# chgserver.py - command server extension for cHg
#
# Copyright 2011 Yuya Nishihara <yuya@tcha.org>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""command server extension for cHg (EXPERIMENTAL)
'S' channel (read/write)
propagate ui.system() request to client
'attachio' command
attach client's stdio passed by sendmsg()
'chdir' command
change current directory
'getpager' command
checks if pager is enabled and which pager should be executed
'setenv' command
replace os.environ completely
'SIGHUP' signal
reload configuration files
"""
from __future__ import absolute_import
import SocketServer
import errno
import os
import re
import signal
import struct
import threading
import time
import traceback
from mercurial.i18n import _
from mercurial import (
cmdutil,
commands,
commandserver,
dispatch,
error,
osutil,
util,
)
# 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'
_log = commandserver.log
# copied from hgext/pager.py:uisetup()
def _setuppagercmd(ui, options, cmd):
if not ui.formatted():
return
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:
attended = ['annotate', 'cat', 'diff', 'export', 'glog', 'log', 'qdiff']
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
if usepager:
ui.setconfig('ui', 'formatted', ui.formatted(), 'pager')
ui.setconfig('ui', 'interactive', False, 'pager')
return p
_envvarre = re.compile(r'\$[a-zA-Z_]+')
def _clearenvaliases(cmdtable):
"""Remove stale command aliases referencing env vars; variable expansion
is done at dispatch.addaliases()"""
for name, tab in cmdtable.items():
cmddef = tab[0]
if (isinstance(cmddef, dispatch.cmdalias) and
not cmddef.definition.startswith('!') and # shell alias
_envvarre.search(cmddef.definition)):
del cmdtable[name]
def _newchgui(srcui, csystem):
class chgui(srcui.__class__):
def __init__(self, src=None):
super(chgui, self).__init__(src)
if src:
self._csystem = getattr(src, '_csystem', csystem)
else:
self._csystem = csystem
def system(self, cmd, environ=None, cwd=None, onerr=None,
errprefix=None):
# copied from mercurial/util.py:system()
self.flush()
def py2shell(val):
if val is None or val is False:
return '0'
if val is True:
return '1'
return str(val)
env = os.environ.copy()
if environ:
env.update((k, py2shell(v)) for k, v in environ.iteritems())
env['HG'] = util.hgexecutable()
rc = self._csystem(cmd, env, cwd)
if rc and onerr:
errmsg = '%s %s' % (os.path.basename(cmd.split(None, 1)[0]),
util.explainexit(rc)[0])
if errprefix:
errmsg = '%s: %s' % (errprefix, errmsg)
raise onerr(errmsg)
return rc
return chgui(srcui)
def _renewui(srcui):
newui = srcui.__class__()
for a in ['fin', 'fout', 'ferr', 'environ']:
setattr(newui, a, getattr(srcui, a))
if util.safehasattr(srcui, '_csystem'):
newui._csystem = srcui._csystem
# stolen from tortoisehg.util.copydynamicconfig()
for section, name, value in srcui.walkconfig():
source = srcui.configsource(section, name)
if ':' in source:
# path:line
continue
if source == 'none':
# ui.configsource returns 'none' by default
source = ''
newui.setconfig(section, name, value, source)
return newui
class channeledsystem(object):
"""Propagate ui.system() request in the following format:
payload length (unsigned int),
cmd, '\0',
cwd, '\0',
envkey, '=', val, '\0',
...
envkey, '=', val
and waits:
exitcode length (unsigned int),
exitcode (int)
"""
def __init__(self, in_, out, channel):
self.in_ = in_
self.out = out
self.channel = channel
def __call__(self, cmd, environ, cwd):
args = [util.quotecommand(cmd), cwd or '.']
