带有twistd插件的UDP服务器

Question

我正在尝试添加 UDP 套接字服务器，监听 NB-IoT 设备。我之前的工作经验只针对 TCP 套接字。

EpicGpsUdpServer.py

#!/usr/bin/env python
#coding: utf-8

from __future__ import print_function

import getopt
import os
import sys
import string
import struct
import binascii
import time
import uuid

from twisted.internet.protocol import DatagramProtocol
from twisted.internet import protocol, reactor, defer
from twisted.python import log
from twisted.enterprise import adbapi


class GpsPro(DatagramProtocol):

    def datagramReceived(self, data, addr):
        print("[Peer]{}:{}".format(addr[0], addr[1]))
        print("[Data]{}".format(data))
        if data:
            self.transport.write(data, addr)            

    # def makeConnection(self, data):
    #     pass

class GpsProFactory(protocol.Factory):
    def buildProtocol(self, addr):
        return GpsPro()

def main():
    log.startLogging(sys.stdout)
    reactor.listenUDP(5863, GpsPro())
    #reactor.listenUDP(5863, GpsProFactory())
    reactor.run()

if __name__ == "__main__":
    main()

为了使用twistd来运行它。我加了

EpicGpsUdpServer_plugin.py

from zope.interface import implements
from twisted.application.service import IServiceMaker
from twisted.application import internet
from twisted.plugin import IPlugin
from twisted.python import usage
#from EpicGlinkUdpServer import GpsFactory
from EpicGpsUdpServer import GpsPro

class Options(usage.Options):
    optParameters = [["port","p", 5863, "The port number to listen on."]]

class GpsServiceMaker(object):
    implements(IServiceMaker, IPlugin)
    tapname = "Gps"
    description = "A UDP-based GPS server."
    options = Options

    def makeService(self, options):
        #return internet.UDPServer(int(options["port"]), GpsFactory)
        return internet.UDPServer(int(options["port"]), GpsPro)

serviceMaker = GpsServiceMaker()    

如果我运行“twistd --help”，Gps 将被列为子命令。如果我运行“twistd Gps”，那么它会抛出如下错误：

2018-03-14 14:16:41+0800 Log opened.
2018-03-14 14:16:41+0800 twistd 15.0.0 (/usr/bin/python 2.7.3) starting up.
2018-03-14 14:16:41+0800 reactor class: twisted.internet.epollreactor.EPollReactor.
2018-03-14 14:16:41+0800 Traceback (most recent call last):
2018-03-14 14:16:41+0800   File "/usr/local/bin/twistd", line 5, in <module>
2018-03-14 14:16:41+0800     pkg_resources.run_script('Twisted==15.0.0', 'twistd')
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 748, in run_script
2018-03-14 14:16:41+0800     self.require(requires)[0].run_script(script_name, ns)
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 1517, in run_script
2018-03-14 14:16:41+0800     exec(code, namespace, namespace)
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/EGG-INFO/scripts/twistd", line 14, in <module>
2018-03-14 14:16:41+0800     run()
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/scripts/twistd.py", line 27, in run
2018-03-14 14:16:41+0800     app.run(runApp, ServerOptions)
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/application/app.py", line 645, in run
2018-03-14 14:16:41+0800     runApp(config)
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/scripts/twistd.py", line 23, in runApp
2018-03-14 14:16:41+0800     _SomeApplicationRunner(config).run()
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/application/app.py", line 383, in run
2018-03-14 14:16:41+0800     self.postApplication()
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/scripts/_twistd_unix.py", line 193, in postApplication
2018-03-14 14:16:41+0800     self.startApplication(self.application)
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/scripts/_twistd_unix.py", line 381, in startApplication
2018-03-14 14:16:41+0800     service.IService(application).privilegedStartService()
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/application/service.py", line 275, in privilegedStartService
2018-03-14 14:16:41+0800     service.privilegedStartService()
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/application/internet.py", line 105, in privilegedStartService
2018-03-14 14:16:41+0800     self._port = self._getPort()
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/application/internet.py", line 133, in _getPort
2018-03-14 14:16:41+0800     'listen%s' % (self.method,))(*self.args, **self.kwargs)
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/internet/posixbase.py", line 373, in listenUDP
2018-03-14 14:16:41+0800     p = udp.Port(port, protocol, interface, maxPacketSize, self)
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/internet/udp.py", line 114, in __init__
2018-03-14 14:16:41+0800     self.setLogStr()
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/internet/udp.py", line 364, in setLogStr
2018-03-14 14:16:41+0800     logPrefix = self._getLogPrefix(self.protocol)
2018-03-14 14:16:41+0800   File "/usr/local/lib/python2.7/dist-packages/Twisted-15.0.0-py2.7-linux-i686.egg/twisted/internet/abstract.py", line 143, in _getLogPrefix
2018-03-14 14:16:41+0800     return applicationObject.__class__.__name__
2018-03-14 14:16:41+0800 AttributeError: class GpsPro has no attribute '__class__'

问题

对不起，UDP服务器带来了很多问题，我想澄清一下。

1. 我的协议的 class 属性是什么？
2. UDP 服务器协议是否支持工厂？由于 TCP 服务器确实支持工厂，我尝试了但我得到了一些额外的错误。在 DNS 服务器中，扭曲的文档显示它有工厂，但我找不到原始 UDP 套接字的参考代码。
3. 虽然UDP服务器不是面向连接的，但是服务器可以用peer ip:port在短时间内写回，1分钟内，在NBIoT设备中，大约20秒。但由于没有工厂，代码无处保存上下文，就像 TCP 连接中的对应物一样。

任何简单的代码/项目都会有所帮助。谢谢。

Answer 1

我的协议的__class__ 属性是什么？

如果你有一个类Foo，那么Foo().__class__ 就是Foo。发生此错误是因为您将 GpsPro 而不是 GpsPro() 传递给 internet.UDPServer。

UDP 服务器协议是否支持工厂？由于 TCP 服务器确实支持工厂，我尝试了但我得到了一些额外的错误。在 DNS 服务器中，扭曲的文档显示它有工厂，但我找不到原始 UDP 套接字的参考代码。

Twisted 的 UDP 不适用于工厂。您只需使用协议实例。

虽然 UDP 服务器不是面向连接的，但是服务器可以在短时间内用 peer ip:port 写回，1 分钟内，在 NBIoT 设备中，大约 20 秒。但由于没有工厂，代码无处保存上下文，就像 TCP 连接中的对应物一样。

您可以在协议实例上为此创建必要的状态。