sensorReporter.py

#!/usr/bin/python
"""
 Script:  sensorReporter.py
 Author: Sascha Sambale
 Date:   June 7th, 2016
 Purpose: Uses the REST API or MQTT to report updates to the configured sensors
"""

import signal
import sys
import time
import traceback
from threading import *
from signalProc import *
from configLoader import *

actuators = []
# The decorators below causes the creation of a SignalHandler attached to this function for each of the
# signals we care about using the handles function above. The resultant SignalHandler is registered with
# the signal.signal so cleanup_and_exit is called when they are received.
#@handles(signal.SIGTERM)
#@handles(signal.SIGHUP)
#@handles(signal.SIGINT)
def cleanup_and_exit():
    """ Signal handler to ensure we disconnect cleanly in the event of a SIGTERM or SIGINT. """

    logger.warn("Terminating the program")
    try:
       config_loader.get_mqtt().client.disconnect()
       logger.info("Successfully disconnected from the MQTT server")
    except:
        pass
    sys.exit(0)

# This decorator registers the function with the SignalHandler blocks_on so the SignalHandler knows
# when the function is running
#@cleanup_and_exit.blocks_on
def check(s):
    """Gets the current state of the passed in sensor and publishes it"""
    s.check_state()

def main():
    """Polls the sensor pins and publishes any changes"""

    if len(sys.argv) < 2:
        print "No config file specified on the command line!"
        sys.exit(1)


    config_loader = ConfigLoader(sys.argv[1])
    logger = config_loader.config_logger()
    loaded_sensors = config_loader.load_config(logger)

    for s in loaded_sensors:
        s.lastPoll = time.time()

    logger.debug("Kicking off polling threads...")
    while True:

        # Kick off a poll of the sensor in a separate process
        for s in loaded_sensors:
            if s.poll > 0 and (time.time() - s.lastPoll) > s.poll:
                s.lastPoll = time.time()
                Thread(target=check, args=(s,)).start()

        time.sleep(0.5) # give the processor a chance if REST is being slow

if __name__ == "__main__":
    main()