bindings/python/bt2/bt2/component.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_iterator
  25 import collections.abc
  26 import bt2.value
  27 import traceback
  28 import bt2.port
  29 import sys
  30 import bt2
  31 import os
  32
  33
  34 _env_var = os.environ.get('BABELTRACE_PYTHON_BT2_NO_TRACEBACK')
  35 _NO_PRINT_TRACEBACK = _env_var == '1'
  36
  37
  38 # This class wraps a component class pointer. This component class could
  39 # have been created by Python code, but since we only have the pointer,
  40 # we can only wrap it in a generic way and lose the original Python
  41 # class.
  42 #
  43 # Subclasses must implement some methods that this base class uses:
  44 #
  45 #   - _as_component_class_ptr: static method, convert the passed component class
  46 #     pointer to a 'bt_component_class *'.
  47
  48 class _GenericComponentClass(object._SharedObject):
  49     @property
  50     def name(self):
  51         ptr = self._as_component_class_ptr(self._ptr)
  52         name = native_bt.component_class_get_name(ptr)
  53         assert name is not None
  54         return name
  55
  56     @property
  57     def description(self):
  58         ptr = self._as_component_class_ptr(self._ptr)
  59         return native_bt.component_class_get_description(ptr)
  60
  61     @property
  62     def help(self):
  63         ptr = self._as_component_class_ptr(self._ptr)
  64         return native_bt.component_class_get_help(ptr)
  65
  66     def _component_class_ptr(self):
  67         return self._as_component_class_ptr(self._ptr)
  68
  69     def __eq__(self, other):
  70         if not isinstance(other, _GenericComponentClass):
  71             try:
  72                 if not issubclass(other, _UserComponent):
  73                     return False
  74             except TypeError:
  75                 return False
  76
  77         return self.addr == other.addr
  78
  79
  80 class _GenericSourceComponentClass(_GenericComponentClass):
  81     _get_ref = staticmethod(native_bt.component_class_source_get_ref)
  82     _put_ref = staticmethod(native_bt.component_class_source_put_ref)
  83     _as_component_class_ptr = staticmethod(native_bt.component_class_source_as_component_class)
  84
  85
  86 class _GenericFilterComponentClass(_GenericComponentClass):
  87     _get_ref = staticmethod(native_bt.component_class_filter_get_ref)
  88     _put_ref = staticmethod(native_bt.component_class_filter_put_ref)
  89     _as_component_class_ptr = staticmethod(native_bt.component_class_filter_as_component_class)
  90
  91
  92 class _GenericSinkComponentClass(_GenericComponentClass):
  93     _get_ref = staticmethod(native_bt.component_class_sink_get_ref)
  94     _put_ref = staticmethod(native_bt.component_class_sink_put_ref)
  95     _as_component_class_ptr = staticmethod(native_bt.component_class_sink_as_component_class)
  96
  97
  98 def _handle_component_status(status, gen_error_msg):
  99     if status == native_bt.SELF_COMPONENT_STATUS_END:
 100         raise bt2.Stop
 101     elif status == native_bt.SELF_COMPONENT_STATUS_AGAIN:
 102         raise bt2.TryAgain
 103     elif status == native_bt.SELF_COMPONENT_STATUS_REFUSE_PORT_CONNECTION:
 104         raise bt2.PortConnectionRefused
 105     elif status < 0:
 106         raise bt2.Error(gen_error_msg)
 107
 108
 109 class _PortIterator(collections.abc.Iterator):
 110     def __init__(self, comp_ports):
 111         self._comp_ports = comp_ports
 112         self._at = 0
 113
 114     def __next__(self):
 115         if self._at == len(self._comp_ports):
 116             raise StopIteration
 117
 118         comp_ports = self._comp_ports
 119         comp_ptr = comp_ports._component_ptr
 120
 121         port_ptr = comp_ports._borrow_port_ptr_at_index(comp_ptr, self._at)
 122         assert port_ptr is not None
 123
 124         name = native_bt.port_get_name(comp_ports._port_pycls._as_port_ptr(port_ptr))
 125         assert name is not None
 126
 127         self._at += 1
 128         return name
 129
 130
 131 class _ComponentPorts(collections.abc.Mapping):
 132
 133     # component_ptr is a bt_component_source *, bt_component_filter * or
 134     # bt_component_sink *.  Its type must match the type expected by the
 135     # functions passed as arguments.
