This file is indexed.

/usr/lib/python2.7/dist-packages/distlib/wheel.py is in python-distlib 0.2.2-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  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
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
# -*- coding: utf-8 -*-
#
# Copyright (C) 2013-2016 Vinay Sajip.
# Licensed to the Python Software Foundation under a contributor agreement.
# See LICENSE.txt and CONTRIBUTORS.txt.
#
from __future__ import unicode_literals

import base64
import codecs
import datetime
import distutils.util
from email import message_from_file
import hashlib
import imp
import json
import logging
import os
import posixpath
import re
import shutil
import sys
import tempfile
import zipfile

from . import __version__, DistlibException
from .compat import sysconfig, ZipFile, fsdecode, text_type, filter
from .database import InstalledDistribution
from .metadata import Metadata, METADATA_FILENAME
from .util import (FileOperator, convert_path, CSVReader, CSVWriter, Cache,
                   cached_property, get_cache_base, read_exports, tempdir)
from .version import NormalizedVersion, UnsupportedVersionError

logger = logging.getLogger(__name__)

cache = None    # created when needed

if hasattr(sys, 'pypy_version_info'):
    IMP_PREFIX = 'pp'
elif sys.platform.startswith('java'):
    IMP_PREFIX = 'jy'
elif sys.platform == 'cli':
    IMP_PREFIX = 'ip'
else:
    IMP_PREFIX = 'cp'

VER_SUFFIX = sysconfig.get_config_var('py_version_nodot')
if not VER_SUFFIX:   # pragma: no cover
    VER_SUFFIX = '%s%s' % sys.version_info[:2]
PYVER = 'py' + VER_SUFFIX
IMPVER = IMP_PREFIX + VER_SUFFIX

ARCH = distutils.util.get_platform().replace('-', '_').replace('.', '_')

ABI = sysconfig.get_config_var('SOABI')
if ABI and ABI.startswith('cpython-'):
    ABI = ABI.replace('cpython-', 'cp')
else:
    def _derive_abi():
        parts = ['cp', VER_SUFFIX]
        if sysconfig.get_config_var('Py_DEBUG'):
            parts.append('d')
        if sysconfig.get_config_var('WITH_PYMALLOC'):
            parts.append('m')
        if sysconfig.get_config_var('Py_UNICODE_SIZE') == 4:
            parts.append('u')
        return ''.join(parts)
    ABI = _derive_abi()
    del _derive_abi

FILENAME_RE = re.compile(r'''
(?P<nm>[^-]+)
-(?P<vn>\d+[^-]*)
(-(?P<bn>\d+[^-]*))?
-(?P<py>\w+\d+(\.\w+\d+)*)
-(?P<bi>\w+)
-(?P<ar>\w+(\.\w+)*)
\.whl$
''', re.IGNORECASE | re.VERBOSE)

NAME_VERSION_RE = re.compile(r'''
(?P<nm>[^-]+)
-(?P<vn>\d+[^-]*)
(-(?P<bn>\d+[^-]*))?$
''', re.IGNORECASE | re.VERBOSE)

SHEBANG_RE = re.compile(br'\s*#![^\r\n]*')
SHEBANG_DETAIL_RE = re.compile(br'^(\s*#!("[^"]+"|\S+))\s+(.*)$')
SHEBANG_PYTHON = b'#!python'
SHEBANG_PYTHONW = b'#!pythonw'

if os.sep == '/':
    to_posix = lambda o: o
else:
    to_posix = lambda o: o.replace(os.sep, '/')


class Mounter(object):
    def __init__(self):
        self.impure_wheels = {}
        self.libs = {}

    def add(self, pathname, extensions):
        self.impure_wheels[pathname] = extensions
        self.libs.update(extensions)

    def remove(self, pathname):
        extensions = self.impure_wheels.pop(pathname)
        for k, v in extensions:
            if k in self.libs:
                del self.libs[k]

    def find_module(self, fullname, path=None):
        if fullname in self.libs:
            result = self
        else:
            result = None
        return result

    def load_module(self, fullname):
        if fullname in sys.modules:
            result = sys.modules[fullname]
        else:
            if fullname not in self.libs:
                raise ImportError('unable to find extension for %s' % fullname)
            result = imp.load_dynamic(fullname, self.libs[fullname])
            result.__loader__ = self
            parts = fullname.rsplit('.', 1)
            if len(parts) > 1:
                result.__package__ = parts[0]
        return result

