init

.venv/lib/python3.8/site-packages/virtualenv/seed/__init__.py

@@ -0,0 +1 @@
+from __future__ import absolute_import, unicode_literals

.venv/lib/python3.8/site-packages/virtualenv/seed/embed/base_embed.py

@@ -0,0 +1,118 @@
+from __future__ import absolute_import, unicode_literals
+
+from abc import ABCMeta
+
+from six import add_metaclass
+
+from virtualenv.util.path import Path
+from virtualenv.util.six import ensure_str, ensure_text
+
+from ..seeder import Seeder
+from ..wheels import Version
+
+PERIODIC_UPDATE_ON_BY_DEFAULT = True
+
+
+@add_metaclass(ABCMeta)
+class BaseEmbed(Seeder):
+    def __init__(self, options):
+        super(BaseEmbed, self).__init__(options, enabled=options.no_seed is False)
+
+        self.download = options.download
+        self.extra_search_dir = [i.resolve() for i in options.extra_search_dir if i.exists()]
+
+        self.pip_version = options.pip
+        self.setuptools_version = options.setuptools
+        self.wheel_version = options.wheel
+
+        self.no_pip = options.no_pip
+        self.no_setuptools = options.no_setuptools
+        self.no_wheel = options.no_wheel
+        self.app_data = options.app_data
+        self.periodic_update = not options.no_periodic_update
+
+        if not self.distribution_to_versions():
+            self.enabled = False
+
+    @classmethod
+    def distributions(cls):
+        return {
+            "pip": Version.bundle,
+            "setuptools": Version.bundle,
+            "wheel": Version.bundle,
+        }
+
+    def distribution_to_versions(self):
+        return {
+            distribution: getattr(self, "{}_version".format(distribution))
+            for distribution in self.distributions()
+            if getattr(self, "no_{}".format(distribution)) is False
+        }
+
+    @classmethod
+    def add_parser_arguments(cls, parser, interpreter, app_data):
+        group = parser.add_mutually_exclusive_group()
+        group.add_argument(
+            "--no-download",
+            "--never-download",
+            dest="download",
+            action="store_false",
+            help="pass to disable download of the latest {} from PyPI".format("/".join(cls.distributions())),
+            default=True,
+        )
+        group.add_argument(
+            "--download",
+            dest="download",
+            action="store_true",
+            help="pass to enable download of the latest {} from PyPI".format("/".join(cls.distributions())),
+            default=False,
+        )
+        parser.add_argument(
+            "--extra-search-dir",
+            metavar="d",
+            type=Path,
+            nargs="+",
+            help="a path containing wheels to extend the internal wheel list (can be set 1+ times)",
+            default=[],
+        )
+        for distribution, default in cls.distributions().items():
+            parser.add_argument(
+                "--{}".format(distribution),
+                dest=distribution,
+                metavar="version",
+                help="version of {} to install as seed: embed, bundle or exact version".format(distribution),
+                default=default,
+            )
+        for distribution in cls.distributions():
+            parser.add_argument(
+                "--no-{}".format(distribution),
+                dest="no_{}".format(distribution),
+                action="store_true",
+                help="do not install {}".format(distribution),
+                default=False,
+            )
+        parser.add_argument(
+            "--no-periodic-update",
+            dest="no_periodic_update",
+            action="store_true",
+            help="disable the periodic (once every 14 days) update of the embedded wheels",
+            default=not PERIODIC_UPDATE_ON_BY_DEFAULT,
+        )
+
+    def __unicode__(self):
+        result = self.__class__.__name__
+        result += "("
+        if self.extra_search_dir:
+            result += "extra_search_dir={},".format(", ".join(ensure_text(str(i)) for i in self.extra_search_dir))
+        result += "download={},".format(self.download)
+        for distribution in self.distributions():
+            if getattr(self, "no_{}".format(distribution)):
+                continue
+            result += " {}{},".format(
+                distribution,
+                "={}".format(getattr(self, "{}_version".format(distribution), None) or "latest"),
+            )
+        return result[:-1] + ")"
+
+    def __repr__(self):
+        return ensure_str(self.__unicode__())

.venv/lib/python3.8/site-packages/virtualenv/seed/embed/pip_invoke.py

@@ -0,0 +1,57 @@
+from __future__ import absolute_import, unicode_literals
+
+import logging
+from contextlib import contextmanager
+
+from virtualenv.discovery.cached_py_info import LogCmd
+from virtualenv.seed.embed.base_embed import BaseEmbed
+from virtualenv.util.subprocess import Popen
+
+from ..wheels import Version, get_wheel, pip_wheel_env_run
+
+
+class PipInvoke(BaseEmbed):
+    def __init__(self, options):
+        super(PipInvoke, self).__init__(options)
+
+    def run(self, creator):
+        if not self.enabled:
+            return
+        for_py_version = creator.interpreter.version_release_str
+        with self.get_pip_install_cmd(creator.exe, for_py_version) as cmd:
+            env = pip_wheel_env_run(self.extra_search_dir, self.app_data, self.env)
+            self._execute(cmd, env)
+
+    @staticmethod
+    def _execute(cmd, env):
+        logging.debug("pip seed by running: %s", LogCmd(cmd, env))
+        process = Popen(cmd, env=env)
+        process.communicate()
+        if process.returncode != 0:
+            raise RuntimeError("failed seed with code {}".format(process.returncode))
+        return process
+
+    @contextmanager
+    def get_pip_install_cmd(self, exe, for_py_version):
+        cmd = [str(exe), "-m", "pip", "-q", "install", "--only-binary", ":all:", "--disable-pip-version-check"]
+        if not self.download:
+            cmd.append("--no-index")
+        folders = set()
+        for dist, version in self.distribution_to_versions().items():
+            wheel = get_wheel(
+                distribution=dist,
+                version=version,
+                for_py_version=for_py_version,
+                search_dirs=self.extra_search_dir,
+                download=False,
+                app_data=self.app_data,
+                do_periodic_update=self.periodic_update,
+                env=self.env,
+            )
+            if wheel is None:
+                raise RuntimeError("could not get wheel for distribution {}".format(dist))
+            folders.add(str(wheel.path.parent))
+            cmd.append(Version.as_pip_req(dist, wheel.version))
+        for folder in sorted(folders):
+            cmd.extend(["--find-links", str(folder)])
+        yield cmd

.venv/lib/python3.8/site-packages/virtualenv/seed/embed/via_app_data/pip_install/base.py