 136
 137     def __init__(self, component_ptr,
 138                  borrow_port_ptr_by_name,
 139                  borrow_port_ptr_at_index,
 140                  get_port_count,
 141                  port_pycls):
 142         self._component_ptr = component_ptr
 143         self._borrow_port_ptr_by_name = borrow_port_ptr_by_name
 144         self._borrow_port_ptr_at_index = borrow_port_ptr_at_index
 145         self._get_port_count = get_port_count
 146         self._port_pycls = port_pycls
 147
 148     def __getitem__(self, key):
 149         utils._check_str(key)
 150         port_ptr = self._borrow_port_ptr_by_name(self._component_ptr, key)
 151
 152         if port_ptr is None:
 153             raise KeyError(key)
 154
 155         return self._port_pycls._create_from_ptr_and_get_ref(port_ptr)
 156
 157     def __len__(self):
 158         count = self._get_port_count(self._component_ptr)
 159         assert count >= 0
 160         return count
 161
 162     def __iter__(self):
 163         return _PortIterator(self)
 164
 165
 166 # This class holds the methods which are common to both generic
 167 # component objects and Python user component objects.
 168 #
 169 # Subclasses must provide these methods or property:
 170 #
 171 #   - _borrow_component_class_ptr: static method, must return a pointer to the
 172 #     specialized component class (e.g. 'bt_component_class_sink *') of the
 173 #     passed specialized component pointer (e.g. 'bt_component_sink *').
 174 #   - _comp_cls_type: property, one of the native_bt.COMPONENT_CLASS_TYPE_*
 175 #     constants.
 176 #   - _as_component_ptr: static method, must return the passed specialized
 177 #     component pointer (e.g. 'bt_component_sink *') as a 'bt_component *'.
 178
 179 class _Component:
 180     @property
 181     def name(self):
 182         ptr = self._as_component_ptr(self._ptr)
 183         name = native_bt.component_get_name(ptr)
 184         assert name is not None
 185         return name
 186
 187     @property
 188     def cls(self):
 189         cc_ptr = self._borrow_component_class_ptr(self._ptr)
 190         assert cc_ptr is not None
 191         return _create_component_class_from_ptr_and_get_ref(cc_ptr, self._comp_cls_type)
 192
 193     def __eq__(self, other):
 194         if not hasattr(other, 'addr'):
 195             return False
 196
 197         return self.addr == other.addr
 198
 199
 200 class _SourceComponent(_Component):
 201     _borrow_component_class_ptr = staticmethod(native_bt.component_source_borrow_class_const)
 202     _comp_cls_type = native_bt.COMPONENT_CLASS_TYPE_SOURCE
 203     _as_component_class_ptr = staticmethod(native_bt.component_class_source_as_component_class)
 204     _as_component_ptr = staticmethod(native_bt.component_source_as_component_const)
 205
 206
 207 class _FilterComponent(_Component):
 208     _borrow_component_class_ptr = staticmethod(native_bt.component_filter_borrow_class_const)
 209     _comp_cls_type = native_bt.COMPONENT_CLASS_TYPE_FILTER
 210     _as_component_class_ptr = staticmethod(native_bt.component_class_filter_as_component_class)
 211     _as_component_ptr = staticmethod(native_bt.component_filter_as_component_const)
 212
 213
 214 class _SinkComponent(_Component):
 215     _borrow_component_class_ptr = staticmethod(native_bt.component_sink_borrow_class_const)
 216     _comp_cls_type = native_bt.COMPONENT_CLASS_TYPE_SINK
 217     _as_component_class_ptr = staticmethod(native_bt.component_class_sink_as_component_class)
 218     _as_component_ptr = staticmethod(native_bt.component_sink_as_component_const)
 219
 220
 221 # This is analogous to _GenericSourceComponentClass, but for source
 222 # component objects.
