bindings/python/bt2/notification_iterator.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.notification
  25 import collections.abc
  26 import bt2.component
  27 import bt2
  28
  29
  30 class _NotificationIterator(collections.abc.Iterator):
  31     def _handle_status(self, status, gen_error_msg):
  32         if status == native_bt.NOTIFICATION_ITERATOR_STATUS_CANCELED:
  33             raise bt2.NotificationIteratorCanceled
  34         elif status == native_bt.NOTIFICATION_ITERATOR_STATUS_AGAIN:
  35             raise bt2.TryAgain
  36         elif status == native_bt.NOTIFICATION_ITERATOR_STATUS_END:
  37             raise bt2.Stop
  38         elif status == native_bt.NOTIFICATION_ITERATOR_STATUS_UNSUPPORTED:
  39             raise bt2.UnsupportedFeature
  40         elif status < 0:
  41             raise bt2.Error(gen_error_msg)
  42
  43     def __next__(self):
  44         raise NotImplementedError
  45
  46
  47 class _GenericNotificationIterator(object._Object, _NotificationIterator):
  48     @property
  49     def component(self):
  50         comp_ptr = native_bt.notification_iterator_get_component(self._ptr)
  51         assert(comp_ptr)
  52         return bt2.component._create_generic_component_from_ptr(comp_ptr)
  53
  54     def _get_notif(self):
  55         notif_ptr = native_bt.notification_iterator_get_notification(self._ptr)
  56         utils._handle_ptr(notif_ptr, "cannot get notification iterator object's current notification object")
  57         return bt2.notification._create_from_ptr(notif_ptr)
  58
  59     def _next(self):
  60         status = native_bt.notification_iterator_next(self._ptr)
  61         self._handle_status(status,
  62                             'unexpected error: cannot advance the notification iterator')
  63
  64     def __next__(self):
  65         self._next()
  66         return self._get_notif()
  67
  68
  69 class _UserNotificationIterator(_NotificationIterator):
  70     def __new__(cls, ptr):
  71         # User iterator objects are always created by the native side,
  72         # that is, never instantiated directly by Python code.
  73         #
  74         # The native code calls this, then manually calls
  75         # self.__init__() without the `ptr` argument. The user has
  76         # access to self.component during this call, thanks to this
  77         # self._ptr argument being set.
  78         #
  79         # self._ptr is NOT owned by this object here, so there's nothing
  80         # to do in __del__().
  81         self = super().__new__(cls)
  82         self._ptr = ptr
  83         return self
  84
  85     def __init__(self):
  86         pass
  87
  88     @property
  89     def _component(self):
  90         return native_bt.py3_get_user_component_from_user_notif_iter(self._ptr)
  91
  92     @property
  93     def addr(self):
  94         return int(self._ptr)
  95
  96     def _finalize(self):
  97         pass
  98
  99     def __next__(self):
 100         raise bt2.Stop
 101
 102     def _next_from_native(self):
 103         # this can raise anything: it's catched by the native part
 104         try:
 105             notif = next(self)
 106         except StopIteration:
 107             raise bt2.Stop
 108         except:
 109             raise
 110
 111         utils._check_type(notif, bt2.notification._Notification)
 112
 113         # take a new reference for the native part
 114         notif._get()
 115         return int(notif._ptr)