File: test_mmap.py

package info (click to toggle)
pypy3 7.3.19%2Bdfsg-2
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 212,236 kB
  • sloc: python: 2,098,316; ansic: 540,565; sh: 21,462; asm: 14,419; cpp: 4,451; makefile: 4,209; objc: 761; xml: 530; exp: 499; javascript: 314; pascal: 244; lisp: 45; csh: 12; awk: 4
file content (942 lines) | stat: -rw-r--r-- 29,050 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
from __future__ import with_statement
from rpython.tool.udir import udir
import os, sys, py

class AppTestMMap:
    spaceconfig = dict(usemodules=('mmap',))

    def setup_class(cls):
        cls.w_tmpname = cls.space.wrap(str(udir.join('mmap-')))

    def setup_method(self, meth):
        if getattr(meth, 'is_large', False):
            if sys.maxsize < 2**32 and not self.runappdirect:
                # this fails because it uses ll2ctypes to call the posix
                # functions like 'open' and 'lseek', whereas a real compiled
                # C program would macro-define them to their longlong versions
                py.test.skip("emulation of files can't use "
                             "larger-than-long offsets")

    def test_page_size(self):
        import mmap
        assert mmap.PAGESIZE > 0
        assert mmap.ALLOCATIONGRANULARITY > 0
        assert isinstance(mmap.PAGESIZE, int)
        assert isinstance(mmap.ALLOCATIONGRANULARITY, int)
        assert mmap.ALLOCATIONGRANULARITY % mmap.PAGESIZE == 0

    def test_attributes(self):
        import mmap
        import os, sys
        assert isinstance(mmap.ACCESS_READ, int)
        assert isinstance(mmap.ACCESS_WRITE, int)
        assert isinstance(mmap.ACCESS_COPY, int)
        assert isinstance(mmap.ACCESS_DEFAULT, int)
        if os.name == "posix":
            assert isinstance(mmap.MAP_ANON, int)
            assert isinstance(mmap.MAP_ANONYMOUS, int)
            assert isinstance(mmap.MAP_PRIVATE, int)
            assert isinstance(mmap.MAP_SHARED, int)
            assert isinstance(mmap.PROT_EXEC, int)
            assert isinstance(mmap.PROT_READ, int)
            assert isinstance(mmap.PROT_WRITE, int)
            if sys.platform.startswith('linux'):
                assert isinstance(mmap.MAP_POPULATE, int)

        assert mmap.error is OSError

    def test_args(self):
        from mmap import mmap
        import os
        import sys

        raises(TypeError, mmap, "foo")
        raises(TypeError, mmap, 0, "foo")

        if os.name == "posix":
            raises(ValueError, mmap, 0, 1, 2, 3, 4)
            raises(TypeError, mmap, 0, 1, 2, 3, "foo", 5)
            raises(TypeError, mmap, 0, 1, foo="foo")
            raises((TypeError, OverflowError), mmap, 0, -1)
            raises(OverflowError, mmap, 0, sys.maxsize ** 3)
            raises(ValueError, mmap, 0, 1, flags=2, access=3)
            raises(ValueError, mmap, 0, 1, access=123)
        elif os.name == "nt":
            raises(TypeError, mmap, 0, 1, 2, 3, 4)
            raises(TypeError, mmap, 0, 1, tagname=123)
            raises(TypeError, mmap, 0, 1, access="foo")
            raises(ValueError, mmap, 0, 1, access=-1)

    def test_subclass(self):
        import mmap
        class anon_mmap(mmap.mmap):
            def __new__(klass, *args, **kwargs):
                return mmap.mmap.__new__(klass, -1, *args, **kwargs)
        anon_mmap(mmap.PAGESIZE)

    def test_file_size(self):
        import os
        if os.name == "nt":
            skip("Only Unix checks file size")

        from mmap import mmap
        f = open(self.tmpname + "a", "wb+")

        f.write(b"c")
        ret = f.flush()
        assert ret is None
        raises(ValueError, mmap, f.fileno(), 123)
        f.close()

    def test_create(self):
        from mmap import mmap
        f = open(self.tmpname + "b", "wb+")

        f.write(b"c")
        f.flush()
        m = mmap(f.fileno(), 1)
        assert m.read(99) == b"c"

        f.close()

    def test_close(self):
        from mmap import mmap
        f = open(self.tmpname + "c", "wb+")