 223 class _GenericSourceComponent(object._SharedObject, _SourceComponent):
 224     _get_ref = staticmethod(native_bt.component_source_get_ref)
 225     _put_ref = staticmethod(native_bt.component_source_put_ref)
 226
 227     @property
 228     def output_ports(self):
 229         return _ComponentPorts(self._ptr,
 230                                native_bt.component_source_borrow_output_port_by_name_const,
 231                                native_bt.component_source_borrow_output_port_by_index_const,
 232                                native_bt.component_source_get_output_port_count,
 233                                bt2.port._OutputPort)
 234
 235
 236 # This is analogous to _GenericFilterComponentClass, but for filter
 237 # component objects.
 238 class _GenericFilterComponent(object._SharedObject, _FilterComponent):
 239     _get_ref = staticmethod(native_bt.component_filter_get_ref)
 240     _put_ref = staticmethod(native_bt.component_filter_put_ref)
 241
 242     @property
 243     def output_ports(self):
 244         return _ComponentPorts(self._ptr,
 245                                native_bt.component_filter_borrow_output_port_by_name_const,
 246                                native_bt.component_filter_borrow_output_port_by_index_const,
 247                                native_bt.component_filter_get_output_port_count,
 248                                bt2.port._OutputPort)
 249
 250     @property
 251     def input_ports(self):
 252         return _ComponentPorts(self._ptr,
 253                                native_bt.component_filter_borrow_input_port_by_name_const,
 254                                native_bt.component_filter_borrow_input_port_by_index_const,
 255                                native_bt.component_filter_get_input_port_count,
 256                                bt2.port._InputPort)
 257
 258
 259 # This is analogous to _GenericSinkComponentClass, but for sink
 260 # component objects.
 261 class _GenericSinkComponent(object._SharedObject, _SinkComponent):
 262     _get_ref = staticmethod(native_bt.component_sink_get_ref)
 263     _put_ref = staticmethod(native_bt.component_sink_put_ref)
 264
 265     @property
 266     def input_ports(self):
 267         return _ComponentPorts(self._ptr,
 268                                native_bt.component_sink_borrow_input_port_by_name_const,
 269                                native_bt.component_sink_borrow_input_port_by_index_const,
 270                                native_bt.component_sink_get_input_port_count,
 271                                bt2.port._InputPort)
 272
 273
 274 _COMP_CLS_TYPE_TO_GENERIC_COMP_PYCLS = {
 275     native_bt.COMPONENT_CLASS_TYPE_SOURCE: _GenericSourceComponent,
 276     native_bt.COMPONENT_CLASS_TYPE_FILTER: _GenericFilterComponent,
 277     native_bt.COMPONENT_CLASS_TYPE_SINK: _GenericSinkComponent,
 278 }
 279
 280
 281 _COMP_CLS_TYPE_TO_GENERIC_COMP_CLS_PYCLS = {
 282     native_bt.COMPONENT_CLASS_TYPE_SOURCE: _GenericSourceComponentClass,
 283     native_bt.COMPONENT_CLASS_TYPE_FILTER: _GenericFilterComponentClass,
 284     native_bt.COMPONENT_CLASS_TYPE_SINK: _GenericSinkComponentClass,
 285 }
 286
 287
 288 # Create a component Python object of type _GenericSourceComponent,
 289 # _GenericFilterComponent or _GenericSinkComponent, depending on
 290 # comp_cls_type.
 291 #
 292 #    Steals the reference to ptr from the caller.
 293
 294 def _create_component_from_ptr(ptr, comp_cls_type):
 295     return _COMP_CLS_TYPE_TO_GENERIC_COMP_PYCLS[comp_cls_type]._create_from_ptr(ptr)
 296
 297
 298 # Same as the above, but acquire a new reference instead of stealing the
 299 # reference from the caller.
