File Content: tracing.py # 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 Submit