def test_ops(self):
a = (b'01234567'
b'456789ab'
b'89abcdef')
v = memoryview(a).cast('b', shape=[3, 8])
b = containers.StridedArrayView2D(v).transposed(0, 1).flipped(0)
self.assertEqual(b.size, (8, 3))
self.assertEqual(b.stride, (-1, 8))
self.assertEqual(bytes(b), b'7bf6ae59d48c37b26a159048')
c = containers.StridedArrayView2D(v).transposed(1, 0).flipped(1)
self.assertEqual(c.size, (8, 3))
self.assertEqual(c.stride, (1, -8))
self.assertEqual(bytes(c), b'840951a62b73c84d95ea6fb7')
d = containers.StridedArrayView2D(v).transposed(0, 1)[3:4].broadcasted(0, 5)
self.assertEqual(d.size, (5, 3))
self.assertEqual(d.stride, (0, 8))
self.assertEqual(bytes(d), b'37b37b37b37b37b')
d = containers.StridedArrayView2D(v)[:, 3:4].broadcasted(1, 2)
self.assertEqual(d.size, (3, 2))
self.assertEqual(d.stride, (8, 0))
self.assertEqual(bytes(d), b'3377bb')
def test_slice_multidimensional(self):
a = memoryview(b'01234567'
b'456789ab'
b'89abcdef').cast('b', shape=[3, 8])
a_refcount = sys.getrefcount(a)
b = containers.StridedArrayView2D(a)
b_refcount = sys.getrefcount(b)
# memoryview's buffer protocol returns itself, not the underlying
# bytes, as it manages the Py_buffer instance. So this is expected.
self.assertIs(b.owner, a)
self.assertEqual(sys.getrefcount(a), a_refcount + 1)
# When slicing, b's refcount should not change but a's refcount should
# increase
c = b[1:3, 4:7]
self.assertIsInstance(c, containers.StridedArrayView2D)
self.assertEqual(c.size, (2, 3))
self.assertEqual(c.stride, (8, 1))
self.assertEqual(bytes(c[0]), b'89a')
self.assertEqual(bytes(c[1]), b'cde')
self.assertEqual(sys.getrefcount(b), b_refcount)
self.assertEqual(sys.getrefcount(a), a_refcount + 2)
# Deleting a slice should reduce a's refcount again, keep b's unchanged
del c
self.assertEqual(sys.getrefcount(b), b_refcount)
self.assertEqual(sys.getrefcount(a), a_refcount + 1)
def test_init_buffer(self):
a = (b'01234567' b'456789ab' b'89abcdef')
a_refcount = sys.getrefcount(a)
v = memoryview(a).cast('b', shape=[3, 8])
b = containers.StridedArrayView2D(v)
self.assertEqual(len(b), 3)
self.assertEqual(bytes(b), b'01234567' b'456789ab' b'89abcdef')
self.assertEqual(b.size, (3, 8))
self.assertEqual(b.stride, (8, 1))
self.assertIsInstance(b[1], containers.StridedArrayView1D)
self.assertEqual(bytes(b[1]), b'456789ab')
self.assertEqual(b[1, 2], '6')
self.assertEqual(b[1][2], '6')
self.assertEqual(sys.getrefcount(a), a_refcount + 1)
# Not mutable
with self.assertRaisesRegex(TypeError,
"object does not support item assignment"):
b[1, 2] = '!'
