--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/python3.8/site-packages/pip/_internal/models/link.py	Mon Jul 27 03:47:31 2020 -0400
@@ -0,0 +1,227 @@
+import os
+import posixpath
+import re
+
+from pip._vendor.six.moves.urllib import parse as urllib_parse
+
+from pip._internal.utils.filetypes import WHEEL_EXTENSION
+from pip._internal.utils.misc import (
+    redact_auth_from_url,
+    split_auth_from_netloc,
+    splitext,
+)
+from pip._internal.utils.models import KeyBasedCompareMixin
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+from pip._internal.utils.urls import path_to_url, url_to_path
+
+if MYPY_CHECK_RUNNING:
+    from typing import Optional, Text, Tuple, Union
+    from pip._internal.index.collector import HTMLPage
+    from pip._internal.utils.hashes import Hashes
+
+
+class Link(KeyBasedCompareMixin):
+    """Represents a parsed link from a Package Index's simple URL
+    """
+
+    def __init__(
+        self,
+        url,                   # type: str
+        comes_from=None,       # type: Optional[Union[str, HTMLPage]]
+        requires_python=None,  # type: Optional[str]
+        yanked_reason=None,    # type: Optional[Text]
+    ):
+        # type: (...) -> None
+        """
+        :param url: url of the resource pointed to (href of the link)
+        :param comes_from: instance of HTMLPage where the link was found,
+            or string.
+        :param requires_python: String containing the `Requires-Python`
+            metadata field, specified in PEP 345. This may be specified by
+            a data-requires-python attribute in the HTML link tag, as
+            described in PEP 503.
+        :param yanked_reason: the reason the file has been yanked, if the
+            file has been yanked, or None if the file hasn't been yanked.
+            This is the value of the "data-yanked" attribute, if present, in
+            a simple repository HTML link. If the file has been yanked but
+            no reason was provided, this should be the empty string. See
+            PEP 592 for more information and the specification.
+        """
+
+        # url can be a UNC windows share
+        if url.startswith('\\\\'):
+            url = path_to_url(url)
+
+        self._parsed_url = urllib_parse.urlsplit(url)
+        # Store the url as a private attribute to prevent accidentally
+        # trying to set a new value.
+        self._url = url
+
+        self.comes_from = comes_from
+        self.requires_python = requires_python if requires_python else None
+        self.yanked_reason = yanked_reason
+
+        super(Link, self).__init__(key=url, defining_class=Link)
+
+    def __str__(self):
+        # type: () -> str
+        if self.requires_python:
+            rp = ' (requires-python:%s)' % self.requires_python
+        else:
+            rp = ''
+        if self.comes_from:
+            return '%s (from %s)%s' % (redact_auth_from_url(self._url),
+                                       self.comes_from, rp)
+        else:
+            return redact_auth_from_url(str(self._url))
+
+    def __repr__(self):
+        # type: () -> str
+        return '<Link %s>' % self
+
+    @property
+    def url(self):
+        # type: () -> str
+        return self._url
+
+    @property
+    def filename(self):
+        # type: () -> str
+        path = self.path.rstrip('/')
+        name = posixpath.basename(path)
+        if not name:
+            # Make sure we don't leak auth information if the netloc
+            # includes a username and password.
+            netloc, user_pass = split_auth_from_netloc(self.netloc)
+            return netloc
+
+        name = urllib_parse.unquote(name)
+        assert name, ('URL %r produced no filename' % self._url)
+        return name
+
+    @property
+    def file_path(self):
+        # type: () -> str
+        return url_to_path(self.url)
+
+    @property
+    def scheme(self):
+        # type: () -> str
+        return self._parsed_url.scheme
+
+    @property
+    def netloc(self):
+        # type: () -> str
+        """
+        This can contain auth information.
+        """
+        return self._parsed_url.netloc
+
+    @property
+    def path(self):
+        # type: () -> str
+        return urllib_parse.unquote(self._parsed_url.path)
+
+    def splitext(self):
+        # type: () -> Tuple[str, str]
+        return splitext(posixpath.basename(self.path.rstrip('/')))
+
+    @property
+    def ext(self):
+        # type: () -> str
+        return self.splitext()[1]
+
+    @property
+    def url_without_fragment(self):
+        # type: () -> str
+        scheme, netloc, path, query, fragment = self._parsed_url
+        return urllib_parse.urlunsplit((scheme, netloc, path, query, None))
+
+    _egg_fragment_re = re.compile(r'[#&]egg=([^&]*)')
+
+    @property
+    def egg_fragment(self):
+        # type: () -> Optional[str]
+        match = self._egg_fragment_re.search(self._url)
+        if not match:
+            return None
+        return match.group(1)
+
+    _subdirectory_fragment_re = re.compile(r'[#&]subdirectory=([^&]*)')
+
+    @property
+    def subdirectory_fragment(self):
+        # type: () -> Optional[str]
+        match = self._subdirectory_fragment_re.search(self._url)
+        if not match:
+            return None
+        return match.group(1)
+
+    _hash_re = re.compile(
+        r'(sha1|sha224|sha384|sha256|sha512|md5)=([a-f0-9]+)'
+    )
+
+    @property
+    def hash(self):
+        # type: () -> Optional[str]
+        match = self._hash_re.search(self._url)
+        if match:
+            return match.group(2)
+        return None
+
+    @property
+    def hash_name(self):
+        # type: () -> Optional[str]
+        match = self._hash_re.search(self._url)
+        if match:
+            return match.group(1)
+        return None
+
+    @property
+    def show_url(self):
+        # type: () -> str
+        return posixpath.basename(self._url.split('#', 1)[0].split('?', 1)[0])
+
+    @property
+    def is_file(self):
+        # type: () -> bool
+        return self.scheme == 'file'
+
+    def is_existing_dir(self):
+        # type: () -> bool
+        return self.is_file and os.path.isdir(self.file_path)
+
+    @property
+    def is_wheel(self):
+        # type: () -> bool
+        return self.ext == WHEEL_EXTENSION
+
+    @property
+    def is_vcs(self):
+        # type: () -> bool
+        from pip._internal.vcs import vcs
+
+        return self.scheme in vcs.all_schemes
+
+    @property
+    def is_yanked(self):
+        # type: () -> bool
+        return self.yanked_reason is not None
+
+    @property
+    def has_hash(self):
+        # type: () -> bool
+        return self.hash_name is not None
+
+    def is_hash_allowed(self, hashes):
+        # type: (Optional[Hashes]) -> bool
+        """
+        Return True if the link has a hash and it is allowed.
+        """
+        if hashes is None or not self.has_hash:
+            return False
+        # Assert non-None so mypy knows self.hash_name and self.hash are str.
+        assert self.hash_name is not None
+        assert self.hash is not None
+
+        return hashes.is_hash_allowed(self.hash_name, hex_digest=self.hash)