, parent, default_clock_snapshot=None):
 188         utils._check_type(event_class, bt2_event_class._EventClass)
 189
 190         if event_class.stream_class.supports_packets:
 191             utils._check_type(parent, bt2_packet._Packet)
 192         else:
 193             utils._check_type(parent, bt2_stream._Stream)
 194
 195         if default_clock_snapshot is not None:
 196             if event_class.stream_class.default_clock_class is None:
 197                 raise ValueError(
 198                     'event messages in this stream must not have a default clock snapshot'
 199                 )
 200
 201             utils._check_uint64(default_clock_snapshot)
 202
 203             if event_class.stream_class.supports_packets:
 204                 ptr = native_bt.message_event_create_with_packet_and_default_clock_snapshot(
 205                     self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
 206                 )
 207             else:
 208                 ptr = native_bt.message_event_create_with_default_clock_snapshot(
 209                     self._bt_ptr, event_class._ptr, parent._ptr, default_clock_snapshot
 210                 )
 211         else:
 212             if event_class.stream_class.default_clock_class is not None:
 213                 raise ValueError(
 214                     'event messages in this stream must have a default clock snapshot'
 215                 )
 216
 217             if event_class.stream_class.supports_packets:
 218                 ptr = native_bt.message_event_create_with_packet(
 219                     self._bt_ptr, event_class._ptr, parent._ptr
 220                 )
 221             else:
 222                 ptr = native_bt.message_event_create(
 223                     self._bt_ptr, event_class._ptr, parent._ptr
 224                 )
 225
 226         if ptr is None:
 227             raise bt2._MemoryError('cannot create event message object')
 228
 229         return bt2_message._EventMessage(ptr)
 230
 231     def _create_message_iterator_inactivity_message(self, clock_class, clock_snapshot):
 232         utils._check_type(clock_class, bt2_clock_class._ClockClass)
 233         ptr = native_bt.message_message_iterator_inactivity_create(
 234             self._bt_ptr, clock_class._ptr, clock_snapshot
 235         )
 236
 237         if ptr is None:
 238             raise bt2._MemoryError('cannot create inactivity message object')
 239
 240         return bt2_message._MessageIteratorInactivityMessage(ptr)
 241
 242     def _create_stream_beginning_message(self, stream, default_clock_snapshot=None):
 243         utils._check_type(stream, bt2_stream._Stream)
 244
 245         ptr = native_bt.message_stream_beginning_create(self._bt_ptr, stream._ptr)
 246         if ptr is None:
 247             raise bt2._MemoryError('cannot create stream beginning message object')
 248
 249         msg = bt2_message._StreamBeginningMessage(ptr)
 250
 251         if default_clock_snapshot is not None:
 252             msg._default_clock_snapshot = default_clock_snapshot
 253
 254         return msg
 255
 256     def _create_stream_end_message(self, stream, default_clock_snapshot=None):
 257         utils._check_type(stream, bt2_stream._Stream)
 258
 259         ptr = native_bt.message_stream_end_create(self._bt_ptr, stream._ptr)
 260         if ptr is None:
 261             raise bt2._MemoryError('cannot create stream end message object')
 262
 263         msg = bt2_message._StreamEndMessage(ptr)
 264
 265         if default_clock_snapshot is not None:
 266             msg._default_clock_snapshot = default_clock_snapshot
 267
 268         return msg
 269
 270     def _create_packet_beginning_message(self, packet, default_clock_snapshot=None):
 271         utils._check_type(packet, bt2_packet._Packet)
 272
 273         if packet.stream.cls.packets_have_beginning_default_clock_snapshot:
 274             if default_clock_snapshot is None:
 275                 raise ValueError(
 276                     "packet beginning messages in this stream must have a default clock snapshot"
 277                 )
 278
 279             utils._check_uint64(default_clock_snapshot)
 280             ptr = native_bt.message_packet_beginning_create_with_default_clock_snapshot(
 281                 self._bt_ptr, packet._ptr, default_clock_snapshot
 282             )
 283         else:
 284             if default_clock_snapshot is not None:
 285                 raise ValueError(
 286                     "packet beginning messages in this stream must not have a default clock snapshot"
 287                 )
 288
