Lib/test/test_memoryview.py

   1 """Unit tests for the memoryview
   2
   3 XXX We need more tests! Some tests are in test_bytes
   4 """
   5
   6 import unittest
   7 import sys
   8 import gc
   9 import weakref
  10 import array
  11 from test import test_support
  12
  13
  14 class AbstractMemoryTests:
  15     source_bytes = b"abcdef"
  16
  17     @property
  18     def _source(self):
  19         return self.source_bytes
  20
  21     @property
  22     def _types(self):
  23         return filter(None, [self.ro_type, self.rw_type])
  24
  25     def check_getitem_with_type(self, tp):
  26         item = self.getitem_type
  27         b = tp(self._source)
  28         oldrefcount = sys.getrefcount(b)
  29         m = self._view(b)
  30         self.assertEquals(m[0], item(b"a"))
  31         self.assertIsInstance(m[0], bytes)
  32         self.assertEquals(m[5], item(b"f"))
  33         self.assertEquals(m[-1], item(b"f"))
  34         self.assertEquals(m[-6], item(b"a"))
  35         # Bounds checking
  36         self.assertRaises(IndexError, lambda: m[6])
  37         self.assertRaises(IndexError, lambda: m[-7])
  38         self.assertRaises(IndexError, lambda: m[sys.maxsize])
  39         self.assertRaises(IndexError, lambda: m[-sys.maxsize])
  40         # Type checking
  41         self.assertRaises(TypeError, lambda: m[None])
  42         self.assertRaises(TypeError, lambda: m[0.0])
  43         self.assertRaises(TypeError, lambda: m["a"])
  44         m = None
  45         self.assertEquals(sys.getrefcount(b), oldrefcount)
  46
  47     def test_getitem(self):
  48         for tp in self._types:
  49             self.check_getitem_with_type(tp)
  50
  51     def test_iter(self):
  52         for tp in self._types:
  53             b = tp(self._source)
  54             m = self._view(b)
  55             self.assertEqual(list(m), [m[i] for i in range(len(m))])
  56
  57     def test_repr(self):
  58         for tp in self._types:
  59             b = tp(self._source)
  60             m = self._view(b)
  61             self.assertIsInstance(m.__repr__(), str)
  62
  63     def test_setitem_readonly(self):
  64         if not self.ro_type:
  65             return
  66         b = self.ro_type(self._source)
  67         oldrefcount = sys.getrefcount(b)
  68         m = self._view(b)
  69         def setitem(value):
  70             m[0] = value
  71         self.assertRaises(TypeError, setitem, b"a")
  72         self.assertRaises(TypeError, setitem, 65)
  73         self.assertRaises(TypeError, setitem, memoryview(b"a"))
  74         m = None
  75         self.assertEquals(sys.getrefcount(b), oldrefcount)
  76
  77     def test_setitem_writable(self):
  78         if not self.rw_type:
  79             return
  80         tp = self.rw_type
  81         b = self.rw_type(self._source)
  82         oldrefcount = sys.getrefcount(b)
  83         m = self._view(b)
  84         m[0] = tp(b"0")
  85         self._check_contents(tp, b, b"0bcdef")
  86         m[1:3] = tp(b"12")
  87         self._check_contents(tp, b, b"012def")
  88         m[1:1] = tp(b"")
  89         self._check_contents(tp, b, b"012def")
  90         m[:] = tp(b"abcdef")
  91         self._check_contents(tp, b, b"abcdef")
  92
  93         # Overlapping copies of a view into itself
  94         m[0:3] = m[2:5]
  95         self._check_contents(tp, b, b"cdedef")
  96         m[:] = tp(b"abcdef")
  97         m[2:5] = m[0:3]
  98         self._check_contents(tp, b, b"ababcf")
  99
 100         def setitem(key, value):
 101             m[key] = tp(value)
 102         # Bounds checking
 103         self.assertRaises(IndexError, setitem, 6, b"a")
 104         self.assertRaises(IndexError, setitem, -7, b"a")
 105         self.assertRaises(IndexError, setitem, sys.maxsize, b"a")
 106         self.assertRaises(IndexError, setitem, -sys.maxsize, b"a")
 107         # Wrong index/slice types
 108         self.assertRaises(TypeError, setitem, 0.0, b"a")
 109         self.assertRaises(TypeError, setitem, (0,), b"a")
 110         self.assertRaises(TypeError, setitem, "a", b"a")
 111         # Trying to resize the memory object
 112         self.assertRaises(ValueError, setitem, 0, b"")
 113         self.assertRaises(ValueError, setitem, 0, b"ab")
 114         self.assertRaises(ValueError, setitem, slice(1,1), b"a")
 115         self.assertRaises(ValueError, setitem, slice(0,2), b"a")
 116
 117         m = None
 118         self.assertEquals(sys.getrefcount(b), oldrefcount)
 119
 120     def test_tobytes(self):
 121         for tp in self._types:
 122             m = self._view(tp(self._source))
 123             b = m.tobytes()
 124             # This calls self.getitem_type() on each separate byte of b"abcdef"
 125             expected = b"".join(
 126                 self.getitem_type(c) for c in b"abcdef")
 127             self.assertEquals(b, expected)
 128             self.assertIsInstance(b, bytes)
 129
 130     def test_tolist(self):
 131         for tp in self._types:
 132             m = self._view(tp(self._source))
 133             l = m.tolist()
 134             self.assertEquals(l, map(ord, b"abcdef"))
 135
 136     def test_compare(self):
 137         # memoryviews can compare for equality with other objects
 138         # having the buffer interface.