_hook = Mounter()


class Wheel(object):
    """
    Class to build and install from Wheel files (PEP 427).
    """

    wheel_version = (1, 1)
    hash_kind = 'sha256'

    def __init__(self, filename=None, sign=False, verify=False):
        """
        Initialise an instance using a (valid) filename.
        """
        self.sign = sign
        self.should_verify = verify
        self.buildver = ''
        self.pyver = [PYVER]
        self.abi = ['none']
        self.arch = ['any']
        self.dirname = os.getcwd()
        if filename is None:
            self.name = 'dummy'
            self.version = '0.1'
            self._filename = self.filename
        else:
            m = NAME_VERSION_RE.match(filename)
            if m:
                info = m.groupdict('')
                self.name = info['nm']
                # Reinstate the local version separator
                self.version = info['vn'].replace('_', '-')
                self.buildver = info['bn']
                self._filename = self.filename
            else:
                dirname, filename = os.path.split(filename)
                m = FILENAME_RE.match(filename)
                if not m:
                    raise DistlibException('Invalid name or '
                                           'filename: %r' % filename)
                if dirname:
                    self.dirname = os.path.abspath(dirname)
                self._filename = filename
                info = m.groupdict('')
                self.name = info['nm']
                self.version = info['vn']
                self.buildver = info['bn']
                self.pyver = info['py'].split('.')
                self.abi = info['bi'].split('.')
                self.arch = info['ar'].split('.')

    @property
    def filename(self):
        """
        Build and return a filename from the various components.
        """
        if self.buildver:
            buildver = '-' + self.buildver
        else:
            buildver = ''
        pyver = '.'.join(self.pyver)
        abi = '.'.join(self.abi)
        arch = '.'.join(self.arch)
        # replace - with _ as a local version separator
        version = self.version.replace('-', '_')
        return '%s-%s%s-%s-%s-%s.whl' % (self.name, version, buildver,
                                         pyver, abi, arch)

    @property
    def exists(self):
        path = os.path.join(self.dirname, self.filename)
        return os.path.isfile(path)

    @property
    def tags(self):
        for pyver in self.pyver:
            for abi in self.abi:
                for arch in self.arch:
                    yield pyver, abi, arch

    @cached_property
    def metadata(self):
        pathname = os.path.join(self.dirname, self.filename)
        name_ver = '%s-%s' % (self.name, self.version)
        info_dir = '%s.dist-info' % name_ver
        wrapper = codecs.getreader('utf-8')
        with ZipFile(pathname, 'r') as zf:
            wheel_metadata = self.get_wheel_metadata(zf)
            wv = wheel_metadata['Wheel-Version'].split('.', 1)
            file_version = tuple([int(i) for i in wv])
            if file_version < (1, 1):
                fn = 'METADATA'
            else:
                fn = METADATA_FILENAME
            try:
                metadata_filename = posixpath.join(info_dir, fn)
                with zf.open(metadata_filename) as bf:
                    wf = wrapper(bf)
                    result = Metadata(fileobj=wf)
            except KeyError:
                raise ValueError('Invalid wheel, because %s is '
                                 'missing' % fn)
        return result

    def get_wheel_metadata(self, zf):
        name_ver = '%s-%s' % (self.name, self.version)
        info_dir = '%s.dist-info' % name_ver
        metadata_filename = posixpath.join(info_dir, 'WHEEL')
        with zf.open(metadata_filename) as bf:
            wf = codecs.getreader('utf-8')(bf)
            message = message_from_file(wf)
        return dict(message)

