view hgdemandimport/tracing.py @ 42125:bc15e37ecc16

repoview: fix conditional around unserved changesets

The conditional could lead to wrong computation since we have more unserved
changesets than just the "secret" phase.

In addition, now that we have efficient caching of phased changesets, we don't
need the conditional anymore.

# 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