@@ -0,0 +1,200 @@
+from __future__ import absolute_import, unicode_literals
+
+import logging
+import os
+import re
+import zipfile
+from abc import ABCMeta, abstractmethod
+from itertools import chain
+from tempfile import mkdtemp
+
+from distlib.scripts import ScriptMaker, enquote_executable
+from six import PY3, add_metaclass
+
+from virtualenv.util import ConfigParser
+from virtualenv.util.path import Path, safe_delete
+from virtualenv.util.six import ensure_text
+
+
+@add_metaclass(ABCMeta)
+class PipInstall(object):
+    def __init__(self, wheel, creator, image_folder):
+        self._wheel = wheel
+        self._creator = creator
+        self._image_dir = image_folder
+        self._extracted = False
+        self.__dist_info = None
+        self._console_entry_points = None
+
+    @abstractmethod
+    def _sync(self, src, dst):
+        raise NotImplementedError
+
+    def install(self, version_info):
+        self._extracted = True
+        self._uninstall_previous_version()
+        # sync image
+        for filename in self._image_dir.iterdir():
+            into = self._creator.purelib / filename.name
+            self._sync(filename, into)
+        # generate console executables
+        consoles = set()
+        script_dir = self._creator.script_dir
+        for name, module in self._console_scripts.items():
+            consoles.update(self._create_console_entry_point(name, module, script_dir, version_info))
+        logging.debug("generated console scripts %s", " ".join(i.name for i in consoles))
+
+    def build_image(self):
+        # 1. first extract the wheel
+        logging.debug("build install image for %s to %s", self._wheel.name, self._image_dir)
+        with zipfile.ZipFile(str(self._wheel)) as zip_ref:
+            self._shorten_path_if_needed(zip_ref)
+            zip_ref.extractall(str(self._image_dir))
+            self._extracted = True
+        # 2. now add additional files not present in the distribution
+        new_files = self._generate_new_files()
+        # 3. finally fix the records file
+        self._fix_records(new_files)
+
+    def _shorten_path_if_needed(self, zip_ref):
+        if os.name == "nt":
+            to_folder = str(self._image_dir)
+            # https://docs.microsoft.com/en-us/windows/win32/fileio/maximum-file-path-limitation
+            zip_max_len = max(len(i) for i in zip_ref.namelist())
+            path_len = zip_max_len + len(to_folder)
+            if path_len > 260:
+                self._image_dir.mkdir(exist_ok=True)  # to get a short path must exist
+
+                from virtualenv.util.path import get_short_path_name
+
+                to_folder = get_short_path_name(to_folder)
+                self._image_dir = Path(to_folder)
+
+    def _records_text(self, files):
+        record_data = "\n".join(
+            "{},,".format(os.path.relpath(ensure_text(str(rec)), ensure_text(str(self._image_dir)))) for rec in files
+        )
+        return record_data
+
+    def _generate_new_files(self):
+        new_files = set()
+        installer = self._dist_info / "INSTALLER"
+        installer.write_text("pip\n")
+        new_files.add(installer)
+        # inject a no-op root element, as workaround for bug in https://github.com/pypa/pip/issues/7226
+        marker = self._image_dir / "{}.virtualenv".format(self._dist_info.stem)
+        marker.write_text("")
+        new_files.add(marker)
+        folder = mkdtemp()
+        try:
+            to_folder = Path(folder)
+            rel = os.path.relpath(ensure_text(str(self._creator.script_dir)), ensure_text(str(self._creator.purelib)))
+            version_info = self._creator.interpreter.version_info
+            for name, module in self._console_scripts.items():
+                new_files.update(
+                    Path(os.path.normpath(ensure_text(str(self._image_dir / rel / i.name))))
+                    for i in self._create_console_entry_point(name, module, to_folder, version_info)
+                )
+        finally:
+            safe_delete(folder)
+        return new_files
+
+    @property
+    def _dist_info(self):
+        if self._extracted is False:
+            return None  # pragma: no cover
+        if self.__dist_info is None:
+            files = []
+            for filename in self._image_dir.iterdir():
+                files.append(filename.name)
+                if filename.suffix == ".dist-info":
+                    self.__dist_info = filename
+                    break
+            else:
+                msg = "no .dist-info at {}, has {}".format(self._image_dir, ", ".join(files))  # pragma: no cover
+                raise RuntimeError(msg)  # pragma: no cover
+        return self.__dist_info
+
+    @abstractmethod
+    def _fix_records(self, extra_record_data):
+        raise NotImplementedError
+
+    @property
+    def _console_scripts(self):
+        if self._extracted is False:
+            return None  # pragma: no cover
+        if self._console_entry_points is None:
+            self._console_entry_points = {}
+            entry_points = self._dist_info / "entry_points.txt"
+            if entry_points.exists():
+                parser = ConfigParser.ConfigParser()
+                with entry_points.open() as file_handler:
+                    reader = getattr(parser, "read_file" if PY3 else "readfp")
+                    reader(file_handler)
+                if "console_scripts" in parser.sections():
+                    for name, value in parser.items("console_scripts"):
+                        match = re.match(r"(.*?)-?\d\.?\d*", name)
+                        if match:
+                            name = match.groups(1)[0]
+                        self._console_entry_points[name] = value
+        return self._console_entry_points
+
+    def _create_console_entry_point(self, name, value, to_folder, version_info):
+        result = []
+        maker = ScriptMakerCustom(to_folder, version_info, self._creator.exe, name)
+        specification = "{} = {}".format(name, value)
+        new_files = maker.make(specification)
+        result.extend(Path(i) for i in new_files)
+        return result
+
+    def _uninstall_previous_version(self):
+        dist_name = self._dist_info.stem.split("-")[0]
+        in_folders = chain.from_iterable([i.iterdir() for i in {self._creator.purelib, self._creator.platlib}])
+        paths = (p for p in in_folders if p.stem.split("-")[0] == dist_name and p.suffix == ".dist-info" and p.is_dir())
+        existing_dist = next(paths, None)
+        if existing_dist is not None:
+            self._uninstall_dist(existing_dist)
+
+    @staticmethod
+    def _uninstall_dist(dist):
+        dist_base = dist.parent
+        logging.debug("uninstall existing distribution %s from %s", dist.stem, dist_base)
+
+        top_txt = dist / "top_level.txt"  # add top level packages at folder level
+        paths = {dist.parent / i.strip() for i in top_txt.read_text().splitlines()} if top_txt.exists() else set()
+        paths.add(dist)  # add the dist-info folder itself
+
+        base_dirs, record = paths.copy(), dist / "RECORD"  # collect entries in record that we did not register yet
+        for name in (i.split(",")[0] for i in record.read_text().splitlines()) if record.exists() else ():
+            path = dist_base / name
+            if not any(p in base_dirs for p in path.parents):  # only add if not already added as a base dir
+                paths.add(path)
+
+        for path in sorted(paths):  # actually remove stuff in a stable order
+            if path.exists():
+                if path.is_dir() and not path.is_symlink():
+                    safe_delete(path)
+                else:
+                    path.unlink()
+
+    def clear(self):
+        if self._image_dir.exists():
+            safe_delete(self._image_dir)
+
+    def has_image(self):
+        return self._image_dir.exists() and next(self._image_dir.iterdir()) is not None
+
+
+class ScriptMakerCustom(ScriptMaker):
+    def __init__(self, target_dir, version_info, executable, name):
+        super(ScriptMakerCustom, self).__init__(None, str(target_dir))
+        self.clobber = True  # overwrite
+        self.set_mode = True  # ensure they are executable
+        self.executable = enquote_executable(str(executable))
+        self.version_info = version_info.major, version_info.minor
+        self.variants = {"", "X", "X.Y"}
+        self._name = name
+
+    def _write_script(self, names, shebang, script_bytes, filenames, ext):
+        names.add("{}{}.{}".format(self._name, *self.version_info))
+        super(ScriptMakerCustom, self)._write_script(names, shebang, script_bytes, filenames, ext)