 300
 301 def _create_component_from_ptr_and_get_ref(ptr, comp_cls_type):
 302     return _COMP_CLS_TYPE_TO_GENERIC_COMP_PYCLS[comp_cls_type]._create_from_ptr_and_get_ref(ptr)
 303
 304
 305 # Create a component class Python object of type
 306 # _GenericSourceComponentClass, _GenericFilterComponentClass or
 307 # _GenericSinkComponentClass, depending on comp_cls_type.
 308 #
 309 # Acquires a new reference to ptr.
 310
 311 def _create_component_class_from_ptr_and_get_ref(ptr, comp_cls_type):
 312     return _COMP_CLS_TYPE_TO_GENERIC_COMP_CLS_PYCLS[comp_cls_type]._create_from_ptr_and_get_ref(ptr)
 313
 314
 315 def _trim_docstring(docstring):
 316     lines = docstring.expandtabs().splitlines()
 317     indent = sys.maxsize
 318
 319     for line in lines[1:]:
 320         stripped = line.lstrip()
 321
 322         if stripped:
 323             indent = min(indent, len(line) - len(stripped))
 324
 325     trimmed = [lines[0].strip()]
 326
 327     if indent < sys.maxsize:
 328         for line in lines[1:]:
 329             trimmed.append(line[indent:].rstrip())
 330
 331     while trimmed and not trimmed[-1]:
 332         trimmed.pop()
 333
 334     while trimmed and not trimmed[0]:
 335         trimmed.pop(0)
 336
 337     return '\n'.join(trimmed)
 338
 339
 340 # Metaclass for component classes defined by Python code.
 341 #
 342 # The Python user can create a standard Python class which inherits one
 343 # of the three base classes (_UserSourceComponent, _UserFilterComponent,
 344 # or _UserSinkComponent). Those base classes set this class
 345 # (_UserComponentType) as their metaclass.
 346 #
 347 # Once the body of a user-defined component class is executed, this
 348 # metaclass is used to create and initialize the class. The metaclass
 349 # creates a native BT component class of the corresponding type and
 350 # associates it with this user-defined class. The metaclass also defines
 351 # class methods like the `name` and `description` properties to match
 352 # the _GenericComponentClass interface.
 353 #
 354 # The component class name which is used is either:
 355 #
 356 # * The `name` parameter of the class:
 357 #
 358 #       class MySink(bt2.SinkComponent, name='my-custom-sink'):
 359 #           ...
 360 #
 361 # * If the `name` class parameter is not used: the name of the class
 362 #   itself (`MySink` in the example above).
 363 #
 364 # The component class description which is used is the user-defined
 365 # class's docstring:
 366 #
 367 #     class MySink(bt2.SinkComponent):
 368 #         'Description goes here'
 369 #         ...
 370 #
 371 # A user-defined Python component class can have an __init__() method
 372 # which must at least accept the `params` and `name` arguments:
 373 #
 374 #     def __init__(self, params, name, something_else):
 375 #         ...
 376 #
 377 # The user-defined component class can also have a _finalize() method
 378 # (do NOT use __del__()) to be notified when the component object is
 379 # finalized.
 380 #
 381 # User-defined source and filter component classes must use the
 382 # `message_iterator_class` class parameter to specify the
 383 # message iterator class to use for this component class:
 384 #
 385 #     class MyMessageIterator(bt2._UserMessageIterator):
 386 #         ...
 387 #
 388 #     class MySource(bt2._UserSourceComponent,
 389 #                    message_iterator_class=MyMessageIterator):
 390 #         ...
 391 #
 392 # This message iterator class must inherit
 393 # bt2._UserMessageIterator, and it must define the _get() and
 394 # _next() methods. The message iterator class can also define an
 395 # __init__() method: this method has access to the original Python
 396 # component object which was used to create it as the `component`
 397 # property. The message iterator class can also define a
 398 # _finalize() method (again, do NOT use __del__()): this is called when
 399 # the message iterator is (really) destroyed.
