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59\A3R:\F3\CE"\B6\80\88\00\00i1u4ê\E9\F2á\A6\A2\FACM\93WMb*\E0*\00\00\00\00\00(\A8\80\00\00\80\00\00\00\00\00\00\00\00\00\FF\D9<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>C///</title>
</head>
from __future__ import absolute_import

import contextlib
import errno
import hashlib
import logging
import os

from pip._vendor import contextlib2

from pip._internal.utils.temp_dir import TempDirectory
from pip._internal.utils.typing import MYPY_CHECK_RUNNING

if MYPY_CHECK_RUNNING:
    from types import TracebackType
    from typing import Dict, Iterator, Optional, Set, Type, Union
    from pip._internal.req.req_install import InstallRequirement
    from pip._internal.models.link import Link

logger = logging.getLogger(__name__)


@contextlib.contextmanager
def update_env_context_manager(**changes):
    # type: (str) -> Iterator[None]
    target = os.environ

    # Save values from the target and change them.
    non_existent_marker = object()
    saved_values = {}  # type: Dict[str, Union[object, str]]
    for name, new_value in changes.items():
        try:
            saved_values[name] = target[name]
        except KeyError:
            saved_values[name] = non_existent_marker
        target[name] = new_value

    try:
        yield
    finally:
        # Restore original values in the target.
        for name, original_value in saved_values.items():
            if original_value is non_existent_marker:
                del target[name]
            else:
                assert isinstance(original_value, str)  # for mypy
                target[name] = original_value


@contextlib.contextmanager
def get_requirement_tracker():
    # type: () -> Iterator[RequirementTracker]
    root = os.environ.get('PIP_REQ_TRACKER')
    with contextlib2.ExitStack() as ctx:
        if root is None:
            root = ctx.enter_context(
                TempDirectory(kind='req-tracker')
            ).path
            ctx.enter_context(update_env_context_manager(PIP_REQ_TRACKER=root))
            logger.debug("Initialized build tracking at %s", root)

        with RequirementTracker(root) as tracker:
            yield tracker


class RequirementTracker(object):

    def __init__(self, root):
        # type: (str) -> None
        self._root = root
        self._entries = set()  # type: Set[InstallRequirement]
        logger.debug("Created build tracker: %s", self._root)

    def __enter__(self):
        # type: () -> RequirementTracker
        logger.debug("Entered build tracker: %s", self._root)
        return self

    def __exit__(
        self,
        exc_type,  # type: Optional[Type[BaseException]]
        exc_val,  # type: Optional[BaseException]
        exc_tb  # type: Optional[TracebackType]
    ):
        # type: (...) -> None
        self.cleanup()

    def _entry_path(self, link):
        # type: (Link) -> str
        hashed = hashlib.sha224(link.url_without_fragment.encode()).hexdigest()
        return os.path.join(self._root, hashed)

    def add(self, req):
        # type: (InstallRequirement) -> None
        """Add an InstallRequirement to build tracking.
        """

        asse