.venv/lib/python3.8/site-packages/virtualenv/seed/embed/via_app_data/pip_install/copy.py

@@ -0,0 +1,35 @@
+from __future__ import absolute_import, unicode_literals
+
+import os
+
+from virtualenv.util.path import Path, copy
+from virtualenv.util.six import ensure_text
+
+from .base import PipInstall
+
+
+class CopyPipInstall(PipInstall):
+    def _sync(self, src, dst):
+        copy(src, dst)
+
+    def _generate_new_files(self):
+        # create the pyc files
+        new_files = super(CopyPipInstall, self)._generate_new_files()
+        new_files.update(self._cache_files())
+        return new_files
+
+    def _cache_files(self):
+        version = self._creator.interpreter.version_info
+        py_c_ext = ".{}-{}{}.pyc".format(self._creator.interpreter.implementation.lower(), version.major, version.minor)
+        for root, dirs, files in os.walk(ensure_text(str(self._image_dir)), topdown=True):
+            root_path = Path(root)
+            for name in files:
+                if name.endswith(".py"):
+                    yield root_path / "{}{}".format(name[:-3], py_c_ext)
+            for name in dirs:
+                yield root_path / name / "__pycache__"
+
+    def _fix_records(self, new_files):
+        extra_record_data_str = self._records_text(new_files)
+        with open(ensure_text(str(self._dist_info / "RECORD")), "ab") as file_handler:
+            file_handler.write(extra_record_data_str.encode("utf-8"))

.venv/lib/python3.8/site-packages/virtualenv/seed/embed/via_app_data/pip_install/symlink.py

@@ -0,0 +1,61 @@
+from __future__ import absolute_import, unicode_literals
+
+import os
+import subprocess
+from stat import S_IREAD, S_IRGRP, S_IROTH
+
+from virtualenv.util.path import safe_delete, set_tree
+from virtualenv.util.six import ensure_text
+from virtualenv.util.subprocess import Popen
+
+from .base import PipInstall
+
+
+class SymlinkPipInstall(PipInstall):
+    def _sync(self, src, dst):
+        src_str = ensure_text(str(src))
+        dest_str = ensure_text(str(dst))
+        os.symlink(src_str, dest_str)
+
+    def _generate_new_files(self):
+        # create the pyc files, as the build image will be R/O
+        process = Popen(
+            [ensure_text(str(self._creator.exe)), "-m", "compileall", ensure_text(str(self._image_dir))],
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
+        process.communicate()
+        # the root pyc is shared, so we'll not symlink that - but still add the pyc files to the RECORD for close
+        root_py_cache = self._image_dir / "__pycache__"
+        new_files = set()
+        if root_py_cache.exists():
+            new_files.update(root_py_cache.iterdir())
+            new_files.add(root_py_cache)
+            safe_delete(root_py_cache)
+        core_new_files = super(SymlinkPipInstall, self)._generate_new_files()
+        # remove files that are within the image folder deeper than one level (as these will be not linked directly)
+        for file in core_new_files:
+            try:
+                rel = file.relative_to(self._image_dir)
+                if len(rel.parts) > 1:
+                    continue
+            except ValueError:
+                pass
+            new_files.add(file)
+        return new_files
+
+    def _fix_records(self, new_files):
+        new_files.update(i for i in self._image_dir.iterdir())
+        extra_record_data_str = self._records_text(sorted(new_files, key=str))
+        with open(ensure_text(str(self._dist_info / "RECORD")), "wb") as file_handler:
+            file_handler.write(extra_record_data_str.encode("utf-8"))
+
+    def build_image(self):
+        super(SymlinkPipInstall, self).build_image()
+        # protect the image by making it read only
+        set_tree(self._image_dir, S_IREAD | S_IRGRP | S_IROTH)
+
+    def clear(self):
+        if self._image_dir.exists():
+            safe_delete(self._image_dir)
+        super(SymlinkPipInstall, self).clear()

.venv/lib/python3.8/site-packages/virtualenv/seed/embed/via_app_data/via_app_data.py