        f.write(b"c")
        f.flush()
        m = mmap(f.fileno(), 1)
        m.close()
        raises(ValueError, m.read, 1)
        raises(ValueError, len, m)

    def test_read_byte(self):
        from mmap import mmap
        f = open(self.tmpname + "d", "wb+")

        f.write(b"c")
        f.flush()
        m = mmap(f.fileno(), 1)
        assert m.read_byte() == ord(b"c")
        raises(ValueError, m.read_byte)
        m.close()
        f.close()

    def test_readline(self):
        from mmap import mmap
        import os
        with open(self.tmpname + "e", "wb+") as f:
            f.write(b"foo\n")
            f.flush()
            with mmap(f.fileno(), 4) as m:
                result = m.readline()
                assert result == b"foo\n"
                assert m.readline() == b""

    def test_read(self):
        from mmap import mmap
        f = open(self.tmpname + "f", "wb+")

        f.write(b"foobar")
        f.flush()
        m = mmap(f.fileno(), 6)
        raises(TypeError, m.read, b"foo")
        assert m.read(1) == b"f"
        assert m.read(6) == b"oobar"
        assert m.read(1) == b""
        m.close()
        f.close()

    def test_find(self):
        from mmap import mmap
        f = open(self.tmpname + "g", "wb+")

        f.write(b"foobar\0")
        f.flush()
        m = mmap(f.fileno(), 7)
        raises(TypeError, m.find, 123)
        raises(TypeError, m.find, b"foo", b"baz")
        assert m.find(b"b") == 3
        assert m.find(b"z") == -1
        assert m.find(b"o", 5) == -1
        assert m.find(b"ob") == 2
        assert m.find(b"\0") == 6
        assert m.find(b"ob", 1) == 2
        assert m.find(b"ob", 2) == 2
        assert m.find(b"ob", 3) == -1
        assert m.find(b"ob", -4) == -1
        assert m.find(b"ob", -5) == 2
        assert m.find(b"ob", -999999999) == 2
        assert m.find(b"ob", 1, 3) == -1
        assert m.find(b"ob", 1, 4) == 2
        assert m.find(b"ob", 1, 999999999) == 2
        assert m.find(b"ob", 1, 0) == -1
        assert m.find(b"ob", 1, -1) == 2
        assert m.find(b"ob", 1, -3) == 2
        assert m.find(b"ob", 1, -4) == -1
        #
        data = m.read(2)
        assert data == b"fo"
        assert m.find(b"o") == 2
        assert m.find(b"oo") == -1
        assert m.find(b"o", 0) == 1
        m.close()
        f.close()

    def test_rfind(self):
        from mmap import mmap
        f = open(self.tmpname + "g", "wb+")

        f.write(b"foobarfoobar\0")
        f.flush()
        m = mmap(f.fileno(), 13)
        raises(TypeError, m.rfind, 123)
        raises(TypeError, m.rfind, b"foo", b"baz")
        assert m.rfind(b"b") == 9
        assert m.rfind(b"z") == -1
        assert m.rfind(b"o", 11) == -1
        assert m.rfind(b"ob") == 8
        assert m.rfind(b"\0") == 12
        assert m.rfind(b"ob", 7) == 8
        assert m.rfind(b"ob", 8) == 8
        assert m.rfind(b"ob", 9) == -1
        assert m.rfind(b"ob", -4) == -1
        assert m.rfind(b"ob", -5) == 8
        assert m.rfind(b"ob", -999999999) == 8
        assert m.rfind(b"ob", 1, 3) == -1
        assert m.rfind(b"ob", 1, 4) == 2
        assert m.rfind(b"ob", 1, 999999999) == 8
        assert m.rfind(b"ob", 1, 0) == -1
        assert m.rfind(b"ob", 1, -1) == 8
        assert m.rfind(b"ob", 1, -3) == 8
        assert m.rfind(b"ob", 1, -4) == 2
        #
        data = m.read(8)
        assert data == b"foobarfo"
        assert m.rfind(b"o") == 8
        assert m.rfind(b"oo") == -1
        assert m.rfind(b"o", 0) == 8
        m.close()
        f.close()

    def test_is_modifiable(self):
        import mmap
        f = open(self.tmpname + "h", "wb+")

        f.write(b"foobar")
        f.flush()
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_READ)
        raises(TypeError, m.write, b'x')
        raises(TypeError, m.resize, 7)
        m.close()
        f.close()

