One-KVM/kvmd/apps/kvmd/streamer.py
2019-10-11 23:43:59 +03:00

292 lines
11 KiB
Python

# ========================================================================== #
# #
# KVMD - The main Pi-KVM daemon. #
# #
# Copyright (C) 2018 Maxim Devaev <mdevaev@gmail.com> #
# #
# This program 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. #
# #
# 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 General Public License for more details. #
# #
# You should have received a copy of the GNU General Public License #
# along with this program. If not, see <https://www.gnu.org/licenses/>. #
# #
# ========================================================================== #
import os
import signal
import asyncio
import asyncio.subprocess
from typing import List
from typing import Dict
from typing import AsyncGenerator
from typing import Optional
import aiohttp
from ...logging import get_logger
from ... import aiotools
from ... import gpio
from ... import __version__
# =====
class Streamer: # pylint: disable=too-many-instance-attributes
def __init__( # pylint: disable=too-many-arguments,too-many-locals
self,
cap_pin: int,
conv_pin: int,
sync_delay: float,
init_delay: float,
init_restart_after: float,
shutdown_delay: float,
state_poll: float,
quality: int,
desired_fps: int,
max_fps: int,
host: str,
port: int,
unix_path: str,
timeout: float,
process_name_prefix: str,
cmd: List[str],
) -> None:
self.__cap_pin = (gpio.set_output(cap_pin) if cap_pin >= 0 else -1)
self.__conv_pin = (gpio.set_output(conv_pin) if conv_pin >= 0 else -1)
self.__sync_delay = sync_delay
self.__init_delay = init_delay
self.__init_restart_after = init_restart_after
self.shutdown_delay = shutdown_delay
self.__state_poll = state_poll
self.__params = {
"quality": quality,
"desired_fps": desired_fps,
}
self.__max_fps = max_fps
assert port or unix_path
self.__host = host
self.__port = port
self.__unix_path = unix_path
self.__timeout = timeout
self.__process_name_prefix = process_name_prefix
self.__cmd = cmd
self.__streamer_task: Optional[asyncio.Task] = None
self.__streamer_proc: Optional[asyncio.subprocess.Process] = None # pylint: disable=no-member
self.__http_session: Optional[aiohttp.ClientSession] = None
async def start(self, params: Dict, no_init_restart: bool=False) -> None:
logger = get_logger()
logger.info("Starting streamer ...")
self.__params = {
key: min(max(params.get(key, self.__params[key]), a), b)
for (key, a, b) in [
("quality", 0, 100),
("desired_fps", 0, self.__max_fps),
]
}
await self.__inner_start()
if self.__init_restart_after > 0.0 and not no_init_restart:
logger.info("Stopping streamer to restart ...")
await self.__inner_stop()
logger.info("Starting again ...")
await self.__inner_start()
async def stop(self) -> None:
get_logger().info("Stopping streamer ...")
await self.__inner_stop()
def is_running(self) -> bool:
return bool(self.__streamer_task)
def get_params(self) -> Dict:
return dict(self.__params)
async def get_state(self) -> Dict:
session = self.__ensure_session()
state = None
try:
async with session.get(
url=f"http://{self.__host}:{self.__port}/state",
headers={"User-Agent": f"KVMD/{__version__}"},
timeout=self.__timeout,
) as response:
response.raise_for_status()
state = (await response.json())["result"]
except (aiohttp.ClientConnectionError, aiohttp.ServerConnectionError):
pass
except asyncio.CancelledError: # pylint: disable=try-except-raise
raise
except Exception:
get_logger().exception("Invalid streamer response from /state")
return {
"limits": {"max_fps": self.__max_fps},
"params": self.get_params(),
"state": state,
}
async def poll_state(self) -> AsyncGenerator[Dict, None]:
prev_state: Dict = {}
while True:
state = await self.get_state()
if state != prev_state:
yield state
prev_state = state
await asyncio.sleep(self.__state_poll)
def get_app(self) -> str:
