mirror of
https://github.com/sezanzeb/input-remapper
synced 2024-11-04 12:00:16 +00:00
145 lines
4.4 KiB
Python
145 lines
4.4 KiB
Python
#!/usr/bin/python3
|
|
# -*- coding: utf-8 -*-
|
|
# key-mapper - GUI for device specific keyboard mappings
|
|
# Copyright (C) 2021 sezanzeb <proxima@sezanzeb.de>
|
|
#
|
|
# This file is part of key-mapper.
|
|
#
|
|
# key-mapper is free software: you can redistribute it and/or modify
|
|
# it under the terms of the GNU General Public License as published by
|
|
# the Free Software Foundation, either version 3 of the License, or
|
|
# (at your option) any later version.
|
|
#
|
|
# key-mapper 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 General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU General Public License
|
|
# along with key-mapper. If not, see <https://www.gnu.org/licenses/>.
|
|
|
|
|
|
"""Named bidirectional non-blocking pipes.
|
|
|
|
>>> p1 = Pipe('foo')
|
|
>>> p2 = Pipe('foo')
|
|
|
|
>>> p1.send(1)
|
|
>>> p2.poll()
|
|
>>> p2.recv()
|
|
|
|
>>> p2.send(2)
|
|
>>> p1.poll()
|
|
>>> p1.recv()
|
|
|
|
Beware that pipes read any available messages,
|
|
even those written by themselves.
|
|
"""
|
|
|
|
|
|
import os
|
|
import time
|
|
import json
|
|
|
|
from keymapper.logger import logger
|
|
from keymapper.paths import mkdir, chown
|
|
|
|
|
|
class Pipe:
|
|
"""Pipe object."""
|
|
def __init__(self, path):
|
|
"""Create a pipe, or open it if it already exists."""
|
|
self._path = path
|
|
self._unread = []
|
|
self._created_at = time.time()
|
|
|
|
paths = (
|
|
f'{path}r',
|
|
f'{path}w'
|
|
)
|
|
|
|
mkdir(os.path.dirname(path))
|
|
|
|
if not os.path.exists(paths[0]):
|
|
logger.spam('Creating new pipe for "%s"', path)
|
|
# The fd the link points to is closed, or none ever existed
|
|
# If there is a link, remove it.
|
|
if os.path.islink(paths[0]):
|
|
os.remove(paths[0])
|
|
if os.path.islink(paths[1]):
|
|
os.remove(paths[1])
|
|
|
|
self._fds = os.pipe()
|
|
fds_dir = f'/proc/{os.getpid()}/fd/'
|
|
chown(f'{fds_dir}{self._fds[0]}')
|
|
chown(f'{fds_dir}{self._fds[1]}')
|
|
|
|
# to make it accessible by path constants, create symlinks
|
|
os.symlink(f'{fds_dir}{self._fds[0]}', paths[0])
|
|
os.symlink(f'{fds_dir}{self._fds[1]}', paths[1])
|
|
else:
|
|
logger.spam('Using existing pipe for "%s"', path)
|
|
|
|
# thanks to os.O_NONBLOCK, readline will return b'' when there
|
|
# is nothing to read
|
|
self._fds = (
|
|
os.open(paths[0], os.O_RDONLY | os.O_NONBLOCK),
|
|
os.open(paths[1], os.O_WRONLY | os.O_NONBLOCK)
|
|
)
|
|
|
|
self._handles = (
|
|
open(self._fds[0], 'r'),
|
|
open(self._fds[1], 'w')
|
|
)
|
|
|
|
def recv(self):
|
|
"""Read an object from the pipe or None if nothing available.
|
|
|
|
Doesn't transmit pickles, to avoid injection attacks on the
|
|
privileged helper. Only messages that can be converted to json
|
|
are allowed.
|
|
"""
|
|
if len(self._unread) > 0:
|
|
return self._unread.pop(0)
|
|
|
|
line = self._handles[0].readline()
|
|
if len(line) == 0:
|
|
return None
|
|
|
|
parsed = json.loads(line)
|
|
if parsed[0] < self._created_at and os.environ.get('UNITTEST'):
|
|
# important to avoid race conditions between multiple unittests,
|
|
# for example old terminate messages reaching a new instance of
|
|
# the helper.
|
|
logger.spam('Ignoring old message %s', parsed)
|
|
return None
|
|
|
|
return parsed[1]
|
|
|
|
def send(self, message):
|
|
"""Write an object to the pipe."""
|
|
dump = json.dumps((time.time(), message))
|
|
# there aren't any newlines supposed to be,
|
|
# but if there are it breaks readline().
|
|
self._handles[1].write(dump.replace('\n', ''))
|
|
self._handles[1].write('\n')
|
|
self._handles[1].flush()
|
|
|
|
def poll(self):
|
|
"""Check if there is anything that can be read."""
|
|
if len(self._unread) > 0:
|
|
return True
|
|
|
|
# using select.select apparently won't mark the pipe as ready
|
|
# anymore when there are multiple lines to read but only a single
|
|
# line is retreived. Using read instead.
|
|
msg = self.recv()
|
|
if msg is not None:
|
|
self._unread.append(msg)
|
|
|
|
return len(self._unread) > 0
|
|
|
|
def fileno(self):
|
|
"""Compatibility to select.select"""
|
|
return self._handles[0].fileno()
|