    def test_seek(self):
        from mmap import mmap
        f = open(self.tmpname + "i", "wb+")

        f.write(b"foobar")
        f.flush()
        m = mmap(f.fileno(), 6)
        raises(TypeError, m.seek, b"foo")
        raises(TypeError, m.seek, 0, b"foo")
        raises(ValueError, m.seek, -1, 0)
        raises(ValueError, m.seek, -1, 1)
        raises(ValueError, m.seek, -7, 2)
        raises(ValueError, m.seek, 1, 3)
        raises(ValueError, m.seek, 10)
        m.seek(0)
        assert m.tell() == 0
        m.read(1)
        m.seek(1, 1)
        assert m.tell() == 2
        m.seek(0)
        m.seek(-1, 2)
        assert m.tell() == 5
        m.close()
        f.close()

    def test_write(self):
        import mmap
        f = open(self.tmpname + "j", "wb+")

        f.write(b"foobar")
        f.flush()
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_READ)
        raises(TypeError, m.write, b"foo")
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_WRITE)
        raises(TypeError, m.write, 123)
        raises(ValueError, m.write, b"c"*10)
        assert m.write(b"ciao\n") == 5
        m.seek(0)
        assert m.read(6) == b"ciao\nr"
        m.close()

    def test_write_byte(self):
        import mmap
        f = open(self.tmpname + "k", "wb+")

        f.write(b"foobar")
        f.flush()
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_READ)
        raises(TypeError, m.write_byte, b"f")
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_WRITE)
        raises(TypeError, m.write_byte, "a")
        raises(TypeError, m.write_byte, b"a")
        m.write_byte(ord("x"))
        m.seek(0)
        assert m.read(6) == b"xoobar"
        m.close()

    def test_size(self):
        from mmap import mmap
        f = open(self.tmpname + "l", "wb+")

        f.write(b"foobar")
        f.flush()
        m = mmap(f.fileno(), 5)
        assert m.size() == 6 # size of the underline file, not the mmap
        m.close()
        f.close()

    def test_tell(self):
        from mmap import mmap
        f = open(self.tmpname + "m", "wb+")

        f.write(b"c")
        f.flush()
        m = mmap(f.fileno(), 1)
        assert m.tell() >= 0
        m.close()
        f.close()

    def test_flush(self):
        from mmap import mmap
        f = open(self.tmpname + "n", "wb+")

        f.write(b"foobar")
        f.flush()
        m = mmap(f.fileno(), 6)
        raises(TypeError, m.flush, 1, 2, 3)
        raises(TypeError, m.flush, 1, b"a")
        raises(ValueError, m.flush, 0, 99)
        m.flush()    # return value is a bit meaningless, platform-dependent
        m.close()
        f.close()

    def test_length_0_large_offset(self):
        import mmap

        with open(self.tmpname, "wb") as f:
            f.write(115699 * b'm')
        with open(self.tmpname, "w+b") as f:
            raises(ValueError, mmap.mmap, f.fileno(), 0, offset=2147418112)

    def test_move(self):
        import mmap
        f = open(self.tmpname + "o", "wb+")

        f.write(b"foobar")
        f.flush()
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_READ)
        raises(TypeError, m.move, 1)
        raises(TypeError, m.move, 1, b"foo", 2)
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_WRITE)
        raises(ValueError, m.move, 7, 1, 2)
        raises(ValueError, m.move, 1, 7, 2)
        m.move(1, 3, 3)
        assert m.read(6) == b"fbarar"
        m.seek(0)
        m.move(1, 3, 2)
        a = m.read(6)
        assert a == b"frarar"
        m.close()
        f.close()

    def test_resize(self):
        import sys
        if ("darwin" in sys.platform) or ("freebsd" in sys.platform):
            skip("resize does not work under OSX or FreeBSD")

        import mmap
        import os

        f = open(self.tmpname + "p", "wb+")
        f.write(b"foobar")
        f.flush()
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_READ)
        raises(TypeError, m.resize, 1)
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_COPY)
        raises(TypeError, m.resize, 1)
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_WRITE)
        f_size = os.fstat(f.fileno()).st_size
        assert m.size() == f_size == 6
        m.resize(10)
        f_size = os.fstat(f.fileno()).st_size
        assert m.size() == f_size == 10
        m.close()
        f.close()

