nonstop/management/commands/switch-jack.py

   1 import asyncio
   2 import json
   3 import logging
   4
   5 import aiohttp
   6 from django.core.management.base import BaseCommand, CommandError
   7
   8 from nonstop.app_settings import app_settings
   9
  10 try:
  11     import jack
  12 except ImportError:
  13     jack = None
  14
  15 logger = logging.getLogger('switch-jack')
  16
  17
  18 class Command(BaseCommand):
  19     help = 'jack source switch'
  20
  21     def handle(self, verbosity, **options):
  22         if jack is None:
  23             raise CommandError('missing jack module (install python3-jack-client?)')
  24         self.verbosity = verbosity
  25         asyncio.run(self.main())
  26
  27     async def main(self):
  28         if not app_settings.SWITCH_WS_URL:
  29             raise CommandError('missing switch_ws_url')
  30         currently_active = None
  31         sleep_duration = 0.2
  32         while True:
  33             try:
  34                 async with aiohttp.ClientSession() as session:
  35                     async with session.ws_connect(app_settings.SWITCH_WS_URL) as ws:
  36                         logger.info('waiting for messages')
  37                         sleep_duration = 0.2  # reset sleep duration to baseline
  38                         async for msg in ws:
  39                             if msg.type == aiohttp.WSMsgType.TEXT:
  40                                 try:
  41                                     msg = json.loads(msg.data)
  42                                 except ValueError:
  43                                     continue
  44                                 if msg.get('active') != currently_active:
  45                                     currently_active = msg.get('active')
  46                                     self.update_jack_connections(currently_active)
  47                             elif msg.type == aiohttp.WSMsgType.ERROR:
  48                                 break
  49                     logger.debug('lost websocket connection')
  50             except aiohttp.ClientError as e:
  51                 logger.warning('websocket error (%s)' % e)
  52                 sleep_duration *= 2
  53                 await asyncio.sleep(min(sleep_duration, 5))
  54             except asyncio.CancelledError:
  55                 # most probably because of a keyboard interrupt, quit silently
  56                 return
  57
  58     def update_jack_connections(self, active):
  59         if active not in app_settings.SWITCH_IN_PORTS:
  60             logger.info('unsupported source: %s', active)
  61             return
  62         logger.info('setting source: %s', active)
  63         out_ports = app_settings.SWITCH_OUT_PORTS
  64         with jack.Client('switch-jack') as client:
  65             known_ports = {x.name for x in client.get_ports(is_audio=True)}
  66             for dports in out_ports.values():
  67                 if any(x not in known_ports for x in dports):
  68                     logger.error('unavailable destination ports %r', dports)
  69                     continue
  70                 for port_id, port_names in app_settings.SWITCH_IN_PORTS.items():
  71                     if any(x not in known_ports for x in port_names):
  72                         logger.error('unavailable source ports %r', port_names)
  73                         continue
  74                     try:
  75                         if port_id == active:
  76                             self.jack_connect(client, port_names[0], dports[0])
  77                             self.jack_connect(client, port_names[1], dports[1])
  78                         else:
  79                             self.jack_disconnect(client, port_names[0], dports[0])
  80                             self.jack_disconnect(client, port_names[1], dports[1])
  81                     except jack.JackError as e:
  82                         logger.error('jack error: %s' % e)
  83
  84     def jack_connect(self, client, in_port, out_port):
  85         connections = [x.name for x in client.get_all_connections(in_port)]
  86         if out_port not in connections:
  87             if self.verbosity:
  88                 logger.info('connecting %s and %s', in_port, out_port)
  89             client.connect(in_port, out_port)
  90
  91     def jack_disconnect(self, client, in_port, out_port):
  92         connections = [x.name for x in client.get_all_connections(in_port)]
  93         if out_port in connections:
  94             if self.verbosity:
  95                 logger.info('disconnecting %s and %s', in_port, out_port)
  96             client.disconnect(in_port, out_port)