vban-cmd-python/vban_cmd/worker.py

import logging
import socket
import threading
import time
from typing import Optional

from .error import VBANCMDConnectionError
from .packet import HEADER_SIZE, SubscribeHeader, VbanRtPacket, VbanRtPacketHeader

logger = logging.getLogger(__name__)


class Subscriber(threading.Thread):
    """fire a subscription packet every 10 seconds"""

    def __init__(self, remote, stop_event):
        super().__init__(name='subscriber', daemon=False)
        self._remote = remote
        self.stop_event = stop_event
        self.logger = logger.getChild(self.__class__.__name__)
        self.packet = SubscribeHeader()

    def run(self):
        while not self.stopped():
            try:
                self._remote.sock.sendto(
                    self.packet.header,
                    (socket.gethostbyname(self._remote.ip), self._remote.port),
                )
                self.packet.framecounter = (
                    int.from_bytes(self.packet.framecounter, 'little') + 1
                ).to_bytes(4, 'little')
                self.wait_until_stopped(10)
            except socket.gaierror as e:
                self.logger.exception(f'{type(e).__name__}: {e}')
                raise VBANCMDConnectionError(
                    f'unable to resolve hostname {self._remote.ip}'
                ) from e
        self.logger.debug(f'terminating {self.name} thread')

    def stopped(self):
        return self.stop_event.is_set()

    def wait_until_stopped(self, timeout, period=0.2):
        must_end = time.time() + timeout
        while time.time() < must_end:
            if self.stopped():
                break
            time.sleep(period)


class Producer(threading.Thread):
    """Continously send job queue to the Updater thread at a rate of self._remote.ratelimit."""

    def __init__(self, remote, queue, stop_event):
        super().__init__(name='producer', daemon=False)
        self._remote = remote
        self.queue = queue
        self.stop_event = stop_event
        self.logger = logger.getChild(self.__class__.__name__)
        self.packet_expected = VbanRtPacketHeader()
        self._remote.sock.settimeout(self._remote.timeout)
        self._remote._public_packet = self._get_rt()
        (
            self._remote.cache['strip_level'],
            self._remote.cache['bus_level'],
        ) = self._remote._get_levels(self._remote.public_packet)

    def _get_rt(self) -> VbanRtPacket:
        """Attempt to fetch data packet until a valid one found"""

        def fget():
            data = None
            while not data:
                data = self._fetch_rt_packet()
            return data

        return fget()

    def _fetch_rt_packet(self) -> Optional[VbanRtPacket]:
        try:
            data, _ = self._remote.sock.recvfrom(2048)
            # do we have packet data?
            if len(data) > HEADER_SIZE:
                # is the packet of type VBAN RT response?
                if self.packet_expected.header == data[:HEADER_SIZE]:
                    return VbanRtPacket(
                        _kind=self._remote.kind,
                        _voicemeeterType=data[28:29],
                        _reserved=data[29:30],
                        _buffersize=data[30:32],
                        _voicemeeterVersion=data[32:36],
                        _optionBits=data[36:40],
                        _samplerate=data[40:44],
                        _inputLeveldB100=data[44:112],
                        _outputLeveldB100=data[112:240],
                        _TransportBit=data[240:244],
                        _stripState=data[244:276],
                        _busState=data[276:308],
                        _stripGaindB100Layer1=data[308:324],
                        _stripGaindB100Layer2=data[324:340],
                        _stripGaindB100Layer3=data[340:356],
                        _stripGaindB100Layer4=data[356:372],
                        _stripGaindB100Layer5=data[372:388],
                        _stripGaindB100Layer6=data[388:404],
                        _stripGaindB100Layer7=data[404:420],
                        _stripGaindB100Layer8=data[420:436],
                        _busGaindB100=data[436:452],
                        _stripLabelUTF8c60=data[452:932],
                        _busLabelUTF8c60=data[932:1412],
                    )
        except TimeoutError as e:
            self.logger.exception(f'{type(e).__name__}: {e}')
            raise VBANCMDConnectionError(
                f'timeout waiting for RtPacket from {self._remote.ip}'
            ) from e

    def stopped(self):
        return self.stop_event.is_set()

    def run(self):
        while not self.stopped():
            _pp = self._get_rt()
            pdirty = _pp.pdirty(self._remote.public_packet)
            ldirty = _pp.ldirty(
                self._remote.cache['strip_level'], self._remote.cache['bus_level']
            )

            if pdirty or ldirty:
                self._remote._public_packet = _pp
            self._remote._pdirty = pdirty
            self._remote._ldirty = ldirty

            if self._remote.event.pdirty:
                self.queue.put('pdirty')
            if self._remote.event.ldirty:
                self.queue.put('ldirty')
            time.sleep(self._remote.ratelimit)
        self.logger.debug(f'terminating {self.name} thread')
        self.queue.put(None)


class Updater(threading.Thread):
    """
    continously updates the public packet

    notifies observers of event updates
    """

    def __init__(self, remote, queue):
        super().__init__(name='updater', daemon=True)
        self._remote = remote
        self.queue = queue
        self.logger = logger.getChild(self.__class__.__name__)
        self._remote._strip_comp = [False] * (self._remote.kind.num_strip_levels)
        self._remote._bus_comp = [False] * (self._remote.kind.num_bus_levels)

    def run(self):
        """
        Continously update observers of dirty states.

        Generate _strip_comp, _bus_comp and update level cache if ldirty.
        """
        while event := self.queue.get():
            if event == 'pdirty' and self._remote.pdirty:
                self._remote.subject.notify(event)
            elif event == 'ldirty' and self._remote.ldirty:
                self._remote._strip_comp, self._remote._bus_comp = (
                    self._remote._public_packet._strip_comp,
                    self._remote._public_packet._bus_comp,
                )
                (
                    self._remote.cache['strip_level'],
                    self._remote.cache['bus_level'],
                ) = (
                    self._remote._public_packet.inputlevels,
                    self._remote._public_packet.outputlevels,
                )
                self._remote.subject.notify(event)
        self.logger.debug(f'terminating {self.name} thread')