repovfs: add a ward to check if locks are properly taken
When the appropriate developer warnings are enabled, We wrap 'repo.vfs.audit' to
check for locks when accessing file in '.hg' for writing. Another changeset will
add a 'ward' for the store vfs (svfs).
This check system has caught a handful of locking issues that have been fixed
in previous series (mostly in 4.0). I expect another batch to be caught in third
party extensions.
We introduce two real exceptions from extensions 'blackbox.log' (because a lot of
read-only operations add entry to it), and 'last-email.txt' (because 'hg email'
is currently a read only operation and there is value to keep it this way).
In addition we are currently allowing bisect to operate outside of the lock
because the current code is a bit hard to get properly locked for now. Multiple
clean up have been made but there is still a couple of them to do and the freeze
is coming.
# 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
filehandles = {}
def _openlog(vfs):
path = vfs.join('blackbox.log')
if path in filehandles:
return filehandles[path]
filehandles[path] = fp = vfs('blackbox.log', 'a')
return fp
def _closelog(vfs):
path = vfs.join('blackbox.log')
fp = filehandles[path]
del filehandles[path]
fp.close()
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._bbfp = getattr(src, '_bbfp', None)
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._bbfp = None
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))
fp = _openlog(self._bbvfs)
maxsize = self.configbytes('blackbox', 'maxsize')
if maxsize > 0:
st = self._bbvfs.fstat(fp)
if st.st_size >= maxsize:
path = fp.name
_closelog(self._bbvfs)
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')
fp = _openlog(self._bbvfs)
return fp
def _bbwrite(self, fmt, *args):
self._bbfp.write(fmt % args)
self._bbfp.flush()
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._bbfp:
ui = self
elif self._bbvfs:
try:
self._bbfp = self._openlogfile()
except (IOError, OSError) as err:
self.debug('warning: cannot write to blackbox.log: %s\n' %
err.strerror)
del self._bbvfs
self._bbfp = None
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 or not ui._bbfp:
return
if not lastui or ui._bbrepo:
lastui = ui
if ui._bbinlog:
# recursion 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:
ui._bbwrite('%s %s @%s%s (%s)%s> %s',
date, user, rev, changed, pid, src, formattedmsg)
except IOError as err:
self.debug('warning: cannot write to blackbox.log: %s\n' %
err.strerror)
finally:
ui._bbinlog = False
def setrepo(self, repo):
self._bbfp = None
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)))