@@ -0,0 +1,140 @@
+"""Bootstrap"""
+from __future__ import absolute_import, unicode_literals
+
+import logging
+import sys
+import traceback
+from contextlib import contextmanager
+from subprocess import CalledProcessError
+from threading import Lock, Thread
+
+from virtualenv.info import fs_supports_symlink
+from virtualenv.seed.embed.base_embed import BaseEmbed
+from virtualenv.seed.wheels import get_wheel
+from virtualenv.util.path import Path
+
+from .pip_install.copy import CopyPipInstall
+from .pip_install.symlink import SymlinkPipInstall
+
+
+class FromAppData(BaseEmbed):
+    def __init__(self, options):
+        super(FromAppData, self).__init__(options)
+        self.symlinks = options.symlink_app_data
+
+    @classmethod
+    def add_parser_arguments(cls, parser, interpreter, app_data):
+        super(FromAppData, cls).add_parser_arguments(parser, interpreter, app_data)
+        can_symlink = app_data.transient is False and fs_supports_symlink()
+        parser.add_argument(
+            "--symlink-app-data",
+            dest="symlink_app_data",
+            action="store_true" if can_symlink else "store_false",
+            help="{} symlink the python packages from the app-data folder (requires seed pip>=19.3)".format(
+                "" if can_symlink else "not supported - ",
+            ),
+            default=False,
+        )
+
+    def run(self, creator):
+        if not self.enabled:
+            return
+        with self._get_seed_wheels(creator) as name_to_whl:
+            pip_version = name_to_whl["pip"].version_tuple if "pip" in name_to_whl else None
+            installer_class = self.installer_class(pip_version)
+            exceptions = {}
+
+            def _install(name, wheel):
+                try:
+                    logging.debug("install %s from wheel %s via %s", name, wheel, installer_class.__name__)
+                    key = Path(installer_class.__name__) / wheel.path.stem
+                    wheel_img = self.app_data.wheel_image(creator.interpreter.version_release_str, key)
+                    installer = installer_class(wheel.path, creator, wheel_img)
+                    parent = self.app_data.lock / wheel_img.parent
+                    with parent.non_reentrant_lock_for_key(wheel_img.name):
+                        if not installer.has_image():
+                            installer.build_image()
+                    installer.install(creator.interpreter.version_info)
+                except Exception:  # noqa
+                    exceptions[name] = sys.exc_info()
+
+            threads = list(Thread(target=_install, args=(n, w)) for n, w in name_to_whl.items())
+            for thread in threads:
+                thread.start()
+            for thread in threads:
+                thread.join()
+            if exceptions:
+                messages = ["failed to build image {} because:".format(", ".join(exceptions.keys()))]
+                for value in exceptions.values():
+                    exc_type, exc_value, exc_traceback = value
+                    messages.append("".join(traceback.format_exception(exc_type, exc_value, exc_traceback)))
+                raise RuntimeError("\n".join(messages))
+
+    @contextmanager
+    def _get_seed_wheels(self, creator):
+        name_to_whl, lock, fail = {}, Lock(), {}
+
+        def _get(distribution, version):
+            for_py_version = creator.interpreter.version_release_str
+            failure, result = None, None
+            # fallback to download in case the exact version is not available
+            for download in [True] if self.download else [False, True]:
+                failure = None
+                try:
+                    result = get_wheel(
+                        distribution=distribution,
+                        version=version,
+                        for_py_version=for_py_version,
+                        search_dirs=self.extra_search_dir,
+                        download=download,
+                        app_data=self.app_data,
+                        do_periodic_update=self.periodic_update,
+                        env=self.env,
+                    )
+                    if result is not None:
+                        break
+                except Exception as exception:  # noqa
+                    logging.exception("fail")
+                    failure = exception
+            if failure:
+                if isinstance(failure, CalledProcessError):
+                    msg = "failed to download {}".format(distribution)
+                    if version is not None:
+                        msg += " version {}".format(version)
+                    msg += ", pip download exit code {}".format(failure.returncode)
+                    output = failure.output if sys.version_info < (3, 5) else (failure.output + failure.stderr)
+                    if output:
+                        msg += "\n"
+                        msg += output
+                else:
+                    msg = repr(failure)
+                logging.error(msg)
+                with lock:
+                    fail[distribution] = version
+            else:
+                with lock:
+                    name_to_whl[distribution] = result
+
+        threads = list(
+            Thread(target=_get, args=(distribution, version))
+            for distribution, version in self.distribution_to_versions().items()
+        )
+        for thread in threads:
+            thread.start()
+        for thread in threads:
+            thread.join()
+        if fail:
+            raise RuntimeError("seed failed due to failing to download wheels {}".format(", ".join(fail.keys())))
+        yield name_to_whl
+
+    def installer_class(self, pip_version_tuple):
+        if self.symlinks and pip_version_tuple:
+            # symlink support requires pip 19.3+
+            if pip_version_tuple >= (19, 3):
+                return SymlinkPipInstall
+        return CopyPipInstall
+
+    def __unicode__(self):
+        base = super(FromAppData, self).__unicode__()
+        msg = ", via={}, app_data_dir={}".format("symlink" if self.symlinks else "copy", self.app_data)
+        return base[:-1] + msg + base[-1]

.venv/lib/python3.8/site-packages/virtualenv/seed/seeder.py

@@ -0,0 +1,40 @@
+from __future__ import absolute_import, unicode_literals
+
+from abc import ABCMeta, abstractmethod
+
+from six import add_metaclass
+
+
+@add_metaclass(ABCMeta)
+class Seeder(object):
+    """A seeder will install some seed packages into a virtual environment."""
+
+    # noinspection PyUnusedLocal
+    def __init__(self, options, enabled):
+        """
+
+        :param options: the parsed options as defined within :meth:`add_parser_arguments`
+        :param enabled: a flag weather the seeder is enabled or not
+        """
+        self.enabled = enabled
+        self.env = options.env
+
+    @classmethod
+    def add_parser_arguments(cls, parser, interpreter, app_data):
+        """
+        Add CLI arguments for this seed mechanisms.
+
+        :param parser: the CLI parser
+        :param app_data: the CLI parser
+        :param interpreter: the interpreter this virtual environment is based of
+        """
+        raise NotImplementedError
+
+    @abstractmethod
+    def run(self, creator):
+        """Perform the seed operation.
+
+        :param creator: the creator (based of :class:`virtualenv.create.creator.Creator`) we used to create this \
+        virtual environment
+        """
+        raise NotImplementedError

.venv/lib/python3.8/site-packages/virtualenv/seed/wheels/__init__.py

@@ -0,0 +1,11 @@
+from __future__ import absolute_import, unicode_literals
+
+from .acquire import get_wheel, pip_wheel_env_run
+from .util import Version, Wheel
+
+__all__ = (
+    "get_wheel",
+    "pip_wheel_env_run",
+    "Version",
+    "Wheel",
+)

