"""Unit tests for the memoryview
Some tests are in test_bytes. Many tests that require _testbuffer.ndarray
are in test_buffer.
"""
import unittest
import test.support
import sys
import gc
import weakref
import array
import io
import copy
import pickle
import struct
from test.support import import_helper
class MyObject:
pass
class AbstractMemoryTests:
source_bytes = b"abcdef"
@property
def _source(self):
return self.source_bytes
@property
def _types(self):
return filter(None, [self.ro_type, self.rw_type])
def check_getitem_with_type(self, tp):
b = tp(self._source)
oldrefcount = sys.getrefcount(b)
m = self._view(b)
self.assertEqual(m[0], ord(b"a"))
self.assertIsInstance(m[0], int)
self.assertEqual(m[5], ord(b"f"))
self.assertEqual(m[-1], ord(b"f"))
self.assertEqual(m[-6], ord(b"a"))
# Bounds checking
self.assertRaises(IndexError, lambda: m[6])
self.assertRaises(IndexError, lambda: m[-7])
self.assertRaises(IndexError, lambda: m[sys.maxsize])
self.assertRaises(IndexError, lambda: m[-sys.maxsize])
# Type checking
self.assertRaises(TypeError, lambda: m[None])
self.assertRaises(TypeError, lambda: m[0.0])
self.assertRaises(TypeError, lambda: m["a"])
m = None
self.assertEqual(sys.getrefcount(b), oldrefcount)
def test_getitem(self):
for tp in self._types:
self.check_getitem_with_type(tp)
def test_iter(self):
for tp in self._types:
b = tp(self._source)
m = self._view(b)
self.assertEqual(list(m), [m[i] for i in range(len(m))])
def test_setitem_readonly(self):
if not self.ro_type:
self.skipTest("no read-only type to test")
b = self.ro_type(self._source)
oldrefcount = sys.getrefcount(b)
m = self._view(b)
def setitem(value):
m[0] = value
self.assertRaises(TypeError, setitem, b"a")
self.assertRaises(TypeError, setitem, 65)
self.assertRaises(TypeError, setitem, memoryview(b"a"))
m = None
self.assertEqual(sys.getrefcount(b), oldrefcount)
def test_setitem_writable(self):
if not self.rw_type:
self.skipTest("no writable type to test")
tp = self.rw_type
b = self.rw_type(self._source)
oldrefcount = sys.getrefcount(b)
m = self._view(b)
m[0] = ord(b'1')
self._check_contents(tp, b, b"1bcdef")
m[0:1] = tp(b"0")
self._check_contents(tp, b, b"0bcdef")
m[1:3] = tp(b"12")
self._check_contents(tp, b, b"012def")
m[1:1] = tp(b"")
self._check_contents(tp, b, b"012def")
m[:] = tp(b"abcdef")
self._check_contents(tp, b, b"abcdef")
# Overlapping copies of a view into itself
m[0:3] = m[2:5]
self._check_contents(tp, b, b"cdedef")
m[:] = tp(b"abcdef")
m[2:5] = m[0:3]
self._check_contents(tp, b, b"ababcf")
def setitem(key, value):
m[key] = tp(value)
# Bounds checking
self.assertRaises(IndexError, setitem, 6, b"a")
self.assertRaises(IndexError, setitem, -7, b"a")
self.assertRaises(IndexError, setitem, sys.maxsize, b"a")
self.assertRaises(IndexError, setitem, -sys.maxsize, b"a")
# Wrong index/slice types
self.assertRaises(TypeError, setitem, 0.0, b"a")
self.assertRaises(TypeError, setitem, (0,), b"a")
self.assertRaises(TypeError, setitem, (slice(0,1,1), 0), b"a")
self.assertRaises(TypeError, setitem, (0, slice(0,1,1)), b"a")
self.assertRaises(TypeError, setitem, (0,), b"a")
self.assertRaises(TypeError, setitem, "a", b"a")
# Not implemented: multidimensional slices
slices = (slice(0,1,1), slice(0,1,2))
self.assertRaises(NotImplementedError, setitem, slices, b"a")
# Trying to resize the memory object
exc = ValueError if m.format == 'c' else TypeError
self.assertRaises(exc, setitem, 0, b"")
self.assertRaises(exc, setitem, 0, b"ab")
self.assertRaises(ValueError, setitem, slice(1,1), b"a")
self.assertRaises(ValueError, setitem, slice(0,2), b"a")
m = None
self.assertEqual(sys.getrefcount(b), oldrefcount)
def test_delitem(self):
for tp in self._types:
b = tp(self._source)
m = self._view(b)
with self.assertRaises(TypeError):
del m[1]
with self.assertRaises(TypeError):
del m[1:4]
def test_tobytes(self):
for tp in self._types:
m = self._view(tp(self._source))
b = m.tobytes()
# This calls self.getitem_type() on each separate byte of b"abcdef"
expected = b"".join(
self.getitem_type(bytes([c])) for c in b"abcdef")
self.assertEqual(b, expected)
self.assertIsInstance(b, bytes)
def test_tolist(self):
for tp in self._types:
m = self._view(tp(self._source))
l = m.tolist()
self.assertEqual(l, list(b"abcdef"))
def test_compare(self):
