libervia-backend/sat/tools/common/async_process.py

142 lines
5.2 KiB
Python

#!/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