view tests/fakedirstatewritetime.py @ 47315:825d5a5907b4

exewrapper: avoid directly linking against python3X.dll

Subsequent code calls `LoadLibrary()` to attempt to load the DLL, but because of
this symbol reference, there is an attempt to load the DLL used during the build
prior to `_main()` running.  This causes the whole process to fail if the DLL
isn't in the standard search path.  That also means it will never load the DLL
for HackableMercurial.  (Maybe we should get rid of that for py3, since you can
install python for a user without admin rights?)

This could also be resolved by calling `GetProcAddress()` on the symbol and
dereferencing it, but using the environment variable is consistent with the
*.bat file since fc8a5c9ecee0.  (The environment variable persists after the
interpreter is initialized.)

Far more concerning is somehow I've gotten my system into a state where setting
the flag causes any output to the pager to be lost (as if it wasn't set at all)
in MSYS, cmd.exe, WSL, and PowerShell using py3.9.0, but the environment
variable works properly.  I'm sure this flag worked on some versions of py3, so
I'm not sure what's going on here.  This is might be related to init config
related changes in 3.8[1], since it works with 3.7.8, but fails with 3.8.1.
Somebody who understands encoding issues better than I do should give some
thought to if we need to make some changes to our encoding strategy on Windows
with py3.

With or without the flag/envvar, there is proper output if the command is
directly paged by piping to `more.com` (in any environment) or `less` (in MSYS
and WSL), or if paging is disabled with `--pager=no`.  Legacy mode is required
though when Mercurial decides to spin up a pager.

[1] https://bugs.python.org/issue41941

Differential Revision: https://phab.mercurial-scm.org/D10756

# extension to emulate invoking 'dirstate.write()' at the time
# specified by '[fakedirstatewritetime] fakenow', only when
# 'dirstate.write()' is invoked via functions below:
#
#   - 'workingctx._poststatusfixup()' (= 'repo.status()')
#   - 'committablectx.markcommitted()'

from __future__ import absolute_import

from mercurial import (
    context,
    dirstate,
    extensions,
    policy,
    registrar,
)
from mercurial.utils import dateutil

try:
    from mercurial import rustext

    rustext.__name__  # force actual import (see hgdemandimport)
except ImportError:
    rustext = None

configtable = {}
configitem = registrar.configitem(configtable)

configitem(
    b'fakedirstatewritetime',
    b'fakenow',
    default=None,
)

parsers = policy.importmod('parsers')
rustmod = policy.importrust('parsers')


def pack_dirstate(fakenow, orig, dmap, copymap, pl, now):
    # execute what original parsers.pack_dirstate should do actually
    # for consistency
    actualnow = int(now)
    for f, e in dmap.items():
        if e[0] == 'n' and e[3] == actualnow:
            e = parsers.dirstatetuple(e[0], e[1], e[2], -1)
            dmap[f] = e

    return orig(dmap, copymap, pl, fakenow)


def fakewrite(ui, func):
    # fake "now" of 'pack_dirstate' only if it is invoked while 'func'

    fakenow = ui.config(b'fakedirstatewritetime', b'fakenow')
    if not fakenow:
        # Execute original one, if fakenow isn't configured. This is
        # useful to prevent subrepos from executing replaced one,
        # because replacing 'parsers.pack_dirstate' is also effective
        # in subrepos.
        return func()

    # parsing 'fakenow' in YYYYmmddHHMM format makes comparison between
    # 'fakenow' value and 'touch -t YYYYmmddHHMM' argument easy
    fakenow = dateutil.parsedate(fakenow, [b'%Y%m%d%H%M'])[0]

    if rustmod is not None:
        # The Rust implementation does not use public parse/pack dirstate
        # to prevent conversion round-trips
        orig_dirstatemap_write = dirstate.dirstatemap.write
        wrapper = lambda self, st, now: orig_dirstatemap_write(
            self, st, fakenow
        )
        dirstate.dirstatemap.write = wrapper

    orig_dirstate_getfsnow = dirstate._getfsnow
    wrapper = lambda *args: pack_dirstate(fakenow, orig_pack_dirstate, *args)

    orig_module = parsers
    orig_pack_dirstate = parsers.pack_dirstate

    orig_module.pack_dirstate = wrapper
    dirstate._getfsnow = lambda *args: fakenow
    try:
        return func()
    finally:
        orig_module.pack_dirstate = orig_pack_dirstate
        dirstate._getfsnow = orig_dirstate_getfsnow
        if rustmod is not None:
            dirstate.dirstatemap.write = orig_dirstatemap_write


def _poststatusfixup(orig, workingctx, status, fixup):
    ui = workingctx.repo().ui
    return fakewrite(ui, lambda: orig(workingctx, status, fixup))


def markcommitted(orig, committablectx, node):
    ui = committablectx.repo().ui
    return fakewrite(ui, lambda: orig(committablectx, node))


def extsetup(ui):
    extensions.wrapfunction(
        context.workingctx, '_poststatusfixup', _poststatusfixup
    )
    extensions.wrapfunction(context.workingctx, 'markcommitted', markcommitted)