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 logging as bt2_logging
  27 from bt2 import value as bt2_value
  28 import bt2
  29
  30
  31 class _QueryExecutorCommon:
  32     @property
  33     def _common_ptr(self):
  34         return self._as_query_executor_ptr()
  35
  36     @property
  37     def is_interrupted(self):
  38         is_interrupted = native_bt.query_executor_is_interrupted(self._common_ptr)
  39         return bool(is_interrupted)
  40
  41     @property
  42     def logging_level(self):
  43         return native_bt.query_executor_get_logging_level(self._common_ptr)
  44
  45
  46 class QueryExecutor(object._SharedObject, _QueryExecutorCommon):
  47     _get_ref = staticmethod(native_bt.query_executor_get_ref)
  48     _put_ref = staticmethod(native_bt.query_executor_put_ref)
  49
  50     def _as_query_executor_ptr(self):
  51         return self._ptr
  52
  53     def __init__(self, component_class, object, params=None, method_obj=None):
  54         if not isinstance(component_class, bt2_component._ComponentClass):
  55             err = False
  56
  57             try:
  58                 if not issubclass(component_class, bt2_component._UserComponent):
  59                     err = True
  60             except TypeError:
  61                 err = True
  62
  63             if err:
  64                 o = component_class
  65                 raise TypeError("'{}' is not a component class object".format(o))
  66
  67         utils._check_str(object)
  68
  69         if params is None:
  70             params_ptr = native_bt.value_null
  71         else:
  72             params = bt2.create_value(params)
  73             params_ptr = params._ptr
  74
  75         cc_ptr = component_class._bt_component_class_ptr()
  76         assert cc_ptr is not None
  77
  78         if method_obj is not None and not native_bt.bt2_is_python_component_class(
  79             cc_ptr
  80         ):
  81             raise ValueError(
  82                 'cannot pass a Python object to a non-Python component class'
  83             )
  84
  85         ptr = native_bt.bt2_query_executor_create(
  86             cc_ptr, object, params_ptr, method_obj
  87         )
  88
  89         if ptr is None:
  90             raise bt2._MemoryError('cannot create query executor object')
  91
  92         super().__init__(ptr)
  93
  94         # Keep a reference of `method_obj` as the native query executor
  95         # does not have any. This ensures that, when this object's
  96         # query() method is called, the Python object still exists.
  97         self._method_obj = method_obj
  98
  99     def add_interrupter(self, interrupter):
 100         utils._check_type(interrupter, bt2_interrupter.Interrupter)
 101         native_bt.query_executor_add_interrupter(self._ptr, interrupter._ptr)
 102
 103     def interrupt(self):
 104         native_bt.query_executor_interrupt(self._ptr)
 105
 106     def _set_logging_level(self, log_level):
 107         utils._check_log_level(log_level)
 108         status = native_bt.query_executor_set_logging_level(self._ptr, log_level)
 109         utils._handle_func_status(status, "cannot set query executor's logging level")
 110
 111     logging_level = property(
 112         fget=_QueryExecutorCommon.logging_level, fset=_set_logging_level
 113     )
 114
 115     @property
 116     def is_interrupted(self):
 117         is_interrupted = native_bt.query_executor_is_interrupted(self._ptr)
 118         return bool(is_interrupted)
 119
 120     def query(self):
 121         status, result_ptr = native_bt.query_executor_query(self._ptr)
 122         utils._handle_func_status(status, 'cannot query component class')
 123         assert result_ptr is not None
 124         return bt2_value._create_from_ptr(result_ptr)
 125
 126
 127 class _PrivateQueryExecutor(_QueryExecutorCommon):
 128     def __init__(self, ptr):
 129         self._ptr = ptr
 130
 131     def _check_validity(self):
 132         if self._ptr is None:
 133             raise RuntimeError('this object is not valid anymore')
 134
 135     def _as_query_executor_ptr(self):
 136         self._check_validity()
 137         return native_bt.private_query_executor_as_query_executor_const(self._ptr)
 138
 139     def _invalidate(self):
 140         self._ptr = None