1

#!/usr/bin/env python

     2

# -*- coding: utf-8 -*-

     3

     4

# See COPYING file for copyrights details.

     5

     6

import weakref

     7

from zeroconf import ServiceBrowser, Zeroconf, get_all_addresses

     8

import threading

     9

    10

service_type = '_Beremiz._tcp.local.'

    11

    12

class ZeroConfListenerClass:

    13

    def __init__(self, dialog):

    14

        self.dialog = weakref.ref(dialog)

    15

    16

        self.IfacesMonitorState = None

    17

        self.IfacesMonitorTimer = None

    18

        self.Browser = None

    19

        self.ZeroConfInstance = None

    20

        self.PublishedServices = set()

    21

    22

        self.start()

    23

    24

    def __del__(self):

    25

        self.stop()

    26

    27

    def start(self):

    28

        self.ZeroConfInstance = Zeroconf()

    29

        self.Browser = ServiceBrowser(self.ZeroConfInstance, service_type, self)

    30

        # Start the ifaces_monitor timer thread

    31

        self.IfacesMonitorTimer = threading.Timer(1.0, self.ifaces_monitor)

    32

        self.IfacesMonitorTimer.start()

    33

    34

    def stop(self):

    35

        if self.IfacesMonitorTimer is not None:

    36

            self.IfacesMonitorTimer.cancel()

    37

            self.IfacesMonitorTimer = None

    38

    39

        if self.Browser is not None:

    40

            self.Browser.cancel()

    41

            self.Browser = None

    42

    43

        if  self.ZeroConfInstance is not None:

    44

            self.ZeroConfInstance.close()

    45

            self.ZeroConfInstance = None

    46

    47

    def update_service(self, zeroconf, _type, name):

    48

        self.remove_service(zeroconf, _type, name)

    49

        self.add_service(zeroconf, _type, name)

    50

    51

    def add_service(self, zeroconf, _type, name):

    52

        dialog = self.dialog()

    53

        if not dialog:

    54

            return

    55

    56

        info = self.ZeroConfInstance.get_service_info(_type, name)

    57

        if info is None:

    58

            return

    59

    60

        typename = info.properties.get(b"protocol", None).decode()

    61

        ip = str(info.parsed_addresses()[0])

    62

        port = info.port

    63

        dialog.addService(typename, ip, port, name)

    64

        self.PublishedServices.add(name)

    65

    66

    def remove_service(self, zeroconf, _type, name):

    67

        dialog = self.dialog()

    68

        if not dialog:

    69

            return

    70

    71

        if name in self.PublishedServices:

    72

            dialog.removeService(name)

    73

            self.PublishedServices.discard(name)

    74

    75

    def ifaces_monitor(self):

    76

        dialog = self.dialog()

    77

        if not dialog:

    78

            return

    79

    80

        NewState = get_all_addresses()

    81

        OldState = self.IfacesMonitorState

    82

        self.IfacesMonitorState = NewState

    83

        do_restart = False

    84

    85

        if OldState is not None:

    86

            # detect if a new address appeared

    87

            for addr in NewState:

    88

                if addr not in OldState:

    89

                    do_restart = True

    90

                    break

    91

                else:

    92

                    OldState.remove(addr)

    93

            # detect if an address disappeared

    94

            if len(OldState) > 0:

    95

                do_restart = True

    96

    97

    98

        if do_restart:

    99

            self.stop()

   100

   101

            while self.PublishedServices:

   102

                dialog.removeService(self.PublishedServices.pop())

   103

   104

            self.start()

   105

        else:

   106

            # Restart the ifaces_monitor timer thread

   107

            self.IfacesMonitorTimer = threading.Timer(1.0, self.ifaces_monitor)

   108

            self.IfacesMonitorTimer.start()