# memoryviews can compare for equality with other objects
# having the buffer interface.
for tp in self._types:
m = self._view(tp(self._source))
for tp_comp in self._types:
self.assertTrue(m == tp_comp(b"abcdef"))
self.assertFalse(m != tp_comp(b"abcdef"))
self.assertFalse(m == tp_comp(b"abcde"))
self.assertTrue(m != tp_comp(b"abcde"))
self.assertFalse(m == tp_comp(b"abcde1"))
self.assertTrue(m != tp_comp(b"abcde1"))
self.assertTrue(m == m)
self.assertTrue(m == m[:])
self.assertTrue(m[0:6] == m[:])
self.assertFalse(m[0:5] == m)
# Comparison with objects which don't support the buffer API
self.assertFalse(m == "abcdef")
self.assertTrue(m != "abcdef")
self.assertFalse("abcdef" == m)
self.assertTrue("abcdef" != m)
# Unordered comparisons
for c in (m, b"abcdef"):
self.assertRaises(TypeError, lambda: m < c)
self.assertRaises(TypeError, lambda: c <= m)
self.assertRaises(TypeError, lambda: m >= c)
self.assertRaises(TypeError, lambda: c > m)
def check_attributes_with_type(self, tp):
m = self._view(tp(self._source))
self.assertEqual(m.format, self.format)
self.assertEqual(m.itemsize, self.itemsize)
self.assertEqual(m.ndim, 1)
self.assertEqual(m.shape, (6,))
self.assertEqual(len(m), 6)
self.assertEqual(m.strides, (self.itemsize,))
self.assertEqual(m.suboffsets, ())
return m
def test_attributes_readonly(self):
if not self.ro_type:
self.skipTest("no read-only type to test")
m = self.check_attributes_with_type(self.ro_type)
self.assertEqual(m.readonly, True)
def test_attributes_writable(self):
if not self.rw_type:
self.skipTest("no writable type to test")
m = self.check_attributes_with_type(self.rw_type)
self.assertEqual(m.readonly, False)
def test_getbuffer(self):
# Test PyObject_GetBuffer() on a memoryview object.
for tp in self._types:
b = tp(self._source)
oldrefcount = sys.getrefcount(b)
m = self._view(b)
oldviewrefcount = sys.getrefcount(m)
s = str(m, "utf-8")
self._check_contents(tp, b, s.encode("utf-8"))
self.assertEqual(sys.getrefcount(m), oldviewrefcount)
m = None
self.assertEqual(sys.getrefcount(b), oldrefcount)
def test_gc(self):
for tp in self._types:
if not isinstance(tp, type):
# If tp is a factory rather than a plain type, skip
continue
class MyView():
def __init__(self, base):
self.m = memoryview(base)
class MySource(tp):
pass
# Create a reference cycle through a memoryview object.
# This exercises mbuf_clear().
b = MySource(tp(b'abc'))
m = self._view(b)
o = MyObject()
b.m = m
b.o = o
wr = weakref.ref(o)
b = m = o = None
# The cycle must be broken
gc.collect()
self.assertTrue(wr() is None, wr())
