RecurringMultipleReadProperty.py

#!/usr/bin/env python

"""
Recurring Read Property

This application has a static list of points that it would like to read.  It
reads the values of each of them in turn and then quits.
"""

from collections import deque

from bacpypes.debugging import bacpypes_debugging, ModuleLogger
from bacpypes.consolelogging import ConfigArgumentParser

from bacpypes.core import run, deferred
from bacpypes.iocb import IOCB
from bacpypes.task import RecurringTask

from bacpypes.pdu import Address
from bacpypes.object import get_datatype

from bacpypes.apdu import ReadPropertyRequest
from bacpypes.primitivedata import Unsigned, ObjectIdentifier
from bacpypes.constructeddata import Array

from bacpypes.app import BIPSimpleApplication
from bacpypes.local.device import LocalDeviceObject

# some debugging
_debug = 0
_log = ModuleLogger(globals())

# point list
point_list = [
    ('1.2.3.4', 'analogValue:1', 'presentValue'),
    ('1.2.3.4', 'analogValue:2', 'presentValue'),
    ]

#
#   PrairieDog
#

@bacpypes_debugging
class PrairieDog(BIPSimpleApplication, RecurringTask):

    def __init__(self, interval, *args):
        if _debug: PrairieDog._debug("__init__ %r %r", interval, args)
        BIPSimpleApplication.__init__(self, *args)
        RecurringTask.__init__(self, interval * 1000)

        # no longer busy
        self.is_busy = False

        # install the task
        self.install_task()

    def process_task(self):
        if _debug: PrairieDog._debug("process_task")
        global point_list

        # check to see if we're idle
        if self.is_busy:
            if _debug: PrairieDog._debug("    - busy")
            return

        # now we are busy
        self.is_busy = True

        # turn the point list into a queue
        self.point_queue = deque(point_list)

        # clean out the list of the response values
        self.response_values = []

        # fire off the next request
        self.next_request()

    def next_request(self):
        if _debug: PrairieDog._debug("next_request")

        # check to see if we're done
        if not self.point_queue:
            if _debug: PrairieDog._debug("    - done")

            # dump out the results
            for request, response in zip(point_list, self.response_values):
                print(request, response)

            # no longer busy
            self.is_busy = False

            return

        # get the next request
        addr, obj_id, prop_id = self.point_queue.popleft()
        obj_id = ObjectIdentifier(obj_id).value

        # build a request
        request = ReadPropertyRequest(
            objectIdentifier=obj_id,
            propertyIdentifier=prop_id,
            )
        request.pduDestination = Address(addr)
        if _debug: PrairieDog._debug("    - request: %r", request)

        # make an IOCB
        iocb = IOCB(request)
        if _debug: PrairieDog._debug("    - iocb: %r", iocb)

        # set a callback for the response
        iocb.add_callback(self.complete_request)

        # give it to the application
        self.request_io(iocb)

    def complete_request(self, iocb):
        if _debug: PrairieDog._debug("complete_request %r", iocb)

        if iocb.ioResponse:
            apdu = iocb.ioResponse

            # find the datatype
            datatype = get_datatype(apdu.objectIdentifier[0], apdu.propertyIdentifier)
            if _debug: PrairieDog._debug("    - datatype: %r", datatype)
            if not datatype:
                raise TypeError("unknown datatype")

            # special case for array parts, others are managed by cast_out
            if issubclass(datatype, Array) and (apdu.propertyArrayIndex is not None):
                if apdu.propertyArrayIndex == 0:
                    value = apdu.propertyValue.cast_out(Unsigned)
                else:
                    value = apdu.propertyValue.cast_out(datatype.subtype)
            else:
                value = apdu.propertyValue.cast_out(datatype)
            if _debug: PrairieDog._debug("    - value: %r", value)

            # save the value
            self.response_values.append(value)

        if iocb.ioError:
            if _debug: PrairieDog._debug("    - error: %r", iocb.ioError)
            self.response_values.append(iocb.ioError)

        # fire off another request
        deferred(self.next_request)

#
#   __main__
#

def main():
    # parse the command line arguments
    parser = ConfigArgumentParser(description=__doc__)

    # add an argument for interval
    parser.add_argument('interval', type=int,
          help='repeat rate in seconds',
          )

    # now parse the arguments
    args = parser.parse_args()

    if _debug: _log.debug("initialization")
    if _debug: _log.debug("    - args: %r", args)

    # make a device object
    this_device = LocalDeviceObject(ini=args.ini)
    if _debug: _log.debug("    - this_device: %r", this_device)

    # make a dog
    this_application = PrairieDog(args.interval, this_device, args.ini.address)
    if _debug: _log.debug("    - this_application: %r", this_application)

    _log.debug("running")

    run()

    _log.debug("fini")

if __name__ == "__main__":
    main()