view sat/tools/common/async_process.py @ 3405:ecdb3728749e

plugin XEP-0353: Jingle Message Initiation implementation: This plugin uses the new `XEP-0166_initiate` trigger to initiate a Jingle session with messages if the peer jid has no resource specified. On reception, if the sender is not in our roster, a confirmation is requested to user to avoid leaking presence and IP. If user refuses the session for somebody not in roster, nothing is sent at all (the request is just ignored).
author Goffi <goffi@goffi.org>
date Thu, 12 Nov 2020 14:53:15 +0100
parents e86b71b1aa31
children be6d91572633
line wrap: on
line source

#!/usr/bin/env python3


# SAT: a jabber client
# Copyright (C) 2009-2020 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""tools to launch process in a async way (using Twisted)"""

import os.path
from twisted.internet import defer, reactor, protocol
from twisted.python.failure import Failure
from sat.core.i18n import _
from sat.core import exceptions
from sat.core.log import getLogger
log = getLogger(__name__)


class CommandProtocol(protocol.ProcessProtocol):
    """handle an external command"""
    # name of the command (unicode)
    name = None
    # full path to the command (bytes)
    command = None
    # True to activate logging of command outputs (bool)
    log = False

    def __init__(self, deferred, stdin=None):
        """
        @param deferred(defer.Deferred): will be called when command is completed
        @param stdin(str, None): if not None, will be push to standard input
        """
        self._stdin = stdin
        self._deferred = deferred
        self.data = []
        self.err_data = []

    @property
    def command_name(self):
        """returns command name or empty string if it can't be guessed"""
        if self.name is not None:
            return self.name
        elif self.command is not None:
            return os.path.splitext(os.path.basename(self.command))[0].decode('utf-8',
                                                                              'ignore')
        else:
            return ''

    def connectionMade(self):
        if self._stdin is not None:
            self.transport.write(self._stdin)
            self.transport.closeStdin()

    def outReceived(self, data):
        if self.log:
            log.info(data.decode('utf-8', 'replace'))
        self.data.append(data)

    def errReceived(self, data):
        if self.log:
            log.warning(data.decode('utf-8', 'replace'))
        self.err_data.append(data)

    def processEnded(self, reason):
        data = b''.join(self.data)
        if (reason.value.exitCode == 0):
            log.debug(_(f'{self.command_name!r} command succeed'))
            # we don't use "replace" on purpose, we want an exception if decoding
            # is not working properly
            self._deferred.callback(data)
        else:
            err_data = b''.join(self.err_data)

            msg = (_("Can't complete {name} command (error code: {code}):\n"
                     "stderr:\n{stderr}\n{stdout}\n")
                   .format(name = self.command_name,
                           code = reason.value.exitCode,
                           stderr= err_data.decode(errors='replace'),
                           stdout = "stdout: " + data.decode(errors='replace')
                                    if data else '',
                           ))
            self._deferred.errback(Failure(exceptions.CommandException(
                msg, data, err_data)))

    @classmethod
    def run(cls, *args, **kwargs):
        """Create a new CommandProtocol and execute the given command.

        @param *args(unicode): command arguments
            if cls.command is specified, it will be the path to the command to execute
            otherwise, first argument must be the path
        @param **kwargs: can be:
            - stdin(unicode, None): data to push to standard input
            - verbose(bool): if True stdout and stderr will be logged
            other keyword arguments will be used in reactor.spawnProcess
        @return ((D)bytes): stdout in case of success
        @raise RuntimeError: command returned a non zero status
            stdin and stdout will be given as arguments

        """
        stdin = kwargs.pop('stdin', None)
        if stdin is not None:
            stdin = stdin.encode('utf-8')
        verbose = kwargs.pop('verbose', False)
        args = [a.encode('utf-8') for a in args]
        kwargs = {k:v.encode('utf-8') for k,v in list(kwargs.items())}
        d = defer.Deferred()
        prot = cls(d, stdin=stdin)
        if verbose:
            prot.log = True
        if cls.command is None:
            if not args:
                raise ValueError(
                    "You must either specify cls.command or use a full path to command "
                    "to execute as first argument")
            command = args.pop(0)
            if prot.name is None:
                name = os.path.splitext(os.path.basename(command))[0]
                prot.name = name
        else:
            command = cls.command
        cmd_args = [os.path.basename(command)] + args
        reactor.spawnProcess(prot,
                             command,
                             cmd_args,
                             **kwargs)
        return d


run = CommandProtocol.run