^^&&^^

Edit File: via_app_data.py

"""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]