--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/python3.8/site-packages/pip/_internal/utils/wheel.py	Mon Jul 27 03:47:31 2020 -0400
@@ -0,0 +1,225 @@
+"""Support functions for working with wheel files.
+"""
+
+from __future__ import absolute_import
+
+import logging
+from email.parser import Parser
+from zipfile import ZipFile
+
+from pip._vendor.packaging.utils import canonicalize_name
+from pip._vendor.pkg_resources import DistInfoDistribution
+from pip._vendor.six import PY2, ensure_str
+
+from pip._internal.exceptions import UnsupportedWheel
+from pip._internal.utils.pkg_resources import DictMetadata
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from email.message import Message
+    from typing import Dict, Tuple
+
+    from pip._vendor.pkg_resources import Distribution
+
+if PY2:
+    from zipfile import BadZipfile as BadZipFile
+else:
+    from zipfile import BadZipFile
+
+
+VERSION_COMPATIBLE = (1, 0)
+
+
+logger = logging.getLogger(__name__)
+
+
+class WheelMetadata(DictMetadata):
+    """Metadata provider that maps metadata decoding exceptions to our
+    internal exception type.
+    """
+    def __init__(self, metadata, wheel_name):
+        # type: (Dict[str, bytes], str) -> None
+        super(WheelMetadata, self).__init__(metadata)
+        self._wheel_name = wheel_name
+
+    def get_metadata(self, name):
+        # type: (str) -> str
+        try:
+            return super(WheelMetadata, self).get_metadata(name)
+        except UnicodeDecodeError as e:
+            # Augment the default error with the origin of the file.
+            raise UnsupportedWheel(
+                "Error decoding metadata for {}: {}".format(
+                    self._wheel_name, e
+                )
+            )
+
+
+def pkg_resources_distribution_for_wheel(wheel_zip, name, location):
+    # type: (ZipFile, str, str) -> Distribution
+    """Get a pkg_resources distribution given a wheel.
+
+    :raises UnsupportedWheel: on any errors
+    """
+    info_dir, _ = parse_wheel(wheel_zip, name)
+
+    metadata_files = [
+        p for p in wheel_zip.namelist() if p.startswith("{}/".format(info_dir))
+    ]
+
+    metadata_text = {}  # type: Dict[str, bytes]
+    for path in metadata_files:
+        # If a flag is set, namelist entries may be unicode in Python 2.
+        # We coerce them to native str type to match the types used in the rest
+        # of the code. This cannot fail because unicode can always be encoded
+        # with UTF-8.
+        full_path = ensure_str(path)
+        _, metadata_name = full_path.split("/", 1)
+
+        try:
+            metadata_text[metadata_name] = read_wheel_metadata_file(
+                wheel_zip, full_path
+            )
+        except UnsupportedWheel as e:
+            raise UnsupportedWheel(
+                "{} has an invalid wheel, {}".format(name, str(e))
+            )
+
+    metadata = WheelMetadata(metadata_text, location)
+
+    return DistInfoDistribution(
+        location=location, metadata=metadata, project_name=name
+    )
+
+
+def parse_wheel(wheel_zip, name):
+    # type: (ZipFile, str) -> Tuple[str, Message]
+    """Extract information from the provided wheel, ensuring it meets basic
+    standards.
+
+    Returns the name of the .dist-info directory and the parsed WHEEL metadata.
+    """
+    try:
+        info_dir = wheel_dist_info_dir(wheel_zip, name)
+        metadata = wheel_metadata(wheel_zip, info_dir)
+        version = wheel_version(metadata)
+    except UnsupportedWheel as e:
+        raise UnsupportedWheel(
+            "{} has an invalid wheel, {}".format(name, str(e))
+        )
+
+    check_compatibility(version, name)
+
+    return info_dir, metadata
+
+
+def wheel_dist_info_dir(source, name):
+    # type: (ZipFile, str) -> str
+    """Returns the name of the contained .dist-info directory.
