"""Asyncio protocol implementation for handling telegrams."""
from functools import partial
import asyncio
import logging
from serial_asyncio import create_serial_connection
from dsmr_parser import telegram_specifications
from dsmr_parser.clients.telegram_buffer import TelegramBuffer
from dsmr_parser.exceptions import ParseError, InvalidChecksumError
from dsmr_parser.parsers import TelegramParser
from dsmr_parser.clients.settings import SERIAL_SETTINGS_V2_2, \
SERIAL_SETTINGS_V4, SERIAL_SETTINGS_V5
def create_dsmr_protocol(dsmr_version, telegram_callback, loop=None, **kwargs):
"""Creates a DSMR asyncio protocol."""
protocol = _create_dsmr_protocol(dsmr_version, telegram_callback,
DSMRProtocol, loop, **kwargs)
return protocol
def _create_dsmr_protocol(dsmr_version, telegram_callback, protocol, loop=None, **kwargs):
"""Creates a DSMR asyncio protocol."""
if dsmr_version == '2.2':
specification = telegram_specifications.V2_2
serial_settings = SERIAL_SETTINGS_V2_2
elif dsmr_version == '4':
specification = telegram_specifications.V4
serial_settings = SERIAL_SETTINGS_V4
elif dsmr_version == '4+':
specification = telegram_specifications.V5
serial_settings = SERIAL_SETTINGS_V4
elif dsmr_version == '5':
specification = telegram_specifications.V5
serial_settings = SERIAL_SETTINGS_V5
elif dsmr_version == '5B':
specification = telegram_specifications.BELGIUM_FLUVIUS
serial_settings = SERIAL_SETTINGS_V5
elif dsmr_version == "5L":
specification = telegram_specifications.LUXEMBOURG_SMARTY
serial_settings = SERIAL_SETTINGS_V5
elif dsmr_version == "5S":
specification = telegram_specifications.SWEDEN
serial_settings = SERIAL_SETTINGS_V5
elif dsmr_version == "Q3D":
specification = telegram_specifications.Q3D
serial_settings = SERIAL_SETTINGS_V5
else:
raise NotImplementedError("No telegram parser found for version: %s",
dsmr_version)
protocol = partial(protocol, loop, TelegramParser(specification),
telegram_callback=telegram_callback, **kwargs)
return protocol, serial_settings
def create_dsmr_reader(port, dsmr_version, telegram_callback, loop=None):
"""Creates a DSMR asyncio protocol coroutine using serial port."""
protocol, serial_settings = create_dsmr_protocol(
dsmr_version, telegram_callback, loop=None)
serial_settings['url'] = port
conn = create_serial_connection(loop, protocol, **serial_settings)
return conn
def create_tcp_dsmr_reader(host, port, dsmr_version,
telegram_callback, loop=None,
keep_alive_interval=None):
"""Creates a DSMR asyncio protocol coroutine using TCP connection."""
if not loop:
loop = asyncio.get_event_loop()
protocol, _ = create_dsmr_protocol(
dsmr_version, telegram_callback, loop=loop,
keep_alive_interval=keep_alive_interval)
conn = loop.create_connection(protocol, host, port)
return conn
class DSMRProtocol(asyncio.Protocol):
"""Assemble and handle incoming data into complete DSM telegrams."""
transport = None
telegram_callback = None
def __init__(self, loop, telegram_parser,
telegram_callback=None, keep_alive_interval=None):
"""Initialize class."""
self.loop = loop
self.log = logging.getLogger(__name__)
self.telegram_parser = telegram_parser
# callback to call on complete telegram
self.telegram_callback = telegram_callback
# buffer to keep incomplete incoming data
self.telegram_buffer = TelegramBuffer()
# keep a lock until the connection is closed
self._closed = asyncio.Event()
self._keep_alive_interval = keep_alive_interval
self._active = True
def connection_made(self, transport):
"""Just logging for now."""
self.transport = transport
self.log.debug('connected')
self._active = False
if self.loop and self._keep_alive_interval:
self.loop.call_later(self._keep_alive_interval, self.keep_alive)
def data_received(self, data):
"""Add incoming data to buffer."""
# accept latin-1 (8-bit) on the line, to allow for non-ascii transport or padding
data = data.decode("latin1")
self._active = True
self.log.debug('received data: %s', data)
self.telegram_buffer.append(data)
for telegram in self.telegram_buffer.get_all():
# ensure actual telegram is ascii (7-bit) only (ISO 646:1991 IRV required in section 5.5 of IEC 62056-21)
telegram = telegram.encode("latin1").decode("ascii")
self.handle_telegram(telegram)
def keep_alive(self):
if self._active:
self.log.debug('keep-alive checked')
self._active = False
if self.loop:
self.loop.call_later(self._keep_alive_interval, self.keep_alive)
else:
self.log.warning('keep-alive check failed')
if self.transport:
self.transport.close()
def connection_lost(self, exc):
"""Stop when connection is lost."""
if exc:
self.log.exception('disconnected due to exception', exc_info=exc)
else:
self.log.info('disconnected because of close/abort.')
self._closed.set()
def handle_telegram(self, telegram):
"""Send off parsed telegram to handling callback."""
self.log.debug('got telegram: %s', telegram)
try:
parsed_telegram = self.telegram_parser.parse(telegram)
except InvalidChecksumError as e:
self.log.info(str(e))
except ParseError:
self.log.exception("failed to parse telegram")
else:
self.telegram_callback(parsed_telegram)
async def wait_closed(self):
"""Wait until connection is closed."""
await self._closed.wait()