    @cached_property
    def info(self):
        pathname = os.path.join(self.dirname, self.filename)
        with ZipFile(pathname, 'r') as zf:
            result = self.get_wheel_metadata(zf)
        return result

    def process_shebang(self, data):
        m = SHEBANG_RE.match(data)
        if m:
            end = m.end()
            shebang, data_after_shebang = data[:end], data[end:]
            # Preserve any arguments after the interpreter
            if b'pythonw' in shebang.lower():
                shebang_python = SHEBANG_PYTHONW
            else:
                shebang_python = SHEBANG_PYTHON
            m = SHEBANG_DETAIL_RE.match(shebang)
            if m:
                args = b' ' + m.groups()[-1]
            else:
                args = b''
            shebang = shebang_python + args
            data = shebang + data_after_shebang
        else:
            cr = data.find(b'\r')
            lf = data.find(b'\n')
            if cr < 0 or cr > lf:
                term = b'\n'
            else:
                if data[cr:cr + 2] == b'\r\n':
                    term = b'\r\n'
                else:
                    term = b'\r'
            data = SHEBANG_PYTHON + term + data
        return data

    def get_hash(self, data, hash_kind=None):
        if hash_kind is None:
            hash_kind = self.hash_kind
        try:
            hasher = getattr(hashlib, hash_kind)
        except AttributeError:
            raise DistlibException('Unsupported hash algorithm: %r' % hash_kind)
        result = hasher(data).digest()
        result = base64.urlsafe_b64encode(result).rstrip(b'=').decode('ascii')
        return hash_kind, result

    def write_record(self, records, record_path, base):
        with CSVWriter(record_path) as writer:
            for row in records:
                writer.writerow(row)
            p = to_posix(os.path.relpath(record_path, base))
            writer.writerow((p, '', ''))

    def write_records(self, info, libdir, archive_paths):
        records = []
        distinfo, info_dir = info
        hasher = getattr(hashlib, self.hash_kind)
        for ap, p in archive_paths:
            with open(p, 'rb') as f:
                data = f.read()
            digest = '%s=%s' % self.get_hash(data)
            size = os.path.getsize(p)
            records.append((ap, digest, size))

        p = os.path.join(distinfo, 'RECORD')
        self.write_record(records, p, libdir)
        ap = to_posix(os.path.join(info_dir, 'RECORD'))
        archive_paths.append((ap, p))

    def build_zip(self, pathname, archive_paths):
        with ZipFile(pathname, 'w', zipfile.ZIP_DEFLATED) as zf:
            for ap, p in archive_paths:
                logger.debug('Wrote %s to %s in wheel', p, ap)
                zf.write(p, ap)

    def build(self, paths, tags=None, wheel_version=None):
        """
        Build a wheel from files in specified paths, and use any specified tags
        when determining the name of the wheel.
        """
        if tags is None:
            tags = {}

        libkey = list(filter(lambda o: o in paths, ('purelib', 'platlib')))[0]
        if libkey == 'platlib':
            is_pure = 'false'
            default_pyver = [IMPVER]
            default_abi = [ABI]
            default_arch = [ARCH]
        else:
            is_pure = 'true'
            default_pyver = [PYVER]
            default_abi = ['none']
            default_arch = ['any']

        self.pyver = tags.get('pyver', default_pyver)
        self.abi = tags.get('abi', default_abi)
        self.arch = tags.get('arch', default_arch)

        libdir = paths[libkey]

        name_ver = '%s-%s' % (self.name, self.version)
        data_dir = '%s.data' % name_ver
        info_dir = '%s.dist-info' % name_ver

        archive_paths = []

        # First, stuff which is not in site-packages
        for key in ('data', 'headers', 'scripts'):
            if key not in paths:
                continue
            path = paths[key]
            if os.path.isdir(path):
                for root, dirs, files in os.walk(path):
                    for fn in files:
                        p = fsdecode(os.path.join(root, fn))
                        rp = os.path.relpath(p, path)
                        ap = to_posix(os.path.join(data_dir, key, rp))
                        archive_paths.append((ap, p))
                        if key == 'scripts' and not p.endswith('.exe'):
                            with open(p, 'rb') as f:
                                data = f.read()
                            data = self.process_shebang(data)
                            with open(p, 'wb') as f:
                                f.write(data)

        # Now, stuff which is in site-packages, other than the
        # distinfo stuff.
        path = libdir
        distinfo = None
        for root, dirs, files in os.walk(path):
            if root == path:
                # At the top level only, save distinfo for later
                # and skip it for now
                for i, dn in enumerate(dirs):
                    dn = fsdecode(dn)
                    if dn.endswith('.dist-info'):
                        distinfo = os.path.join(root, dn)
                        del dirs[i]
                        break
                assert distinfo, '.dist-info directory expected, not found'

            for fn in files:
                # comment out next suite to leave .pyc files in
                if fsdecode(fn).endswith(('.pyc', '.pyo')):
                    continue
                p = os.path.join(root, fn)
                rp = to_posix(os.path.relpath(p, path))
                archive_paths.append((rp, p))

