kitty/kittens/loop.py
2018-02-04 20:23:52 +05:30

88 lines
2.7 KiB
Python

#!/usr/bin/env python
# vim:fileencoding=utf-8
# License: GPL v3 Copyright: 2018, Kovid Goyal <kovid at kovidgoyal.net>
import fcntl
import os
import selectors
import sys
import termios
import tty
from contextlib import closing, contextmanager
@contextmanager
def non_block(fd):
oldfl = fcntl.fcntl(fd, fcntl.F_GETFL)
fcntl.fcntl(fd, fcntl.F_SETFL, oldfl | os.O_NONBLOCK)
yield
fcntl.fcntl(fd, fcntl.F_SETFL, oldfl)
@contextmanager
def raw_terminal(fd):
isatty = os.isatty(fd)
if isatty:
old = termios.tcgetattr(fd)
tty.setraw(fd)
yield
if isatty:
termios.tcsetattr(fd, termios.TCSADRAIN, old)
class Loop:
def __init__(self, input_fd=None, output_fd=None):
self.input_fd = input_fd or sys.stdin.fileno()
self.output_fd = output_fd or sys.stdout.fileno()
self.wakeup_read_fd, self.wakeup_write_fd = os.pipe()
self.sel = s = selectors.DefaultSelector()
s.register(self.input_fd, selectors.EVENT_READ, self._read_ready)
s.register(self.wakeup_read_fd, selectors.EVENT_READ, self._wakeup_ready)
s.register(self.output_fd, selectors.EVENT_WRITE, self._write_ready)
self.keep_going = True
self.return_code = 0
def _read_ready(self, handler):
pass
def _write_ready(self, handler):
pass
def _on_unhandled_exception(self, tb):
pass
def _wakeup_ready(self, handler):
os.read(self.wakeup_read_fd)
def wakeup(self):
os.write(self.wakeup_write_fd, b'1')
def _loop(self, handler):
select = self.sel.select
tb = None
waiting_for_write = True
with closing(self.sel), non_block(self.input_fd), non_block(self.output_fd), raw_terminal(self.input_fd):
handler.write_buf.insert(0, b'\033 F\033?1049h
while self.keep_going:
has_data_to_write = bool(handler.write_buf)
if has_data_to_write != waiting_for_write:
waiting_for_write = has_data_to_write
self.sel.modify(self.output_fd, selectors.EVENT_WRITE if waiting_for_write else 0, self._write_ready)
events = select()
for key, mask in events:
try:
key.data(handler)
except Exception:
import traceback
tb = traceback.format_exc()
self.keep_going = False
self.return_code = 1
break
if tb is not None:
self._report_error_loop(tb)
def _report_error_loop(self, tb):
raise NotImplementedError('TODO: Implement')