# This exercises memory_clear().
m = MyView(tp(b'abc'))
o = MyObject()
m.x = m
m.o = o
wr = weakref.ref(o)
m = o = None
# The cycle must be broken
gc.collect()
self.assertTrue(wr() is None, wr())
def _check_released(self, m, tp):
check = self.assertRaisesRegex(ValueError, "released")
with check: bytes(m)
with check: m.tobytes()
with check: m.tolist()
with check: m[0]
with check: m[0] = b'x'
with check: len(m)
with check: m.format
with check: m.itemsize
with check: m.ndim
with check: m.readonly
with check: m.shape
with check: m.strides
with check:
with m:
pass
# str() and repr() still function
self.assertIn("released memory", str(m))
self.assertIn("released memory", repr(m))
self.assertEqual(m, m)
self.assertNotEqual(m, memoryview(tp(self._source)))
self.assertNotEqual(m, tp(self._source))
def test_contextmanager(self):
for tp in self._types:
b = tp(self._source)
m = self._view(b)
with m as cm:
self.assertIs(cm, m)
self._check_released(m, tp)
m = self._view(b)
# Can release explicitly inside the context manager
with m:
m.release()
def test_release(self):
for tp in self._types:
b = tp(self._source)
m = self._view(b)
m.release()
self._check_released(m, tp)
# Can be called a second time (it's a no-op)
m.release()
self._check_released(m, tp)
def test_writable_readonly(self):
# Issue #10451: memoryview incorrectly exposes a readonly
# buffer as writable causing a segfault if using mmap
tp = self.ro_type
if tp is None:
self.skipTest("no read-only type to test")
b = tp(self._source)
m = self._view(b)
i = io.BytesIO(b'ZZZZ')
self.assertRaises(TypeError, i.readinto, m)
def test_getbuf_fail(self):
self.assertRaises(TypeError, self._view, {})
def test_hash(self):
# Memoryviews of readonly (hashable) types are hashable, and they
# hash as hash(obj.tobytes()).
tp = self.ro_type
if tp is None:
self.skipTest("no read-only type to test")
b = tp(self._source)
m = self._view(b)
self.assertEqual(hash(m), hash(b"abcdef"))
# Releasing the memoryview keeps the stored hash value (as with weakrefs)
m.release()
self.assertEqual(hash(m), hash(b"abcdef"))
# Hashing a memoryview for the first time after it is released
# results in an error (as with weakrefs).
m = self._view(b)
m.release()
self.assertRaises(ValueError, hash, m)
def test_hash_writable(self):
# Memoryviews of writable types are unhashable
tp = self.rw_type
if tp is None:
self.skipTest("no writable type to test")
b = tp(self._source)
m = self._view(b)
self.assertRaises(ValueError, hash, m)
def test_weakref(self):
# Check memoryviews are weakrefable
for tp in self._types:
b = tp(self._source)
m = self._view(b)
L = []
def callback(wr, b=b):
L.append(b)
wr = weakref.ref(m, callback)
self.assertIs(wr(), m)
del m
test.support.gc_collect()
self.assertIs(wr(), None)
self.assertIs(L[0], b)
def test_reversed(self):
for tp in self._types:
b = tp(self._source)
m = self._view(b)
aslist = list(reversed(m.tolist()))
self.assertEqual(list(reversed(m)), aslist)
self.assertEqual(list(reversed(m)), list(m[::-1]))
def test_toreadonly(self):
for tp in self._types:
b = tp(self._source)
m = self._view(b)
mm = m.toreadonly()
self.assertTrue(mm.readonly)
self.assertTrue(memoryview(mm).readonly)
self.assertEqual(mm.tolist(), m.tolist())
mm.release()
m.tolist()
def test_issue22668(self):
a = array.array('H', [256, 256, 256, 256])
x = memoryview(a)
m = x.cast('B')
b = m.cast('H')
c = b[0:2]
d = memoryview(b)
del b
self.assertEqual(c[0], 256)
self.assertEqual(d[0], 256)
self.assertEqual(c.format, "H")
self.assertEqual(d.format, "H")
_ = m.cast('I')
self.assertEqual(c[0], 256)
self.assertEqual(d[0], 256)
self.assertEqual(c.format, "H")
self.assertEqual(d.format, "H")
