cpython/Lib/test/test_memoryview.py

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"""Unit tests for the memoryview
XXX We need more tests! Some tests are in test_bytes
"""
import unittest
import test.support
import sys
import gc
import weakref
import array
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):
item = self.getitem_type
b = tp(self._source)
oldrefcount = sys.getrefcount(b)
m = self._view(b)
self.assertEquals(m[0], item(b"a"))
self.assert_(isinstance(m[0], bytes), type(m[0]))
self.assertEquals(m[5], item(b"f"))
self.assertEquals(m[-1], item(b"f"))
self.assertEquals(m[-6], item(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.assertEquals(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:
return
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.assertEquals(sys.getrefcount(b), oldrefcount)
def test_setitem_writable(self):
if not self.rw_type:
return
tp = self.rw_type
b = self.rw_type(self._source)
oldrefcount = sys.getrefcount(b)
m = self._view(b)
m[0] = 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, "a", b"a")
# Trying to resize the memory object
self.assertRaises(ValueError, setitem, 0, b"")
self.assertRaises(ValueError, 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.assertEquals(sys.getrefcount(b), oldrefcount)
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.assertEquals(b, expected)
self.assert_(isinstance(b, bytes), type(b))
def test_tolist(self):
for tp in self._types:
m = self._view(tp(self._source))
l = m.tolist()
self.assertEquals(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.assertEquals(m.format, self.format)
self.assertEquals(m.itemsize, self.itemsize)
self.assertEquals(m.ndim, 1)
self.assertEquals(m.shape, (6,))
self.assertEquals(len(m), 6)
self.assertEquals(m.strides, (self.itemsize,))
self.assertEquals(m.suboffsets, None)
return m
def test_attributes_readonly(self):
if not self.ro_type:
return
m = self.check_attributes_with_type(self.ro_type)
self.assertEquals(m.readonly, True)
def test_attributes_writable(self):
if not self.rw_type:
return
m = self.check_attributes_with_type(self.rw_type)
self.assertEquals(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.assertEquals(sys.getrefcount(m), oldviewrefcount)
m = None
self.assertEquals(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 MySource(tp):
pass
class MyObject:
pass
# Create a reference cycle through a memoryview object
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.assert_(wr() is None, wr())
# 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)).tostring()
itemsize = array.array('i').itemsize
format = 'i'
def test_getbuffer(self):
# XXX Test should be adapted for non-byte buffers
pass
def test_tolist(self):
# XXX NotImplementedError: tolist() only supports byte views
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.assertEquals(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.assertEquals(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.assertEquals(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.assertEquals(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.assert_(memoryview(ob))
self.assert_(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.assertEquals(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
def test_main():
test.support.run_unittest(__name__)
if __name__ == "__main__":
test_main()