        # Now distinfo. Assumed to be flat, i.e. os.listdir is enough.
        files = os.listdir(distinfo)
        for fn in files:
            if fn not in ('RECORD', 'INSTALLER', 'SHARED', 'WHEEL'):
                p = fsdecode(os.path.join(distinfo, fn))
                ap = to_posix(os.path.join(info_dir, fn))
                archive_paths.append((ap, p))

        wheel_metadata = [
            'Wheel-Version: %d.%d' % (wheel_version or self.wheel_version),
            'Generator: distlib %s' % __version__,
            'Root-Is-Purelib: %s' % is_pure,
        ]
        for pyver, abi, arch in self.tags:
            wheel_metadata.append('Tag: %s-%s-%s' % (pyver, abi, arch))
        p = os.path.join(distinfo, 'WHEEL')
        with open(p, 'w') as f:
            f.write('\n'.join(wheel_metadata))
        ap = to_posix(os.path.join(info_dir, 'WHEEL'))
        archive_paths.append((ap, p))

        # Now, at last, RECORD.
        # Paths in here are archive paths - nothing else makes sense.
        self.write_records((distinfo, info_dir), libdir, archive_paths)
        # Now, ready to build the zip file
        pathname = os.path.join(self.dirname, self.filename)
        self.build_zip(pathname, archive_paths)
        return pathname

    def install(self, paths, maker, **kwargs):
        """
        Install a wheel to the specified paths. If kwarg ``warner`` is
        specified, it should be a callable, which will be called with two
        tuples indicating the wheel version of this software and the wheel
        version in the file, if there is a discrepancy in the versions.
        This can be used to issue any warnings to raise any exceptions.
        If kwarg ``lib_only`` is True, only the purelib/platlib files are
        installed, and the headers, scripts, data and dist-info metadata are
        not written.

        The return value is a :class:`InstalledDistribution` instance unless
        ``options.lib_only`` is True, in which case the return value is ``None``.
        """

        dry_run = maker.dry_run
        warner = kwargs.get('warner')
        lib_only = kwargs.get('lib_only', False)

        pathname = os.path.join(self.dirname, self.filename)
        name_ver = '%s-%s' % (self.name, self.version)
        data_dir = '%s.data' % name_ver
        info_dir = '%s.dist-info' % name_ver

        metadata_name = posixpath.join(info_dir, METADATA_FILENAME)
        wheel_metadata_name = posixpath.join(info_dir, 'WHEEL')
        record_name = posixpath.join(info_dir, 'RECORD')

        wrapper = codecs.getreader('utf-8')

        with ZipFile(pathname, 'r') as zf:
            with zf.open(wheel_metadata_name) as bwf:
                wf = wrapper(bwf)
                message = message_from_file(wf)
            wv = message['Wheel-Version'].split('.', 1)
            file_version = tuple([int(i) for i in wv])
            if (file_version != self.wheel_version) and warner:
                warner(self.wheel_version, file_version)

            if message['Root-Is-Purelib'] == 'true':
                libdir = paths['purelib']
            else:
                libdir = paths['platlib']

            records = {}
            with zf.open(record_name) as bf:
                with CSVReader(stream=bf) as reader:
                    for row in reader:
                        p = row[0]
                        records[p] = row

            data_pfx = posixpath.join(data_dir, '')
            info_pfx = posixpath.join(info_dir, '')
            script_pfx = posixpath.join(data_dir, 'scripts', '')

            # make a new instance rather than a copy of maker's,
            # as we mutate it
            fileop = FileOperator(dry_run=dry_run)
            fileop.record = True    # so we can rollback if needed

            bc = not sys.dont_write_bytecode    # Double negatives. Lovely!

