停止Avahi服務並返回元素列表

Question

正在關注this example我想在獲取所有元素並將其返回列表中時停止該服務。

要停止無限循環，請致電gobject.MainLoop().quit()，但不知道何時何地致電。 謝謝

Answer 1

你會想要停止服務瀏覽現在最後的服務已經到達。這將爲您提供當前可用服務的快照。

C層有一個標誌讓你可以檢查更多的服務是否即將到來。它被稱爲AVAHI_BROWSER_ALL_FOR_NOW。我對python綁定不熟悉，但也許可以在回調的stype或flags參數中以某種方式檢查此標誌嗎？

當你看到此標誌設置 - 通話gobject.MainLoop().quit()

Answer 2

你要聽AllForNow信號爲好。考慮CacheExhausted和失敗以及。 org.freedesktop.Avahi.ServiceBrowser的接口聲明爲here。

運行在我的機器返回以下約一秒鐘，打印：

browsing ... 
cache exhausted 
New service: name = Lexmark X264dn; address = 10.9.0.93; port = 80 
that's all for now 
done 
0:00:01.004258 

希望它能幫助！

---

from _dbus_glib_bindings import DBusGMainLoop 
import dbus, avahi 
import gobject 

class ServiceBrowser(): 
    def __init__(self, service): 
     loop = DBusGMainLoop(set_as_default=True) 

     bus = dbus.SystemBus(mainloop=loop) 

     self._server = dbus.Interface(bus.get_object(avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER), avahi.DBUS_INTERFACE_SERVER) 

     browser = self._server.ServiceBrowserNew(avahi.IF_UNSPEC, avahi.PROTO_INET, service, '', 0) 
     listener = dbus.Interface(bus.get_object(avahi.DBUS_NAME, browser), avahi.DBUS_INTERFACE_SERVICE_BROWSER) 

     listener.connect_to_signal("ItemNew", self.item_new_handler) 
     listener.connect_to_signal("ItemRemove", self.item_remove_handler) 
     listener.connect_to_signal("AllForNow", self.all_for_now_handler) 
     listener.connect_to_signal("CacheExhausted", self.cache_exhausted_handler) 
     listener.connect_to_signal("Failure", self.failure_handler) 

     self._mainloop = gobject.MainLoop() 


    def service_resolved(self, *args): 
     print 'New service: name = %s; address = %s; port = %s' % (args[2], args[7], args[8]) 


    def print_error(self, *args): 
     print 'error_handler' 
     print args[0] 

    def item_new_handler(self, interface, protocol, name, stype, domain, flags): 
     self._server.ResolveService(interface, protocol, name, stype, domain, avahi.PROTO_UNSPEC, dbus.UInt32(0), reply_handler=self.service_resolved, error_handler=self.print_error) 


    def item_remove_handler(self, interface, protocol, name, stype, domain, flags): 
     print "Removed service: %s" % name 


    def all_for_now_handler(self): 
     print "that's all for now" 
     self._mainloop.quit() 


    def cache_exhausted_handler(self): 
     print "cache exhausted" 


    def failure_handler(self, error): 
     print "failure: %s" % error 


    def browse(self): 
     self._mainloop.run() 


def browse_avahi(service): 
    browser = ServiceBrowser(service) 
    browser.browse() 

def main(): 
    t0 = datetime.utcnow() 
    print "browsing ..." 
    browse_avahi('_http._tcp') 
    print "done" 
    print datetime.utcnow()-t0 

if __name__ == '__main__': 
    main()