args.extend('%s=%s' % (k, v) for k, v in environ.iteritems())
data = '\0'.join(args)
self.out.write(struct.pack('>cI', self.channel, len(data)))
self.out.write(data)
self.out.flush()
length = self.in_.read(4)
length, = struct.unpack('>I', length)
if length != 4:
raise error.Abort(_('invalid response'))
rc, = struct.unpack('>i', self.in_.read(4))
return rc
_iochannels = [
# server.ch, ui.fp, mode
('cin', 'fin', 'rb'),
('cout', 'fout', 'wb'),
('cerr', 'ferr', 'wb'),
]
class chgcmdserver(commandserver.server):
def __init__(self, ui, repo, fin, fout, sock):
super(chgcmdserver, self).__init__(
_newchgui(ui, channeledsystem(fin, fout, 'S')), repo, fin, fout)
self.clientsock = sock
self._oldios = [] # original (self.ch, ui.fp, fd) before "attachio"
def cleanup(self):
# dispatch._runcatch() does not flush outputs if exception is not
# handled by dispatch._dispatch()
self.ui.flush()
self._restoreio()
def attachio(self):
"""Attach to client's stdio passed via unix domain socket; all
channels except cresult will no longer be used
"""
# tell client to sendmsg() with 1-byte payload, which makes it
# distinctive from "attachio\n" command consumed by client.read()
self.clientsock.sendall(struct.pack('>cI', 'I', 1))
clientfds = osutil.recvfds(self.clientsock.fileno())
_log('received fds: %r\n' % clientfds)
ui = self.ui
ui.flush()
first = self._saveio()
for fd, (cn, fn, mode) in zip(clientfds, _iochannels):
assert fd > 0
fp = getattr(ui, fn)
os.dup2(fd, fp.fileno())
os.close(fd)
if not first:
continue
# reset buffering mode when client is first attached. as we want
# to see output immediately on pager, the mode stays unchanged
# when client re-attached. ferr is unchanged because it should
# be unbuffered no matter if it is a tty or not.
if fn == 'ferr':
newfp = fp
else:
# make it line buffered explicitly because the default is
# decided on first write(), where fout could be a pager.
if fp.isatty():
bufsize = 1 # line buffered
else:
bufsize = -1 # system default
newfp = os.fdopen(fp.fileno(), mode, bufsize)
setattr(ui, fn, newfp)
setattr(self, cn, newfp)
self.cresult.write(struct.pack('>i', len(clientfds)))
def _saveio(self):
if self._oldios:
return False
ui = self.ui
for cn, fn, _mode in _iochannels:
ch = getattr(self, cn)
fp = getattr(ui, fn)
fd = os.dup(fp.fileno())
self._oldios.append((ch, fp, fd))
return True
def _restoreio(self):
ui = self.ui
for (ch, fp, fd), (cn, fn, _mode) in zip(self._oldios, _iochannels):
newfp = getattr(ui, fn)
# close newfp while it's associated with client; otherwise it
# would be closed when newfp is deleted
if newfp is not fp:
newfp.close()
# restore original fd: fp is open again
os.dup2(fd, fp.fileno())
os.close(fd)
setattr(self, cn, ch)
setattr(ui, fn, fp)
del self._oldios[:]
def chdir(self):
"""Change current directory
Note that the behavior of --cwd option is bit different from this.
It does not affect --config parameter.
"""
path = self._readstr()
if not path:
return
_log('chdir to %r\n' % path)
os.chdir(path)
def setumask(self):
"""Change umask"""
mask = struct.unpack('>I', self._read(4))[0]
_log('setumask %r\n' % mask)
os.umask(mask)
def getpager(self):
"""Read cmdargs and write pager command to r-channel if enabled
If pager isn't enabled, this writes '\0' because channeledoutput
does not allow to write empty data.
"""
args = self._readlist()
try:
cmd, _func, args, options, _cmdoptions = dispatch._parse(self.ui,
args)
except (error.Abort, error.AmbiguousCommand, error.CommandError,
error.UnknownCommand):
cmd = None
options = {}
if not cmd or 'pager' not in options:
self.cresult.write('\0')
return
pagercmd = _setuppagercmd(self.ui, options, cmd)
if pagercmd:
self.cresult.write(pagercmd)
else:
self.cresult.write('\0')
def setenv(self):
"""Clear and update os.environ
Note that not all variables can make an effect on the running process.