            outfiles = []   # for RECORD writing

            # for script copying/shebang processing
            workdir = tempfile.mkdtemp()
            # set target dir later
            # we default add_launchers to False, as the
            # Python Launcher should be used instead
            maker.source_dir = workdir
            maker.target_dir = None
            try:
                for zinfo in zf.infolist():
                    arcname = zinfo.filename
                    if isinstance(arcname, text_type):
                        u_arcname = arcname
                    else:
                        u_arcname = arcname.decode('utf-8')
                    # The signature file won't be in RECORD,
                    # and we  don't currently don't do anything with it
                    if u_arcname.endswith('/RECORD.jws'):
                        continue
                    row = records[u_arcname]
                    if row[2] and str(zinfo.file_size) != row[2]:
                        raise DistlibException('size mismatch for '
                                               '%s' % u_arcname)
                    if row[1]:
                        kind, value = row[1].split('=', 1)
                        with zf.open(arcname) as bf:
                            data = bf.read()
                        _, digest = self.get_hash(data, kind)
                        if digest != value:
                            raise DistlibException('digest mismatch for '
                                                   '%s' % arcname)

                    if lib_only and u_arcname.startswith((info_pfx, data_pfx)):
                        logger.debug('lib_only: skipping %s', u_arcname)
                        continue
                    is_script = (u_arcname.startswith(script_pfx)
                                 and not u_arcname.endswith('.exe'))

                    if u_arcname.startswith(data_pfx):
                        _, where, rp = u_arcname.split('/', 2)
                        outfile = os.path.join(paths[where], convert_path(rp))
                    else:
                        # meant for site-packages.
                        if u_arcname in (wheel_metadata_name, record_name):
                            continue
                        outfile = os.path.join(libdir, convert_path(u_arcname))
                    if not is_script:
                        with zf.open(arcname) as bf:
                            fileop.copy_stream(bf, outfile)
                        outfiles.append(outfile)
                        # Double check the digest of the written file
                        if not dry_run and row[1]:
                            with open(outfile, 'rb') as bf:
                                data = bf.read()
                                _, newdigest = self.get_hash(data, kind)
                                if newdigest != digest:
                                    raise DistlibException('digest mismatch '
                                                           'on write for '
                                                           '%s' % outfile)
                        if bc and outfile.endswith('.py'):
                            try:
                                pyc = fileop.byte_compile(outfile)
                                outfiles.append(pyc)
                            except Exception:
                                # Don't give up if byte-compilation fails,
                                # but log it and perhaps warn the user
                                logger.warning('Byte-compilation failed',
                                               exc_info=True)
                    else:
                        fn = os.path.basename(convert_path(arcname))
                        workname = os.path.join(workdir, fn)
                        with zf.open(arcname) as bf:
                            fileop.copy_stream(bf, workname)

                        dn, fn = os.path.split(outfile)
                        maker.target_dir = dn
                        filenames = maker.make(fn)
                        fileop.set_executable_mode(filenames)
                        outfiles.extend(filenames)

                if lib_only:
                    logger.debug('lib_only: returning None')
                    dist = None
                else:
                    # Generate scripts

                    # Try to get pydist.json so we can see if there are
                    # any commands to generate. If this fails (e.g. because
                    # of a legacy wheel), log a warning but don't give up.
                    commands = None
                    file_version = self.info['Wheel-Version']
                    if file_version == '1.0':
                        # Use legacy info
                        ep = posixpath.join(info_dir, 'entry_points.txt')
                        try:
                            with zf.open(ep) as bwf:
                                epdata = read_exports(bwf)
                            commands = {}
                            for key in ('console', 'gui'):
                                k = '%s_scripts' % key
                                if k in epdata:
                                    commands['wrap_%s' % key] = d = {}
                                    for v in epdata[k].values():
                                        s = '%s:%s' % (v.prefix, v.suffix)
                                        if v.flags:
                                            s += ' %s' % v.flags
                                        d[v.name] = s
                        except Exception:
                            logger.warning('Unable to read legacy script '
                                           'metadata, so cannot generate '
                                           'scripts')
                    else:
                        try:
                            with zf.open(metadata_name) as bwf:
                                wf = wrapper(bwf)
                                commands = json.load(wf).get('extensions')
                                if commands:
                                    commands = commands.get('python.commands')
                        except Exception:
                            logger.warning('Unable to read JSON metadata, so '
                                           'cannot generate scripts')
                    if commands:
                        console_scripts = commands.get('wrap_console', {})
                        gui_scripts = commands.get('wrap_gui', {})
                        if console_scripts or gui_scripts:
                            script_dir = paths.get('scripts', '')
                            if not os.path.isdir(script_dir):
                                raise ValueError('Valid script path not '
                                                 'specified')
                            maker.target_dir = script_dir
                            for k, v in console_scripts.items():
                                script = '%s = %s' % (k, v)
                                filenames = maker.make(script)
                                fileop.set_executable_mode(filenames)