    def test_resize_bsd(self):
        import sys
        if ("darwin" not in sys.platform) and ("freebsd" not in sys.platform):
            skip("resize works under not OSX or FreeBSD")

        import mmap
        import os

        f = open(self.tmpname + "p", "wb+")
        f.write(b"foobar")
        f.flush()
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_READ)
        raises(TypeError, m.resize, 1)
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_COPY)
        raises(TypeError, m.resize, 1)
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_WRITE)
        f_size = os.fstat(f.fileno()).st_size
        assert m.size() == f_size == 6
        raises(SystemError, m.resize, 10)
        f_size = os.fstat(f.fileno()).st_size
        assert m.size() == f_size == 6

    def test_len(self):
        from mmap import mmap

        f = open(self.tmpname + "q", "wb+")
        f.write(b"foobar")
        f.flush()

        m = mmap(f.fileno(), 6)
        assert len(m) == 6
        m.close()
        f.close()

    def test_get_item(self):
        from mmap import mmap

        f = open(self.tmpname + "r", "wb+")
        f.write(b"foobar")
        f.flush()

        m = mmap(f.fileno(), 6)
        fn = lambda: m[b"foo"]
        raises(TypeError, fn)
        fn = lambda: m[-7]
        raises(IndexError, fn)
        assert m[0] == ord('f')
        assert m[-1] == ord('r')
        assert m[1::2] == b'obr'
        assert m[4:1:-2] == b'ao'
        m.close()
        f.close()

    def test_get_crash(self):
        import sys
        from mmap import mmap
        s = b'hallo!!!'
        m = mmap(-1, len(s))
        m[:] = s
        assert m[1:None:sys.maxsize] == b'a'
        m.close()

    def test_set_item(self):
        import mmap

        f = open(self.tmpname + "s", "wb+")
        f.write(b"foobar")
        f.flush()

        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_READ)
        def fn(): m[1] = b'a'
        raises(TypeError, fn)
        m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_WRITE)
        def fn(): m[b"foo"] = b'a'
        raises(TypeError, fn)
        def fn(): m[-7] = b'a'
        raises(IndexError, fn)
        def fn(): m[1:3] = 'xx'
        raises((IndexError, TypeError), fn)      # IndexError is in CPython,
                                                 # but doesn't make much sense
        def fn(): m[1:4] = b"zz"
        raises((IndexError, ValueError), fn)
        def fn(): m[1:6] = b"z" * 6
        raises((IndexError, ValueError), fn)
        def fn(): m[:2] = b"z" * 5
        raises((IndexError, ValueError), fn)
        def fn(): m[0] = 256
        raises(ValueError, fn)
        m[1:3] = b'xx'
        assert m.read(6) == b"fxxbar"
        m[0] = ord('x')
        assert m[0] == ord('x')
        m[-6] = ord('y')
        m[3:6:2] = b'BR'
        m.seek(0)
        data = m.read(6)
        assert data == b"yxxBaR"
        m.close()
        f.close()

    def test_del_item(self):
        from mmap import mmap

        f = open(self.tmpname + "t", "wb+")
        f.write(b"foobar")
        f.flush()

        m = mmap(f.fileno(), 6)
        def fn(): del m[b"foo"]
        raises(TypeError, fn)
        def fn(): del m[1:3]
        raises(TypeError, fn)
        def fn(): del m[1]
        raises(TypeError, fn)
        m.close()
        f.close()

    def test_concatenation(self):
        from mmap import mmap

        f = open(self.tmpname + "u", "wb+")
        f.write(b"foobar")
        f.flush()

        m = mmap(f.fileno(), 6)
        def fn(): m + 1
        raises((SystemError, TypeError), fn)     # SystemError is in CPython,
        def fn(m): m += 1                        # but it doesn't make much
        raises((SystemError, TypeError), fn, m)  # sense
        def fn(): 1 + m
        raises(TypeError, fn)
        m.close()
        f.close()

    def test_repeatition(self):
        from mmap import mmap

        f = open(self.tmpname + "v", "wb+")
        f.write(b"foobar")
        f.flush()

        m = mmap(f.fileno(), 6)
        def fn(): m * 1
        raises((SystemError, TypeError), fn)      # SystemError is in CPython,
        def fn(m): m *= 1                         # but it
        raises((SystemError, TypeError), fn, m)   # doesn't
        def fn(): 1 * m                           # make much sense
        raises((SystemError, TypeError), fn)
        m.close()
        f.close()

