author | Martin von Zweigbergk <martinvonz@google.com> |
Sun, 20 Jan 2019 21:49:58 -0800 | |
changeset 41342 | fe83040400b7 |
parent 39397 | 452790284a15 |
child 42476 | d0b8a3cfd732 |
permissions | -rw-r--r-- |
# 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