 139         for tp in self._types:
 140             m = self._view(tp(self._source))
 141             for tp_comp in self._types:
 142                 self.assertTrue(m == tp_comp(b"abcdef"))
 143                 self.assertFalse(m != tp_comp(b"abcdef"))
 144                 self.assertFalse(m == tp_comp(b"abcde"))
 145                 self.assertTrue(m != tp_comp(b"abcde"))
 146                 self.assertFalse(m == tp_comp(b"abcde1"))
 147                 self.assertTrue(m != tp_comp(b"abcde1"))
 148             self.assertTrue(m == m)
 149             self.assertTrue(m == m[:])
 150             self.assertTrue(m[0:6] == m[:])
 151             self.assertFalse(m[0:5] == m)
 152
 153             # Comparison with objects which don't support the buffer API
 154             self.assertFalse(m == u"abcdef")
 155             self.assertTrue(m != u"abcdef")
 156             self.assertFalse(u"abcdef" == m)
 157             self.assertTrue(u"abcdef" != m)
 158
 159             # Unordered comparisons are unimplemented, and therefore give
 160             # arbitrary results (they raise a TypeError in py3k)
 161
 162     def check_attributes_with_type(self, tp):
 163         m = self._view(tp(self._source))
 164         self.assertEquals(m.format, self.format)
 165         self.assertIsInstance(m.format, str)
 166         self.assertEquals(m.itemsize, self.itemsize)
 167         self.assertEquals(m.ndim, 1)
 168         self.assertEquals(m.shape, (6,))
 169         self.assertEquals(len(m), 6)
 170         self.assertEquals(m.strides, (self.itemsize,))
 171         self.assertEquals(m.suboffsets, None)
 172         return m
 173
 174     def test_attributes_readonly(self):
 175         if not self.ro_type:
 176             return
 177         m = self.check_attributes_with_type(self.ro_type)
 178         self.assertEquals(m.readonly, True)
 179
 180     def test_attributes_writable(self):
 181         if not self.rw_type:
 182             return
 183         m = self.check_attributes_with_type(self.rw_type)
 184         self.assertEquals(m.readonly, False)
 185
 186     # Disabled: unicode uses the old buffer API in 2.x
 187
 188     #def test_getbuffer(self):
 189         ## Test PyObject_GetBuffer() on a memoryview object.
 190         #for tp in self._types:
 191             #b = tp(self._source)
 192             #oldrefcount = sys.getrefcount(b)
 193             #m = self._view(b)
 194             #oldviewrefcount = sys.getrefcount(m)
 195             #s = unicode(m, "utf-8")
 196             #self._check_contents(tp, b, s.encode("utf-8"))
 197             #self.assertEquals(sys.getrefcount(m), oldviewrefcount)
 198             #m = None
 199             #self.assertEquals(sys.getrefcount(b), oldrefcount)
 200
 201     def test_gc(self):
 202         for tp in self._types:
 203             if not isinstance(tp, type):
 204                 # If tp is a factory rather than a plain type, skip
 205                 continue
 206
 207             class MySource(tp):
 208                 pass
 209             class MyObject:
 210                 pass
 211
 212             # Create a reference cycle through a memoryview object
 213             b = MySource(tp(b'abc'))
 214             m = self._view(b)
 215             o = MyObject()
 216             b.m = m
 217             b.o = o
 218             wr = weakref.ref(o)
 219             b = m = o = None
 220             # The cycle must be broken
 221             gc.collect()
 222             self.assertTrue(wr() is None, wr())
 223
 224
 225 # Variations on source objects for the buffer: bytes-like objects, then arrays
 226 # with itemsize > 1.