                            if gui_scripts:
                                options = {'gui': True }
                                for k, v in gui_scripts.items():
                                    script = '%s = %s' % (k, v)
                                    filenames = maker.make(script, options)
                                    fileop.set_executable_mode(filenames)

                    p = os.path.join(libdir, info_dir)
                    dist = InstalledDistribution(p)

                    # Write SHARED
                    paths = dict(paths)     # don't change passed in dict
                    del paths['purelib']
                    del paths['platlib']
                    paths['lib'] = libdir
                    p = dist.write_shared_locations(paths, dry_run)
                    if p:
                        outfiles.append(p)

                    # Write RECORD
                    dist.write_installed_files(outfiles, paths['prefix'],
                                               dry_run)
                return dist
            except Exception:  # pragma: no cover
                logger.exception('installation failed.')
                fileop.rollback()
                raise
            finally:
                shutil.rmtree(workdir)

    def _get_dylib_cache(self):
        global cache
        if cache is None:
            # Use native string to avoid issues on 2.x: see Python #20140.
            base = os.path.join(get_cache_base(), str('dylib-cache'),
                                sys.version[:3])
            cache = Cache(base)
        return cache

    def _get_extensions(self):
        pathname = os.path.join(self.dirname, self.filename)
        name_ver = '%s-%s' % (self.name, self.version)
        info_dir = '%s.dist-info' % name_ver
        arcname = posixpath.join(info_dir, 'EXTENSIONS')
        wrapper = codecs.getreader('utf-8')
        result = []
        with ZipFile(pathname, 'r') as zf:
            try:
                with zf.open(arcname) as bf:
                    wf = wrapper(bf)
                    extensions = json.load(wf)
                    cache = self._get_dylib_cache()
                    prefix = cache.prefix_to_dir(pathname)
                    cache_base = os.path.join(cache.base, prefix)
                    if not os.path.isdir(cache_base):
                        os.makedirs(cache_base)
                    for name, relpath in extensions.items():
                        dest = os.path.join(cache_base, convert_path(relpath))
                        if not os.path.exists(dest):
                            extract = True
                        else:
                            file_time = os.stat(dest).st_mtime
                            file_time = datetime.datetime.fromtimestamp(file_time)
                            info = zf.getinfo(relpath)
                            wheel_time = datetime.datetime(*info.date_time)
                            extract = wheel_time > file_time
                        if extract:
                            zf.extract(relpath, cache_base)
                        result.append((name, dest))
            except KeyError:
                pass
        return result

    def is_compatible(self):
        """
        Determine if a wheel is compatible with the running system.
        """
        return is_compatible(self)

    def is_mountable(self):
        """
        Determine if a wheel is asserted as mountable by its metadata.
        """
        return True # for now - metadata details TBD

    def mount(self, append=False):
        pathname = os.path.abspath(os.path.join(self.dirname, self.filename))
        if not self.is_compatible():
            msg = 'Wheel %s not compatible with this Python.' % pathname
            raise DistlibException(msg)
        if not self.is_mountable():
            msg = 'Wheel %s is marked as not mountable.' % pathname
            raise DistlibException(msg)
        if pathname in sys.path:
            logger.debug('%s already in path', pathname)
        else:
            if append:
                sys.path.append(pathname)
            else:
                sys.path.insert(0, pathname)
            extensions = self._get_extensions()
            if extensions:
                if _hook not in sys.meta_path:
                    sys.meta_path.append(_hook)
                _hook.add(pathname, extensions)

    def unmount(self):
        pathname = os.path.abspath(os.path.join(self.dirname, self.filename))
        if pathname not in sys.path:
            logger.debug('%s not in path', pathname)
        else:
            sys.path.remove(pathname)
            if pathname in _hook.impure_wheels:
                _hook.remove(pathname)
            if not _hook.impure_wheels:
                if _hook in sys.meta_path:
                    sys.meta_path.remove(_hook)