    def test_slicing(self):
        from mmap import mmap

        f = open(self.tmpname + "v", "wb+")
        f.write(b"foobar")
        f.flush()

        f.seek(0)
        m = mmap(f.fileno(), 6)
        assert m[-3:7] == b"bar"

        assert m[1:0:1] == b""

        f.close()

    def test_memoryview(self):
        from mmap import mmap
        filename = self.tmpname + "y"
        with open(filename, "bw+") as f:
            f.write(b"foobar")
            f.flush()
            with mmap(f.fileno(), 6) as m:
                b = memoryview(m)
                assert len(b) == 6
                assert b.readonly is False
                assert b[3] == ord(b"b")
                assert b[:] == b"foobar"
                del b  # For CPython: "exported pointers exist"
        try:
            from mmap import PROT_READ
        except ImportError:
            skip('no PROT_READ') 
        with open(filename, "rb") as f:
            m = mmap(f.fileno(), 6, prot=PROT_READ)
            b = memoryview(m)
            assert b.readonly is True
            assert b[:] == b"foobar"
            del b
            m.close()

    def test_offset(self):
        from mmap import mmap, ALLOCATIONGRANULARITY
        filename = self.tmpname + "y"
        with open(filename, "wb+") as f:
            f.write(b"foobar" * ALLOCATIONGRANULARITY)
            f.flush()
            size = ALLOCATIONGRANULARITY
            offset = 2 * ALLOCATIONGRANULARITY
            m = mmap(f.fileno(), size, offset=offset)
            assert m[:] == (b"foobar" * ALLOCATIONGRANULARITY)[offset:offset+size]
            assert len(m) == size
            m.close()

    def test_offset_more(self):
        from mmap import mmap, ALLOCATIONGRANULARITY

        with open(self.tmpname, "w+b") as f:
            halfsize = ALLOCATIONGRANULARITY
            f.write(b"\0" * halfsize)
            f.write(b"foo")
            f.write(b"\0" * (halfsize - 3))
            m = mmap(f.fileno(), 0)
            m.close()

        with open(self.tmpname, "r+b") as f:
            m = mmap(f.fileno(), halfsize, offset=halfsize)
            assert m[0:3] == b"foo"

        try:
            m.resize(512)
        except SystemError:
            pass
        else:
            assert len(m) == 512
            raises(ValueError, m.seek, 513, 0)
            assert m[0:3] == b"foo"
            with open(self.tmpname) as f:
                f.seek(0, 2)
                assert f.tell() == halfsize + 512
            assert m.size() == halfsize + 512
        m.close()

    def test_large_offset(self):
        import mmap
        import sys
        size = 0x14FFFFFFF
        if sys.platform.startswith('win') or sys.platform == 'darwin':
            skip('test requires %s bytes and a long time to run' % size)

        with open(self.tmpname, "w+b") as f:
            f.seek(size)
            f.write(b"A")
            f.flush()
        with open(self.tmpname, 'rb') as f2:
            f2.seek(size)
            c = f2.read(1)
            assert c == b'A'
            m = mmap.mmap(f2.fileno(), 0, offset=0x140000000,
                          access=mmap.ACCESS_READ)
            try:
                assert m[0xFFFFFFF] == ord('A')
            finally:
                m.close()
    test_large_offset.is_large = True

    def test_large_filesize(self):
        import mmap
        import sys
        size = 0x17FFFFFFF
        if sys.platform.startswith('win') or sys.platform == 'darwin':
            skip('test requires %s bytes and a long time to run' % size)

        with open(self.tmpname, "w+b") as f:
            f.seek(size)
            f.write(b" ")
            f.flush()
            m = mmap.mmap(f.fileno(), 0x10000, access=mmap.ACCESS_READ)
            try:
                assert m.size() ==  0x180000000
            finally:
                m.close()
    test_large_filesize.is_large = True

    def test_context_manager(self):
        import mmap
        with mmap.mmap(-1, 10) as m:
            assert not m.closed
        assert m.closed

    def test_all(self):
        # this is a global test, ported from test_mmap.py
        import mmap
        from mmap import PAGESIZE
        import sys
        import os

        filename = self.tmpname + "w"

        f = open(filename, "wb+")

        # write 2 pages worth of data to the file
        f.write(b'\0' * PAGESIZE)
        f.write(b'foo')
        f.write(b'\0' * (PAGESIZE - 3))
        f.flush()
        m = mmap.mmap(f.fileno(), 2 * PAGESIZE)
        f.close()

