Mercurial > hg
view hgdemandimport/tracing.py @ 41078:46e0563c67db
merge with stable
author | Yuya Nishihara <yuya@tcha.org> |
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date | Sun, 30 Dec 2018 17:31:57 +0900 |
parents | 452790284a15 |
children | d0b8a3cfd732 |
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# 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