    def verify(self):
        pathname = os.path.join(self.dirname, self.filename)
        name_ver = '%s-%s' % (self.name, self.version)
        data_dir = '%s.data' % name_ver
        info_dir = '%s.dist-info' % name_ver

        metadata_name = posixpath.join(info_dir, METADATA_FILENAME)
        wheel_metadata_name = posixpath.join(info_dir, 'WHEEL')
        record_name = posixpath.join(info_dir, 'RECORD')

        wrapper = codecs.getreader('utf-8')

        with ZipFile(pathname, 'r') as zf:
            with zf.open(wheel_metadata_name) as bwf:
                wf = wrapper(bwf)
                message = message_from_file(wf)
            wv = message['Wheel-Version'].split('.', 1)
            file_version = tuple([int(i) for i in wv])
            # TODO version verification

            records = {}
            with zf.open(record_name) as bf:
                with CSVReader(stream=bf) as reader:
                    for row in reader:
                        p = row[0]
                        records[p] = row

            for zinfo in zf.infolist():
                arcname = zinfo.filename
                if isinstance(arcname, text_type):
                    u_arcname = arcname
                else:
                    u_arcname = arcname.decode('utf-8')
                if '..' in u_arcname:
                    raise DistlibException('invalid entry in '
                                           'wheel: %r' % u_arcname)

                # The signature file won't be in RECORD,
                # and we  don't currently don't do anything with it
                if u_arcname.endswith('/RECORD.jws'):
                    continue
                row = records[u_arcname]
                if row[2] and str(zinfo.file_size) != row[2]:
                    raise DistlibException('size mismatch for '
                                           '%s' % u_arcname)
                if row[1]:
                    kind, value = row[1].split('=', 1)
                    with zf.open(arcname) as bf:
                        data = bf.read()
                    _, digest = self.get_hash(data, kind)
                    if digest != value:
                        raise DistlibException('digest mismatch for '
                                               '%s' % arcname)

    def update(self, modifier, dest_dir=None, **kwargs):
        """
        Update the contents of a wheel in a generic way. The modifier should
        be a callable which expects a dictionary argument: its keys are
        archive-entry paths, and its values are absolute filesystem paths
        where the contents the corresponding archive entries can be found. The
        modifier is free to change the contents of the files pointed to, add
        new entries and remove entries, before returning. This method will
        extract the entire contents of the wheel to a temporary location, call
        the modifier, and then use the passed (and possibly updated)
        dictionary to write a new wheel. If ``dest_dir`` is specified, the new
        wheel is written there -- otherwise, the original wheel is overwritten.

        The modifier should return True if it updated the wheel, else False.
        This method returns the same value the modifier returns.
        """

        def get_version(path_map, info_dir):
            version = path = None
            key = '%s/%s' % (info_dir, METADATA_FILENAME)
            if key not in path_map:
                key = '%s/PKG-INFO' % info_dir
            if key in path_map:
                path = path_map[key]
                version = Metadata(path=path).version
            return version, path

        def update_version(version, path):
            updated = None
            try:
                v = NormalizedVersion(version)
                i = version.find('-')
                if i < 0:
                    updated = '%s+1' % version
                else:
                    parts = [int(s) for s in version[i + 1:].split('.')]
                    parts[-1] += 1
                    updated = '%s+%s' % (version[:i],
                                         '.'.join(str(i) for i in parts))
            except UnsupportedVersionError:
                logger.debug('Cannot update non-compliant (PEP-440) '
                             'version %r', version)
            if updated:
                md = Metadata(path=path)
                md.version = updated
                legacy = not path.endswith(METADATA_FILENAME)
                md.write(path=path, legacy=legacy)
                logger.debug('Version updated from %r to %r', version,
                             updated)

        pathname = os.path.join(self.dirname, self.filename)
        name_ver = '%s-%s' % (self.name, self.version)
        info_dir = '%s.dist-info' % name_ver
        record_name = posixpath.join(info_dir, 'RECORD')
        with tempdir() as workdir:
            with ZipFile(pathname, 'r') as zf:
                path_map = {}
                for zinfo in zf.infolist():
                    arcname = zinfo.filename
                    if isinstance(arcname, text_type):
                        u_arcname = arcname
                    else:
                        u_arcname = arcname.decode('utf-8')
                    if u_arcname == record_name:
                        continue
                    if '..' in u_arcname:
                        raise DistlibException('invalid entry in '
                                               'wheel: %r' % u_arcname)
                    zf.extract(zinfo, workdir)
                    path = os.path.join(workdir, convert_path(u_arcname))
                    path_map[u_arcname] = path