.venv/lib/python3.8/site-packages/virtualenv/seed/wheels/acquire.py

@@ -0,0 +1,128 @@
+"""Bootstrap"""
+from __future__ import absolute_import, unicode_literals
+
+import logging
+import sys
+from operator import eq, lt
+
+from virtualenv.util.path import Path
+from virtualenv.util.six import ensure_str
+from virtualenv.util.subprocess import Popen, subprocess
+
+from .bundle import from_bundle
+from .periodic_update import add_wheel_to_update_log
+from .util import Version, Wheel, discover_wheels
+
+
+def get_wheel(distribution, version, for_py_version, search_dirs, download, app_data, do_periodic_update, env):
+    """
+    Get a wheel with the given distribution-version-for_py_version trio, by using the extra search dir + download
+    """
+    # not all wheels are compatible with all python versions, so we need to py version qualify it
+    wheel = None
+
+    if not download or version != Version.bundle:
+        # 1. acquire from bundle
+        wheel = from_bundle(distribution, version, for_py_version, search_dirs, app_data, do_periodic_update, env)
+
+    if download and wheel is None and version != Version.embed:
+        # 2. download from the internet
+        wheel = download_wheel(
+            distribution=distribution,
+            version_spec=Version.as_version_spec(version),
+            for_py_version=for_py_version,
+            search_dirs=search_dirs,
+            app_data=app_data,
+            to_folder=app_data.house,
+            env=env,
+        )
+        if wheel is not None and app_data.can_update:
+            add_wheel_to_update_log(wheel, for_py_version, app_data)
+
+    return wheel
+
+
+def download_wheel(distribution, version_spec, for_py_version, search_dirs, app_data, to_folder, env):
+    to_download = "{}{}".format(distribution, version_spec or "")
+    logging.debug("download wheel %s %s to %s", to_download, for_py_version, to_folder)
+    cmd = [
+        sys.executable,
+        "-m",
+        "pip",
+        "download",
+        "--progress-bar",
+        "off",
+        "--disable-pip-version-check",
+        "--only-binary=:all:",
+        "--no-deps",
+        "--python-version",
+        for_py_version,
+        "-d",
+        str(to_folder),
+        to_download,
+    ]
+    # pip has no interface in python - must be a new sub-process
+    env = pip_wheel_env_run(search_dirs, app_data, env)
+    process = Popen(cmd, env=env, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
+    out, err = process.communicate()
+    if process.returncode != 0:
+        kwargs = {"output": out}
+        if sys.version_info < (3, 5):
+            kwargs["output"] += err
+        else:
+            kwargs["stderr"] = err
+        raise subprocess.CalledProcessError(process.returncode, cmd, **kwargs)
+    result = _find_downloaded_wheel(distribution, version_spec, for_py_version, to_folder, out)
+    logging.debug("downloaded wheel %s", result.name)
+    return result
+
+
+def _find_downloaded_wheel(distribution, version_spec, for_py_version, to_folder, out):
+    for line in out.splitlines():
+        line = line.lstrip()
+        for marker in ("Saved ", "File was already downloaded "):
+            if line.startswith(marker):
+                return Wheel(Path(line[len(marker) :]).absolute())
+    # if for some reason the output does not match fallback to latest version with that spec
+    return find_compatible_in_house(distribution, version_spec, for_py_version, to_folder)
+
+
+def find_compatible_in_house(distribution, version_spec, for_py_version, in_folder):
+    wheels = discover_wheels(in_folder, distribution, None, for_py_version)
+    start, end = 0, len(wheels)
+    if version_spec is not None:
+        if version_spec.startswith("<"):
+            from_pos, op = 1, lt
+        elif version_spec.startswith("=="):
+            from_pos, op = 2, eq
+        else:
+            raise ValueError(version_spec)
+        version = Wheel.as_version_tuple(version_spec[from_pos:])
+        start = next((at for at, w in enumerate(wheels) if op(w.version_tuple, version)), len(wheels))
+
+    return None if start == end else wheels[start]
+
+
+def pip_wheel_env_run(search_dirs, app_data, env):
+    for_py_version = "{}.{}".format(*sys.version_info[0:2])
+    env = env.copy()
+    env.update(
+        {
+            ensure_str(k): str(v)  # python 2 requires these to be string only (non-unicode)
+            for k, v in {"PIP_USE_WHEEL": "1", "PIP_USER": "0", "PIP_NO_INPUT": "1"}.items()
+        },
+    )
+    wheel = get_wheel(
+        distribution="pip",
+        version=None,
+        for_py_version=for_py_version,
+        search_dirs=search_dirs,
+        download=False,
+        app_data=app_data,
+        do_periodic_update=False,
+        env=env,
+    )
+    if wheel is None:
+        raise RuntimeError("could not find the embedded pip")
+    env[str("PYTHONPATH")] = str(wheel.path)
+    return env

.venv/lib/python3.8/site-packages/virtualenv/seed/wheels/bundle.py

@@ -0,0 +1,51 @@
+from __future__ import absolute_import, unicode_literals
+
+from ..wheels.embed import get_embed_wheel
+from .periodic_update import periodic_update
+from .util import Version, Wheel, discover_wheels
+
+
+def from_bundle(distribution, version, for_py_version, search_dirs, app_data, do_periodic_update, env):
+    """
+    Load the bundled wheel to a cache directory.
+    """
+    of_version = Version.of_version(version)
+    wheel = load_embed_wheel(app_data, distribution, for_py_version, of_version)
+
+    if version != Version.embed:
+        # 2. check if we have upgraded embed
+        if app_data.can_update:
+            wheel = periodic_update(
+                distribution, of_version, for_py_version, wheel, search_dirs, app_data, do_periodic_update, env
+            )
+
+        # 3. acquire from extra search dir
+        found_wheel = from_dir(distribution, of_version, for_py_version, search_dirs)
+        if found_wheel is not None:
+            if wheel is None:
+                wheel = found_wheel
+            elif found_wheel.version_tuple > wheel.version_tuple:
+                wheel = found_wheel
+    return wheel
+
+
+def load_embed_wheel(app_data, distribution, for_py_version, version):
+    wheel = get_embed_wheel(distribution, for_py_version)
+    if wheel is not None:
+        version_match = version == wheel.version
+        if version is None or version_match:
+            with app_data.ensure_extracted(wheel.path, lambda: app_data.house) as wheel_path:
+                wheel = Wheel(wheel_path)
+        else:  # if version does not match ignore
+            wheel = None
+    return wheel
+
+
+def from_dir(distribution, version, for_py_version, directories):
+    """
+    Load a compatible wheel from a given folder.
+    """
+    for folder in directories:
+        for wheel in discover_wheels(folder, distribution, version, for_py_version):
+            return wheel
+    return None

.venv/lib/python3.8/site-packages/virtualenv/seed/wheels/embed/__init__.py

@@ -0,0 +1,62 @@
+from __future__ import absolute_import, unicode_literals
+
+from virtualenv.seed.wheels.util import Wheel
+from virtualenv.util.path import Path
+
+BUNDLE_FOLDER = Path(__file__).absolute().parent
+BUNDLE_SUPPORT = {
+    "3.11": {
+        "pip": "pip-22.0.4-py3-none-any.whl",
+        "setuptools": "setuptools-61.0.0-py3-none-any.whl",
+        "wheel": "wheel-0.37.1-py2.py3-none-any.whl",
+    },
+    "3.10": {
+        "pip": "pip-22.0.4-py3-none-any.whl",
+        "setuptools": "setuptools-61.0.0-py3-none-any.whl",
+        "wheel": "wheel-0.37.1-py2.py3-none-any.whl",
+    },
+    "3.9": {
+        "pip": "pip-22.0.4-py3-none-any.whl",
+        "setuptools": "setuptools-61.0.0-py3-none-any.whl",
+        "wheel": "wheel-0.37.1-py2.py3-none-any.whl",
+    },
+    "3.8": {
+        "pip": "pip-22.0.4-py3-none-any.whl",
+        "setuptools": "setuptools-61.0.0-py3-none-any.whl",
+        "wheel": "wheel-0.37.1-py2.py3-none-any.whl",
+    },
+    "3.7": {
+        "pip": "pip-22.0.4-py3-none-any.whl",
+        "setuptools": "setuptools-61.0.0-py3-none-any.whl",
+        "wheel": "wheel-0.37.1-py2.py3-none-any.whl",
+    },
+    "3.6": {
+        "pip": "pip-21.3.1-py3-none-any.whl",
+        "setuptools": "setuptools-59.6.0-py3-none-any.whl",
+        "wheel": "wheel-0.37.1-py2.py3-none-any.whl",
+    },
+    "3.5": {
+        "pip": "pip-20.3.4-py2.py3-none-any.whl",
+        "setuptools": "setuptools-50.3.2-py3-none-any.whl",
+        "wheel": "wheel-0.37.1-py2.py3-none-any.whl",
+    },
+    "2.7": {
+        "pip": "pip-20.3.4-py2.py3-none-any.whl",
+        "setuptools": "setuptools-44.1.1-py2.py3-none-any.whl",
+        "wheel": "wheel-0.37.1-py2.py3-none-any.whl",
+    },
+}
+MAX = "3.11"
+
+
+def get_embed_wheel(distribution, for_py_version):
+    path = BUNDLE_FOLDER / (BUNDLE_SUPPORT.get(for_py_version, {}) or BUNDLE_SUPPORT[MAX]).get(distribution)
+    return Wheel.from_path(path)
+
+
+__all__ = (
+    "get_embed_wheel",
+    "BUNDLE_SUPPORT",
+    "MAX",
+    "BUNDLE_FOLDER",
+)

