commandserver: do not set nontty flag if channel is replaced by a real file
This prepares for porting the chg server. In chg, a server receives client's
stdio over a UNIX domain socket to override server channels. This is because
chg should behave as if it is a normal hg command attached to tty. "nontty"
is not wanted.
This patch is corresponding to the following change. This doesn't test the
identity of "cin" object because the current version of chg reopens stdio
to apply buffering mode.
https://bitbucket.org/yuja/chg/commits/
c48c7aed5fc0
# commandserver.py - communicate with Mercurial's API over a pipe
#
# Copyright 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 SocketServer
import errno
import os
import struct
import sys
import traceback
from .i18n import _
from . import (
encoding,
error,
util,
)
logfile = None
def log(*args):
if not logfile:
return
for a in args:
logfile.write(str(a))
logfile.flush()
class channeledoutput(object):
"""
Write data to out in the following format:
data length (unsigned int),
data
"""
def __init__(self, out, channel):
self.out = out
self.channel = channel
@property
def name(self):
return '<%c-channel>' % self.channel
def write(self, data):
if not data:
return
self.out.write(struct.pack('>cI', self.channel, len(data)))
self.out.write(data)
self.out.flush()
def __getattr__(self, attr):
if attr in ('isatty', 'fileno'):
raise AttributeError(attr)
return getattr(self.out, attr)
class channeledinput(object):
"""
Read data from in_.
Requests for input are written to out in the following format:
channel identifier - 'I' for plain input, 'L' line based (1 byte)
how many bytes to send at most (unsigned int),
The client replies with:
data length (unsigned int), 0 meaning EOF
data
"""
maxchunksize = 4 * 1024
def __init__(self, in_, out, channel):
self.in_ = in_
self.out = out
self.channel = channel
@property
def name(self):
return '<%c-channel>' % self.channel
def read(self, size=-1):
if size < 0:
# if we need to consume all the clients input, ask for 4k chunks
# so the pipe doesn't fill up risking a deadlock
size = self.maxchunksize
s = self._read(size, self.channel)
buf = s
while s:
s = self._read(size, self.channel)
buf += s
return buf
else:
return self._read(size, self.channel)
def _read(self, size, channel):
if not size:
return ''
assert size > 0
# tell the client we need at most size bytes
self.out.write(struct.pack('>cI', channel, size))
self.out.flush()
length = self.in_.read(4)
length = struct.unpack('>I', length)[0]
if not length:
return ''
else:
return self.in_.read(length)
def readline(self, size=-1):
if size < 0:
size = self.maxchunksize
s = self._read(size, 'L')
buf = s
# keep asking for more until there's either no more or
# we got a full line
while s and s[-1] != '\n':
s = self._read(size, 'L')
buf += s
return buf
else:
return self._read(size, 'L')
def __iter__(self):
return self
def next(self):
l = self.readline()
if not l:
raise StopIteration
return l
def __getattr__(self, attr):
if attr in ('isatty', 'fileno'):
raise AttributeError(attr)
return getattr(self.in_, attr)
class server(object):
"""
Listens for commands on fin, runs them and writes the output on a channel
based stream to fout.
"""
def __init__(self, ui, repo, fin, fout):
self.cwd = os.getcwd()
# developer config: cmdserver.log
logpath = ui.config("cmdserver", "log", None)
if logpath:
global logfile
if logpath == '-':
# write log on a special 'd' (debug) channel
logfile = channeledoutput(fout, 'd')
else:
logfile = open(logpath, 'a')
if repo:
# the ui here is really the repo ui so take its baseui so we don't
# end up with its local configuration
self.ui = repo.baseui
self.repo = repo
self.repoui = repo.ui
else:
self.ui = ui
self.repo = self.repoui = None
self.cerr = channeledoutput(fout, 'e')
self.cout = channeledoutput(fout, 'o')
self.cin = channeledinput(fin, fout, 'I')
self.cresult = channeledoutput(fout, 'r')
self.client = fin
def _read(self, size):
if not size:
return ''
data = self.client.read(size)
