src/bindings/python/bt2/bt2/component_descriptor.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
  24 from bt2 import component as bt2_component
  25 import bt2
  26
  27
  28 def _is_source_comp_cls(comp_cls):
  29     if isinstance(comp_cls, bt2_component._SourceComponentClass):
  30         return True
  31
  32     try:
  33         return issubclass(comp_cls, bt2_component._UserSourceComponent)
  34     except:
  35         return False
  36
  37
  38 def _is_filter_comp_cls(comp_cls):
  39     if isinstance(comp_cls, bt2_component._FilterComponentClass):
  40         return True
  41
  42     try:
  43         return issubclass(comp_cls, bt2_component._UserFilterComponent)
  44     except:
  45         return False
  46
  47
  48 def _is_sink_comp_cls(comp_cls):
  49     if isinstance(comp_cls, bt2_component._SinkComponentClass):
  50         return True
  51
  52     try:
  53         return issubclass(comp_cls, bt2_component._UserSinkComponent)
  54     except:
  55         return False
  56
  57
  58 class ComponentDescriptor:
  59     def __init__(self, component_class, params=None, obj=None):
  60         if (
  61             not _is_source_comp_cls(component_class)
  62             and not _is_filter_comp_cls(component_class)
  63             and not _is_sink_comp_cls(component_class)
  64         ):
  65             raise TypeError(
  66                 "'{}' is not a component class".format(
  67                     component_class.__class__.__name__
  68                 )
  69             )
  70
  71         base_cc_ptr = component_class._bt_component_class_ptr()
  72
  73         if obj is not None and not native_bt.bt2_is_python_component_class(base_cc_ptr):
  74             raise ValueError('cannot pass a Python object to a non-Python component')
  75
  76         self._comp_cls = component_class
  77         self._params = bt2.create_value(params)
  78         self._obj = obj
  79
  80     @property
  81     def component_class(self):
  82         return self._comp_cls
  83
  84     @property
  85     def params(self):
  86         return self._params
  87
  88     @property
  89     def obj(self):
  90         return self._obj