+
+    Raises AssertionError or UnsupportedWheel if not found, >1 found, or
+    it doesn't match the provided name.
+    """
+    # Zip file path separators must be /
+    subdirs = list(set(p.split("/")[0] for p in source.namelist()))
+
+    info_dirs = [s for s in subdirs if s.endswith('.dist-info')]
+
+    if not info_dirs:
+        raise UnsupportedWheel(".dist-info directory not found")
+
+    if len(info_dirs) > 1:
+        raise UnsupportedWheel(
+            "multiple .dist-info directories found: {}".format(
+                ", ".join(info_dirs)
+            )
+        )
+
+    info_dir = info_dirs[0]
+
+    info_dir_name = canonicalize_name(info_dir)
+    canonical_name = canonicalize_name(name)
+    if not info_dir_name.startswith(canonical_name):
+        raise UnsupportedWheel(
+            ".dist-info directory {!r} does not start with {!r}".format(
+                info_dir, canonical_name
+            )
+        )
+
+    # Zip file paths can be unicode or str depending on the zip entry flags,
+    # so normalize it.
+    return ensure_str(info_dir)
+
+
+def read_wheel_metadata_file(source, path):
+    # type: (ZipFile, str) -> bytes
+    try:
+        return source.read(path)
+        # BadZipFile for general corruption, KeyError for missing entry,
+        # and RuntimeError for password-protected files
+    except (BadZipFile, KeyError, RuntimeError) as e:
+        raise UnsupportedWheel(
+            "could not read {!r} file: {!r}".format(path, e)
+        )
+
+
+def wheel_metadata(source, dist_info_dir):
+    # type: (ZipFile, str) -> Message
+    """Return the WHEEL metadata of an extracted wheel, if possible.
+    Otherwise, raise UnsupportedWheel.
+    """
+    path = "{}/WHEEL".format(dist_info_dir)
+    # Zip file path separators must be /
+    wheel_contents = read_wheel_metadata_file(source, path)
+
+    try:
+        wheel_text = ensure_str(wheel_contents)
+    except UnicodeDecodeError as e:
+        raise UnsupportedWheel("error decoding {!r}: {!r}".format(path, e))
+
+    # FeedParser (used by Parser) does not raise any exceptions. The returned
+    # message may have .defects populated, but for backwards-compatibility we
+    # currently ignore them.
+    return Parser().parsestr(wheel_text)
+
+
+def wheel_version(wheel_data):
+    # type: (Message) -> Tuple[int, ...]
+    """Given WHEEL metadata, return the parsed Wheel-Version.
+    Otherwise, raise UnsupportedWheel.
+    """
+    version_text = wheel_data["Wheel-Version"]
+    if version_text is None:
+        raise UnsupportedWheel("WHEEL is missing Wheel-Version")
+
+    version = version_text.strip()
+
+    try:
+        return tuple(map(int, version.split('.')))
+    except ValueError:
+        raise UnsupportedWheel("invalid Wheel-Version: {!r}".format(version))
+
+
+def check_compatibility(version, name):
+    # type: (Tuple[int, ...], str) -> None
+    """Raises errors or warns if called with an incompatible Wheel-Version.
+
+    Pip should refuse to install a Wheel-Version that's a major series
+    ahead of what it's compatible with (e.g 2.0 > 1.1); and warn when
+    installing a version only minor version ahead (e.g 1.2 > 1.1).
+
+    version: a 2-tuple representing a Wheel-Version (Major, Minor)
+    name: name of wheel or package to raise exception about
+
+    :raises UnsupportedWheel: when an incompatible Wheel-Version is given
+    """
+    if version[0] > VERSION_COMPATIBLE[0]:
+        raise UnsupportedWheel(
+            "%s's Wheel-Version (%s) is not compatible with this version "
+            "of pip" % (name, '.'.join(map(str, version)))
+        )
+    elif version > VERSION_COMPATIBLE:
+        logger.warning(
+            'Installing from a newer Wheel-Version (%s)',
+            '.'.join(map(str, version)),
+        )