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