bindings/python/bt2/bt2/graph.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 import bt2.connection
  25 import bt2.component
  26 import functools
  27 import bt2.port
  28 import bt2
  29
  30
  31 def _graph_port_added_listener_from_native(user_listener,
  32                                            component_ptr, component_type,
  33                                            port_ptr, port_type):
  34     component = bt2.component._create_component_from_ptr_and_get_ref(component_ptr, component_type)
  35     port = bt2.port._create_from_ptr_and_get_ref(port_ptr, port_type)
  36     user_listener(component, port)
  37
  38
  39 def _graph_ports_connected_listener_from_native(user_listener,
  40                                                 upstream_component_ptr, upstream_component_type,
  41                                                 upstream_port_ptr,
  42                                                 downstream_component_ptr, downstream_component_type,
  43                                                 downstream_port_ptr):
  44     upstream_component = bt2.component._create_component_from_ptr_and_get_ref(
  45         upstream_component_ptr, upstream_component_type)
  46     upstream_port = bt2.port._create_from_ptr_and_get_ref(
  47         upstream_port_ptr, native_bt.PORT_TYPE_OUTPUT)
  48     downstream_component = bt2.component._create_component_from_ptr_and_get_ref(
  49         downstream_component_ptr, downstream_component_type)
  50     downstream_port = bt2.port._create_from_ptr_and_get_ref(
  51         downstream_port_ptr, native_bt.PORT_TYPE_INPUT)
  52     user_listener(upstream_component, upstream_port, downstream_component, downstream_port)
  53
  54
  55 class Graph(object._SharedObject):
  56     _get_ref = staticmethod(native_bt.graph_get_ref)
  57     _put_ref = staticmethod(native_bt.graph_put_ref)
  58
  59     def __init__(self):
  60         ptr = native_bt.graph_create()
  61
  62         if ptr is None:
  63             raise bt2.CreationError('cannot create graph object')
  64
  65         super().__init__(ptr)
  66
  67     def _handle_status(self, status, gen_error_msg):
  68         if status == native_bt.GRAPH_STATUS_COMPONENT_REFUSES_PORT_CONNECTION:
  69             raise bt2.PortConnectionRefused
  70         elif status == native_bt.GRAPH_STATUS_CANCELED:
  71             raise bt2.GraphCanceled
  72         elif status == native_bt.GRAPH_STATUS_END:
  73             raise bt2.Stop
  74         elif status == native_bt.GRAPH_STATUS_AGAIN:
  75             raise bt2.TryAgain
  76         elif status < 0:
  77             raise bt2.Error(gen_error_msg)
  78
  79     def add_component(self, component_class, name, params=None):
  80         if isinstance(component_class, bt2.component._GenericSourceComponentClass):
  81             cc_ptr = component_class._ptr
  82             add_fn = native_bt.graph_add_source_component
  83             cc_type = native_bt.COMPONENT_CLASS_TYPE_SOURCE
  84         elif isinstance(component_class, bt2.component._GenericFilterComponentClass):
  85             cc_ptr = component_class._ptr
  86             add_fn = native_bt.graph_add_filter_component
  87             cc_type = native_bt.COMPONENT_CLASS_TYPE_FILTER
  88         elif isinstance(component_class, bt2.component._GenericSinkComponentClass):
  89             cc_ptr = component_class._ptr
  90             add_fn = native_bt.graph_add_sink_component
  91             cc_type = native_bt.COMPONENT_CLASS_TYPE_SINK
  92         elif issubclass(component_class, bt2.component._UserSourceComponent):
  93             cc_ptr = component_class._cc_ptr
  94             add_fn = native_bt.graph_add_source_component
  95             cc_type = native_bt.COMPONENT_CLASS_TYPE_SOURCE
  96         elif issubclass(component_class, bt2.component._UserSinkComponent):
  97             cc_ptr = component_class._cc_ptr
  98             add_fn = native_bt.graph_add_sink_component
  99             cc_type = native_bt.COMPONENT_CLASS_TYPE_SINK
 100         elif issubclass(component_class, bt2.component._UserFilterComponent):
 101             cc_ptr = component_class._cc_ptr
 102             add_fn = native_bt.graph_add_filter_component
 103             cc_type = native_bt.COMPONENT_CLASS_TYPE_FILTER
 104         else:
 105             raise TypeError("'{}' is not a component class".format(
 106                 component_class.__class__.__name__))
 107
 108         utils._check_str(name)
 109         params = bt2.create_value(params)
 110
 111         params_ptr = params._ptr if params is not None else None
 112
 113         status, comp_ptr = add_fn(self._ptr, cc_ptr, name, params_ptr)
 114         self._handle_status(status, 'cannot add component to graph')
 115         assert comp_ptr
 116         return bt2.component._create_component_from_ptr(comp_ptr, cc_type)
 117
 118     def connect_ports(self, upstream_port, downstream_port):
 119         utils._check_type(upstream_port, bt2.port._OutputPort)
 120         utils._check_type(downstream_port, bt2.port._InputPort)
 121         status, conn_ptr = native_bt.graph_connect_ports(self._ptr,
 122                                                          upstream_port._ptr,
 123                                                          downstream_port._ptr)
 124         self._handle_status(status, 'cannot connect component ports within graph')
 125         assert(conn_ptr)
 126         return bt2.connection._Connection._create_from_ptr(conn_ptr)
 127
 128     def add_port_added_listener(self, listener):
 129         if not callable(listener):
 130             raise TypeError("'listener' parameter is not callable")
 131
 132         fn = native_bt.py3_graph_add_port_added_listener
 133         listener_from_native = functools.partial(_graph_port_added_listener_from_native,
 134                                                  listener)
 135
 136         listener_ids = fn(self._ptr, listener_from_native)
 137         if listener_ids is None:
 138             utils._raise_bt2_error('cannot add listener to graph object')
 139         return bt2._ListenerHandle(listener_ids, self)
 140
 141     def add_ports_connected_listener(self, listener):
 142         if not callable(listener):
 143             raise TypeError("'listener' parameter is not callable")
 144
 145         fn = native_bt.py3_graph_add_ports_connected_listener
 146         listener_from_native = functools.partial(_graph_ports_connected_listener_from_native,
 147                                                  listener)
 148
 149         listener_ids = fn(self._ptr, listener_from_native)
 150         if listener_ids is None:
 151             utils._raise_bt2_error('cannot add listener to graph object')
 152         return bt2._ListenerHandle(listener_ids, self)
 153
 154     def run(self):
 155         status = native_bt.graph_run(self._ptr)
 156
 157         if status == native_bt.GRAPH_STATUS_END:
 158             return
 159
 160         self._handle_status(status, 'graph object stopped running because of an unexpected error')
 161
 162     def cancel(self):
 163         status = native_bt.graph_cancel(self._ptr)
 164         self._handle_status(status, 'cannot cancel graph object')
 165
 166     @property
 167     def is_canceled(self):
 168         is_canceled = native_bt.graph_is_canceled(self._ptr)
 169         assert(is_canceled >= 0)
 170         return is_canceled > 0
 171
 172     def create_output_port_message_iterator(self, output_port):
 173         utils._check_type(output_port, bt2.port._OutputPort)
 174         msg_iter_ptr = native_bt.port_output_message_iterator_create(self._ptr, output_port._ptr)
 175
 176         if msg_iter_ptr is None:
 177             raise bt2.CreationError('cannot create output port message iterator')
 178
 179         return bt2.message_iterator._OutputPortMessageIterator(msg_iter_ptr)