hgdemandimport/__init__.py

revlog: use the user facing filename as the display_id for filelogs

I had trouble isolating some LFS blob corruption detected by `hg verify` because
the traceback referenced a file, but with the `data/` prefix in the `.hg/store`
path, so it couldn't be located with the `file()` revset:

```
    Traceback (most recent call last):
      File "/mnt/d/mercurial/mercurial/revlog.py", line 3209, in verifyintegrity
        _verify_revision(self, skipflags, state, node)
      File "/mnt/d/mercurial/hgext/lfs/wrapper.py", line 246, in _verify_revision
        orig(rl, skipflags, state, node)
      File "/mnt/d/mercurial/mercurial/revlog.py", line 158, in _verify_revision
        rl.revision(node)
      File "/mnt/d/mercurial/mercurial/revlog.py", line 1816, in revision
        return self._revisiondata(nodeorrev, _df)
      File "/mnt/d/mercurial/mercurial/revlog.py", line 1870, in _revisiondata
        self.checkhash(text, node, rev=rev)
      File "/mnt/d/mercurial/mercurial/revlog.py", line 1996, in checkhash
        % (self.display_id, pycompat.bytestr(revornode))
    mercurial.error.RevlogError: integrity check failed on data/EXE/PPC/shrinksrec.exe:0
```

(I'm a little surprised it resulted in a stacktrace instead of just a message,
but that's a different issue.  I'm also not sure how to trigger the simplestore
case, since IIUC, it's also a revlog based store.)

It's not clear how to handle the changelog and manifest (because the user
doesn't interact with them as a file), so those cases are left alone.  The other
thing that would be nice to improve somehow is to indicate that the ":0" is a
revlog revision, not the changeset revision that users are used to.  I'm not
sure how to handle the "or node" part though.

# hgdemandimport - global demand-loading of modules for Mercurial
#
# Copyright 2017 Facebook Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''demandimport - automatic demand-loading of modules'''

# This is in a separate package from mercurial because in Python 3,
# demand loading is per-package. Keeping demandimport in the mercurial package
# would disable demand loading for any modules in mercurial.


import os
import sys

from . import demandimportpy3 as demandimport

# Full module names which can't be lazy imported.
# Extensions can add to this set.
IGNORES = {
    '__future__',
    '_hashlib',
    # ImportError during pkg_resources/__init__.py:fixup_namespace_package
    '_imp',
    '_xmlplus',
    'fcntl',
    'nt',  # pathlib2 tests the existence of built-in 'nt' module
    'win32com.gen_py',
    'win32com.shell',  # 'appdirs' tries to import win32com.shell
    '_winreg',  # 2.7 mimetypes needs immediate ImportError
    'pythoncom',
    # imported by tarfile, not available under Windows
    'pwd',
    'grp',
    # imported by profile, itself imported by hotshot.stats,
    # not available under Windows
    'resource',
    # this trips up many extension authors
    'gtk',
    # setuptools' pkg_resources.py expects "from __main__ import x" to
    # raise ImportError if x not defined
    '__main__',
    '_ast',  # https://bugs.python.org/issue41631
    '_ssl',  # conditional imports in the stdlib, issue1964
    '_sre',  # issue4920
    'rfc822',
    'mimetools',
    'sqlalchemy.events',  # has import-time side effects (issue5085)
    'sqlalchemy.dialects',  # similar problems as above
    # setuptools 8 expects this module to explode early when not on windows
    'distutils.msvc9compiler',
    '__builtin__',
    'builtins',
    'urwid.command_map',  # for pudb
    'lzma',
}

_pypy = '__pypy__' in sys.builtin_module_names

if _pypy:
    # _ctypes.pointer is shadowed by "from ... import pointer" (PyPy 5)
    IGNORES.add('_ctypes.pointer')
    # pure Python module on PyPy, must be loaded to raise ModuleNotFoundError
    # on non-Windows platforms
    IGNORES.add('msvcrt')

demandimport.init(IGNORES)

# Re-export.
isenabled = demandimport.isenabled
disable = demandimport.disable
deactivated = demandimport.deactivated


def enable():
    # chg pre-imports modules so do not enable demandimport for it
    if (
        'CHGINTERNALMARK' not in os.environ
        and os.environ.get('HGDEMANDIMPORT') != 'disable'
    ):
        demandimport.enable()