view hgdemandimport/__init__.py @ 36534:5faeabb07cf5

debugcommands: support for triggering push protocol

The mechanism for pushing to a remote is a bit more complicated
than other commands. On SSH, we wait for a positive reply from
the server before we start sending the bundle payload.

This commit adds a mechanism to the "command" action in
`hg debugwireproto` to trigger the "push protocol" and to
specify a file whose contents should be submitted as the command
payload.

With this new feature, we implement a handful of tests for the
"unbundle" command. We try to cover various server failures and
hook/output scenarios so protocol behavior is as comprehensively
tested as possible. Even with so much test output, we only cover
bundle1 with Python hooks. There's still a lot of test coverage
that needs to be implemented. But this is certainly a good start.

Because there are so many new tests, we split these tests into their
own test file.

In order to make output deterministic, we need to disable the
doublepipe primitive. We add an option to `hg debugwireproto`
to do that. Because something in the bowels of the peer does a
read of stderr, we still capture read I/O from stderr. So there
is test coverage of what the server emits.

The tests around I/O capture some wonkiness. For example,
interleaved ui.write() and ui.write_err() calls are emitted in
order. However, (presumably due to buffering), print() to
sys.stdout and sys.stderr aren't in order.

We currently only test bundle1 because bundle2 is substantially
harder to test because it is more complicated (the server responds
with a stream containing a bundle2 instead of a frame).

Differential Revision: https://phab.mercurial-scm.org/D2471

# 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.

from __future__ import absolute_import

import os
import sys

if sys.version_info[0] >= 3:
    from . import demandimportpy3 as demandimport
else:
    from . import demandimportpy2 as demandimport

# Extensions can add to this list if necessary.
ignore = [
    '__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__',
    '_ssl', # conditional imports in the stdlib, issue1964
    '_sre', # issue4920
    'rfc822',
    'mimetools',
    'sqlalchemy.events', # has import-time side effects (issue5085)
    # setuptools 8 expects this module to explode early when not on windows
    'distutils.msvc9compiler',
    '__builtin__',
    'builtins',
    'urwid.command_map', # for pudb
    ]

_pypy = '__pypy__' in sys.builtin_module_names

if _pypy:
    ignore.extend([
        # _ctypes.pointer is shadowed by "from ... import pointer" (PyPy 5)
        '_ctypes.pointer',
    ])

demandimport.init(ignore)

# 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()