blackbox: do not cache file objects
Having the blackbox file objects cached in `ui._bbfp` could in theory be
troublesome if multiple processes (ex. chg servers) have file objects
referring to a same file. (Although I spent some time and failed to build a
convincing test case)
This patch makes blackbox re-open the file every time to make the situation
better. Ideally we also need proper locking.
The caching logic traces back to the commit introducing blackbox
(
18242716a). That commit does not have details about why caching is
necessary. Consider the fact that blackbox logs are not many, it seems fine
to remove the fp cache to be more confident.
Differential Revision: https://phab.mercurial-scm.org/D650
# 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 config key.
Examples::
[blackbox]
track = *
# 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
"""
from __future__ import absolute_import
import errno
import re
from mercurial.i18n import _
from mercurial.node import hex
from mercurial import (
registrar,
ui as uimod,
util,
)
# 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 = 'ships-with-hg-core'
cmdtable = {}
command = registrar.command(cmdtable)
configtable = {}
configitem = registrar.configitem(configtable)
configitem('blackbox', 'dirty',
default=False,
)
configitem('blackbox', 'maxsize',
default='1 MB',
)
configitem('blackbox', 'logsource',
default=False,
)
lastui = None
def wrapui(ui):
class blackboxui(ui.__class__):
def __init__(self, src=None):
super(blackboxui, self).__init__(src)
if src is None:
self._partialinit()
else:
self._bbinlog = False
self._bbrepo = getattr(src, '_bbrepo', None)
self._bbvfs = getattr(src, '_bbvfs', None)
def _partialinit(self):
if util.safehasattr(self, '_bbvfs'):
return
self._bbinlog = False
self._bbrepo = None
self._bbvfs = None
def copy(self):
self._partialinit()
return self.__class__(self)
@util.propertycache
def track(self):
return self.configlist('blackbox', 'track', ['*'])
def _openlogfile(self):
def rotate(oldpath, newpath):
try:
self._bbvfs.unlink(newpath)
except OSError as err:
if err.errno != errno.ENOENT:
self.debug("warning: cannot remove '%s': %s\n" %
(newpath, err.strerror))
try:
if newpath:
self._bbvfs.rename(oldpath, newpath)
except OSError as err:
if err.errno != errno.ENOENT:
self.debug("warning: cannot rename '%s' to '%s': %s\n" %
(newpath, oldpath, err.strerror))
maxsize = self.configbytes('blackbox', 'maxsize')
name = 'blackbox.log'
if maxsize > 0:
try:
st = self._bbvfs.stat(name)
except OSError:
pass
else:
if st.st_size >= maxsize:
path = self._bbvfs.join(name)
maxfiles = self.configint('blackbox', 'maxfiles', 7)
for i in xrange(maxfiles - 1, 1, -1):
rotate(oldpath='%s.%d' % (path, i - 1),
newpath='%s.%d' % (path, i))
rotate(oldpath=path,
newpath=maxfiles > 0 and path + '.1')
return self._bbvfs(name, 'a')
def log(self, event, *msg, **opts):
global lastui
super(blackboxui, self).log(event, *msg, **opts)
self._partialinit()
if not '*' in self.track and not event in self.track:
return
if self._bbvfs:
ui = self
else:
# certain ui instances exist outside the context of
# a repo, so just default to the last blackbox that
# was seen.
ui = lastui
if not ui:
return
if not lastui or ui._bbrepo:
lastui = ui
if ui._bbinlog:
# recursion and failure guard
return
try:
ui._bbinlog = True
default = self.configdate('devel', 'default-date')
date = util.datestr(default, '%Y/%m/%d %H:%M:%S')
user = util.getuser()
pid = '%d' % util.getpid()
formattedmsg = msg[0] % msg[1:]
rev = '(unknown)'
changed = ''
if ui._bbrepo:
ctx = ui._bbrepo[None]
parents = ctx.parents()
rev = ('+'.join([hex(p.node()) for p in parents]))
if (ui.configbool('blackbox', 'dirty') and
ctx.dirty(missing=True, merge=False, branch=False)):
changed = '+'
if ui.configbool('blackbox', 'logsource'):
src = ' [%s]' % event
else:
src = ''
try:
fmt = '%s %s @%s%s (%s)%s> %s'
args = (date, user, rev, changed, pid, src, formattedmsg)
with ui._openlogfile() as fp:
fp.write(fmt % args)
except (IOError, OSError) as err:
self.debug('warning: cannot write to blackbox.log: %s\n' %
err.strerror)
# do not restore _bbinlog intentionally to avoid failed
# logging again
else:
ui._bbinlog = False
finally:
pass
def setrepo(self, repo):
self._bbinlog = False
self._bbrepo = repo
self._bbvfs = repo.vfs
ui.__class__ = blackboxui
uimod.ui = blackboxui
def uisetup(ui):
wrapui(ui)
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
if util.safehasattr(ui, 'setrepo'):
ui.setrepo(repo)
repo._wlockfreeprefix.add('blackbox.log')
@command('^blackbox',
[('l', 'limit', 10, _('the number of events to show')),
],
_('hg blackbox [OPTION]...'))
def blackbox(ui, repo, *revs, **opts):
'''view the recent repository events
'''
if not repo.vfs.exists('blackbox.log'):
return
limit = opts.get('limit')
fp = repo.vfs('blackbox.log', 'r')
lines = fp.read().split('\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>
if re.match('^\d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} .*> .*', line):
count += 1
output.append(line)
ui.status('\n'.join(reversed(output)))