hgdemandimport/tracing.py
author Gregory Szorc <gregory.szorc@gmail.com>
Wed, 15 Aug 2018 19:45:39 +0000
changeset 39345 c03c5f528e9b
parent 39282 284440041141
child 39424 452790284a15
permissions -rw-r--r--
perf: use storage API for resolving manifest node lookup() isn't part of the storage API. And this code shouldn't be accessing manifestlog._revlog directly for the modern code base. So let's port it to the modern API. Note that the previous code was busted for cases where we needed to call lookup() because lookup() isn't exposed by manifestrevlog any more. This change is strictly BC breaking because we no longer support resolving partial nodes. But it is a perf* command and I don't think we should flag the change as such. Differential Revision: https://phab.mercurial-scm.org/D4390

# 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:
        _pipe.write('START %s %s\n' % (_session, whence))
        yield
    finally:
        _pipe.write('END %s %s\n' % (_session, whence))