 227 # NOTE: support for multi-dimensional objects is unimplemented.
 228
 229 class BaseBytesMemoryTests(AbstractMemoryTests):
 230     ro_type = bytes
 231     rw_type = bytearray
 232     getitem_type = bytes
 233     itemsize = 1
 234     format = 'B'
 235
 236 # Disabled: array.array() does not support the new buffer API in 2.x
 237
 238 #class BaseArrayMemoryTests(AbstractMemoryTests):
 239     #ro_type = None
 240     #rw_type = lambda self, b: array.array('i', map(ord, b))
 241     #getitem_type = lambda self, b: array.array('i', map(ord, b)).tostring()
 242     #itemsize = array.array('i').itemsize
 243     #format = 'i'
 244
 245     #def test_getbuffer(self):
 246         ## XXX Test should be adapted for non-byte buffers
 247         #pass
 248
 249     #def test_tolist(self):
 250         ## XXX NotImplementedError: tolist() only supports byte views
 251         #pass
 252
 253
 254 # Variations on indirection levels: memoryview, slice of memoryview,
 255 # slice of slice of memoryview.
 256 # This is important to test allocation subtleties.
 257
 258 class BaseMemoryviewTests:
 259     def _view(self, obj):
 260         return memoryview(obj)
 261
 262     def _check_contents(self, tp, obj, contents):
 263         self.assertEquals(obj, tp(contents))
 264
 265 class BaseMemorySliceTests:
 266     source_bytes = b"XabcdefY"
 267
 268     def _view(self, obj):
 269         m = memoryview(obj)
 270         return m[1:7]
 271
 272     def _check_contents(self, tp, obj, contents):
 273         self.assertEquals(obj[1:7], tp(contents))
 274
 275     def test_refs(self):
 276         for tp in self._types:
 277             m = memoryview(tp(self._source))
 278             oldrefcount = sys.getrefcount(m)
 279             m[1:2]
 280             self.assertEquals(sys.getrefcount(m), oldrefcount)
 281
 282 class BaseMemorySliceSliceTests:
 283     source_bytes = b"XabcdefY"
 284
 285     def _view(self, obj):
 286         m = memoryview(obj)
 287         return m[:7][1:]
 288
 289     def _check_contents(self, tp, obj, contents):
 290         self.assertEquals(obj[1:7], tp(contents))
 291
 292
 293 # Concrete test classes
 294
 295 class BytesMemoryviewTest(unittest.TestCase,
 296     BaseMemoryviewTests, BaseBytesMemoryTests):
 297
 298     def test_constructor(self):
 299         for tp in self._types:
 300             ob = tp(self._source)
 301             self.assertTrue(memoryview(ob))
 302             self.assertTrue(memoryview(object=ob))
 303             self.assertRaises(TypeError, memoryview)
 304             self.assertRaises(TypeError, memoryview, ob, ob)
 305             self.assertRaises(TypeError, memoryview, argument=ob)
 306             self.assertRaises(TypeError, memoryview, ob, argument=True)
 307
 308 #class ArrayMemoryviewTest(unittest.TestCase,
 309     #BaseMemoryviewTests, BaseArrayMemoryTests):
 310
 311     #def test_array_assign(self):
 312         ## Issue #4569: segfault when mutating a memoryview with itemsize != 1
 313         #a = array.array('i', range(10))
 314         #m = memoryview(a)
 315         #new_a = array.array('i', range(9, -1, -1))
 316         #m[:] = new_a
 317         #self.assertEquals(a, new_a)
 318
 319
 320 class BytesMemorySliceTest(unittest.TestCase,
 321     BaseMemorySliceTests, BaseBytesMemoryTests):
 322     pass
 323
 324 #class ArrayMemorySliceTest(unittest.TestCase,
 325     #BaseMemorySliceTests, BaseArrayMemoryTests):
 326     #pass
 327
 328 class BytesMemorySliceSliceTest(unittest.TestCase,
 329     BaseMemorySliceSliceTests, BaseBytesMemoryTests):
 330     pass
 331
 332 #class ArrayMemorySliceSliceTest(unittest.TestCase,
 333     #BaseMemorySliceSliceTests, BaseArrayMemoryTests):
 334     #pass
 335
 336
 337 def test_main():
 338     test_support.run_unittest(__name__)
 339
 340 if __name__ == "__main__":
 341     test_main()