fsmonitor: hook up state-enter, state-leave signals
Keeping the codebase in sync with upstream:
Watchman 4.4 introduced an advanced settling feature that allows publishing
tools to notify subscribing tools of the boundaries for important filesystem
operations.
https://facebook.github.io/watchman/docs/cmd/subscribe.html#advanced-settling
has more information about how this feature works.
This diff connects a signal that we're calling `hg.update` to the mercurial
update function so that mercurial can indirectly notify tools (such as IDEs or
build machinery) when it is changing the working copy. This will allow those
tools to pause their normal actions as the files are changing and defer them
until the end of the operation.
In addition to sending the enter/leave signals for the state, we are able to
publish useful metadata along the same channel. In this case we are passing
the following pieces of information:
1. destination revision hash
2. An estimate of the distance between the current state and the target state
3. A success indicator.
4. Whether it is a partial update
The distance is estimate may be useful to tools that wish to change their
strategy after the update has complete. For example, a large update may be
efficient to deal with by walking some internal state in the subscriber rather
than feeding every individual file notification through its normal (small)
delta mechanism.
We estimate the distance by comparing the repository revision number. In some
cases we cannot come up with a number so we report 0. This is ok; we're
offering this for informational purposes only and don't guarantee its accuracy.
The success indicator is only really meaningful when we generate the
state-leave notification; it indicates the overall success of the update.
# 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 (
cmdutil,
ui as uimod,
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'
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 = src._bbfp
self._bbinlog = False
self._bbrepo = src._bbrepo
self._bbvfs = src._bbvfs
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', 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 _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
date = util.datestr(None, '%Y/%m/%d %H:%M:%S')
user = util.getuser()
pid = str(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', False) and (
any(ui._bbrepo.status()) or
any(ctx.sub(s).dirty() for s in ctx.substate)
)):
changed = '+'
if ui.configbool('blackbox', 'logsource', False):
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)
@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)))