 400 #
 401 # When the user-defined class is destroyed, this metaclass's __del__()
 402 # method is called: the native BT component class pointer is put (not
 403 # needed anymore, at least not by any Python code since all references
 404 # are dropped for __del__() to be called).
 405 class _UserComponentType(type):
 406     # __new__() is used to catch custom class parameters
 407     def __new__(meta_cls, class_name, bases, attrs, **kwargs):
 408         return super().__new__(meta_cls, class_name, bases, attrs)
 409
 410     def __init__(cls, class_name, bases, namespace, **kwargs):
 411         super().__init__(class_name, bases, namespace)
 412
 413         # skip our own bases; they are never directly instantiated by the user
 414         own_bases = (
 415             '_UserComponent',
 416             '_UserFilterSinkComponent',
 417             '_UserSourceComponent',
 418             '_UserFilterComponent',
 419             '_UserSinkComponent',
 420         )
 421
 422         if class_name in own_bases:
 423             return
 424
 425         comp_cls_name = kwargs.get('name', class_name)
 426         utils._check_str(comp_cls_name)
 427         comp_cls_descr = None
 428         comp_cls_help = None
 429
 430         if hasattr(cls, '__doc__') and cls.__doc__ is not None:
 431             utils._check_str(cls.__doc__)
 432             docstring = _trim_docstring(cls.__doc__)
 433             lines = docstring.splitlines()
 434
 435             if len(lines) >= 1:
 436                 comp_cls_descr = lines[0]
 437
 438             if len(lines) >= 3:
 439                 comp_cls_help = '\n'.join(lines[2:])
 440
 441         iter_cls = kwargs.get('message_iterator_class')
 442
 443         if _UserSourceComponent in bases:
 444             _UserComponentType._set_iterator_class(cls, iter_cls)
 445             cc_ptr = native_bt.py3_component_class_source_create(cls,
 446                                                                  comp_cls_name,
 447                                                                  comp_cls_descr,
 448                                                                  comp_cls_help)
 449         elif _UserFilterComponent in bases:
 450             _UserComponentType._set_iterator_class(cls, iter_cls)
 451             cc_ptr = native_bt.py3_component_class_filter_create(cls,
 452                                                                  comp_cls_name,
 453                                                                  comp_cls_descr,
 454                                                                  comp_cls_help)
 455         elif _UserSinkComponent in bases:
 456             if not hasattr(cls, '_consume'):
 457                 raise bt2.IncompleteUserClass("cannot create component class '{}': missing a _consume() method".format(class_name))
 458
 459             cc_ptr = native_bt.py3_component_class_sink_create(cls,
 460                                                                comp_cls_name,
 461                                                                comp_cls_descr,
 462                                                                comp_cls_help)
 463         else:
 464             raise bt2.IncompleteUserClass("cannot find a known component class base in the bases of '{}'".format(class_name))
 465
 466         if cc_ptr is None:
 467             raise bt2.CreationError("cannot create component class '{}'".format(class_name))
 468
 469         cls._cc_ptr = cc_ptr
 470
 471     def _init_from_native(cls, comp_ptr, params_ptr):
 472         # create instance, not user-initialized yet
 473         self = cls.__new__(cls)
 474
 475         # pointer to native self component object (weak/borrowed)
 476         self._ptr = comp_ptr
 477
 478         # call user's __init__() method
