fsmonitor: warn when fsmonitor could be used
fsmonitor can significantly speed up operations on large working
directories. But fsmonitor isn't enabled by default, so naive users
may not realize there is a potential to make Mercurial faster.
This commit introduces a warning to working directory updates when
fsmonitor could be used.
The following conditions must be met:
* Working directory is previously empty
* New working directory adds >= N files (currently 50,000)
* Running on Linux or MacOS
* fsmonitor not enabled
* Warning not disabled via config override
Because of the empty working directory restriction, most users will
only see this warning during `hg clone` (assuming very few users
actually do an `hg up null`).
The addition of a warning may be considered a BC change. However, clone
has printed warnings before. Until recently, Mercurial printed a warning
with the server's certificate fingerprint when it wasn't explicitly
trusted for example. The warning goes to stderr. So it shouldn't
interfere with scripts parsing meaningful output.
The OS restriction was on the advice of Facebook engineers, who only
feel confident with watchman's stability on the supported platforms.
.. feature::
Print warning when fsmonitor isn't being used on a large repository
Differential Revision: https://phab.mercurial-scm.org/D894
# server.py - utility and factory of server
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import os
import tempfile
from .i18n import _
from . import (
chgserver,
cmdutil,
commandserver,
error,
hgweb,
pycompat,
util,
)
def runservice(opts, parentfn=None, initfn=None, runfn=None, logfile=None,
runargs=None, appendpid=False):
'''Run a command as a service.'''
def writepid(pid):
if opts['pid_file']:
if appendpid:
mode = 'ab'
else:
mode = 'wb'
fp = open(opts['pid_file'], mode)
fp.write('%d\n' % pid)
fp.close()
if opts['daemon'] and not opts['daemon_postexec']:
# Signal child process startup with file removal
lockfd, lockpath = tempfile.mkstemp(prefix='hg-service-')
os.close(lockfd)
try:
if not runargs:
runargs = util.hgcmd() + pycompat.sysargv[1:]
runargs.append('--daemon-postexec=unlink:%s' % lockpath)
# Don't pass --cwd to the child process, because we've already
# changed directory.
for i in xrange(1, len(runargs)):
if runargs[i].startswith('--cwd='):
del runargs[i]
break
elif runargs[i].startswith('--cwd'):
del runargs[i:i + 2]
break
def condfn():
return not os.path.exists(lockpath)
pid = util.rundetached(runargs, condfn)
if pid < 0:
raise error.Abort(_('child process failed to start'))
writepid(pid)
finally:
util.tryunlink(lockpath)
if parentfn:
return parentfn(pid)
else:
return
if initfn:
initfn()
if not opts['daemon']:
writepid(util.getpid())
if opts['daemon_postexec']:
try:
os.setsid()
except AttributeError:
pass
for inst in opts['daemon_postexec']:
if inst.startswith('unlink:'):
lockpath = inst[7:]
os.unlink(lockpath)
elif inst.startswith('chdir:'):
os.chdir(inst[6:])
elif inst != 'none':
raise error.Abort(_('invalid value for --daemon-postexec: %s')
% inst)
util.hidewindow()
util.stdout.flush()
util.stderr.flush()
nullfd = os.open(os.devnull, os.O_RDWR)
logfilefd = nullfd
if logfile:
logfilefd = os.open(logfile, os.O_RDWR | os.O_CREAT | os.O_APPEND)
os.dup2(nullfd, 0)
os.dup2(logfilefd, 1)
os.dup2(logfilefd, 2)
if nullfd not in (0, 1, 2):
os.close(nullfd)
if logfile and logfilefd not in (0, 1, 2):
os.close(logfilefd)
if runfn:
return runfn()
_cmdservicemap = {
'chgunix': chgserver.chgunixservice,
'pipe': commandserver.pipeservice,
'unix': commandserver.unixforkingservice,
}
def _createcmdservice(ui, repo, opts):
mode = opts['cmdserver']
try:
return _cmdservicemap[mode](ui, repo, opts)
except KeyError:
raise error.Abort(_('unknown mode %s') % mode)
def _createhgwebservice(ui, repo, opts):
# this way we can check if something was given in the command-line
if opts.get('port'):
opts['port'] = util.getport(opts.get('port'))
alluis = {ui}
if repo:
baseui = repo.baseui
alluis.update([repo.baseui, repo.ui])
else:
baseui = ui
webconf = opts.get('web_conf') or opts.get('webdir_conf')
if webconf:
if opts.get('subrepos'):
raise error.Abort(_('--web-conf cannot be used with --subrepos'))
# load server settings (e.g. web.port) to "copied" ui, which allows
# hgwebdir to reload webconf cleanly
servui = ui.copy()
servui.readconfig(webconf, sections=['web'])
alluis.add(servui)
elif opts.get('subrepos'):
servui = ui
# If repo is None, hgweb.createapp() already raises a proper abort
# message as long as webconf is None.
if repo:
webconf = dict()
cmdutil.addwebdirpath(repo, "", webconf)
else:
servui = ui
optlist = ("name templates style address port prefix ipv6"
" accesslog errorlog certificate encoding")
for o in optlist.split():
val = opts.get(o, '')
if val in (None, ''): # should check against default options instead
continue
for u in alluis:
u.setconfig("web", o, val, 'serve')
app = hgweb.createapp(baseui, repo, webconf)
return hgweb.httpservice(servui, app, opts)
def createservice(ui, repo, opts):
if opts["cmdserver"]:
return _createcmdservice(ui, repo, opts)
else:
return _createhgwebservice(ui, repo, opts)