pyudev Twisted integration

import pyudev
from twisted.internet import abstract

class UDevMonitor(abstract.FileDescriptor):
    """
    Protocol wrapper for pyudev.Monitor.

    @see: U{http://packages.python.org/pyudev/api/monitor.html}.
    """

    def __init__(self, reactor, protocol, subsystem=None, deviceType=None):
        abstract.FileDescriptor.__init__(self, reactor)

        # Set up monitor
        context = pyudev.Context()
        self.monitor = pyudev.Monitor.from_netlink(context)
        if subsystem:
            self.monitor.filter_by(subsystem=subsystem, device_type=deviceType)

        # Connect protocol
        self.protocol = protocol
        self.protocol.makeConnection(self)


    def fileno(self):
        """
        Return monitor's file descriptor.
        """
        return self.monitor.fileno()


    def startReading(self):
        """
        Start waiting for read availability.
        """
        self.monitor.start()
        abstract.FileDescriptor.startReading(self)


    def doRead(self):
        """
        An event is ready, decode it through Monitor and call our protocol.
        """
        event = self.monitor.receive_device()
        if event:
            action, device = event
            self.protocol.eventReceived(action, device)