-# The MIT License (MIT)
-#
-# Copyright (c) 2017 Philippe Proulx <pproulx@efficios.com>
-#
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to deal
-# in the Software without restriction, including without limitation the rights
-# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-# copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-# THE SOFTWARE.
-
-
-class _BaseObject:
- # Ensure that the object always has _ptr set, even if it throws during
- # construction.
-
- def __new__(cls, *args, **kwargs):
- obj = super().__new__(cls)
- obj._ptr = None
- return obj
-
- def __init__(self, ptr):
- self._ptr = ptr
-
- @property
- def addr(self):
- return int(self._ptr)
-
- def __repr__(self):
- return '<{}.{} object @ {}>'.format(self.__class__.__module__,
- self.__class__.__name__,
- hex(self.addr))
-
- def __copy__(self):
- raise NotImplementedError
-
- def __deepcopy__(self, memo):
- raise NotImplementedError
-
-
-# A Python object that is itself not refcounted, but is wholly owned by an
-# object that is itself refcounted (a _SharedObject). A Babeltrace unique
-# object gets destroyed once its owner gets destroyed (its refcount drops to
-# 0).
-#
-# In the Python bindings, to avoid having to deal with issues with the lifetime
-# of unique objects, we make it so acquiring a reference on a unique object
-# acquires a reference on its owner.
-
-class _UniqueObject(_BaseObject):
-
- # Create a _UniqueObject.
- #
- # - ptr: SWIG Object, pointer to the unique object.
- # - owner_ptr: SWIG Object, pointer to the owner of the unique
- # object. A new reference is acquired.
- # - owner_get_ref: Callback to get a reference on the owner
- # - owner_put_ref: Callback to put a reference on the owner.
-
- @classmethod
- def _create_from_ptr_and_get_ref(cls, ptr, owner_ptr,
- owner_get_ref, owner_put_ref):
- obj = cls.__new__(cls)
-
- obj._ptr = ptr
- obj._owner_ptr = owner_ptr
- obj._owner_get_ref = owner_get_ref
- obj._owner_put_ref = owner_put_ref
-
- obj._owner_get_ref(obj._owner_ptr)
-
- return obj
-
- def __del__(self):
- self._owner_put_ref(self._owner_ptr)
-
-
-# Python object that owns a reference to a Babeltrace object.
-class _SharedObject(_BaseObject):
-
- # Get a new reference on ptr.
- #
- # This must be implemented by subclasses to work correctly with a pointer
- # of the native type they wrap.
-
- @staticmethod
- def _get_ref(ptr):
- raise NotImplementedError
-
- # Put a reference on ptr.
- #
- # This must be implemented by subclasses to work correctly with a pointer
- # of the native type they wrap.
-
- @staticmethod
- def _put_ref(ptr):
- raise NotImplementedError
-
- # Create a _SharedObject from an existing reference.
- #
- # This assumes that the caller owns a reference to the Babeltrace object
- # and transfers this ownership to the newly created Python object.
-
- @classmethod
- def _create_from_ptr(cls, ptr_owned):
- obj = cls.__new__(cls)
- obj._ptr = ptr_owned
- return obj
-
- # Like _create_from_ptr, but acquire a new reference rather than
- # stealing the caller's reference.
-
- @classmethod
- def _create_from_ptr_and_get_ref(cls, ptr):
- obj = cls._create_from_ptr(ptr)
- cls._get_ref(obj._ptr)
- return obj
-
- def _release(self):
- """Return the wrapped pointer, transfer its ownership to the
- caller."""
- ptr = self._ptr
- self._ptr = None
- return ptr
-
- def __del__(self):
- self._put_ref(self._ptr)
projects / babeltrace.git / blobdiff