New BusState members per #736

[bggardner]

No description provided.

[bggardner]

I also have a change ready that queries the system for the state of a SocketcanBus, but it depends on the pyroute2 package. I didn't want to cause another dependency, but this seemed to be the most efficient way to query the interface state. Should it be a package-wide dependency, or lazily loaded within the class/method?

@propertydefstate(self) ->BusState:
try:
withpyroute2.IPRoute() asipr:
operstate=ipr.get_links(ipr.link_lookup(ifname=self.channel)[0])[0].get_attr('IFLA_OPERSTATE')
except:
returnBusState.UNKNOWN# Could be BusState.STOPPED instead (channel doesn't exist)ifoperstate=='ERROR-ACTIVE':
returnBusState.ERROR_ACTIVEelifoperstate=='ERROR-PASSIVE':
returnBusState.ERROR_PASSIVEelifoperstate=='BUS-OFF':
returnBusState.BUS_OFFelifoperstate=='STOPPED':
returnBusState.STOPPEDelse:
returnBusState.UNKNOWN

[zariiii9003]

Generally i agree with this, but the consequence is, that BusState should not be passed to BusABC.__init__() anymore. That could be replaced with a universal parameter listen_only: bool for all interfaces. The BusABC.state.setter should also be removed and replaced with a BusABC.listen_only property,

It's a breaking change, but we could do this in a 5.0 release. We have to cleanup all the deprecations at some point anyway.
@hardbyte What do you think?

[bggardner]

I'm not sure I follow you since BusState isn't passed to BusABC.__init__(). I agree that BusABC.state.setter should be removed, though I think listen_only: bool is not a direct replacement, but a "feature" of the specific interface. To prevent a breaking change, we could just add the BUS_OFF and UNKNOWN members, then replace them with the more appropriate names in 5.0 (ACTIVE => ERROR_ACTIVE, PASSIVE => ERROR_PASSIVE, ERROR => STOPPED).

[zariiii9003]

state is passed to subclasses of BusABC to enable monitoring mode like here:

python-can/can/interfaces/pcan/pcan.py

Line 124 in 654a02a

state: BusState=BusState.ACTIVE,

It's ugly and should be replaced with listen_only (same name as in socketcan) in my opinion...