largefiles: prevent in-memory merge instead of switching to on-disk
I enabled in-memory merge by default while testing some changes. I
spent quite some time troubleshooting why largefiles was still
creating an on-disk mergestate. Then I found out that it ignores the
callers `wc` argument to `mergemod._update()` and always uses on-disk
merge. This patch changes that so we raise an error if largefiles is
used with in-memory merge. That way we'll notice if in-memory merge is
used with largefiles instead of silently replacing ignoring the
`overlayworkingctx` instance and updating the working copy instead.
I felt a little bad that this would break things more for users with
both largefiles and in-memory rebase enabled. So I also added a
higher-level override to make sure that largefiles disables in-memory
rebase. It turns out that that fixes `run-tests.py -k largefiles
--extra-config-opt rebase.experimental.inmemory=1`.
Differential Revision: https://phab.mercurial-scm.org/D9069
# 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
_session = 'none'
def _isactive():
global _pipe, _session, _checked
if _pipe is None:
if _checked:
return False
_checked = True
if 'HGCATAPULTSERVERPIPE' not in os.environ:
return False
_pipe = open(os.environ['HGCATAPULTSERVERPIPE'], 'w', 1)
_session = os.environ.get('HGCATAPULTSESSION', 'none')
return True
@contextlib.contextmanager
def log(whencefmt, *whenceargs):
if not _isactive():
yield
return
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
def counter(label, amount, *labelargs):
if not _isactive():
return
l = label % labelargs
# See above in log() for why this is in a try/except.
try:
_pipe.write('COUNTER %s %d %s\n' % (_session, amount, l))
except IOError:
pass