# b should keep a reference to a, so deleting the local reference
# shouldn't affect it
del a
self.assertTrue(sys.getrefcount(b.owner), a_refcount)
self.assertEqual(b[1][2], '6')
# Now, if we delete b, a should not be referenced by anything anymore
a = b.owner
del b
self.assertTrue(sys.getrefcount(a), a_refcount)
def test_slice_multidimensional_empty(self):
a = memoryview(b'01234567'
b'456789ab'
b'89abcdef').cast('b', shape=[3, 8])
a_refcount = sys.getrefcount(a)
b = containers.StridedArrayView2D(a)[1:1, 2:2]
self.assertEqual(b.size, (0, 0))
# Empty view, original data not referenced at all
self.assertIs(b.owner, None)
self.assertEqual(sys.getrefcount(a), a_refcount)
def test_init_buffer_stride(self):
a = memoryview(b'01234567'
b'456789ab'
b'89abcdef').cast('b', shape=[3, 8])[::2]
self.assertEqual(bytes(a), b'0123456789abcdef')
b = containers.StridedArrayView2D(a)
self.assertEqual(len(b), 2)
self.assertEqual(bytes(b), b'0123456789abcdef')
self.assertEqual(b.size, (2, 8))
self.assertEqual(b.stride, (16, 1))
self.assertEqual(bytes(b[1]), b'89abcdef')
self.assertEqual(b[1][3], 'b')
def test_init(self):
a = containers.StridedArrayView2D()
b = containers.MutableStridedArrayView2D()
self.assertIs(a.owner, None)
self.assertIs(b.owner, None)
self.assertEqual(len(a), 0)
self.assertEqual(len(b), 0)
self.assertEqual(bytes(a), b'')
self.assertEqual(bytes(b), b'')
self.assertEqual(a.size, (0, 0))
self.assertEqual(b.size, (0, 0))
self.assertEqual(a.stride, (0, 0))
self.assertEqual(b.stride, (0, 0))
self.assertEqual(a.dimensions, 2)
self.assertEqual(b.dimensions, 2)
def test_slice_stride(self):
a = (b'01234567' b'456789ab' b'89abcdef')
v = memoryview(a).cast('b', shape=[3, 8])
b = containers.StridedArrayView2D(v)
# Check consistency with slices on memoryview
c1 = v[0:3:2]
c2 = b[0:3:2]
self.assertEqual(len(c1), 2)
self.assertEqual(len(c2), 2)
self.assertIsInstance(c2, containers.StridedArrayView2D)
self.assertEqual(bytes(c1), b'0123456789abcdef')
self.assertEqual(bytes(c2), b'0123456789abcdef')
self.assertEqual(c2.size, (2, 8))
self.assertEqual(c2.stride, (16, 1))
self.assertEqual(bytes(c2[1]), b'89abcdef')
def test_slice_stride_negative_multidimensional(self):
a = (b'01234567' b'456789ab' b'89abcdef')
v = memoryview(a).cast('b', shape=[3, 8])
b = containers.StridedArrayView2D(v)
# Check consistency with slices on memoryview
self.assertEqual(v.shape, (3, 8))
self.assertEqual(b.size, (3, 8))
self.assertEqual(v.strides, (8, 1))
self.assertEqual(b.stride, (8, 1))
with self.assertRaises(NotImplementedError):
c1 = v[-1:None:-2, -2:2:-3] # HAH!
c2 = b[-1:None:-2, -2:2:-3]
self.assertEqual(len(c2), 2)
self.assertEqual(bytes(c2), b'eb63')
self.assertEqual(c2.size, (2, 2))
self.assertEqual(c2.stride, (-16, -3))
def test_convert_memoryview(self):
a = memoryview(b'01234567'
b'456789ab'
b'89abcdef').cast('b', shape=[3, 8])
a_refcount = sys.getrefcount(a)
b = containers.StridedArrayView2D(a)
b_refcount = sys.getrefcount(b)
# memoryview's buffer protocol returns itself, not the underlying
# bytes, as it manages the Py_buffer instance. So this is expected.
self.assertIs(b.owner, a)
self.assertEqual(sys.getrefcount(a), a_refcount + 1)
c = memoryview(b)
self.assertEqual(c.ndim, 2)
self.assertEqual(c.shape, (3, 8))
self.assertEqual(c.strides, (8, 1))
self.assertIs(c.obj, b)
self.assertEqual(sys.getrefcount(a), a_refcount + 1)
self.assertEqual(sys.getrefcount(b), b_refcount + 1)
def test_slice_stride_negative(self):
a = (b'01234567' b'456789ab' b'89abcdef')
v = memoryview(a).cast('b', shape=[3, 8])
b = containers.StridedArrayView2D(v)
# Check consistency with slices on memoryview
self.assertEqual(v.shape, (3, 8))
self.assertEqual(b.size, (3, 8))
self.assertEqual(v.strides, (8, 1))
self.assertEqual(b.stride, (8, 1))
c1 = v[-1:None:-2] # like [0:3:2] above, but reverted
c2 = b[-1:None:-2]
self.assertEqual(len(c1), 2)
self.assertEqual(len(c2), 2)
self.assertEqual(bytes(c1),
b'89abcdef01234567') # like above but reverted
self.assertEqual(bytes(c2), b'89abcdef01234567')
self.assertEqual(c1.shape, (2, 8))
self.assertEqual(c2.size, (2, 8))
self.assertEqual(c1.strides, (-16, 1))
self.assertEqual(c2.stride, (-16, 1))
def test_init_buffer_unexpected_dimensions(self):
a = b'123456'
with self.assertRaisesRegex(BufferError,
"expected 2 dimensions but got 1"):
b = containers.StridedArrayView2D(a)
