view hgdemandimport/tracing.py @ 51815:460e80488cf0

typing: lock in correct changes from pytype 2023.04.11 -> 2023.06.16

There were a handful of other changes to the pyi files generated when updating
pytype locally (and jumping from python 3.8.0 to python 3.10.11), but they were
not as clear (e.g. the embedded type in a list changing from `nothing` to `Any`
or similar).  These looked obviously correct, and agreed with PyCharm's thoughts
on the signatures.

Oddly, even though pytype starting inferring `obsutil._getfilteredreason()` as
returning bytes, it (correctly) complained about the None path when it was typed
that way.  Instead, raise a ProgrammingError if an unhandled fate is calculated.
(Currently, all possibilities are handled, so this isn't reachable unless
another fate is added in the future.)

# 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.

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