.venv/lib/python3.8/site-packages/virtualenv/seed/wheels/periodic_update.py

@@ -0,0 +1,428 @@
+"""
+Periodically update bundled versions.
+"""
+
+from __future__ import absolute_import, unicode_literals
+
+import json
+import logging
+import os
+import ssl
+import subprocess
+import sys
+from datetime import datetime, timedelta
+from itertools import groupby
+from shutil import copy2
+from textwrap import dedent
+from threading import Thread
+
+from six.moves.urllib.error import URLError
+from six.moves.urllib.request import urlopen
+
+from virtualenv.app_data import AppDataDiskFolder
+from virtualenv.info import PY2
+from virtualenv.util.path import Path
+from virtualenv.util.subprocess import CREATE_NO_WINDOW, Popen
+
+from ..wheels.embed import BUNDLE_SUPPORT
+from ..wheels.util import Wheel
+
+if PY2:
+    # on Python 2 datetime.strptime throws the error below if the import did not trigger on main thread
+    # Failed to import _strptime because the import lock is held by
+    try:
+        import _strptime  # noqa
+    except ImportError:  # pragma: no cov
+        pass  # pragma: no cov
+
+
+GRACE_PERIOD_CI = timedelta(hours=1)  # prevent version switch in the middle of a CI run
+GRACE_PERIOD_MINOR = timedelta(days=28)
+UPDATE_PERIOD = timedelta(days=14)
+UPDATE_ABORTED_DELAY = timedelta(hours=1)
+
+
+def periodic_update(distribution, of_version, for_py_version, wheel, search_dirs, app_data, do_periodic_update, env):
+    if do_periodic_update:
+        handle_auto_update(distribution, for_py_version, wheel, search_dirs, app_data, env)
+
+    now = datetime.now()
+
+    def _update_wheel(ver):
+        updated_wheel = Wheel(app_data.house / ver.filename)
+        logging.debug("using %supdated wheel %s", "periodically " if updated_wheel else "", updated_wheel)
+        return updated_wheel
+
+    u_log = UpdateLog.from_app_data(app_data, distribution, for_py_version)
+    if of_version is None:
+        for _, group in groupby(u_log.versions, key=lambda v: v.wheel.version_tuple[0:2]):
+            # use only latest patch version per minor, earlier assumed to be buggy
+            all_patches = list(group)
+            ignore_grace_period_minor = any(version for version in all_patches if version.use(now))
+            for version in all_patches:
+                if wheel is not None and Path(version.filename).name == wheel.name:
+                    return wheel
+                if version.use(now, ignore_grace_period_minor):
+                    return _update_wheel(version)
+    else:
+        for version in u_log.versions:
+            if version.wheel.version == of_version:
+                return _update_wheel(version)
+
+    return wheel
+
+
+def handle_auto_update(distribution, for_py_version, wheel, search_dirs, app_data, env):
+    embed_update_log = app_data.embed_update_log(distribution, for_py_version)
+    u_log = UpdateLog.from_dict(embed_update_log.read())
+    if u_log.needs_update:
+        u_log.periodic = True
+        u_log.started = datetime.now()
+        embed_update_log.write(u_log.to_dict())
+        trigger_update(distribution, for_py_version, wheel, search_dirs, app_data, periodic=True, env=env)
+
+
+def add_wheel_to_update_log(wheel, for_py_version, app_data):
+    embed_update_log = app_data.embed_update_log(wheel.distribution, for_py_version)
+    logging.debug("adding %s information to %s", wheel.name, embed_update_log.file)
+    u_log = UpdateLog.from_dict(embed_update_log.read())
+    if any(version.filename == wheel.name for version in u_log.versions):
+        logging.warning("%s already present in %s", wheel.name, embed_update_log.file)
+        return
+    # we don't need a release date for sources other than "periodic"
+    version = NewVersion(wheel.name, datetime.now(), None, "download")
+    u_log.versions.append(version)  # always write at the end for proper updates
+    embed_update_log.write(u_log.to_dict())
+
+
+DATETIME_FMT = "%Y-%m-%dT%H:%M:%S.%fZ"
+
+
+def dump_datetime(value):
+    return None if value is None else value.strftime(DATETIME_FMT)
+
+
+def load_datetime(value):
+    return None if value is None else datetime.strptime(value, DATETIME_FMT)
+
+
+class NewVersion(object):
+    def __init__(self, filename, found_date, release_date, source):
+        self.filename = filename
+        self.found_date = found_date
+        self.release_date = release_date
+        self.source = source
+
+    @classmethod
+    def from_dict(cls, dictionary):
+        return cls(
+            filename=dictionary["filename"],
+            found_date=load_datetime(dictionary["found_date"]),
+            release_date=load_datetime(dictionary["release_date"]),
+            source=dictionary["source"],
+        )
+
+    def to_dict(self):
+        return {
+            "filename": self.filename,
+            "release_date": dump_datetime(self.release_date),
+            "found_date": dump_datetime(self.found_date),
+            "source": self.source,
+        }
+
+    def use(self, now, ignore_grace_period_minor=False, ignore_grace_period_ci=False):
+        if self.source == "manual":
+            return True
+        elif self.source == "periodic":
+            if self.found_date < now - GRACE_PERIOD_CI or ignore_grace_period_ci:
+                if not ignore_grace_period_minor:
+                    compare_from = self.release_date or self.found_date
+                    return now - compare_from >= GRACE_PERIOD_MINOR
+                return True
+        return False
+
+    def __repr__(self):
+        return "{}(filename={}), found_date={}, release_date={}, source={})".format(
+            self.__class__.__name__,
+            self.filename,
+            self.found_date,
+            self.release_date,
+            self.source,
+        )
+
+    def __eq__(self, other):
+        return type(self) == type(other) and all(
+            getattr(self, k) == getattr(other, k) for k in ["filename", "release_date", "found_date", "source"]
+        )
+
+    def __ne__(self, other):
+        return not (self == other)
+
+    @property
+    def wheel(self):
+        return Wheel(Path(self.filename))
+
+
+class UpdateLog(object):
+    def __init__(self, started, completed, versions, periodic):
+        self.started = started
+        self.completed = completed
+        self.versions = versions
+        self.periodic = periodic
+
+    @classmethod
+    def from_dict(cls, dictionary):
+        if dictionary is None:
+            dictionary = {}
+        return cls(
+            load_datetime(dictionary.get("started")),
+            load_datetime(dictionary.get("completed")),
+            [NewVersion.from_dict(v) for v in dictionary.get("versions", [])],
+            dictionary.get("periodic"),
+        )
+
+    @classmethod
+    def from_app_data(cls, app_data, distribution, for_py_version):
+        raw_json = app_data.embed_update_log(distribution, for_py_version).read()
+        return cls.from_dict(raw_json)
+
+    def to_dict(self):
+        return {
+            "started": dump_datetime(self.started),
+            "completed": dump_datetime(self.completed),
+            "periodic": self.periodic,
+            "versions": [r.to_dict() for r in self.versions],
+        }
+
+    @property
+    def needs_update(self):
+        now = datetime.now()
+        if self.completed is None:  # never completed
+            return self._check_start(now)
+        else:
+            if now - self.completed <= UPDATE_PERIOD:
+                return False
+            return self._check_start(now)
+
+    def _check_start(self, now):
+        return self.started is None or now - self.started > UPDATE_ABORTED_DELAY
+
+
+def trigger_update(distribution, for_py_version, wheel, search_dirs, app_data, env, periodic):
+    wheel_path = None if wheel is None else str(wheel.path)
+    cmd = [
+        sys.executable,
+        "-c",
+        dedent(
+            """
