event.py

#!/usr/bin/env python
##
## This file is part of the OpenSIPS Python Package
## (see https://github.com/OpenSIPS/python-opensips).
##
## This program is free software: you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program. If not, see <http://www.gnu.org/licenses/>.
##


""" Module that implements OpenSIPS Event behavior """

from threading import Thread, Event
from ..mi import OpenSIPSMIException

class OpenSIPSEventException(Exception):
    """ Exceptions generated by OpenSIPS Events """

class OpenSIPSEvent():

    """ Implementation of the OpenSIPS Event """

    def __init__(self, handler, name: str, callback, expire=None):
        self._handler = handler
        self.name = name
        self.callback = callback
        self.thread = None
        self.thread_stop = Event()
        self.thread_stop.clear()

        try:
            self.socket = self._handler.__new_socket__()
            self._handler.__mi_subscribe__(self.name, self.socket.create(), expire)
            self._handler.events[self.name] = self
            self.thread = Thread(target=self.handle, args=(callback,))
            self.thread.start()
        except OpenSIPSEventException as e:
            raise e
        except OpenSIPSMIException as e:
            raise e
        except ValueError as e:
            raise OpenSIPSEventException("Invalid arguments for socket creation: {}".format(e))

    def handle(self, callback):
        """ Handles the event callbacks """
        while not self.thread_stop.is_set():
            data = self.socket.read()
            if data:
                callback(data)

    def unsubscribe(self):
        """ Unsubscribes the event """
        try:
            self._handler.__mi_unsubscribe__(self.name, self.socket.sock_name)
            self.stop()
            del self._handler.events[self.name]
        except OpenSIPSEventException as e:
            raise e
        except OpenSIPSMIException as e:
            raise e

    def stop(self):
        """ Stops the current event processing """
        self.thread_stop.set()
        self.thread.join()
        self.socket.destroy()