        # sanity checks
        assert m.find(b"foo") == PAGESIZE
        assert len(m) == 2 * PAGESIZE
        assert m[0] == 0
        assert m[0:3] == b'\0\0\0'

        # modify the file's content
        m[0] = ord('3')
        m[PAGESIZE+3:PAGESIZE+3+3] = b'bar'

        # check that the modification worked
        assert m[0] == ord('3')
        assert m[0:3] == b'3\0\0'
        assert m[PAGESIZE-1:PAGESIZE+7] == b'\0foobar\0'

        m.flush()

        # test seeking around
        m.seek(0,0)
        assert m.tell() == 0
        m.seek(42, 1)
        assert m.tell() == 42
        m.seek(0, 2)
        assert m.tell() == len(m)

        raises(ValueError, m.seek, -1)
        raises(ValueError, m.seek, 1, 2)
        raises(ValueError, m.seek, -len(m) - 1, 2)

        # try resizing map
        if not (("darwin" in sys.platform) or ("freebsd" in sys.platform)):
            m.resize(512)

            assert len(m) == 512
            raises(ValueError, m.seek, 513, 0)

            # check that the underlying file is truncated too
            f = open(filename)
            f.seek(0, 2)
            assert f.tell() == 512
            f.close()
            assert m.size() == 512

        m.close()
        f.close()

        # test access=ACCESS_READ
        mapsize = 10
        f = open(filename, "wb")
        f.write(b"a" * mapsize)
        f.close()
        f = open(filename, "rb")
        m = mmap.mmap(f.fileno(), mapsize, access=mmap.ACCESS_READ)
        assert m[:] == b'a' * mapsize
        def f(m): m[:] = b'b' * mapsize
        raises(TypeError, f, m)
        def fn(): m[0] = b'b'
        raises(TypeError, fn)
        def fn(m): m.seek(0, 0); m.write(b"abc")
        raises(TypeError, fn, m)
        def fn(m): m.seek(0, 0); m.write_byte(b"d")
        raises(TypeError, fn, m)
        if not (("darwin" in sys.platform) or ("freebsd" in sys.platform)):
            raises(TypeError, m.resize, 2 * mapsize)
            assert open(filename, "rb").read() == b'a' * mapsize

        # opening with size too big
        f = open(filename, "r+b")
        if not os.name == "nt":
            # this should work under windows
            raises(ValueError, mmap.mmap, f.fileno(), mapsize + 1)
        f.close()

        # if _MS_WINDOWS:
        #     # repair damage from the resizing test.
        #     f = open(filename, 'r+b')
        #     f.truncate(mapsize)
        #     f.close()
        m.close()

        # test access=ACCESS_WRITE"
        f = open(filename, "r+b")
        m = mmap.mmap(f.fileno(), mapsize, access=mmap.ACCESS_WRITE)
        m.write(b'c' * mapsize)
        m.seek(0)
        data = m.read(mapsize)
        assert data == b'c' * mapsize
        m.flush()
        m.close()
        f.close()
        f = open(filename, 'rb')
        stuff = f.read()
        f.close()
        assert stuff == b'c' * mapsize

        # test access=ACCESS_COPY
        f = open(filename, "r+b")
        m = mmap.mmap(f.fileno(), mapsize, access=mmap.ACCESS_COPY)
        m.write(b'd' * mapsize)
        m.seek(0)
        data = m.read(mapsize)
        assert data == b'd' * mapsize
        m.flush()
        assert open(filename, "rb").read() == b'c' * mapsize
        if not (("darwin" in sys.platform) or ("freebsd" in sys.platform)):
            raises(TypeError, m.resize, 2 * mapsize)
        m.close()
        f.close()

        # test invalid access
        f = open(filename, "r+b")
        raises(ValueError, mmap.mmap, f.fileno(), mapsize, access=4)
        f.close()

        # test incompatible parameters
        if os.name == "posix":
            f = open(filename, "r+b")
            raises(ValueError, mmap.mmap, f.fileno(), mapsize, flags=mmap.MAP_PRIVATE,
                prot=mmap.PROT_READ, access=mmap.ACCESS_WRITE)
            f.close()