 479         if params_ptr is not None:
 480             params = bt2.value._create_from_ptr_and_get_ref(params_ptr)
 481         else:
 482             params = None
 483
 484         self.__init__(params)
 485         return self
 486
 487     def __call__(cls, *args, **kwargs):
 488         raise bt2.Error('cannot directly instantiate a user component from a Python module')
 489
 490     @staticmethod
 491     def _set_iterator_class(cls, iter_cls):
 492         if iter_cls is None:
 493             raise bt2.IncompleteUserClass("cannot create component class '{}': missing message iterator class".format(cls.__name__))
 494
 495         if not issubclass(iter_cls, bt2.message_iterator._UserMessageIterator):
 496             raise bt2.IncompleteUserClass("cannot create component class '{}': message iterator class does not inherit bt2._UserMessageIterator".format(cls.__name__))
 497
 498         if not hasattr(iter_cls, '__next__'):
 499             raise bt2.IncompleteUserClass("cannot create component class '{}': message iterator class is missing a __next__() method".format(cls.__name__))
 500
 501         cls._iter_cls = iter_cls
 502
 503     @property
 504     def name(cls):
 505         ptr = cls._as_component_class_ptr(cls._cc_ptr)
 506         return native_bt.component_class_get_name(ptr)
 507
 508     @property
 509     def description(cls):
 510         ptr = cls._as_component_class_ptr(cls._cc_ptr)
 511         return native_bt.component_class_get_description(ptr)
 512
 513     @property
 514     def help(cls):
 515         ptr = cls._as_component_class_ptr(cls._cc_ptr)
 516         return native_bt.component_class_get_help(ptr)
 517
 518     @property
 519     def addr(cls):
 520         return int(cls._cc_ptr)
 521
 522     def _query_from_native(cls, query_exec_ptr, obj, params_ptr):
 523         # this can raise, in which case the native call to
 524         # bt_component_class_query() returns NULL
 525         if params_ptr is not None:
 526             params = bt2.value._create_from_ptr_and_get_ref(params_ptr)
 527         else:
 528             params = None
 529
 530         query_exec = bt2.QueryExecutor._create_from_ptr_and_get_ref(
 531             query_exec_ptr)
 532
 533         # this can raise, but the native side checks the exception
 534         results = cls._query(query_exec, obj, params)
 535
 536         # this can raise, but the native side checks the exception
 537         results = bt2.create_value(results)
 538
 539         if results is None:
 540             results_addr = int(native_bt.value_null)
 541         else:
 542             # return new reference
 543             results_addr = int(results._release())
 544
 545         return results_addr
 546
 547     def _query(cls, query_executor, obj, params):
 548         raise NotImplementedError
 549
 550     def _component_class_ptr(self):
 551         return self._as_component_class_ptr(self._cc_ptr)
 552
 553     def __del__(cls):
 554         if hasattr(cls, '_cc_ptr'):
 555             cc_ptr = cls._as_component_class_ptr(cls._cc_ptr)
 556             native_bt.component_class_put_ref(cc_ptr)
 557
 558 # Subclasses must provide these methods or property:
 559 #
 560 #   - _as_not_self_specific_component_ptr: static method, must return the passed
 561 #     specialized self component pointer (e.g. 'bt_self_component_sink *') as a
 562 #     specialized non-self pointer (e.g. 'bt_component_sink *').
 563 #   - _borrow_component_class_ptr: static method, must return a pointer to the
 564 #     specialized component class (e.g. 'bt_component_class_sink *') of the
 565 #     passed specialized component pointer (e.g. 'bt_component_sink *').
 566 #   - _comp_cls_type: property, one of the native_bt.COMPONENT_CLASS_TYPE_*
 567 #     constants.
