--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/python3.8/site-packages/pip/_internal/utils/temp_dir.py	Mon Jul 27 03:47:31 2020 -0400
@@ -0,0 +1,250 @@
+from __future__ import absolute_import
+
+import errno
+import itertools
+import logging
+import os.path
+import tempfile
+from contextlib import contextmanager
+
+from pip._vendor.contextlib2 import ExitStack
+
+from pip._internal.utils.misc import rmtree
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Any, Dict, Iterator, Optional, TypeVar
+
+    _T = TypeVar('_T', bound='TempDirectory')
+
+
+logger = logging.getLogger(__name__)
+
+
+_tempdir_manager = None  # type: Optional[ExitStack]
+
+
+@contextmanager
+def global_tempdir_manager():
+    # type: () -> Iterator[None]
+    global _tempdir_manager
+    with ExitStack() as stack:
+        old_tempdir_manager, _tempdir_manager = _tempdir_manager, stack
+        try:
+            yield
+        finally:
+            _tempdir_manager = old_tempdir_manager
+
+
+class TempDirectoryTypeRegistry(object):
+    """Manages temp directory behavior
+    """
+
+    def __init__(self):
+        # type: () -> None
+        self._should_delete = {}  # type: Dict[str, bool]
+
+    def set_delete(self, kind, value):
+        # type: (str, bool) -> None
+        """Indicate whether a TempDirectory of the given kind should be
+        auto-deleted.
+        """
+        self._should_delete[kind] = value
+
+    def get_delete(self, kind):
+        # type: (str) -> bool
+        """Get configured auto-delete flag for a given TempDirectory type,
+        default True.
+        """
+        return self._should_delete.get(kind, True)
+
+
+_tempdir_registry = None  # type: Optional[TempDirectoryTypeRegistry]
+
+
+@contextmanager
+def tempdir_registry():
+    # type: () -> Iterator[TempDirectoryTypeRegistry]
+    """Provides a scoped global tempdir registry that can be used to dictate
+    whether directories should be deleted.
+    """
+    global _tempdir_registry
+    old_tempdir_registry = _tempdir_registry
+    _tempdir_registry = TempDirectoryTypeRegistry()
+    try:
+        yield _tempdir_registry
+    finally:
+        _tempdir_registry = old_tempdir_registry
+
+
+class TempDirectory(object):
+    """Helper class that owns and cleans up a temporary directory.
+
+    This class can be used as a context manager or as an OO representation of a
+    temporary directory.
+
+    Attributes:
+        path
+            Location to the created temporary directory
+        delete
+            Whether the directory should be deleted when exiting
+            (when used as a contextmanager)
+
+    Methods:
+        cleanup()
+            Deletes the temporary directory
+
+    When used as a context manager, if the delete attribute is True, on
+    exiting the context the temporary directory is deleted.
+    """
+
+    def __init__(
+        self,
+        path=None,    # type: Optional[str]
+        delete=None,  # type: Optional[bool]
+        kind="temp",  # type: str
+        globally_managed=False,  # type: bool
+    ):
+        super(TempDirectory, self).__init__()
+
+        # If we were given an explicit directory, resolve delete option now.
+        # Otherwise we wait until cleanup and see what tempdir_registry says.
+        if path is not None and delete is None:
+            delete = False
+
+        if path is None:
+            path = self._create(kind)
+
+        self._path = path
+        self._deleted = False
+        self.delete = delete
+        self.kind = kind
+
+        if globally_managed:
+            assert _tempdir_manager is not None
+            _tempdir_manager.enter_context(self)
+
+    @property
+    def path(self):
+        # type: () -> str
+        assert not self._deleted, (
+            "Attempted to access deleted path: {}".format(self._path)
+        )
+        return self._path
+
+    def __repr__(self):
+        # type: () -> str
+        return "<{} {!r}>".format(self.__class__.__name__, self.path)
+
+    def __enter__(self):
+        # type: (_T) -> _T
+        return self
+
+    def __exit__(self, exc, value, tb):
+        # type: (Any, Any, Any) -> None
+        if self.delete is not None:
+            delete = self.delete
+        elif _tempdir_registry:
+            delete = _tempdir_registry.get_delete(self.kind)
+        else:
+            delete = True
+
+        if delete:
+            self.cleanup()
+
+    def _create(self, kind):
+        # type: (str) -> str
+        """Create a temporary directory and store its path in self.path
+        """
+        # We realpath here because some systems have their default tmpdir
+        # symlinked to another directory.  This tends to confuse build
+        # scripts, so we canonicalize the path by traversing potential
+        # symlinks here.
+        path = os.path.realpath(
+            tempfile.mkdtemp(prefix="pip-{}-".format(kind))
+        )
+        logger.debug("Created temporary directory: {}".format(path))
+        return path
+
+    def cleanup(self):
+        # type: () -> None
+        """Remove the temporary directory created and reset state
+        """
+        self._deleted = True
+        if os.path.exists(self._path):
+            rmtree(self._path)
+
+
+class AdjacentTempDirectory(TempDirectory):
+    """Helper class that creates a temporary directory adjacent to a real one.
+
+    Attributes:
+        original
+            The original directory to create a temp directory for.
+        path
+            After calling create() or entering, contains the full
+            path to the temporary directory.
+        delete
+            Whether the directory should be deleted when exiting
+            (when used as a contextmanager)
+
+    """
+    # The characters that may be used to name the temp directory
+    # We always prepend a ~ and then rotate through these until
+    # a usable name is found.
+    # pkg_resources raises a different error for .dist-info folder
+    # with leading '-' and invalid metadata
+    LEADING_CHARS = "-~.=%0123456789"
+
+    def __init__(self, original, delete=None):
+        # type: (str, Optional[bool]) -> None
+        self.original = original.rstrip('/\\')
+        super(AdjacentTempDirectory, self).__init__(delete=delete)
+
+    @classmethod
+    def _generate_names(cls, name):
+        # type: (str) -> Iterator[str]
+        """Generates a series of temporary names.
+
+        The algorithm replaces the leading characters in the name
+        with ones that are valid filesystem characters, but are not
+        valid package names (for both Python and pip definitions of
+        package).
+        """
+        for i in range(1, len(name)):
+            for candidate in itertools.combinations_with_replacement(
+                    cls.LEADING_CHARS, i - 1):
+                new_name = '~' + ''.join(candidate) + name[i:]
+                if new_name != name:
+                    yield new_name
+
+        # If we make it this far, we will have to make a longer name
+        for i in range(len(cls.LEADING_CHARS)):
+            for candidate in itertools.combinations_with_replacement(
+                    cls.LEADING_CHARS, i):
+                new_name = '~' + ''.join(candidate) + name
+                if new_name != name:
+                    yield new_name
+
+    def _create(self, kind):
+        # type: (str) -> str
+        root, name = os.path.split(self.original)
+        for candidate in self._generate_names(name):
+            path = os.path.join(root, candidate)
+            try:
+                os.mkdir(path)
+            except OSError as ex:
+                # Continue if the name exists already
+                if ex.errno != errno.EEXIST:
+                    raise
+            else:
+                path = os.path.realpath(path)
+                break
+        else:
+            # Final fallback on the default behavior.
+            path = os.path.realpath(
+                tempfile.mkdtemp(prefix="pip-{}-".format(kind))
+            )
+
+        logger.debug("Created temporary directory: {}".format(path))
+        return path