worker: avoid potential partial write of pickled data
Previously, the code wrote the pickled data using os.write(). However,
os.write() can write less bytes than passed to it. To trigger the problem, the
pickled data had to be larger than
2147479552 bytes on my system.
Instead, open a file object and pass it to pickle.dump(). This also has the
advantage that it doesn’t buffer the whole pickled data in memory.
Note that the opened file must be buffered because pickle doesn’t support
unbuffered streams because unbuffered streams’ write() method might write less
bytes than passed to it (like os.write()) but pickle.dump() relies on that all
bytes are written (see https://github.com/python/cpython/issues/93050).
The side effect of using a file object and a with statement is that wfd is
explicitly closed now while it seems like before it was implicitly closed by
process exit.
# blackbox.py - log repository events to a file for post-mortem debugging
#
# Copyright 2010 Nicolas Dumazet
# Copyright 2013 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""log repository events to a blackbox for debugging
Logs event information to .hg/blackbox.log to help debug and diagnose problems.
The events that get logged can be configured via the blackbox.track and
blackbox.ignore config keys.
Examples::
[blackbox]
track = *
ignore = pythonhook
# dirty is *EXPENSIVE* (slow);
# each log entry indicates `+` if the repository is dirty, like :hg:`id`.
dirty = True
# record the source of log messages
logsource = True
[blackbox]
track = command, commandfinish, commandexception, exthook, pythonhook
[blackbox]
track = incoming
[blackbox]
# limit the size of a log file
maxsize = 1.5 MB
# rotate up to N log files when the current one gets too big
maxfiles = 3
[blackbox]
# Include microseconds in log entries with %f (see Python function
# datetime.datetime.strftime)
date-format = %Y-%m-%d @ %H:%M:%S.%f
"""
import re
from mercurial.i18n import _
from mercurial.node import hex
from mercurial import (
encoding,
loggingutil,
registrar,
)
from mercurial.utils import (
dateutil,
procutil,
)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = b'ships-with-hg-core'
cmdtable = {}
command = registrar.command(cmdtable)
configtable = {}
configitem = registrar.configitem(configtable)
configitem(
b'blackbox',
b'dirty',
default=False,
)
configitem(
b'blackbox',
b'maxsize',
default=b'1 MB',
)
configitem(
b'blackbox',
b'logsource',
default=False,
)
configitem(
b'blackbox',
b'maxfiles',
default=7,
)
configitem(
b'blackbox',
b'track',
default=lambda: [b'*'],
)
configitem(
b'blackbox',
b'ignore',
default=lambda: [b'chgserver', b'cmdserver', b'extension'],
)
configitem(b'blackbox', b'date-format', default=b'')
_lastlogger = loggingutil.proxylogger()
class blackboxlogger:
def __init__(self, ui, repo):
self._repo = repo
self._trackedevents = set(ui.configlist(b'blackbox', b'track'))
self._ignoredevents = set(ui.configlist(b'blackbox', b'ignore'))
self._maxfiles = ui.configint(b'blackbox', b'maxfiles')
self._maxsize = ui.configbytes(b'blackbox', b'maxsize')
self._inlog = False
def tracked(self, event):
return (
b'*' in self._trackedevents and event not in self._ignoredevents
) or event in self._trackedevents
def log(self, ui, event, msg, opts):
# self._log() -> ctx.dirty() may create new subrepo instance, which
# ui is derived from baseui. So the recursion guard in ui.log()
# doesn't work as it's local to the ui instance.
if self._inlog:
return
self._inlog = True
try:
self._log(ui, event, msg, opts)
finally:
self._inlog = False
def _log(self, ui, event, msg, opts):
default = ui.configdate(b'devel', b'default-date')
dateformat = ui.config(b'blackbox', b'date-format')
if dateformat:
date = dateutil.datestr(default, dateformat)
else:
# We want to display milliseconds (more precision seems
# unnecessary). Since %.3f is not supported, use %f and truncate
# microseconds.
date = dateutil.datestr(default, b'%Y-%m-%d %H:%M:%S.%f')[:-3]
user = procutil.getuser()
pid = b'%d' % procutil.getpid()
changed = b''
ctx = self._repo[None]
parents = ctx.parents()
rev = b'+'.join([hex(p.node()) for p in parents])
if ui.configbool(b'blackbox', b'dirty') and ctx.dirty(
missing=True, merge=False, branch=False
):
changed = b'+'
if ui.configbool(b'blackbox', b'logsource'):
src = b' [%s]' % event
else:
src = b''
try:
fmt = b'%s %s @%s%s (%s)%s> %s'
args = (date, user, rev, changed, pid, src, msg)
with loggingutil.openlogfile(
ui,
self._repo.vfs,
name=b'blackbox.log',
maxfiles=self._maxfiles,
maxsize=self._maxsize,
) as fp:
fp.write(fmt % args)
except (IOError, OSError) as err:
# deactivate this to avoid failed logging again
self._trackedevents.clear()
ui.debug(
b'warning: cannot write to blackbox.log: %s\n'
% encoding.strtolocal(err.strerror)
)
return
_lastlogger.logger = self
def uipopulate(ui):
ui.setlogger(b'blackbox', _lastlogger)
def reposetup(ui, repo):
# During 'hg pull' a httppeer repo is created to represent the remote repo.
# It doesn't have a .hg directory to put a blackbox in, so we don't do
# the blackbox setup for it.
if not repo.local():
return
# Since blackbox.log is stored in the repo directory, the logger should be
# instantiated per repository.
logger = blackboxlogger(ui, repo)
ui.setlogger(b'blackbox', logger)
# Set _lastlogger even if ui.log is not called. This gives blackbox a
# fallback place to log
if _lastlogger.logger is None:
_lastlogger.logger = logger
repo._wlockfreeprefix.add(b'blackbox.log')
@command(
b'blackbox',
[
(b'l', b'limit', 10, _(b'the number of events to show')),
],
_(b'hg blackbox [OPTION]...'),
helpcategory=command.CATEGORY_MAINTENANCE,
helpbasic=True,
)
def blackbox(ui, repo, *revs, **opts):
"""view the recent repository events"""
if not repo.vfs.exists(b'blackbox.log'):
return
limit = opts.get('limit')
fp = repo.vfs(b'blackbox.log', b'r')
lines = fp.read().split(b'\n')
count = 0
output = []
for line in reversed(lines):
if count >= limit:
break
# count the commands by matching lines like:
# 2013/01/23 19:13:36 root>
# 2013/01/23 19:13:36 root (1234)>
# 2013/01/23 19:13:36 root @0000000000000000000000000000000000000000 (1234)>
# 2013-01-23 19:13:36.000 root @0000000000000000000000000000000000000000 (1234)>
if re.match(
br'^\d{4}[-/]\d{2}[-/]\d{2} \d{2}:\d{2}:\d{2}(.\d*)? .*> .*', line
):
count += 1
output.append(line)
ui.status(b'\n'.join(reversed(output)))