            # Remember the version.
            original_version, _ = get_version(path_map, info_dir)
            # Files extracted. Call the modifier.
            modified = modifier(path_map, **kwargs)
            if modified:
                # Something changed - need to build a new wheel.
                current_version, path = get_version(path_map, info_dir)
                if current_version and (current_version == original_version):
                    # Add or update local version to signify changes.
                    update_version(current_version, path)
                # Decide where the new wheel goes.
                if dest_dir is None:
                    fd, newpath = tempfile.mkstemp(suffix='.whl',
                                                   prefix='wheel-update-',
                                                   dir=workdir)
                    os.close(fd)
                else:
                    if not os.path.isdir(dest_dir):
                        raise DistlibException('Not a directory: %r' % dest_dir)
                    newpath = os.path.join(dest_dir, self.filename)
                archive_paths = list(path_map.items())
                distinfo = os.path.join(workdir, info_dir)
                info = distinfo, info_dir
                self.write_records(info, workdir, archive_paths)
                self.build_zip(newpath, archive_paths)
                if dest_dir is None:
                    shutil.copyfile(newpath, pathname)
        return modified

def compatible_tags():
    """
    Return (pyver, abi, arch) tuples compatible with this Python.
    """
    versions = [VER_SUFFIX]
    major = VER_SUFFIX[0]
    for minor in range(sys.version_info[1] - 1, - 1, -1):
        versions.append(''.join([major, str(minor)]))

    abis = []
    for suffix, _, _ in imp.get_suffixes():
        if suffix.startswith('.abi'):
            abis.append(suffix.split('.', 2)[1])
    abis.sort()
    if ABI != 'none':
        abis.insert(0, ABI)
    abis.append('none')
    result = []

    arches = [ARCH]
    if sys.platform == 'darwin':
        m = re.match('(\w+)_(\d+)_(\d+)_(\w+)$', ARCH)
        if m:
            name, major, minor, arch = m.groups()
            minor = int(minor)
            matches = [arch]
            if arch in ('i386', 'ppc'):
                matches.append('fat')
            if arch in ('i386', 'ppc', 'x86_64'):
                matches.append('fat3')
            if arch in ('ppc64', 'x86_64'):
                matches.append('fat64')
            if arch in ('i386', 'x86_64'):
                matches.append('intel')
            if arch in ('i386', 'x86_64', 'intel', 'ppc', 'ppc64'):
                matches.append('universal')
            while minor >= 0:
                for match in matches:
                    s = '%s_%s_%s_%s' % (name, major, minor, match)
                    if s != ARCH:   # already there
                        arches.append(s)
                minor -= 1

    # Most specific - our Python version, ABI and arch
    for abi in abis:
        for arch in arches:
            result.append((''.join((IMP_PREFIX, versions[0])), abi, arch))

    # where no ABI / arch dependency, but IMP_PREFIX dependency
    for i, version in enumerate(versions):
        result.append((''.join((IMP_PREFIX, version)), 'none', 'any'))
        if i == 0:
            result.append((''.join((IMP_PREFIX, version[0])), 'none', 'any'))

    # no IMP_PREFIX, ABI or arch dependency
    for i, version in enumerate(versions):
        result.append((''.join(('py', version)), 'none', 'any'))
        if i == 0:
            result.append((''.join(('py', version[0])), 'none', 'any'))
    return set(result)


COMPATIBLE_TAGS = compatible_tags()

del compatible_tags


def is_compatible(wheel, tags=None):
    if not isinstance(wheel, Wheel):
        wheel = Wheel(wheel)    # assume it's a filename
    result = False
    if tags is None:
        tags = COMPATIBLE_TAGS
    for ver, abi, arch in tags:
        if ver in wheel.pyver and abi in wheel.abi and arch in wheel.arch:
            result = True
            break
    return result