Mercurial > hg
view hgdemandimport/tracing.py @ 47349:7138c863d0a1
dirstate-v2: Skip readdir in status based on directory mtime
When calling `read_dir` during `status` and the directory is found to be
eligible for caching (see code comments), write the directory’s mtime to the
dirstate. The presence of a directory mtime in the dirstate is meaningful
and indicates eligibility.
When an eligible directory mtime is found in the dirstate and `stat()` shows
that the mtime has not changed, `status` can skip calling `read_dir` again
and instead rely on the names of child nodes in the dirstate tree.
The `tempfile` crate is used to create a temporary file in order to use its
modification time as "current time" with the same truncation as other files
and directories would have in their own modification time.
Differential Revision: https://phab.mercurial-scm.org/D10826
author | Simon Sapin <simon.sapin@octobus.net> |
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date | Fri, 28 May 2021 11:48:59 +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