annotate hgdemandimport/tracing.py @ 39762:edaa40dc5fe5

py3: create built in exceptions with str type messages in win32.py

I hit an IOError in unlink() in test-pathconflicts-basic.t, that then crashed as
it was handled:

    File "mercurial\dispatch.py", line 359, in _runcatch
      return _callcatch(ui, _runcatchfunc)
    File "mercurial\dispatch.py", line 367, in _callcatch
      return scmutil.callcatch(ui, func)
    File "mercurial\scmutil.py", line 252, in callcatch
      ui.error(_("abort: %s\n") % encoding.strtolocal(inst.strerror))
    File "mercurial\encoding.py", line 205, in unitolocal
      return tolocal(u.encode('utf-8'))
  AttributeError: 'bytes' object has no attribute 'encode'

# 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