src/bindings/python/bt2/bt2/query_executor.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 interrupter as bt2_interrupter
  25 from bt2 import value as bt2_value
  26 import bt2
  27
  28
  29 def _bt2_component():
  30     from bt2 import component as bt2_component
  31
  32     return bt2_component
  33
  34
  35 class _QueryExecutorCommon:
  36     @property
  37     def _common_ptr(self):
  38         return self._as_query_executor_ptr()
  39
  40     @property
  41     def is_interrupted(self):
  42         is_interrupted = native_bt.query_executor_is_interrupted(self._common_ptr)
  43         return bool(is_interrupted)
  44
  45     @property
  46     def logging_level(self):
  47         return native_bt.query_executor_get_logging_level(self._common_ptr)
  48
  49
  50 class QueryExecutor(object._SharedObject, _QueryExecutorCommon):
  51     _get_ref = staticmethod(native_bt.query_executor_get_ref)
  52     _put_ref = staticmethod(native_bt.query_executor_put_ref)
  53
  54     def _as_query_executor_ptr(self):
  55         return self._ptr
  56
  57     def __init__(self, component_class, object_name, params=None, method_obj=None):
  58         if not isinstance(component_class, _bt2_component()._ComponentClassConst):
  59             err = False
  60
  61             try:
  62                 if not issubclass(component_class, _bt2_component()._UserComponent):
  63                     err = True
  64             except TypeError:
  65                 err = True
  66
  67             if err:
  68                 o = component_class
  69                 raise TypeError("'{}' is not a component class object".format(o))
  70
  71         utils._check_str(object_name)
  72
  73         if params is None:
  74             params_ptr = native_bt.value_null
  75         else:
  76             params = bt2.create_value(params)
  77             params_ptr = params._ptr
  78
  79         cc_ptr = component_class._bt_component_class_ptr()
  80         assert cc_ptr is not None
  81
  82         if method_obj is not None and not native_bt.bt2_is_python_component_class(
  83             cc_ptr
  84         ):
  85             raise ValueError(
  86                 'cannot pass a Python object to a non-Python component class'
  87             )
  88
  89         ptr = native_bt.bt2_query_executor_create(
  90             cc_ptr, object_name, params_ptr, method_obj
  91         )
  92
  93         if ptr is None:
  94             raise bt2._MemoryError('cannot create query executor object')
  95
  96         super().__init__(ptr)
  97
  98         # Keep a reference of `method_obj` as the native query executor
  99         # does not have any. This ensures that, when this object's
 100         # query() method is called, the Python object still exists.
 101         self._method_obj = method_obj
 102
 103     def add_interrupter(self, interrupter):
 104         utils._check_type(interrupter, bt2_interrupter.Interrupter)
 105         native_bt.query_executor_add_interrupter(self._ptr, interrupter._ptr)
 106
 107     @property
 108     def default_interrupter(self):
 109         ptr = native_bt.query_executor_borrow_default_interrupter(self._ptr)
 110         return bt2_interrupter.Interrupter._create_from_ptr_and_get_ref(ptr)
 111
 112     def _set_logging_level(self, log_level):
 113         utils._check_log_level(log_level)
 114         status = native_bt.query_executor_set_logging_level(self._ptr, log_level)
 115         utils._handle_func_status(status, "cannot set query executor's logging level")
 116
 117     logging_level = property(
 118         fget=_QueryExecutorCommon.logging_level, fset=_set_logging_level
 119     )
 120
 121     @property
 122     def is_interrupted(self):
 123         is_interrupted = native_bt.query_executor_is_interrupted(self._ptr)
 124         return bool(is_interrupted)
 125
 126     def query(self):
 127         status, result_ptr = native_bt.query_executor_query(self._ptr)
 128         utils._handle_func_status(status, 'cannot query component class')
 129         assert result_ptr is not None
 130         return bt2_value._create_from_const_ptr(result_ptr)
 131
 132
 133 class _PrivateQueryExecutor(_QueryExecutorCommon):
 134     def __init__(self, ptr):
 135         self._ptr = ptr
 136
 137     def _check_validity(self):
 138         if self._ptr is None:
 139             raise RuntimeError('this object is not valid anymore')
 140
 141     def _as_query_executor_ptr(self):
 142         self._check_validity()
 143         return native_bt.private_query_executor_as_query_executor_const(self._ptr)
 144
 145     def _invalidate(self):
 146         self._ptr = None