# Variations on source objects for the buffer: bytes-like objects, then arrays
# with itemsize > 1.
# NOTE: support for multi-dimensional objects is unimplemented.
class BaseBytesMemoryTests(AbstractMemoryTests):
ro_type = bytes
rw_type = bytearray
getitem_type = bytes
itemsize = 1
format = 'B'
class BaseArrayMemoryTests(AbstractMemoryTests):
ro_type = None
rw_type = lambda self, b: array.array('i', list(b))
getitem_type = lambda self, b: array.array('i', list(b)).tobytes()
itemsize = array.array('i').itemsize
format = 'i'
@unittest.skip('XXX test should be adapted for non-byte buffers')
def test_getbuffer(self):
pass
@unittest.skip('XXX NotImplementedError: tolist() only supports byte views')
def test_tolist(self):
pass
# Variations on indirection levels: memoryview, slice of memoryview,
# slice of slice of memoryview.
# This is important to test allocation subtleties.
class BaseMemoryviewTests:
def _view(self, obj):
return memoryview(obj)
def _check_contents(self, tp, obj, contents):
self.assertEqual(obj, tp(contents))
class BaseMemorySliceTests:
source_bytes = b"XabcdefY"
def _view(self, obj):
m = memoryview(obj)
return m[1:7]
def _check_contents(self, tp, obj, contents):
self.assertEqual(obj[1:7], tp(contents))
def test_refs(self):
for tp in self._types:
m = memoryview(tp(self._source))
oldrefcount = sys.getrefcount(m)
m[1:2]
self.assertEqual(sys.getrefcount(m), oldrefcount)
class BaseMemorySliceSliceTests:
source_bytes = b"XabcdefY"
def _view(self, obj):
m = memoryview(obj)
return m[:7][1:]
def _check_contents(self, tp, obj, contents):
self.assertEqual(obj[1:7], tp(contents))
# Concrete test classes
class BytesMemoryviewTest(unittest.TestCase,
BaseMemoryviewTests, BaseBytesMemoryTests):
def test_constructor(self):
for tp in self._types:
ob = tp(self._source)
self.assertTrue(memoryview(ob))
self.assertTrue(memoryview(object=ob))
self.assertRaises(TypeError, memoryview)
self.assertRaises(TypeError, memoryview, ob, ob)
self.assertRaises(TypeError, memoryview, argument=ob)
self.assertRaises(TypeError, memoryview, ob, argument=True)
class ArrayMemoryviewTest(unittest.TestCase,
BaseMemoryviewTests, BaseArrayMemoryTests):
def test_array_assign(self):
# Issue #4569: segfault when mutating a memoryview with itemsize != 1
a = array.array('i', range(10))
m = memoryview(a)
new_a = array.array('i', range(9, -1, -1))
m[:] = new_a
self.assertEqual(a, new_a)
class BytesMemorySliceTest(unittest.TestCase,
BaseMemorySliceTests, BaseBytesMemoryTests):
pass
class ArrayMemorySliceTest(unittest.TestCase,
BaseMemorySliceTests, BaseArrayMemoryTests):
pass
class BytesMemorySliceSliceTest(unittest.TestCase,
BaseMemorySliceSliceTests, BaseBytesMemoryTests):
pass
class ArrayMemorySliceSliceTest(unittest.TestCase,
BaseMemorySliceSliceTests, BaseArrayMemoryTests):
pass
class OtherTest(unittest.TestCase):
def test_ctypes_cast(self):
# Issue 15944: Allow all source formats when casting to bytes.
ctypes = import_helper.import_module("ctypes")
p6 = bytes(ctypes.c_double(0.6))
d = ctypes.c_double()
m = memoryview(d).cast("B")
m[:2] = p6[:2]
m[2:] = p6[2:]
self.assertEqual(d.value, 0.6)
for format in "Bbc":
with self.subTest(format):
d = ctypes.c_double()
m = memoryview(d).cast(format)
m[:2] = memoryview(p6).cast(format)[:2]
m[2:] = memoryview(p6).cast(format)[2:]
self.assertEqual(d.value, 0.6)
def test_half_float(self):
half_data = struct.pack('eee', 0.0, -1.5, 1.5)
float_data = struct.pack('fff', 0.0, -1.5, 1.5)
half_view = memoryview(half_data).cast('e')
float_view = memoryview(float_data).cast('f')
self.assertEqual(half_view.nbytes * 2, float_view.nbytes)
self.assertListEqual(half_view.tolist(), float_view.tolist())
def test_memoryview_hex(self):