        # bad file descriptor
        raises(EnvironmentError, mmap.mmap, -2, 4096)

        # do a tougher .find() test.  SF bug 515943 pointed out that, in 2.2,
        # searching for data with embedded \0 bytes didn't work.
        f = open(filename, 'wb+')
        data = b'aabaac\x00deef\x00\x00aa\x00'
        n = len(data)
        f.write(data)
        f.flush()
        m = mmap.mmap(f.fileno(), n)
        f.close()

        for start in range(n + 1):
            for finish in range(start, n + 1):
                sl = data[start:finish]
                assert m.find(sl) == data.find(sl)
                assert m.find(sl + b'x') ==  -1
        m.close()

        # test mapping of entire file by passing 0 for map length
        f = open(filename, "wb+")
        f.write(2**16 * b'm')
        f.close()
        f = open(filename, "rb+")
        m = mmap.mmap(f.fileno(), 0)
        assert len(m) == 2**16
        assert m.read(2**16) == 2**16 * b"m"
        m.close()
        f.close()

        # make move works everywhere (64-bit format problem earlier)
        f = open(filename, 'wb+')
        f.write(b"ABCDEabcde")
        f.flush()
        m = mmap.mmap(f.fileno(), 10)
        m.move(5, 0, 5)
        assert m.read(10) == b"ABCDEABCDE"
        m.close()
        f.close()

    def test_empty_file(self):
        import mmap
        f = open(self.tmpname, 'w+b')
        f.close()
        with open(self.tmpname, 'rb') as f:
            try:
                m = mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ)
                m.close()
                assert False, "should not have been able to mmap empty file"
            except ValueError as e:
                assert str(e) == "cannot mmap an empty file"
            except BaseException as e:
                assert False, "unexpected exception: " + str(e)

    def test_read_all(self):
        from mmap import mmap
        f = open(self.tmpname + "f", "wb+")
        f.write(b"foobar")
        f.flush()

        m = mmap(f.fileno(), 6)
        assert m.read(None) == b"foobar"

    def test_resize_past_pos(self):
        import os, mmap, sys
        if os.name == "nt":
            skip("cannot resize anonymous mmaps on Windows")
        if sys.version_info < (2, 7, 13):
            skip("cannot resize anonymous mmaps before 2.7.13")
        m = mmap.mmap(-1, 8192)
        m.read(5000)
        try:
            m.resize(4096)
        except SystemError:
            skip("resizing not supported")
        assert m.tell() == 5000
        assert m.read(14) == b''
        assert m.read(-1) == b''
        raises(ValueError, m.read_byte)
        assert m.readline() == b''
        raises(ValueError, m.write_byte, ord(b'b'))
        raises(ValueError, m.write, b'abc')
        assert m.tell() == 5000
        m.close()

    def test_close_while_indexing(self):
        import mmap
        with open(self.tmpname + "_crash", 'w+b') as f:
            f.write(b"foobar")
            f.flush()

            class X(object):
                def __index__(self):
                    m.close()
                    return 1

            m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_READ)
            assert m[1] == ord(b"o")
            with raises(ValueError):
                m[X()]

            m = mmap.mmap(f.fileno(), 6, access=mmap.ACCESS_READ)
            with raises(ValueError):
                m[X()] = b"u"

    def test_iter_yields_bytes(self):
        # issue 3282: inconsistency in Python 3
        from mmap import mmap
        f = open(self.tmpname + "iter", "wb+")
        f.write(b"AB")
        f.flush()

        m = mmap(f.fileno(), 2)
        assert [m[0], m[1]] == [65, 66]
        assert list(m) == [b"A", b"B"]
        assert list(iter(m)) == [b"A", b"B"]
        assert list(reversed(m)) == [b"B", b"A"]
        assert list(enumerate(m)) == [(0, b"A"), (1, b"B")]

    def test_madvise(self):
        import mmap, sys
        m = mmap.mmap(-1, 1024)
        if not hasattr(m, "madvise"):
            m.close()
            skip("no madvise")

        m.madvise(mmap.MADV_NORMAL)
        m.close()

    def test_repr(self):
        import mmap
        m = mmap.mmap(-1, 1024)
        assert repr(m) == "<mmap.mmap closed=False, access=ACCESS_DEFAULT, length=1024, pos=0, offset=0>"
        m.close()
        assert repr(m) == "<mmap.mmap closed=True>"

    def test_assign_buffer(self):
        import mmap
        m = mmap.mmap(-1, 1024)
        m[0:5] = bytearray(b'12345')
        assert m[0:5] == b'12345'