return os.path.basename(self.__cmd[0])
async def get_version(self) -> str:
proc = await asyncio.create_subprocess_exec(
*[self.__cmd[0], "--version"],
stdout=asyncio.subprocess.PIPE,
stderr=asyncio.subprocess.DEVNULL,
preexec_fn=(lambda: signal.signal(signal.SIGINT, signal.SIG_IGN)),
)
(stdout, _) = await proc.communicate()
return stdout.decode(errors="ignore").strip()
@aiotools.atomic
async def cleanup(self) -> None:
try:
if self.is_running():
await self.stop()
if self.__http_session:
await self.__http_session.close()
self.__http_session = None
finally:
await self.__set_hw_enabled(False)
def __ensure_session(self) -> aiohttp.ClientSession:
if not self.__http_session:
if self.__unix_path:
self.__http_session = aiohttp.ClientSession(connector=aiohttp.UnixConnector(path=self.__unix_path))
else:
self.__http_session = aiohttp.ClientSession()
return self.__http_session
async def __inner_start(self) -> None:
assert not self.__streamer_task
await self.__set_hw_enabled(True)
self.__streamer_task = asyncio.create_task(self.__streamer_task_loop())
async def __inner_stop(self) -> None:
assert self.__streamer_task
self.__streamer_task.cancel()
await asyncio.gather(self.__streamer_task, return_exceptions=True)
await self.__kill_streamer_proc()
await self.__set_hw_enabled(False)
self.__streamer_task = None
async def __set_hw_enabled(self, enabled: bool) -> None:
# XXX: This sequence is very important to enable converter and cap board
if self.__cap_pin >= 0:
gpio.write(self.__cap_pin, enabled)
if self.__conv_pin >= 0:
if enabled:
await asyncio.sleep(self.__sync_delay)
gpio.write(self.__conv_pin, enabled)
if enabled:
await asyncio.sleep(self.__init_delay)
async def __streamer_task_loop(self) -> None: # pylint: disable=too-many-branches
logger = get_logger(0)
while True: # pylint: disable=too-many-nested-blocks
try:
await self.__start_streamer_proc()
empty = 0
async for line_bytes in self.__streamer_proc.stdout: # type: ignore
line = line_bytes.decode(errors="ignore").strip()
if line:
logger.info("Console: %s", line)
empty = 0
else:
empty += 1
if empty == 100: # asyncio bug
raise RuntimeError("Streamer/asyncio: too many empty lines")
raise RuntimeError("Streamer unexpectedly died")
except asyncio.CancelledError:
break
except Exception as err:
if self.__streamer_proc:
logger.exception("Unexpected streamer error: pid=%d", self.__streamer_proc.pid)
else:
logger.exception("Can't start streamer: %s", err)
await self.__kill_streamer_proc()
await asyncio.sleep(1)
async def __start_streamer_proc(self) -> None:
assert self.__streamer_proc is None
cmd = [
part.format(
host=self.__host,
port=self.__port,
unix=self.__unix_path,
process_name_prefix=self.__process_name_prefix,
**self.__params,
)
for part in self.__cmd
]
self.__streamer_proc = await asyncio.create_subprocess_exec(
*cmd,
stdout=asyncio.subprocess.PIPE,
stderr=asyncio.subprocess.STDOUT,
preexec_fn=(lambda: signal.signal(signal.SIGINT, signal.SIG_IGN)),
)
get_logger(0).info("Started streamer pid=%d: %s", self.__streamer_proc.pid, cmd)
async def __kill_streamer_proc(self) -> None:
logger = get_logger(0)
if self.__streamer_proc and self.__streamer_proc.returncode is None:
try:
self.__streamer_proc.terminate()
await asyncio.sleep(1)
if self.__streamer_proc.returncode is None:
try:
self.__streamer_proc.kill()
except Exception:
if self.__streamer_proc.returncode is not None:
raise
await self.__streamer_proc.wait()
logger.info("Streamer killed: pid=%d; retcode=%d",
self.__streamer_proc.pid, self.__streamer_proc.returncode)
except asyncio.CancelledError:
pass
except Exception:
if self.__streamer_proc.returncode is None:
logger.exception("Can't kill streamer pid=%d", self.__streamer_proc.pid)
else:
logger.info("Streamer killed: pid=%d; retcode=%d",
self.__streamer_proc.pid, self.__streamer_proc.returncode)
self.__streamer_proc = None