chgserver: auto exit after being idle for too long or lose the socket file
This is a part of the one server per config series. In multiple-server setup,
new server may be started for a temporary config change like in command line,
--config extensions.foo=bar.py. This may end up with a lot of not so useful
server processes. Other questions are about socket file and process management,
How to stop these processes? What if a new server wants to listen on a same
address, replacing the old one?
This patch introduces AutoExitMixIn, which will:
1. Exit after being idle for too long. So useless servers won't run forever.
2. Periodically check the ownership of socket file, exit if it is no longer
owned. This brings strong consistency between the filesystem and the
process, and handles some race conditions neatly.
Since rename is atomic, a new server can just have a same server address
with an old one and won't worry about how to make sure the old server is
killed, address conflict, service downtime issues.
The user can safely stop all servers by simply removing the socket files,
without worrying about outdated or accidentally removed pidfiles.
# pager.py - display output using a pager
#
# Copyright 2008 David Soria Parra <dsp@php.net>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
#
# To load the extension, add it to your configuration file:
#
# [extension]
# pager =
#
# Run "hg help pager" to get info on configuration.
'''browse command output with an external pager
To set the pager that should be used, set the application variable::
[pager]
pager = less -FRX
If no pager is set, the pager extensions uses the environment variable
$PAGER. If neither pager.pager, nor $PAGER is set, no pager is used.
You can disable the pager for certain commands by adding them to the
pager.ignore list::
[pager]
ignore = version, help, update
You can also enable the pager only for certain commands using
pager.attend. Below is the default list of commands to be paged::
[pager]
attend = annotate, cat, diff, export, glog, log, qdiff
Setting pager.attend to an empty value will cause all commands to be
paged.
If pager.attend is present, pager.ignore will be ignored.
Lastly, you can enable and disable paging for individual commands with
the attend-<command> option. This setting takes precedence over
existing attend and ignore options and defaults::
[pager]
attend-cat = false
To ignore global commands like :hg:`version` or :hg:`help`, you have
to specify them in your user configuration file.
To control whether the pager is used at all for an individual command,
you can use --pager=<value>::
- use as needed: `auto`.
- require the pager: `yes` or `on`.
- suppress the pager: `no` or `off` (any unrecognized value
will also work).
'''
import atexit, sys, os, signal, subprocess
from mercurial import commands, dispatch, util, extensions, cmdutil
from mercurial.i18n import _
# 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'
def _runpager(ui, p):
pager = subprocess.Popen(p, shell=True, bufsize=-1,
close_fds=util.closefds, stdin=subprocess.PIPE,
stdout=sys.stdout, stderr=sys.stderr)
# back up original file objects and descriptors
olduifout = ui.fout
oldstdout = sys.stdout
stdoutfd = os.dup(sys.stdout.fileno())
stderrfd = os.dup(sys.stderr.fileno())
# create new line-buffered stdout so that output can show up immediately
ui.fout = sys.stdout = newstdout = os.fdopen(sys.stdout.fileno(), 'wb', 1)
os.dup2(pager.stdin.fileno(), sys.stdout.fileno())
if ui._isatty(sys.stderr):
os.dup2(pager.stdin.fileno(), sys.stderr.fileno())
@atexit.register
def killpager():
if util.safehasattr(signal, "SIGINT"):
signal.signal(signal.SIGINT, signal.SIG_IGN)
pager.stdin.close()
ui.fout = olduifout
sys.stdout = oldstdout
# close new stdout while it's associated with pager; otherwise stdout
# fd would be closed when newstdout is deleted
newstdout.close()
# restore original fds: stdout is open again
os.dup2(stdoutfd, sys.stdout.fileno())
os.dup2(stderrfd, sys.stderr.fileno())
pager.wait()
def uisetup(ui):
if '--debugger' in sys.argv or not ui.formatted():
return
def pagecmd(orig, ui, options, cmd, cmdfunc):
p = ui.config("pager", "pager", os.environ.get("PAGER"))
usepager = False
always = util.parsebool(options['pager'])
auto = options['pager'] == 'auto'
if not p:
pass
elif always:
usepager = True
elif not auto:
usepager = False
else:
attend = ui.configlist('pager', 'attend', attended)
ignore = ui.configlist('pager', 'ignore')
cmds, _ = cmdutil.findcmd(cmd, commands.table)
for cmd in cmds:
var = 'attend-%s' % cmd
if ui.config('pager', var):
usepager = ui.configbool('pager', var)
break
if (cmd in attend or
(cmd not in ignore and not attend)):
usepager = True
break
setattr(ui, 'pageractive', usepager)
if usepager:
ui.setconfig('ui', 'formatted', ui.formatted(), 'pager')
ui.setconfig('ui', 'interactive', False, 'pager')
if util.safehasattr(signal, "SIGPIPE"):
signal.signal(signal.SIGPIPE, signal.SIG_DFL)
_runpager(ui, p)
return orig(ui, options, cmd, cmdfunc)
# Wrap dispatch._runcommand after color is loaded so color can see
# ui.pageractive. Otherwise, if we loaded first, color's wrapped
# dispatch._runcommand would run without having access to ui.pageractive.
def afterloaded(loaded):
extensions.wrapfunction(dispatch, '_runcommand', pagecmd)
extensions.afterloaded('color', afterloaded)
def extsetup(ui):
commands.globalopts.append(
('', 'pager', 'auto',
_("when to paginate (boolean, always, auto, or never)"),
_('TYPE')))
attended = ['annotate', 'cat', 'diff', 'export', 'glog', 'log', 'qdiff']