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 import bt2.message
  25 import collections.abc
  26 import bt2.component
  27 import bt2
  28
  29
  30 class _MessageIterator(collections.abc.Iterator):
  31     def _handle_status(self, status, gen_error_msg):
  32         if status == native_bt.MESSAGE_ITERATOR_STATUS_AGAIN:
  33             raise bt2.TryAgain
  34         elif status == native_bt.MESSAGE_ITERATOR_STATUS_END:
  35             raise bt2.Stop
  36         elif status < 0:
  37             raise bt2.Error(gen_error_msg)
  38
  39     def __next__(self):
  40         raise NotImplementedError
  41
  42
  43 class _GenericMessageIterator(object._SharedObject, _MessageIterator):
  44     def __init__(self, ptr):
  45             self._current_msgs = []
  46             self._at = 0
  47             super().__init__(ptr)
  48
  49     def __next__(self):
  50         if len(self._current_msgs) == self._at:
  51             status, msgs = self._get_msg_range(self._ptr)
  52             self._handle_status(status,
  53                                 'unexpected error: cannot advance the message iterator')
  54             self._current_msgs = msgs
  55             self._at = 0
  56
  57         msg_ptr = self._current_msgs[self._at]
  58         self._at += 1
  59
  60         return bt2.message._create_from_ptr(msg_ptr)
  61
  62
  63 # This is created when a component wants to iterate on one of its input ports.
  64 class _UserComponentInputPortMessageIterator(_GenericMessageIterator):
  65     _get_msg_range = staticmethod(native_bt.py3_self_component_port_input_get_msg_range)
  66     _get_ref = staticmethod(native_bt.self_component_port_input_message_iterator_get_ref)
  67     _put_ref = staticmethod(native_bt.self_component_port_input_message_iterator_put_ref)
  68
  69
  70 # This is created when the user wants to iterate on a component's output port,
  71 # from outside the graph.
  72 class _OutputPortMessageIterator(_GenericMessageIterator):
  73     _get_msg_range = staticmethod(native_bt.py3_port_output_get_msg_range)
  74     _get_ref = staticmethod(native_bt.port_output_message_iterator_get_ref)
  75     _put_ref = staticmethod(native_bt.port_output_message_iterator_put_ref)
  76
  77
  78 # This is extended by the user to implement component classes in Python.  It
  79 # is created for a given output port when an input port message iterator is
  80 # created on the input port on the other side of the connection.  It is also
  81 # created when an output port message iterator is created on this output port.
  82 #
  83 # Its purpose is to feed the messages that should go out through this output
  84 # port.
  85 class _UserMessageIterator(_MessageIterator):
  86     def __new__(cls, ptr):
  87         # User iterator objects are always created by the native side,
  88         # that is, never instantiated directly by Python code.
  89         #
  90         # The native code calls this, then manually calls
  91         # self.__init__() without the `ptr` argument. The user has
  92         # access to self.component during this call, thanks to this
  93         # self._ptr argument being set.
  94         #
  95         # self._ptr is NOT owned by this object here, so there's nothing
  96         # to do in __del__().
  97         self = super().__new__(cls)
  98         self._ptr = ptr
  99         return self
 100
 101     def _init_from_native(self, self_output_port_ptr):
 102         self_output_port = bt2.port._create_self_from_ptr_and_get_ref(
 103             self_output_port_ptr, native_bt.PORT_TYPE_OUTPUT)
 104         self.__init__(self_output_port)
 105
 106     def __init__(self, output_port):
 107         pass
 108
 109     @property
 110     def _component(self):
 111         return native_bt.py3_get_user_component_from_user_msg_iter(self._ptr)
 112
 113     @property
 114     def addr(self):
 115         return int(self._ptr)
 116
 117     def _finalize(self):
 118         pass
 119
 120     def __next__(self):
 121         raise bt2.Stop
 122
 123     def _next_from_native(self):
 124         # this can raise anything: it's catched by the native part
 125         try:
 126             msg = next(self)
 127         except StopIteration:
 128             raise bt2.Stop
 129         except:
 130             raise
 131
 132         utils._check_type(msg, bt2.message._Message)
 133
 134         # Release the reference to the native part.
 135         ptr = msg._release()
 136         return int(ptr)
 137
 138     # Validate that the presence or lack of presence of a
 139     # `default_clock_snapshot` value is valid in the context of `stream_class`.