# Issue #9951: memoryview.hex() segfaults with non-contiguous buffers.
x = b'0' * 200000
m1 = memoryview(x)
m2 = m1[::-1]
self.assertEqual(m2.hex(), '30' * 200000)
def test_copy(self):
m = memoryview(b'abc')
with self.assertRaises(TypeError):
copy.copy(m)
def test_pickle(self):
m = memoryview(b'abc')
for proto in range(pickle.HIGHEST_PROTOCOL + 1):
with self.assertRaises(TypeError):
pickle.dumps(m, proto)
def test_use_released_memory(self):
# gh-92888: Previously it was possible to use a memoryview even after
# backing buffer is freed in certain cases. This tests that those
# cases raise an exception.
size = 128
def release():
m.release()
nonlocal ba
ba = bytearray(size)
class MyIndex:
def __index__(self):
release()
return 4
class MyFloat:
def __float__(self):
release()
return 4.25
class MyBool:
def __bool__(self):
release()
return True
ba = None
m = memoryview(bytearray(b'\xff'*size))
with self.assertRaises(ValueError):
m[MyIndex()]
ba = None
m = memoryview(bytearray(b'\xff'*size))
self.assertEqual(list(m[:MyIndex()]), [255] * 4)
ba = None
m = memoryview(bytearray(b'\xff'*size))
self.assertEqual(list(m[MyIndex():8]), [255] * 4)
ba = None
m = memoryview(bytearray(b'\xff'*size)).cast('B', (64, 2))
with self.assertRaisesRegex(ValueError, "operation forbidden"):
m[MyIndex(), 0]
ba = None
m = memoryview(bytearray(b'\xff'*size)).cast('B', (2, 64))
with self.assertRaisesRegex(ValueError, "operation forbidden"):
m[0, MyIndex()]
ba = None
m = memoryview(bytearray(b'\xff'*size))
with self.assertRaisesRegex(ValueError, "operation forbidden"):
m[MyIndex()] = 42
self.assertEqual(ba[:8], b'\0'*8)
ba = None
m = memoryview(bytearray(b'\xff'*size))
with self.assertRaisesRegex(ValueError, "operation forbidden"):
m[:MyIndex()] = b'spam'
self.assertEqual(ba[:8], b'\0'*8)
ba = None
m = memoryview(bytearray(b'\xff'*size))
with self.assertRaisesRegex(ValueError, "operation forbidden"):
m[MyIndex():8] = b'spam'
self.assertEqual(ba[:8], b'\0'*8)
ba = None
m = memoryview(bytearray(b'\xff'*size)).cast('B', (64, 2))
with self.assertRaisesRegex(ValueError, "operation forbidden"):
m[MyIndex(), 0] = 42
self.assertEqual(ba[8:16], b'\0'*8)
ba = None
m = memoryview(bytearray(b'\xff'*size)).cast('B', (2, 64))
with self.assertRaisesRegex(ValueError, "operation forbidden"):
m[0, MyIndex()] = 42
self.assertEqual(ba[:8], b'\0'*8)
ba = None
m = memoryview(bytearray(b'\xff'*size))
with self.assertRaisesRegex(ValueError, "operation forbidden"):
m[0] = MyIndex()
self.assertEqual(ba[:8], b'\0'*8)
for fmt in 'bhilqnBHILQN':
with self.subTest(fmt=fmt):
ba = None
m = memoryview(bytearray(b'\xff'*size)).cast(fmt)
with self.assertRaisesRegex(ValueError, "operation forbidden"):
m[0] = MyIndex()
self.assertEqual(ba[:8], b'\0'*8)
for fmt in 'fd':
with self.subTest(fmt=fmt):
ba = None
m = memoryview(bytearray(b'\xff'*size)).cast(fmt)
with self.assertRaisesRegex(ValueError, "operation forbidden"):
m[0] = MyFloat()
self.assertEqual(ba[:8], b'\0'*8)
ba = None
m = memoryview(bytearray(b'\xff'*size)).cast('?')
with self.assertRaisesRegex(ValueError, "operation forbidden"):
m[0] = MyBool()
self.assertEqual(ba[:8], b'\0'*8)
def test_buffer_reference_loop(self):
m = memoryview(b'abc').__buffer__(0)
o = MyObject()
o.m = m
o.o = o
wr = weakref.ref(o)
del m, o
gc.collect()
self.assertIsNone(wr())
def test_picklebuffer_reference_loop(self):
pb = pickle.PickleBuffer(memoryview(b'abc'))
o = MyObject()
o.pb = pb
o.o = o
wr = weakref.ref(o)
del pb, o
gc.collect()
self.assertIsNone(wr())
if __name__ == "__main__":
unittest.main()
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