src/bindings/python/bt2/bt2/component_descriptor.py

   1 # SPDX-License-Identifier: MIT
   2 #
   3 # Copyright (c) 2017 Philippe Proulx <pproulx@efficios.com>
   4
   5 from bt2 import native_bt
   6 from bt2 import component as bt2_component
   7 import bt2
   8
   9
  10 def _is_source_comp_cls(comp_cls):
  11     if isinstance(comp_cls, bt2_component._SourceComponentClassConst):
  12         return True
  13
  14     try:
  15         return issubclass(comp_cls, bt2_component._UserSourceComponent)
  16     except Exception:
  17         return False
  18
  19
  20 def _is_filter_comp_cls(comp_cls):
  21     if isinstance(comp_cls, bt2_component._FilterComponentClassConst):
  22         return True
  23
  24     try:
  25         return issubclass(comp_cls, bt2_component._UserFilterComponent)
  26     except Exception:
  27         return False
  28
  29
  30 def _is_sink_comp_cls(comp_cls):
  31     if isinstance(comp_cls, bt2_component._SinkComponentClassConst):
  32         return True
  33
  34     try:
  35         return issubclass(comp_cls, bt2_component._UserSinkComponent)
  36     except Exception:
  37         return False
  38
  39
  40 class ComponentDescriptor:
  41     def __init__(self, component_class, params=None, obj=None):
  42         if (
  43             not _is_source_comp_cls(component_class)
  44             and not _is_filter_comp_cls(component_class)
  45             and not _is_sink_comp_cls(component_class)
  46         ):
  47             raise TypeError(
  48                 "'{}' is not a component class".format(
  49                     component_class.__class__.__name__
  50                 )
  51             )
  52
  53         base_cc_ptr = component_class._bt_component_class_ptr()
  54
  55         if obj is not None and not native_bt.bt2_is_python_component_class(base_cc_ptr):
  56             raise ValueError('cannot pass a Python object to a non-Python component')
  57
  58         self._comp_cls = component_class
  59         self._params = bt2.create_value(params)
  60         self._obj = obj
  61
  62     @property
  63     def component_class(self):
  64         return self._comp_cls
  65
  66     @property
  67     def params(self):
  68         return self._params
  69
  70     @property
  71     def obj(self):
  72         return self._obj