 140     @staticmethod
 141     def _validate_default_clock_snapshot(stream_class, default_clock_snapshot):
 142         stream_class_has_default_clock_class = stream_class.default_clock_class is not None
 143
 144         if stream_class_has_default_clock_class and default_clock_snapshot is None:
 145             raise bt2.Error(
 146                 'stream class has a default clock class, default_clock_snapshot should not be None')
 147
 148         if not stream_class_has_default_clock_class and default_clock_snapshot is not None:
 149             raise bt2.Error(
 150                 'stream class has no default clock class, default_clock_snapshot should be None')
 151
 152     def _create_event_message(self, event_class, packet, default_clock_snapshot=None):
 153         utils._check_type(event_class, bt2.event_class._EventClass)
 154         utils._check_type(packet, bt2.packet._Packet)
 155         self._validate_default_clock_snapshot(packet.stream.cls, default_clock_snapshot)
 156
 157         if default_clock_snapshot is not None:
 158             utils._check_uint64(default_clock_snapshot)
 159             ptr = native_bt.message_event_create_with_default_clock_snapshot(
 160                 self._ptr, event_class._ptr, packet._ptr, default_clock_snapshot)
 161         else:
 162             ptr = native_bt.message_event_create(
 163                 self._ptr, event_class._ptr, packet._ptr)
 164
 165         if ptr is None:
 166             raise bt2.CreationError('cannot create event message object')
 167
 168         return bt2.message._EventMessage(ptr)
 169
 170     def _create_message_iterator_inactivity_message(self, clock_class, clock_snapshot):
 171         utils._check_type(clock_class, bt2.clock_class._ClockClass)
 172         ptr = native_bt.message_message_iterator_inactivity_create(
 173             self._ptr, clock_class._ptr, clock_snapshot)
 174
 175         if ptr is None:
 176             raise bt2.CreationError('cannot create inactivity message object')
 177
 178         return bt2.message._MessageIteratorInactivityMessage(ptr)
 179
 180     def _create_stream_beginning_message(self, stream):
 181         utils._check_type(stream, bt2.stream._Stream)
 182
 183         ptr = native_bt.message_stream_beginning_create(self._ptr, stream._ptr)
 184         if ptr is None:
 185             raise bt2.CreationError('cannot create stream beginning message object')
 186
 187         return bt2.message._StreamBeginningMessage(ptr)
 188
 189     def _create_stream_activity_beginning_message(self, stream, default_clock_snapshot=None):
 190         utils._check_type(stream, bt2.stream._Stream)
 191         self._validate_default_clock_snapshot(stream.cls, default_clock_snapshot)
 192
 193         ptr = native_bt.message_stream_activity_beginning_create(self._ptr, stream._ptr)
 194
 195         if ptr is None:
 196             raise bt2.CreationError(
 197                 'cannot create stream activity beginning message object')
 198
 199         msg = bt2.message._StreamActivityBeginningMessage(ptr)
 200
 201         if default_clock_snapshot is not None:
 202             msg._default_clock_snapshot = default_clock_snapshot
 203
 204         return msg
 205
 206     def _create_stream_activity_end_message(self, stream, default_clock_snapshot=None):
 207         utils._check_type(stream, bt2.stream._Stream)
 208         self._validate_default_clock_snapshot(stream.cls, default_clock_snapshot)
 209
 210         ptr = native_bt.message_stream_activity_end_create(self._ptr, stream._ptr)
 211
 212         if ptr is None:
 213             raise bt2.CreationError(
 214                 'cannot create stream activity end message object')
 215
 216         msg = bt2.message._StreamActivityEndMessage(ptr)
 217
 218         if default_clock_snapshot is not None:
 219             msg._default_clock_snapshot = default_clock_snapshot
 220
 221         return msg
 222
 223     def _create_stream_end_message(self, stream):
 224         utils._check_type(stream, bt2.stream._Stream)
 225
 226         ptr = native_bt.message_stream_end_create(self._ptr, stream._ptr)
 227         if ptr is None:
 228             raise bt2.CreationError('cannot create stream end message object')
 229
 230         return bt2.message._StreamEndMessage(ptr)
 231
 232     def _create_packet_beginning_message(self, packet, default_clock_snapshot=None):
 233         utils._check_type(packet, bt2.packet._Packet)
 234
 235         if packet.stream.cls.packets_have_beginning_default_clock_snapshot:
 236             if default_clock_snapshot is None:
 237                 raise ValueError("packet beginning messages in this stream must have a default clock snapshots")
 238
 239             utils._check_uint64(default_clock_snapshot)
