Mercurial > hg
view hgdemandimport/tracing.py @ 47682:78f7f0d490ee
dirstate-v2: Move fixed-size tree metadata into the docket file
Before this changeset, the dirstate-v2 data file contained not only nodes
and paths that may be reused when appending to an existing file,
but also some fixed-size metadata that applies to the entire tree
and was added at the end of the data file for every append.
This moves that metadata into the docket file, so that repeated "append"
operations without meaningful changes don’t actually need to grow any file.
Differential Revision: https://phab.mercurial-scm.org/D11098
author | Simon Sapin <simon.sapin@octobus.net> |
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date | Thu, 15 Jul 2021 23:02:17 +0200 |
parents | 2372284d9457 |
children | 6000f5b25c9b |
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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 _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