 289             ptr = native_bt.message_packet_beginning_create(self._bt_ptr, packet._ptr)
 290
 291         if ptr is None:
 292             raise bt2._MemoryError('cannot create packet beginning message object')
 293
 294         return bt2_message._PacketBeginningMessage(ptr)
 295
 296     def _create_packet_end_message(self, packet, default_clock_snapshot=None):
 297         utils._check_type(packet, bt2_packet._Packet)
 298
 299         if packet.stream.cls.packets_have_end_default_clock_snapshot:
 300             if default_clock_snapshot is None:
 301                 raise ValueError(
 302                     "packet end messages in this stream must have a default clock snapshot"
 303                 )
 304
 305             utils._check_uint64(default_clock_snapshot)
 306             ptr = native_bt.message_packet_end_create_with_default_clock_snapshot(
 307                 self._bt_ptr, packet._ptr, default_clock_snapshot
 308             )
 309         else:
 310             if default_clock_snapshot is not None:
 311                 raise ValueError(
 312                     "packet end messages in this stream must not have a default clock snapshot"
 313                 )
 314
 315             ptr = native_bt.message_packet_end_create(self._bt_ptr, packet._ptr)
 316
 317         if ptr is None:
 318             raise bt2._MemoryError('cannot create packet end message object')
 319
 320         return bt2_message._PacketEndMessage(ptr)
 321
 322     def _create_discarded_events_message(
 323         self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
 324     ):
 325         utils._check_type(stream, bt2_stream._Stream)
 326
 327         if not stream.cls.supports_discarded_events:
 328             raise ValueError('stream class does not support discarded events')
 329
 330         if stream.cls.discarded_events_have_default_clock_snapshots:
 331             if beg_clock_snapshot is None or end_clock_snapshot is None:
 332                 raise ValueError(
 333                     'discarded events have default clock snapshots for this stream class'
 334                 )
 335
 336             utils._check_uint64(beg_clock_snapshot)
 337             utils._check_uint64(end_clock_snapshot)
 338             ptr = native_bt.message_discarded_events_create_with_default_clock_snapshots(
 339                 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
 340             )
 341         else:
 342             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 343                 raise ValueError(
 344                     'discarded events have no default clock snapshots for this stream class'
 345                 )
 346
 347             ptr = native_bt.message_discarded_events_create(self._bt_ptr, stream._ptr)
 348
 349         if ptr is None:
 350             raise bt2._MemoryError('cannot discarded events message object')
 351
 352         msg = bt2_message._DiscardedEventsMessage(ptr)
 353
 354         if count is not None:
 355             msg._count = count
 356
 357         return msg
 358
 359     def _create_discarded_packets_message(
 360         self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None
 361     ):
 362         utils._check_type(stream, bt2_stream._Stream)
 363
 364         if not stream.cls.supports_discarded_packets:
 365             raise ValueError('stream class does not support discarded packets')
 366
 367         if stream.cls.discarded_packets_have_default_clock_snapshots:
 368             if beg_clock_snapshot is None or end_clock_snapshot is None:
 369                 raise ValueError(
 370                     'discarded packets have default clock snapshots for this stream class'
 371                 )
 372
 373             utils._check_uint64(beg_clock_snapshot)
 374             utils._check_uint64(end_clock_snapshot)
 375             ptr = native_bt.message_discarded_packets_create_with_default_clock_snapshots(
 376                 self._bt_ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot
 377             )
 378         else:
 379             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 380                 raise ValueError(
 381                     'discarded packets have no default clock snapshots for this stream class'
 382                 )
 383
 384             ptr = native_bt.message_discarded_packets_create(self._bt_ptr, stream._ptr)
 385
 386         if ptr is None:
 387             raise bt2._MemoryError('cannot discarded packets message object')
 388
 389         msg = bt2_message._DiscardedPacketsMessage(ptr)
 390
 391         if count is not None:
 392             msg._count = count
 393
 394         return msg