+        from virtualenv.report import setup_report, MAX_LEVEL
+        from virtualenv.seed.wheels.periodic_update import do_update
+        setup_report(MAX_LEVEL, show_pid=True)
+        do_update({!r}, {!r}, {!r}, {!r}, {!r}, {!r})
+        """,
+        )
+        .strip()
+        .format(distribution, for_py_version, wheel_path, str(app_data), [str(p) for p in search_dirs], periodic),
+    ]
+    debug = env.get(str("_VIRTUALENV_PERIODIC_UPDATE_INLINE")) == str("1")
+    pipe = None if debug else subprocess.PIPE
+    kwargs = {"stdout": pipe, "stderr": pipe}
+    if not debug and sys.platform == "win32":
+        kwargs["creationflags"] = CREATE_NO_WINDOW
+    process = Popen(cmd, **kwargs)
+    logging.info(
+        "triggered periodic upgrade of %s%s (for python %s) via background process having PID %d",
+        distribution,
+        "" if wheel is None else "=={}".format(wheel.version),
+        for_py_version,
+        process.pid,
+    )
+    if debug:
+        process.communicate()  # on purpose not called to make it a background process
+
+
+def do_update(distribution, for_py_version, embed_filename, app_data, search_dirs, periodic):
+    versions = None
+    try:
+        versions = _run_do_update(app_data, distribution, embed_filename, for_py_version, periodic, search_dirs)
+    finally:
+        logging.debug("done %s %s with %s", distribution, for_py_version, versions)
+    return versions
+
+
+def _run_do_update(app_data, distribution, embed_filename, for_py_version, periodic, search_dirs):
+    from virtualenv.seed.wheels import acquire
+
+    wheel_filename = None if embed_filename is None else Path(embed_filename)
+    embed_version = None if wheel_filename is None else Wheel(wheel_filename).version_tuple
+    app_data = AppDataDiskFolder(app_data) if isinstance(app_data, str) else app_data
+    search_dirs = [Path(p) if isinstance(p, str) else p for p in search_dirs]
+    wheelhouse = app_data.house
+    embed_update_log = app_data.embed_update_log(distribution, for_py_version)
+    u_log = UpdateLog.from_dict(embed_update_log.read())
+    now = datetime.now()
+
+    update_versions, other_versions = [], []
+    for version in u_log.versions:
+        if version.source in {"periodic", "manual"}:
+            update_versions.append(version)
+        else:
+            other_versions.append(version)
+
+    if periodic:
+        source = "periodic"
+    else:
+        source = "manual"
+        # mark the most recent one as source "manual"
+        if update_versions:
+            update_versions[0].source = source
+
+    if wheel_filename is not None:
+        dest = wheelhouse / wheel_filename.name
+        if not dest.exists():
+            copy2(str(wheel_filename), str(wheelhouse))
+    last, last_version, versions, filenames = None, None, [], set()
+    while last is None or not last.use(now, ignore_grace_period_ci=True):
+        download_time = datetime.now()
+        dest = acquire.download_wheel(
+            distribution=distribution,
+            version_spec=None if last_version is None else "<{}".format(last_version),
+            for_py_version=for_py_version,
+            search_dirs=search_dirs,
+            app_data=app_data,
+            to_folder=wheelhouse,
+            env=os.environ,
+        )
+        if dest is None or (update_versions and update_versions[0].filename == dest.name):
+            break
+        release_date = release_date_for_wheel_path(dest.path)
+        last = NewVersion(filename=dest.path.name, release_date=release_date, found_date=download_time, source=source)
+        logging.info("detected %s in %s", last, datetime.now() - download_time)
+        versions.append(last)
+        filenames.add(last.filename)
+        last_wheel = last.wheel
+        last_version = last_wheel.version
+        if embed_version is not None:
+            if embed_version >= last_wheel.version_tuple:  # stop download if we reach the embed version
+                break
+    u_log.periodic = periodic
+    if not u_log.periodic:
+        u_log.started = now
+    # update other_versions by removing version we just found
+    other_versions = [version for version in other_versions if version.filename not in filenames]
+    u_log.versions = versions + update_versions + other_versions
+    u_log.completed = datetime.now()
+    embed_update_log.write(u_log.to_dict())
+    return versions
+
+
+def release_date_for_wheel_path(dest):
+    wheel = Wheel(dest)
+    # the most accurate is to ask PyPi - e.g. https://pypi.org/pypi/pip/json,
+    # see https://warehouse.pypa.io/api-reference/json/ for more details
+    content = _pypi_get_distribution_info_cached(wheel.distribution)
+    if content is not None:
+        try:
+            upload_time = content["releases"][wheel.version][0]["upload_time"]
+            return datetime.strptime(upload_time, "%Y-%m-%dT%H:%M:%S")
+        except Exception as exception:
+            logging.error("could not load release date %s because %r", content, exception)
+    return None
+
+
+def _request_context():
+    yield None
+    # fallback to non verified HTTPS (the information we request is not sensitive, so fallback)
+    yield ssl._create_unverified_context()  # noqa
+
+
+_PYPI_CACHE = {}
+
+
+def _pypi_get_distribution_info_cached(distribution):
+    if distribution not in _PYPI_CACHE:
+        _PYPI_CACHE[distribution] = _pypi_get_distribution_info(distribution)
+    return _PYPI_CACHE[distribution]
+
+
+def _pypi_get_distribution_info(distribution):
+    content, url = None, "https://pypi.org/pypi/{}/json".format(distribution)
+    try:
+        for context in _request_context():
+            try:
+                with urlopen(url, context=context) as file_handler:
+                    content = json.load(file_handler)
+                break
+            except URLError as exception:
+                logging.error("failed to access %s because %r", url, exception)
+    except Exception as exception:
+        logging.error("failed to access %s because %r", url, exception)
+    return content
+
+
+def manual_upgrade(app_data, env):
+    threads = []
+
+    for for_py_version, distribution_to_package in BUNDLE_SUPPORT.items():
+        # load extra search dir for the given for_py
+        for distribution in distribution_to_package.keys():
+            thread = Thread(target=_run_manual_upgrade, args=(app_data, distribution, for_py_version, env))
+            thread.start()
+            threads.append(thread)
+
+    for thread in threads:
+        thread.join()
+
+
+def _run_manual_upgrade(app_data, distribution, for_py_version, env):
+    start = datetime.now()
+    from .bundle import from_bundle
+
+    current = from_bundle(
+        distribution=distribution,
+        version=None,
+        for_py_version=for_py_version,
+        search_dirs=[],
+        app_data=app_data,
+        do_periodic_update=False,
+        env=env,
+    )
+    logging.warning(
+        "upgrade %s for python %s with current %s",
+        distribution,
+        for_py_version,
+        "" if current is None else current.name,
+    )
+    versions = do_update(
+        distribution=distribution,
+        for_py_version=for_py_version,
+        embed_filename=current.path,
+        app_data=app_data,
+        search_dirs=[],
+        periodic=False,
+    )
+    msg = "upgraded %s for python %s in %s {}".format(
+        "new entries found:\n%s" if versions else "no new versions found",
+    )
+    args = [
+        distribution,
+        for_py_version,
+        datetime.now() - start,
+    ]
+    if versions:
+        args.append("\n".join("\t{}".format(v) for v in versions))
+    logging.warning(msg, *args)
+
+
+__all__ = (
+    "add_wheel_to_update_log",
+    "periodic_update",
+    "do_update",
+    "manual_upgrade",
+    "NewVersion",
+    "UpdateLog",
+    "load_datetime",
+    "dump_datetime",
+    "trigger_update",
+    "release_date_for_wheel_path",
+)

