blackbox: avoid creating multiple file handles for a single log
There are multiple ui objects in Mercurial that can relate to a repository,
before this change, each one would have its own file pointer, which
results in unfortunate logging behavior.
Also, any log rotation results would be bad because only the
active blackboxui object's file pointer would be refreshed.
Note that this does not prevent two long running hg commands for the same
repository from causing problems.
# 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 = *
[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 import (
cmdutil,
util,
)
cmdtable = {}
command = cmdutil.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'internal' 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 = 'internal'
lastblackbox = 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__):
@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', 1048576)
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 log(self, event, *msg, **opts):
global lastblackbox
super(blackboxui, self).log(event, *msg, **opts)
if not '*' in self.track and not event in self.track:
return
if util.safehasattr(self, '_blackbox'):
blackbox = self._blackbox
elif util.safehasattr(self, '_bbvfs'):
try:
self._blackbox = self._openlogfile()
except (IOError, OSError) as err:
self.debug('warning: cannot write to blackbox.log: %s\n' %
err.strerror)
del self._bbvfs
self._blackbox = None
blackbox = self._blackbox
else:
# certain ui instances exist outside the context of
# a repo, so just default to the last blackbox that
# was seen.
blackbox = lastblackbox
if blackbox:
date = util.datestr(None, '%Y/%m/%d %H:%M:%S')
user = util.getuser()
pid = str(util.getpid())
formattedmsg = msg[0] % msg[1:]
try:
blackbox.write('%s %s (%s)> %s' %
(date, user, pid, formattedmsg))
blackbox.flush()
except IOError as err:
self.debug('warning: cannot write to blackbox.log: %s\n' %
err.strerror)
lastblackbox = blackbox
def setrepo(self, repo):
self._bbvfs = repo.vfs
ui.__class__ = 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)
@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')
blackbox = repo.vfs('blackbox.log', 'r')
lines = blackbox.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)))