 240             ptr = native_bt.message_packet_beginning_create_with_default_clock_snapshot(
 241                 self._ptr, packet._ptr, default_clock_snapshot)
 242         else:
 243             if default_clock_snapshot is not None:
 244                 raise ValueError("packet beginning messages in this stream must not have a default clock snapshots")
 245
 246             ptr = native_bt.message_packet_beginning_create(self._ptr, packet._ptr)
 247
 248         if ptr is None:
 249             raise bt2.CreationError('cannot create packet beginning message object')
 250
 251         return bt2.message._PacketBeginningMessage(ptr)
 252
 253     def _create_packet_end_message(self, packet, default_clock_snapshot=None):
 254         utils._check_type(packet, bt2.packet._Packet)
 255
 256         if packet.stream.cls.packets_have_end_default_clock_snapshot:
 257             if default_clock_snapshot is None:
 258                 raise ValueError("packet end messages in this stream must have a default clock snapshots")
 259
 260             utils._check_uint64(default_clock_snapshot)
 261             ptr = native_bt.message_packet_end_create_with_default_clock_snapshot(
 262                 self._ptr, packet._ptr, default_clock_snapshot)
 263         else:
 264             if default_clock_snapshot is not None:
 265                 raise ValueError("packet end messages in this stream must not have a default clock snapshots")
 266
 267             ptr = native_bt.message_packet_end_create(self._ptr, packet._ptr)
 268
 269         if ptr is None:
 270             raise bt2.CreationError('cannot create packet end message object')
 271
 272         return bt2.message._PacketEndMessage(ptr)
 273
 274     def _create_discarded_events_message(self, stream, count=None,
 275                                          beg_clock_snapshot=None,
 276                                          end_clock_snapshot=None):
 277         utils._check_type(stream, bt2.stream._Stream)
 278
 279         if not stream.cls.supports_discarded_events:
 280             raise ValueError('stream class does not support discarded events')
 281
 282         if stream.cls.discarded_events_have_default_clock_snapshots:
 283             if beg_clock_snapshot is None or end_clock_snapshot is None:
 284                 raise ValueError('discarded events have default clock snapshots for this stream class')
 285
 286             utils._check_uint64(beg_clock_snapshot)
 287             utils._check_uint64(end_clock_snapshot)
 288             ptr = native_bt.message_discarded_events_create_with_default_clock_snapshots(
 289                 self._ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot)
 290         else:
 291             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 292                 raise ValueError('discarded events have no default clock snapshots for this stream class')
 293
 294             ptr = native_bt.message_discarded_events_create(
 295                 self._ptr, stream._ptr)
 296
 297         if ptr is None:
 298             raise bt2.CreationError('cannot discarded events message object')
 299
 300         msg = bt2.message._DiscardedEventsMessage(ptr)
 301
 302         if count is not None:
 303             msg._count = count
 304
 305         return msg
 306
 307     def _create_discarded_packets_message(self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None):
 308         utils._check_type(stream, bt2.stream._Stream)
 309
 310         if not stream.cls.supports_discarded_packets:
 311             raise ValueError('stream class does not support discarded packets')
 312
 313         if stream.cls.discarded_packets_have_default_clock_snapshots:
 314             if beg_clock_snapshot is None or end_clock_snapshot is None:
 315                 raise ValueError('discarded packets have default clock snapshots for this stream class')
 316
 317             utils._check_uint64(beg_clock_snapshot)
 318             utils._check_uint64(end_clock_snapshot)
 319             ptr = native_bt.message_discarded_packets_create_with_default_clock_snapshots(
 320                 self._ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot)
 321         else:
 322             if beg_clock_snapshot is not None or end_clock_snapshot is not None:
 323                 raise ValueError('discarded packets have no default clock snapshots for this stream class')
 324
 325             ptr = native_bt.message_discarded_packets_create(
 326                 self._ptr, stream._ptr)
 327
 328         if ptr is None:
 329             raise bt2.CreationError('cannot discarded packets message object')
 330
 331         msg = bt2.message._DiscardedPacketsMessage(ptr)
 332
 333         if count is not None:
 334             msg._count = count
 335
 336         return msg
 337