.venv/lib/python3.8/site-packages/virtualenv/seed/wheels/util.py

@@ -0,0 +1,116 @@
+from __future__ import absolute_import, unicode_literals
+
+from operator import attrgetter
+from zipfile import ZipFile
+
+from virtualenv.util.six import ensure_text
+
+
+class Wheel(object):
+    def __init__(self, path):
+        # https://www.python.org/dev/peps/pep-0427/#file-name-convention
+        # The wheel filename is {distribution}-{version}(-{build tag})?-{python tag}-{abi tag}-{platform tag}.whl
+        self.path = path
+        self._parts = path.stem.split("-")
+
+    @classmethod
+    def from_path(cls, path):
+        if path is not None and path.suffix == ".whl" and len(path.stem.split("-")) >= 5:
+            return cls(path)
+        return None
+
+    @property
+    def distribution(self):
+        return self._parts[0]
+
+    @property
+    def version(self):
+        return self._parts[1]
+
+    @property
+    def version_tuple(self):
+        return self.as_version_tuple(self.version)
+
+    @staticmethod
+    def as_version_tuple(version):
+        result = []
+        for part in version.split(".")[0:3]:
+            try:
+                result.append(int(part))
+            except ValueError:
+                break
+        if not result:
+            raise ValueError(version)
+        return tuple(result)
+
+    @property
+    def name(self):
+        return self.path.name
+
+    def support_py(self, py_version):
+        name = "{}.dist-info/METADATA".format("-".join(self.path.stem.split("-")[0:2]))
+        with ZipFile(ensure_text(str(self.path)), "r") as zip_file:
+            metadata = zip_file.read(name).decode("utf-8")
+        marker = "Requires-Python:"
+        requires = next((i[len(marker) :] for i in metadata.splitlines() if i.startswith(marker)), None)
+        if requires is None:  # if it does not specify a python requires the assumption is compatible
+            return True
+        py_version_int = tuple(int(i) for i in py_version.split("."))
+        for require in (i.strip() for i in requires.split(",")):
+            # https://www.python.org/dev/peps/pep-0345/#version-specifiers
+            for operator, check in [
+                ("!=", lambda v: py_version_int != v),
+                ("==", lambda v: py_version_int == v),
+                ("<=", lambda v: py_version_int <= v),
+                (">=", lambda v: py_version_int >= v),
+                ("<", lambda v: py_version_int < v),
+                (">", lambda v: py_version_int > v),
+            ]:
+                if require.startswith(operator):
+                    ver_str = require[len(operator) :].strip()
+                    version = tuple((int(i) if i != "*" else None) for i in ver_str.split("."))[0:2]
+                    if not check(version):
+                        return False
+                    break
+        return True
+
+    def __repr__(self):
+        return "{}({})".format(self.__class__.__name__, self.path)
+
+    def __str__(self):
+        return str(self.path)
+
+
+def discover_wheels(from_folder, distribution, version, for_py_version):
+    wheels = []
+    for filename in from_folder.iterdir():
+        wheel = Wheel.from_path(filename)
+        if wheel and wheel.distribution == distribution:
+            if version is None or wheel.version == version:
+                if wheel.support_py(for_py_version):
+                    wheels.append(wheel)
+    return sorted(wheels, key=attrgetter("version_tuple", "distribution"), reverse=True)
+
+
+class Version:
+    #: the version bundled with virtualenv
+    bundle = "bundle"
+    embed = "embed"
+    #: custom version handlers
+    non_version = (
+        bundle,
+        embed,
+    )
+
+    @staticmethod
+    def of_version(value):
+        return None if value in Version.non_version else value
+
+    @staticmethod
+    def as_pip_req(distribution, version):
+        return "{}{}".format(distribution, Version.as_version_spec(version))
+
+    @staticmethod
+    def as_version_spec(version):
+        of_version = Version.of_version(version)
+        return "" if of_version is None else "=={}".format(of_version)