view hgdemandimport/tracing.py @ 39405:cb70501d8b71

revert: fix the inconsistency of status msgs in --interactive mode

Before this patch we were priting every action msg before actually
performing that action and that was resulting in inconsistencies;
like in --interactive session if user decided to not revert any
changes in a file foo, still there will be a msg on console saying
"reverting foo".

To fix this, I have made some changes to print status msg just
before the action it is going to perform, no matter if --interactive
or not.

Changes made in test-revert-interactive.t reflect the changed behavior.
There are also some changes in test-revert.t because of change in the
order of messages.

Differential Revision: https://phab.mercurial-scm.org/D4380

# Support code for event tracing in Mercurial. Lives in demandimport
# so it can also be used in demandimport.
#
# Copyright 2018 Google LLC.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import

import contextlib
import os

_pipe = None
_checked = False

@contextlib.contextmanager
def log(whencefmt, *whenceargs):
    global _pipe, _session, _checked
    if _pipe is None:
        if _checked:
            yield
            return
        _checked = True
        if 'HGCATAPULTSERVERPIPE' not in os.environ:
            yield
            return
        _pipe = open(os.environ['HGCATAPULTSERVERPIPE'], 'w', 1)
        _session = os.environ.get('HGCATAPULTSESSION', 'none')
    whence = whencefmt % whenceargs
    try:
        # Both writes to the pipe are wrapped in try/except to ignore
        # errors, as we can see mysterious errors in here if the pager
        # is active. Presumably other conditions could trigger
        # problems too.
        try:
            _pipe.write('START %s %s\n' % (_session, whence))
        except IOError:
            pass
        yield
    finally:
        try:
            _pipe.write('END %s %s\n' % (_session, whence))
        except IOError:
            pass