gajim-plural/gajim/command_system/implementation/execute.py

121 lines
4.0 KiB
Python

# Copyright (c) 2010, Alexander Cherniuk (ts33kr@gmail.com)
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""
Provides facilities to safely execute expressions inside a shell process
and capture the resulting output, in an asynchronous fashion, avoiding
deadlocks. If the process execution time reaches the threshold - it is
forced to terminate. Consists of a tiny framework and a couple of
commands as a frontend.
"""
from subprocess import Popen, PIPE
from os.path import expanduser
from gi.repository import GLib
from ..framework import CommandContainer, command, doc
from .hosts import ChatCommands, PrivateChatCommands, GroupChatCommands
class Execute(CommandContainer):
AUTOMATIC = True
HOSTS = ChatCommands, PrivateChatCommands, GroupChatCommands
DIRECTORY = "~"
POLL_INTERVAL = 100
POLL_COUNT = 5
@command("exec", raw=True)
@doc(_("Execute expression inside a shell, show output"))
def execute(self, expression):
Execute.spawn(self, expression)
@classmethod
def spawn(cls, processor, expression):
pipes = dict(stdout=PIPE, stderr=PIPE)
directory = expanduser(cls.DIRECTORY)
popen = Popen(expression, shell=True, cwd=directory, **pipes)
cls.monitor(processor, popen)
@classmethod
def monitor(cls, processor, popen):
poller = cls.poller(processor, popen)
GLib.timeout_add(cls.POLL_INTERVAL, next, poller)
@classmethod
def poller(cls, processor, popen):
for _ in range(cls.POLL_COUNT):
yield cls.brush(processor, popen)
cls.overdue(processor, popen)
yield False
@classmethod
def brush(cls, processor, popen):
if popen.poll() is not None:
cls.terminated(processor, popen)
return False
return True
@classmethod
def terminated(cls, processor, popen):
stdout, stderr = cls.fetch(popen)
success = popen.returncode == 0
if success and stdout:
processor.echo(stdout)
elif not success and stderr:
processor.echo_error(stderr)
@classmethod
def overdue(cls, processor, popen):
popen.terminate()
@classmethod
def fetch(cls, popen):
data = popen.communicate()
return map(cls.clean, data)
@staticmethod
def clean(text):
strip = chr(10) + chr(32)
return text.decode().strip(strip)
class Show(Execute):
@command("sh", raw=True)
@doc(_("Execute expression inside a shell, send output"))
def show(self, expression):
Show.spawn(self, expression)
@classmethod
def terminated(cls, processor, popen):
stdout, stderr = cls.fetch(popen)
success = popen.returncode == 0
if success and stdout:
processor.send(stdout)
elif not success and stderr:
processor.echo_error(stderr)