mail: take --encoding and HGENCODING into account
Fall back to our encoding strategy for sending MIME text
that's neither ASCII nor UTF-8.
# 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 errno
import gc
import os
import random
import select
import signal
import socket
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', 'tell', 'seek'):
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', 'tell', 'seek'):
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 cleanup(self):
"""release and restore resources taken during server session"""
pass
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 _readstr(self):
"""read a string from the channel
format:
data length (uint32), data
"""
length = struct.unpack('>I', self._read(4))[0]
if not length:
return ''
return self._read(length)
def _readlist(self):
"""read a list of NULL separated strings from the channel"""
s = self._readstr()
if s:
return s.split('\0')
else:
return []
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
args = self._readlist()
# 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:
ui.resetstate()
# 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' % util.getpid()
if util.safehasattr(os, 'getpgid'):
hellomsg += '\n'
hellomsg += 'pgid: %d' % os.getpgid(0)
# 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:
sv.cleanup()
_restoreio(ui, fin, fout)
def _initworkerprocess():
# use a different process group from the master process, in order to:
# 1. make the current process group no longer "orphaned" (because the
# parent of this process is in a different process group while
# remains in a same session)
# according to POSIX 2.2.2.52, orphaned process group will ignore
# terminal-generated stop signals like SIGTSTP (Ctrl+Z), which will
# cause trouble for things like ncurses.
# 2. the client can use kill(-pgid, sig) to simulate terminal-generated
# SIGINT (Ctrl+C) and process-exit-generated SIGHUP. our child
# processes like ssh will be killed properly, without affecting
# unrelated processes.
os.setpgid(0, 0)
# change random state otherwise forked request handlers would have a
# same state inherited from parent.
random.seed()
def _serverequest(ui, repo, conn, createcmdserver):
fin = conn.makefile('rb')
fout = conn.makefile('wb')
sv = None
try:
sv = createcmdserver(repo, conn, fin, fout)
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.
if sv:
cerr = sv.cerr
else:
cerr = channeledoutput(fout, 'e')
traceback.print_exc(file=cerr)
raise
finally:
fin.close()
try:
fout.close() # implicit flush() may cause another EPIPE
except IOError as inst:
if inst.errno != errno.EPIPE:
raise
class unixservicehandler(object):
"""Set of pluggable operations for unix-mode services
Almost all methods except for createcmdserver() are called in the main
process. You can't pass mutable resource back from createcmdserver().
"""
pollinterval = None
def __init__(self, ui):
self.ui = ui
def bindsocket(self, sock, address):
util.bindunixsocket(sock, address)
def unlinksocket(self, address):
os.unlink(address)
def printbanner(self, address):
self.ui.status(_('listening at %s\n') % address)
self.ui.flush() # avoid buffering of status message
def shouldexit(self):
"""True if server should shut down; checked per pollinterval"""
return False
def newconnection(self):
"""Called when main process notices new connection"""
pass
def createcmdserver(self, repo, conn, fin, fout):
"""Create new command server instance; called in the process that
serves for the current connection"""
return server(self.ui, repo, fin, fout)
class unixforkingservice(object):
"""
Listens on unix domain socket and forks server per connection
"""
def __init__(self, ui, repo, opts, handler=None):
self.ui = ui
self.repo = repo
self.address = opts['address']
if not util.safehasattr(socket, 'AF_UNIX'):
raise error.Abort(_('unsupported platform'))
if not self.address:
raise error.Abort(_('no socket path specified with --address'))
self._servicehandler = handler or unixservicehandler(ui)
self._sock = None
self._oldsigchldhandler = None
self._workerpids = set() # updated by signal handler; do not iterate
def init(self):
self._sock = socket.socket(socket.AF_UNIX)
self._servicehandler.bindsocket(self._sock, self.address)
self._sock.listen(socket.SOMAXCONN)
o = signal.signal(signal.SIGCHLD, self._sigchldhandler)
self._oldsigchldhandler = o
self._servicehandler.printbanner(self.address)
def _cleanup(self):
signal.signal(signal.SIGCHLD, self._oldsigchldhandler)
self._sock.close()
self._servicehandler.unlinksocket(self.address)
# don't kill child processes as they have active clients, just wait
self._reapworkers(0)
def run(self):
try:
self._mainloop()
finally:
self._cleanup()
def _mainloop(self):
h = self._servicehandler
while not h.shouldexit():
try:
ready = select.select([self._sock], [], [], h.pollinterval)[0]
if not ready:
continue
conn, _addr = self._sock.accept()
except (select.error, socket.error) as inst:
if inst.args[0] == errno.EINTR:
continue
raise
pid = os.fork()
if pid:
try:
self.ui.debug('forked worker process (pid=%d)\n' % pid)
self._workerpids.add(pid)
h.newconnection()
finally:
conn.close() # release handle in parent process
else:
try:
self._runworker(conn)
conn.close()
os._exit(0)
except: # never return, hence no re-raises
try:
self.ui.traceback(force=True)
finally:
os._exit(255)
def _sigchldhandler(self, signal, frame):
self._reapworkers(os.WNOHANG)
def _reapworkers(self, options):
while self._workerpids:
try:
pid, _status = os.waitpid(-1, options)
except OSError as inst:
if inst.errno == errno.EINTR:
continue
if inst.errno != errno.ECHILD:
raise
# no child processes at all (reaped by other waitpid()?)
self._workerpids.clear()
return
if pid == 0:
# no waitable child processes
return
self.ui.debug('worker process exited (pid=%d)\n' % pid)
self._workerpids.discard(pid)
def _runworker(self, conn):
signal.signal(signal.SIGCHLD, self._oldsigchldhandler)
_initworkerprocess()
h = self._servicehandler
try:
_serverequest(self.ui, self.repo, conn, h.createcmdserver)
finally:
gc.collect() # trigger __del__ since worker process uses os._exit
_servicemap = {
'pipe': pipeservice,
'unix': unixforkingservice,
}
def createservice(ui, repo, opts):
mode = opts['cmdserver']
try:
return _servicemap[mode](ui, repo, opts)
except KeyError:
raise error.Abort(_('unknown mode %s') % mode)