--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/python3.8/site-packages/wheel/wheelfile.py	Mon Jul 27 03:47:31 2020 -0400
@@ -0,0 +1,169 @@
+from __future__ import print_function
+
+import csv
+import hashlib
+import os.path
+import re
+import stat
+import time
+from collections import OrderedDict
+from distutils import log as logger
+from zipfile import ZIP_DEFLATED, ZipInfo, ZipFile
+
+from wheel.cli import WheelError
+from wheel.util import urlsafe_b64decode, as_unicode, native, urlsafe_b64encode, as_bytes, StringIO
+
+# Non-greedy matching of an optional build number may be too clever (more
+# invalid wheel filenames will match). Separate regex for .dist-info?
+WHEEL_INFO_RE = re.compile(
+    r"""^(?P<namever>(?P<name>.+?)-(?P<ver>.+?))(-(?P<build>\d[^-]*))?
+     -(?P<pyver>.+?)-(?P<abi>.+?)-(?P<plat>.+?)\.whl$""",
+    re.VERBOSE)
+
+
+def get_zipinfo_datetime(timestamp=None):
+    # Some applications need reproducible .whl files, but they can't do this without forcing
+    # the timestamp of the individual ZipInfo objects. See issue #143.
+    timestamp = int(os.environ.get('SOURCE_DATE_EPOCH', timestamp or time.time()))
+    return time.gmtime(timestamp)[0:6]
+
+
+class WheelFile(ZipFile):
+    """A ZipFile derivative class that also reads SHA-256 hashes from
+    .dist-info/RECORD and checks any read files against those.
+    """
+
+    _default_algorithm = hashlib.sha256
+
+    def __init__(self, file, mode='r', compression=ZIP_DEFLATED):
+        basename = os.path.basename(file)
+        self.parsed_filename = WHEEL_INFO_RE.match(basename)
+        if not basename.endswith('.whl') or self.parsed_filename is None:
+            raise WheelError("Bad wheel filename {!r}".format(basename))
+
+        ZipFile.__init__(self, file, mode, compression=compression, allowZip64=True)
+
+        self.dist_info_path = '{}.dist-info'.format(self.parsed_filename.group('namever'))
+        self.record_path = self.dist_info_path + '/RECORD'
+        self._file_hashes = OrderedDict()
+        self._file_sizes = {}
+        if mode == 'r':
+            # Ignore RECORD and any embedded wheel signatures
+            self._file_hashes[self.record_path] = None, None
+            self._file_hashes[self.record_path + '.jws'] = None, None
+            self._file_hashes[self.record_path + '.p7s'] = None, None
+
+            # Fill in the expected hashes by reading them from RECORD
+            try:
+                record = self.open(self.record_path)
+            except KeyError:
+                raise WheelError('Missing {} file'.format(self.record_path))
+
+            with record:
+                for line in record:
+                    line = line.decode('utf-8')
+                    path, hash_sum, size = line.rsplit(u',', 2)
+                    if hash_sum:
+                        algorithm, hash_sum = hash_sum.split(u'=')
+                        try:
+                            hashlib.new(algorithm)
+                        except ValueError:
+                            raise WheelError('Unsupported hash algorithm: {}'.format(algorithm))
+
+                        if algorithm.lower() in {'md5', 'sha1'}:
+                            raise WheelError(
+                                'Weak hash algorithm ({}) is not permitted by PEP 427'
+                                .format(algorithm))
+
+                        self._file_hashes[path] = (
+                            algorithm, urlsafe_b64decode(hash_sum.encode('ascii')))
+
+    def open(self, name_or_info, mode="r", pwd=None):
+        def _update_crc(newdata, eof=None):
+            if eof is None:
+                eof = ef._eof
+                update_crc_orig(newdata)
+            else:  # Python 2
+                update_crc_orig(newdata, eof)
+
+            running_hash.update(newdata)
+            if eof and running_hash.digest() != expected_hash:
+                raise WheelError("Hash mismatch for file '{}'".format(native(ef_name)))
+
+        ef = ZipFile.open(self, name_or_info, mode, pwd)
+        ef_name = as_unicode(name_or_info.filename if isinstance(name_or_info, ZipInfo)
+                             else name_or_info)
+        if mode == 'r' and not ef_name.endswith('/'):
+            if ef_name not in self._file_hashes:
+                raise WheelError("No hash found for file '{}'".format(native(ef_name)))
+
+            algorithm, expected_hash = self._file_hashes[ef_name]
+            if expected_hash is not None:
+                # Monkey patch the _update_crc method to also check for the hash from RECORD
+                running_hash = hashlib.new(algorithm)
+                update_crc_orig, ef._update_crc = ef._update_crc, _update_crc
+
+        return ef
+
+    def write_files(self, base_dir):
+        logger.info("creating '%s' and adding '%s' to it", self.filename, base_dir)
+        deferred = []
+        for root, dirnames, filenames in os.walk(base_dir):
+            # Sort the directory names so that `os.walk` will walk them in a
+            # defined order on the next iteration.
+            dirnames.sort()
+            for name in sorted(filenames):
+                path = os.path.normpath(os.path.join(root, name))
+                if os.path.isfile(path):
+                    arcname = os.path.relpath(path, base_dir).replace(os.path.sep, '/')
+                    if arcname == self.record_path:
+                        pass
+                    elif root.endswith('.dist-info'):
+                        deferred.append((path, arcname))
+                    else:
+                        self.write(path, arcname)
+
+        deferred.sort()
+        for path, arcname in deferred:
+            self.write(path, arcname)
+
+    def write(self, filename, arcname=None, compress_type=None):
+        with open(filename, 'rb') as f:
+            st = os.fstat(f.fileno())
+            data = f.read()
+
+        zinfo = ZipInfo(arcname or filename, date_time=get_zipinfo_datetime(st.st_mtime))
+        zinfo.external_attr = (stat.S_IMODE(st.st_mode) | stat.S_IFMT(st.st_mode)) << 16
+        zinfo.compress_type = compress_type or self.compression
+        self.writestr(zinfo, data, compress_type)
+
+    def writestr(self, zinfo_or_arcname, bytes, compress_type=None):
+        ZipFile.writestr(self, zinfo_or_arcname, bytes, compress_type)
+        fname = (zinfo_or_arcname.filename if isinstance(zinfo_or_arcname, ZipInfo)
+                 else zinfo_or_arcname)
+        logger.info("adding '%s'", fname)
+        if fname != self.record_path:
+            hash_ = self._default_algorithm(bytes)
+            self._file_hashes[fname] = hash_.name, native(urlsafe_b64encode(hash_.digest()))
+            self._file_sizes[fname] = len(bytes)
+
+    def close(self):
+        # Write RECORD
+        if self.fp is not None and self.mode == 'w' and self._file_hashes:
+            data = StringIO()
+            writer = csv.writer(data, delimiter=',', quotechar='"', lineterminator='\n')
+            writer.writerows((
+                (
+                    fname,
+                    algorithm + "=" + hash_,
+                    self._file_sizes[fname]
+                )
+                for fname, (algorithm, hash_) in self._file_hashes.items()
+            ))
+            writer.writerow((format(self.record_path), "", ""))
+            zinfo = ZipInfo(native(self.record_path), date_time=get_zipinfo_datetime())
+            zinfo.compress_type = self.compression
+            zinfo.external_attr = 0o664 << 16
+            self.writestr(zinfo, as_bytes(data.getvalue()))
+
+        ZipFile.close(self)