 568
 569 class _UserComponent(metaclass=_UserComponentType):
 570     @property
 571     def name(self):
 572         ptr = self._as_not_self_specific_component_ptr(self._ptr)
 573         ptr = self._as_component_ptr(ptr)
 574         name = native_bt.component_get_name(ptr)
 575         assert name is not None
 576         return name
 577
 578     @property
 579     def cls(self):
 580         comp_ptr = self._as_not_self_specific_component_ptr(self._ptr)
 581         cc_ptr = self._borrow_component_class_ptr(comp_ptr)
 582         return _create_component_class_from_ptr_and_get_ref(cc_ptr, self._comp_cls_type)
 583
 584     @property
 585     def addr(self):
 586         return int(self._ptr)
 587
 588     def __init__(self, params=None):
 589         pass
 590
 591     def _finalize(self):
 592         pass
 593
 594     def _accept_port_connection(self, port, other_port):
 595         return True
 596
 597     def _accept_port_connection_from_native(self, self_port_ptr, self_port_type, other_port_ptr):
 598         port = bt2.port._create_self_from_ptr_and_get_ref(
 599             self_port_ptr, self_port_type)
 600
 601         if self_port_type == native_bt.PORT_TYPE_OUTPUT:
 602             other_port_type = native_bt.PORT_TYPE_INPUT
 603         else:
 604             other_port_type = native_bt.PORT_TYPE_OUTPUT
 605
 606         other_port = bt2.port._create_from_ptr_and_get_ref(
 607             other_port_ptr, other_port_type)
 608         res = self._accept_port_connection(port, other_port_ptr)
 609
 610         if type(res) is not bool:
 611             raise TypeError("'{}' is not a 'bool' object")
 612
 613         return res
 614
 615     def _port_connected(self, port, other_port):
 616         pass
 617
 618     def _port_connected_from_native(self, self_port_ptr, self_port_type, other_port_ptr):
 619         port = bt2.port._create_self_from_ptr_and_get_ref(
 620             self_port_ptr, self_port_type)
 621
 622         if self_port_type == native_bt.PORT_TYPE_OUTPUT:
 623             other_port_type = native_bt.PORT_TYPE_INPUT
 624         else:
 625             other_port_type = native_bt.PORT_TYPE_OUTPUT
 626
 627         other_port = bt2.port._create_from_ptr_and_get_ref(
 628             other_port_ptr, other_port_type)
 629         self._port_connected(port, other_port)
 630
 631     def _graph_is_configured_from_native(self):
 632         self._graph_is_configured()
 633
 634     def _create_trace_class(self, env=None, uuid=None,
 635                             assigns_automatic_stream_class_id=True):
 636         ptr = self._as_self_component_ptr(self._ptr)
 637         tc_ptr = native_bt.trace_class_create(ptr)
 638
 639         if tc_ptr is None:
 640             raise bt2.CreationError('could not create trace class')
 641
 642         tc = bt2._TraceClass._create_from_ptr(tc_ptr)
 643
 644         if env is not None:
 645             for key, value in env.items():
 646                 tc.env[key] = value
 647
 648         if uuid is not None:
 649             tc._uuid = uuid
 650
 651         tc._assigns_automatic_stream_class_id = assigns_automatic_stream_class_id
 652
 653         return tc
 654
 655     def _create_clock_class(self, frequency=None, name=None, description=None,
 656                             precision=None, offset=None, origin_is_unix_epoch=True,
 657                             uuid=None):
 658         ptr = self._as_self_component_ptr(self._ptr)
 659         cc_ptr = native_bt.clock_class_create(ptr)
 660
 661         if cc_ptr is None:
 662             raise bt2.CreationError('could not create clock class')
 663
 664         cc = bt2.clock_class._ClockClass._create_from_ptr(cc_ptr)
 665
 666         if frequency is not None:
 667             cc._frequency = frequency
 668
 669         if name is not None:
 670             cc._name = name
 671
 672         if description is not None:
 673             cc._description = description
 674
 675         if precision is not None:
 676             cc._precision = precision
 677
 678         if offset is not None:
 679             cc._offset = offset
 680
 681         cc._origin_is_unix_epoch = origin_is_unix_epoch
 682
 683         if uuid is not None:
 684             cc._uuid = uuid
 685
 686         return cc
 687
 688
 689 class _UserSourceComponent(_UserComponent, _SourceComponent):
 690     _as_not_self_specific_component_ptr = staticmethod(native_bt.self_component_source_as_component_source)
 691     _as_self_component_ptr = staticmethod(native_bt.self_component_source_as_self_component)
 692
 693     @property
 694     def _output_ports(self):
 695         def get_output_port_count(self_ptr):
 696             ptr = self._as_not_self_specific_component_ptr(self_ptr)
 697             return native_bt.component_source_get_output_port_count(ptr)
