--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/planemo/lib/python3.7/site-packages/virtualenv/seed/wheels/periodic_update.py	Fri Jul 31 00:32:28 2020 -0400
@@ -0,0 +1,364 @@
+"""
+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 DETACHED_PROCESS, 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
+
+
+def periodic_update(distribution, for_py_version, wheel, search_dirs, app_data, do_periodic_update):
+    if do_periodic_update:
+        handle_auto_update(distribution, for_py_version, wheel, search_dirs, app_data)
+
+    now = datetime.now()
+
+    u_log = UpdateLog.from_app_data(app_data, distribution, for_py_version)
+    u_log_older_than_hour = now - u_log.completed > timedelta(hours=1) if u_log.completed is not None else False
+    for _, group in groupby(u_log.versions, key=lambda v: v.wheel.version_tuple[0:2]):
+        version = next(group)  # use only latest patch version per minor, earlier assumed to be buggy
+        if wheel is not None and Path(version.filename).name == wheel.name:
+            break
+        if u_log.periodic is False or (u_log_older_than_hour and version.use(now)):
+            updated_wheel = Wheel(app_data.house / version.filename)
+            logging.debug("using %supdated wheel %s", "periodically " if updated_wheel else "", updated_wheel)
+            wheel = updated_wheel
+            break
+
+    return wheel
+
+
+def handle_auto_update(distribution, for_py_version, wheel, search_dirs, app_data):
+    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)
+
+
+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):
+        self.filename = filename
+        self.found_date = found_date
+        self.release_date = release_date
+
+    @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"]),
+        )
+
+    def to_dict(self):
+        return {
+            "filename": self.filename,
+            "release_date": dump_datetime(self.release_date),
+            "found_date": dump_datetime(self.found_date),
+        }
+
+    def use(self, now):
+        compare_from = self.release_date or self.found_date
+        return now - compare_from >= timedelta(days=28)
+
+    def __repr__(self):
+        return "{}(filename={}), found_date={}, release_date={})".format(
+            self.__class__.__name__, self.filename, self.found_date, self.release_date,
+        )
+
+    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"]
+        )
+
+    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 <= timedelta(days=14):
+                return False
+            return self._check_start(now)
+
+    def _check_start(self, now):
+        return self.started is None or now - self.started > timedelta(hours=1)
+
+
+def trigger_update(distribution, for_py_version, wheel, search_dirs, app_data, 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 = os.environ.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"] = DETACHED_PROCESS
+    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()
+    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 = None, None, []
+    while last is None or not last.use(now):
+        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,
+        )
+        if dest is None or (u_log.versions and u_log.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)
+        logging.info("detected %s in %s", last, datetime.now() - download_time)
+        versions.append(last)
+        last_wheel = Wheel(Path(last.filename))
+        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
+    u_log.versions = versions + u_log.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):
+    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))
+            thread.start()
+            threads.append(thread)
+
+    for thread in threads:
+        thread.join()
+
+
+def _run_manual_upgrade(app_data, distribution, for_py_version):
+    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,
+    )
+    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__ = (
+    "periodic_update",
+    "do_update",
+    "manual_upgrade",
+    "NewVersion",
+    "UpdateLog",
+    "load_datetime",
+    "dump_datetime",
+    "trigger_update",
+    "release_date_for_wheel_path",
+)