mirror of
https://github.com/django/django.git
synced 2024-11-28 21:43:13 +01:00
74 lines
2.3 KiB
Python
74 lines
2.3 KiB
Python
import ctypes
|
|
from unittest import mock
|
|
|
|
from django.contrib.gis.ptr import CPointerBase
|
|
from django.test import SimpleTestCase
|
|
|
|
|
|
class CPointerBaseTests(SimpleTestCase):
|
|
def test(self):
|
|
destructor_mock = mock.Mock()
|
|
|
|
class NullPointerException(Exception):
|
|
pass
|
|
|
|
class FakeGeom1(CPointerBase):
|
|
null_ptr_exception_class = NullPointerException
|
|
|
|
class FakeGeom2(FakeGeom1):
|
|
ptr_type = ctypes.POINTER(ctypes.c_float)
|
|
destructor = destructor_mock
|
|
|
|
fg1 = FakeGeom1()
|
|
fg2 = FakeGeom2()
|
|
|
|
# These assignments are OK. None is allowed because it's equivalent
|
|
# to the NULL pointer.
|
|
fg1.ptr = fg1.ptr_type()
|
|
fg1.ptr = None
|
|
fg2.ptr = fg2.ptr_type(ctypes.c_float(5.23))
|
|
fg2.ptr = None
|
|
|
|
# Because pointers have been set to NULL, an exception is raised on
|
|
# access. Raising an exception is preferable to a segmentation fault
|
|
# that commonly occurs when a C method is given a NULL reference.
|
|
for fg in (fg1, fg2):
|
|
with self.assertRaises(NullPointerException):
|
|
fg.ptr
|
|
|
|
# Anything that's either not None or the acceptable pointer type
|
|
# results in a TypeError when trying to assign it to the `ptr` property.
|
|
# Thus, memory addresses (integers) and pointers of the incorrect type
|
|
# (in `bad_ptrs`) aren't allowed.
|
|
bad_ptrs = (5, ctypes.c_char_p(b"foobar"))
|
|
for bad_ptr in bad_ptrs:
|
|
for fg in (fg1, fg2):
|
|
with self.assertRaisesMessage(TypeError, "Incompatible pointer type"):
|
|
fg.ptr = bad_ptr
|
|
|
|
# Object can be deleted without a destructor set.
|
|
fg = FakeGeom1()
|
|
fg.ptr = fg.ptr_type(1)
|
|
del fg
|
|
|
|
# A NULL pointer isn't passed to the destructor.
|
|
fg = FakeGeom2()
|
|
fg.ptr = None
|
|
del fg
|
|
self.assertFalse(destructor_mock.called)
|
|
|
|
# The destructor is called if set.
|
|
fg = FakeGeom2()
|
|
ptr = fg.ptr_type(ctypes.c_float(1.0))
|
|
fg.ptr = ptr
|
|
del fg
|
|
destructor_mock.assert_called_with(ptr)
|
|
|
|
def test_destructor_catches_importerror(self):
|
|
class FakeGeom(CPointerBase):
|
|
destructor = mock.Mock(side_effect=ImportError)
|
|
|
|
fg = FakeGeom()
|
|
fg.ptr = fg.ptr_type(1)
|
|
del fg
|