 698
 699         return _ComponentPorts(self._ptr,
 700                                native_bt.self_component_source_borrow_output_port_by_name,
 701                                native_bt.self_component_source_borrow_output_port_by_index,
 702                                get_output_port_count,
 703                                bt2.port._UserComponentOutputPort)
 704
 705     def _add_output_port(self, name, user_data=None):
 706         utils._check_str(name)
 707         fn = native_bt.self_component_source_add_output_port
 708         comp_status, self_port_ptr = fn(self._ptr, name, user_data)
 709         _handle_component_status(comp_status,
 710                                  'cannot add output port to source component object')
 711         assert self_port_ptr is not None
 712         return bt2.port._UserComponentOutputPort._create_from_ptr(self_port_ptr)
 713
 714
 715 class _UserFilterComponent(_UserComponent, _FilterComponent):
 716     _as_not_self_specific_component_ptr = staticmethod(native_bt.self_component_filter_as_component_filter)
 717     _as_self_component_ptr = staticmethod(native_bt.self_component_filter_as_self_component)
 718
 719     @property
 720     def _output_ports(self):
 721         def get_output_port_count(self_ptr):
 722             ptr = self._as_not_self_specific_component_ptr(self_ptr)
 723             return native_bt.component_filter_get_output_port_count(ptr)
 724
 725         return _ComponentPorts(self._ptr,
 726                                native_bt.self_component_filter_borrow_output_port_by_name,
 727                                native_bt.self_component_filter_borrow_output_port_by_index,
 728                                get_output_port_count,
 729                                bt2.port._UserComponentOutputPort)
 730
 731     @property
 732     def _input_ports(self):
 733         def get_input_port_count(self_ptr):
 734             ptr = self._as_not_self_specific_component_ptr(self_ptr)
 735             return native_bt.component_filter_get_input_port_count(ptr)
 736
 737         return _ComponentPorts(self._ptr,
 738                                native_bt.self_component_filter_borrow_input_port_by_name,
 739                                native_bt.self_component_filter_borrow_input_port_by_index,
 740                                get_input_port_count,
 741                                bt2.port._UserComponentInputPort)
 742
 743     def _add_output_port(self, name, user_data=None):
 744         utils._check_str(name)
 745         fn = native_bt.self_component_filter_add_output_port
 746         comp_status, self_port_ptr = fn(self._ptr, name, user_data)
 747         _handle_component_status(comp_status,
 748                                  'cannot add output port to filter component object')
 749         assert self_port_ptr
 750         return bt2.port._UserComponentOutputPort._create_from_ptr(self_port_ptr)
 751
 752     def _add_input_port(self, name, user_data=None):
 753         utils._check_str(name)
 754         fn = native_bt.self_component_filter_add_input_port
 755         comp_status, self_port_ptr = fn(self._ptr, name, user_data)
 756         _handle_component_status(comp_status,
 757                                  'cannot add input port to filter component object')
 758         assert self_port_ptr
 759         return bt2.port._UserComponentInputPort._create_from_ptr(self_port_ptr)
 760
 761
 762 class _UserSinkComponent(_UserComponent, _SinkComponent):
 763     _as_not_self_specific_component_ptr = staticmethod(native_bt.self_component_sink_as_component_sink)
 764     _as_self_component_ptr = staticmethod(native_bt.self_component_sink_as_self_component)
 765
 766     @property
 767     def _input_ports(self):
 768         def get_input_port_count(self_ptr):
 769             ptr = self._as_not_self_specific_component_ptr(self_ptr)
 770             return native_bt.component_sink_get_input_port_count(ptr)
 771
 772         return _ComponentPorts(self._ptr,
 773                                native_bt.self_component_sink_borrow_input_port_by_name,
 774                                native_bt.self_component_sink_borrow_input_port_by_index,
 775                                get_input_port_count,
 776                                bt2.port._UserComponentInputPort)
 777
 778     def _add_input_port(self, name, user_data=None):
 779         utils._check_str(name)
 780         fn = native_bt.self_component_sink_add_input_port
 781         comp_status, self_port_ptr = fn(self._ptr, name, user_data)
 782         _handle_component_status(comp_status,
 783                                  'cannot add input port to sink component object')
 784         assert self_port_ptr
 785         return bt2.port._UserComponentInputPort._create_from_ptr(self_port_ptr)