"""
l = self._readlist()
try:
newenv = dict(s.split('=', 1) for s in l)
except ValueError:
raise ValueError('unexpected value in setenv request')
diffkeys = set(k for k in set(os.environ.keys() + newenv.keys())
if os.environ.get(k) != newenv.get(k))
_log('change env: %r\n' % sorted(diffkeys))
os.environ.clear()
os.environ.update(newenv)
if set(['HGPLAIN', 'HGPLAINEXCEPT']) & diffkeys:
# reload config so that ui.plain() takes effect
self.ui = _renewui(self.ui)
_clearenvaliases(commands.table)
capabilities = commandserver.server.capabilities.copy()
capabilities.update({'attachio': attachio,
'chdir': chdir,
'getpager': getpager,
'setenv': setenv,
'setumask': setumask})
# copied from mercurial/commandserver.py
class _requesthandler(SocketServer.StreamRequestHandler):
def handle(self):
# use a different process group from the master process, making this
# process pass kernel "is_current_pgrp_orphaned" check so signals like
# SIGTSTP, SIGTTIN, SIGTTOU are not ignored.
os.setpgid(0, 0)
ui = self.server.ui
repo = self.server.repo
sv = chgcmdserver(ui, repo, self.rfile, self.wfile, self.connection)
try:
try:
sv.serve()
# handle exceptions that may be raised by command server. most of
# known exceptions are caught by dispatch.
except error.Abort as inst:
ui.warn(_('abort: %s\n') % inst)
except IOError as inst:
if inst.errno != errno.EPIPE:
raise
except KeyboardInterrupt:
pass
finally:
sv.cleanup()
except: # re-raises
# also write traceback to error channel. otherwise client cannot
# see it because it is written to server's stderr by default.
traceback.print_exc(file=sv.cerr)
raise
def _tempaddress(address):
return '%s.%d.tmp' % (address, os.getpid())
class AutoExitMixIn: # use old-style to comply with SocketServer design
lastactive = time.time()
idletimeout = 3600 # default 1 hour
def startautoexitthread(self):
# note: the auto-exit check here is cheap enough to not use a thread,
# be done in serve_forever. however SocketServer is hook-unfriendly,
# you simply cannot hook serve_forever without copying a lot of code.
# besides, serve_forever's docstring suggests using thread.
thread = threading.Thread(target=self._autoexitloop)
thread.daemon = True
thread.start()
def _autoexitloop(self, interval=1):
while True:
time.sleep(interval)
if not self.issocketowner():
_log('%s is not owned, exiting.\n' % self.server_address)
break
if time.time() - self.lastactive > self.idletimeout:
_log('being idle too long. exiting.\n')
break
self.shutdown()
def process_request(self, request, address):
self.lastactive = time.time()
return SocketServer.ForkingMixIn.process_request(
self, request, address)
def server_bind(self):
# use a unique temp address so we can stat the file and do ownership
# check later
tempaddress = _tempaddress(self.server_address)
self.socket.bind(tempaddress)
self._socketstat = os.stat(tempaddress)
# rename will replace the old socket file if exists atomically. the
# old server will detect ownership change and exit.
util.rename(tempaddress, self.server_address)
def issocketowner(self):
try:
stat = os.stat(self.server_address)
return (stat.st_ino == self._socketstat.st_ino and
stat.st_mtime == self._socketstat.st_mtime)
except OSError:
return False
def unlinksocketfile(self):
if not self.issocketowner():
return
# it is possible to have a race condition here that we may
# remove another server's socket file. but that's okay
# since that server will detect and exit automatically and
# the client will start a new server on demand.
try:
os.unlink(self.server_address)
except OSError as exc:
if exc.errno != errno.ENOENT:
raise
class chgunixservice(commandserver.unixservice):
def init(self):
# drop options set for "hg serve --cmdserver" command
self.ui.setconfig('progress', 'assume-tty', None)
signal.signal(signal.SIGHUP, self._reloadconfig)
class cls(AutoExitMixIn, SocketServer.ForkingMixIn,
SocketServer.UnixStreamServer):
ui = self.ui
repo = self.repo
self.server = cls(self.address, _requesthandler)
self.server.idletimeout = self.ui.configint(
'chgserver', 'idletimeout', self.server.idletimeout)
self.server.startautoexitthread()
# avoid writing "listening at" message to stdout before attachio
# request, which calls setvbuf()
def _reloadconfig(self, signum, frame):
self.ui = self.server.ui = _renewui(self.ui)
def run(self):
try:
self.server.serve_forever()
finally:
self.server.unlinksocketfile()
def uisetup(ui):
commandserver._servicemap['chgunix'] = chgunixservice