使用Twisted Python的UDP客戶端和服務器

Question

我想創建一個服務器和客戶端，使用Twisted從網絡發送和接收UDP數據包。 我已經用Python中的套接字編寫了這個，但是想要利用Twisted的回調和線程功能。 但是，我需要幫助設計Twisted。

我有多種類型的包我想收到，但讓我們假裝只有一個：

class Packet(object):
    def __init__(self, data=None):
        self.packet_type = 1
        self.payload = ''
        self.structure = '!H6s'
        if data == None:
            return

        self.packet_type, self.payload = struct.unpack(self.structure, data)

    def pack(self):
        return struct.pack(self.structure, self.packet_type, self.payload)

    def __str__(self):
        return "Type: {0}\nPayload {1}\n\n".format(self.packet_type, self.payload)

我制作了一個協議類（幾乎是示例的直接副本），當我從另一個程序發送數據時，這似乎有效：

class MyProtocol(DatagramProtocol):
    def datagramReceived(self, data, (host, port)):
        p = Packet(data)
        print p

reactor.listenUDP(3000, MyProtocol())
reactor.run()

我不知道的是我如何創建一個可以在網絡上發送任意數據包的客戶端，這些數據包會被反應堆接收：

# Something like this:
s = Sender()
p = Packet()
p.packet_type = 3
s.send(p.pack())
p.packet_type = 99
s.send(p.pack())

我還需要確保在客戶端和服務器上設置重用地址標志，以便我可以在同一設備上同時運行每個實例的多個實例（例如，一個腳本發送心跳，另一個腳本響應心跳等）。

有人能告訴我如何用Twisted完成這項工作嗎？

更新 ：

這就是我在Python中使用套接字的方法。 我可以同時運行多個聽眾和發送者，他們都會互相聽到。 如何使用Twisted獲得此結果？ （聽力部分不必是一個單獨的過程。）

class Listener(Process):
    def __init__(self, ip='127.0.0.1', port=3000):
        Process.__init__(self)
        self.ip = ip
        self.port = port

    def run(self):
        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        sock.bind((self.ip, self.port))

        data, from_ip = sock.recvfrom(4096)
        p = Packet(data)
        print p

class Sender(object):
    def __init__(self, ip='127.255.255.255', port=3000):
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.ip = (ip, port)

    def send(self, data):
        self.sock.sendto(data, self.ip)

if __name__ == "__main__":
    l = Listener()
    l.start()
    s = Sender()
    p = Packet()
    p.packet_type = 4
    p.payload = 'jake'
    s.send(p.pack())

工作方案 ：

class MySender(DatagramProtocol):
    def __init__(self, packet, host='127.255.255.255', port=3000):
        self.packet = packet.pack()
        self.host = host
        self.port = port

    def startProtocol(self):
        self.transport.write(self.packet, (self.host, self.port))

if __name__ == "__main__":
    packet = Packet()
    packet.packet_type = 1
    packet.payload = 'jake'

    s = MySender(packet)

    reactor.listenMulticast(3000, MyProtocol(), listenMultiple=True)
    reactor.listenMulticast(3000, s, listenMultiple=True)
    reactor.callLater(4, reactor.stop)
    reactor.run()

Answer 1

就像上面的服務器示例一樣，有一個客戶端示例。 這應該可以幫助您入門：

• https://twistedmatrix.com/documents/current/core/howto/udp.html
• https://github.com/twisted/twisted/blob/trunk/docs/core/examples/echoclient_udp.py

好的，這是一個簡單的心跳發送器和接收器使用數據報協議。

from twisted.internet.protocol import DatagramProtocol
from twisted.internet import reactor
from twisted.internet.task import LoopingCall
import sys, time

class HeartbeatSender(DatagramProtocol):
    def __init__(self, name, host, port):
        self.name = name
        self.loopObj = None
        self.host = host
        self.port = port

    def startProtocol(self):
        # Called when transport is connected
        # I am ready to send heart beats
        self.loopObj = LoopingCall(self.sendHeartBeat)
        self.loopObj.start(2, now=False)

    def stopProtocol(self):
        "Called after all transport is teared down"
        pass

    def datagramReceived(self, data, (host, port)):
        print "received %r from %s:%d" % (data, host, port)


    def sendHeartBeat(self):
        self.transport.write(self.name, (self.host, self.port))



class HeartbeatReciever(DatagramProtocol):
    def __init__(self):
        pass

    def startProtocol(self):
        "Called when transport is connected"
        pass

    def stopProtocol(self):
        "Called after all transport is teared down"


    def datagramReceived(self, data, (host, port)):
        now = time.localtime(time.time())  
        timeStr = str(time.strftime("%y/%m/%d %H:%M:%S",now)) 
        print "received %r from %s:%d at %s" % (data, host, port, timeStr)



heartBeatSenderObj = HeartbeatSender("sender", "127.0.0.1", 8005)

reactor.listenMulticast(8005, HeartbeatReciever(), listenMultiple=True)
reactor.listenMulticast(8005, heartBeatSenderObj, listenMultiple=True)
reactor.run()

廣播示例只是修改了上述方法：

from twisted.internet.protocol import DatagramProtocol
from twisted.internet import reactor
from twisted.internet.task import LoopingCall
import sys, time

class HeartbeatSender(DatagramProtocol):
    def __init__(self, name, host, port):
        self.name = name
        self.loopObj = None
        self.host = host
        self.port = port

    def startProtocol(self):
        # Called when transport is connected
        # I am ready to send heart beats
        self.transport.joinGroup('224.0.0.1')
        self.loopObj = LoopingCall(self.sendHeartBeat)
        self.loopObj.start(2, now=False)

    def stopProtocol(self):
        "Called after all transport is teared down"
        pass

    def datagramReceived(self, data, (host, port)):
        print "received %r from %s:%d" % (data, host, port)


    def sendHeartBeat(self):
        self.transport.write(self.name, (self.host, self.port))



class HeartbeatReciever(DatagramProtocol):
    def __init__(self, name):
        self.name = name

    def startProtocol(self):
        "Called when transport is connected"
        self.transport.joinGroup('224.0.0.1')
        pass

    def stopProtocol(self):
        "Called after all transport is teared down"


    def datagramReceived(self, data, (host, port)):
        now = time.localtime(time.time())  
        timeStr = str(time.strftime("%y/%m/%d %H:%M:%S",now)) 
        print "%s received %r from %s:%d at %s" % (self.name, data, host, port, timeStr)



heartBeatSenderObj = HeartbeatSender("sender", "224.0.0.1", 8005)

reactor.listenMulticast(8005, HeartbeatReciever("listner1"), listenMultiple=True)
reactor.listenMulticast(8005, HeartbeatReciever("listner2"), listenMultiple=True)
reactor.listenMulticast(8005, heartBeatSenderObj, listenMultiple=True)
reactor.run()

Answer 2

查看echoclient_udp.py示例。

由於UDP在客戶端和服務器之間非常對稱，您只需要在那里運行reactor.listenUDP ， connect到服務器（實際上只設置發送數據包的默認目標），然后transport.write來發送數據包。