# is the other end closed?
if not data:
raise EOFError
return data
def runcommand(self):
""" reads a list of \0 terminated arguments, executes
and writes the return code to the result channel """
from . import dispatch # avoid cycle
length = struct.unpack('>I', self._read(4))[0]
if not length:
args = []
else:
args = self._read(length).split('\0')
# copy the uis so changes (e.g. --config or --verbose) don't
# persist between requests
copiedui = self.ui.copy()
uis = [copiedui]
if self.repo:
self.repo.baseui = copiedui
# clone ui without using ui.copy because this is protected
repoui = self.repoui.__class__(self.repoui)
repoui.copy = copiedui.copy # redo copy protection
uis.append(repoui)
self.repo.ui = self.repo.dirstate._ui = repoui
self.repo.invalidateall()
for ui in uis:
# any kind of interaction must use server channels, but chg may
# replace channels by fully functional tty files. so nontty is
# enforced only if cin is a channel.
if not util.safehasattr(self.cin, 'fileno'):
ui.setconfig('ui', 'nontty', 'true', 'commandserver')
req = dispatch.request(args[:], copiedui, self.repo, self.cin,
self.cout, self.cerr)
ret = (dispatch.dispatch(req) or 0) & 255 # might return None
# restore old cwd
if '--cwd' in args:
os.chdir(self.cwd)
self.cresult.write(struct.pack('>i', int(ret)))
def getencoding(self):
""" writes the current encoding to the result channel """
self.cresult.write(encoding.encoding)
def serveone(self):
cmd = self.client.readline()[:-1]
if cmd:
handler = self.capabilities.get(cmd)
if handler:
handler(self)
else:
# clients are expected to check what commands are supported by
# looking at the servers capabilities
raise error.Abort(_('unknown command %s') % cmd)
return cmd != ''
capabilities = {'runcommand' : runcommand,
'getencoding' : getencoding}
def serve(self):
hellomsg = 'capabilities: ' + ' '.join(sorted(self.capabilities))
hellomsg += '\n'
hellomsg += 'encoding: ' + encoding.encoding
hellomsg += '\n'
hellomsg += 'pid: %d' % os.getpid()
# write the hello msg in -one- chunk
self.cout.write(hellomsg)
try:
while self.serveone():
pass
except EOFError:
# we'll get here if the client disconnected while we were reading
# its request
return 1
return 0
def _protectio(ui):
""" duplicates streams and redirect original to null if ui uses stdio """
ui.flush()
newfiles = []
nullfd = os.open(os.devnull, os.O_RDWR)
for f, sysf, mode in [(ui.fin, sys.stdin, 'rb'),
(ui.fout, sys.stdout, 'wb')]:
if f is sysf:
newfd = os.dup(f.fileno())
os.dup2(nullfd, f.fileno())
f = os.fdopen(newfd, mode)
newfiles.append(f)
os.close(nullfd)
return tuple(newfiles)
def _restoreio(ui, fin, fout):
""" restores streams from duplicated ones """
ui.flush()
for f, uif in [(fin, ui.fin), (fout, ui.fout)]:
if f is not uif:
os.dup2(f.fileno(), uif.fileno())
f.close()
class pipeservice(object):
def __init__(self, ui, repo, opts):
self.ui = ui
self.repo = repo
def init(self):
pass
def run(self):
ui = self.ui
# redirect stdio to null device so that broken extensions or in-process
# hooks will never cause corruption of channel protocol.
fin, fout = _protectio(ui)
try:
sv = server(ui, self.repo, fin, fout)
return sv.serve()
finally:
_restoreio(ui, fin, fout)
class _requesthandler(SocketServer.StreamRequestHandler):
def handle(self):
ui = self.server.ui
repo = self.server.repo
sv = server(ui, repo, self.rfile, self.wfile)
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
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
class unixservice(object):
"""
Listens on unix domain socket and forks server per connection
"""
def __init__(self, ui, repo, opts):
self.ui = ui
self.repo = repo
self.address = opts['address']
if not util.safehasattr(SocketServer, 'UnixStreamServer'):
raise error.Abort(_('unsupported platform'))
if not self.address:
raise error.Abort(_('no socket path specified with --address'))
def init(self):
class cls(SocketServer.ForkingMixIn, SocketServer.UnixStreamServer):
ui = self.ui
repo = self.repo
self.server = cls(self.address, _requesthandler)
self.ui.status(_('listening at %s\n') % self.address)
self.ui.flush() # avoid buffering of status message
def run(self):
try:
self.server.serve_forever()
finally:
os.unlink(self.address)
_servicemap = {
'pipe': pipeservice,
'unix': unixservice,
}
def createservice(ui, repo, opts):
mode = opts['cmdserver']
try:
return _servicemap[mode](ui, repo, opts)
except KeyError:
raise error.Abort(_('unknown mode %s') % mode)