##########################################################################
# Copyright (c) 2010-2022 Robert Bosch GmbH
# This program and the accompanying materials are made available under the
# terms of the Eclipse Public License 2.0 which is available at
# http://www.eclipse.org/legal/epl-2.0.
#
# SPDX-License-Identifier: EPL-2.0
##########################################################################
"""
Proxy Channel
*************
:module: cc_proxy
:synopsis: CChannel implementation for multi-auxiliary usage.
CCProxy channel was created, in order to enable the connection of
multiple auxiliaries on one and only one CChannel. This CChannel
has to be used with a so called proxy auxiliary.
.. currentmodule:: cc_proxy
"""
import logging
import queue
import threading
from typing import Callable, Dict, Union
from pykiso import Message
from pykiso.connector import CChannel
ProxyReturn = Union[
Dict[str, Union[bytes, int]],
Dict[str, Union[bytes, None]],
Dict[str, Union[Message, None]],
Dict[str, Union[None, None]],
]
log = logging.getLogger(__name__)
[docs]class CCProxy(CChannel):
"""Proxy CChannel for multi auxiliary usage."""
def __init__(self, **kwargs):
"""Initialize attributes."""
super().__init__(**kwargs)
self.queue_out = None
self.timeout = 1
self._lock = threading.Lock()
self._tx_callback = None
[docs] def detach_tx_callback(self) -> None:
"""Detach the current callback."""
with self._lock:
log.internal_warning("reset current attached transmit callback!")
self._tx_callback = None
[docs] def attach_tx_callback(self, func: Callable) -> None:
"""Attach to a callback to the _cc_send method.
:param func: function to call when _cc_send is called
"""
with self._lock:
log.internal_debug(f"attached function {func.__name__}")
if self._tx_callback is not None:
log.internal_warning(
f"function {func.__name__} will replace current transmit callback {self._tx_callback.__name__}"
)
self._tx_callback = func
[docs] def _cc_open(self) -> None:
"""Open proxy channel."""
log.internal_debug("Open proxy channel")
self.queue_out = queue.Queue()
[docs] def _cc_close(self) -> None:
"""Close proxy channel."""
log.internal_debug("Close proxy channel")
self.queue_out = queue.Queue()
[docs] def _cc_send(self, *args: tuple, **kwargs: dict) -> None:
"""Populate the queue in of the proxy connector.
:param args: tuple containing positionnal arguments
:param kwargs: dictionary containing named arguments
"""
log.internal_debug(f"put at proxy level: {args} {kwargs}")
if self._tx_callback is not None:
self._tx_callback(self, *args, **kwargs)
[docs] def _cc_receive(self, timeout: float = 0.1, raw: bool = False) -> ProxyReturn:
"""Depopulate the queue out of the proxy connector.
:param timeout: not used
:param raw: not used
:return: raw bytes and source when it exist. if queue timeout
is reached return None
"""
try:
return_response = self.queue_out.get(True, self.timeout)
log.internal_debug(f"received at proxy level : {return_response}")
return return_response
except queue.Empty:
return {"msg": None}