Python Twisted从TCP接收命令写入串口设备返回响应

Question

我已经成功连接了USB调制解调器，并且客户端可以通过TCP连接到我的reactor.listenTCP。调制解调器接收到的数据会发送回客户端。我想把客户端发送过来的数据再发送给调制解调器，但我在实现这个功能时遇到了困难。任何帮助都将非常感谢！以下是我的代码：

from twisted.internet import win32eventreactor
win32eventreactor.install()
from twisted.internet import reactor
from twisted.internet.serialport import SerialPort
from twisted.internet.protocol import Protocol, Factory
from twisted.python import log
import sys

log.startLogging(sys.stdout)
client_list = []#TCP clients connecting to me

class USBClient(Protocol):

    def connectionFailed(self):
        print "Connection Failed:", self
        reactor.stop()

    def connectionMade(self):
        print 'Connected to USB modem'
        USBClient.sendLine(self, 'AT\r\n')

    def dataReceived(self, data):
        print "Data received", repr(data)
        print "Data received! with %d bytes!" % len(data)
        #check & perhaps modify response and return to client
        for cli in client_list:
            cli.notifyClient(data)
        pass

    def lineReceived(self, line):
        print "Line received", repr(line)

    def sendLine(self, cmd):
        print cmd
        self.transport.write(cmd + "\r\n")

    def outReceived(self, data):
        print "outReceived! with %d bytes!" % len(data)
        self.data = self.data + data

class CommandRx(Protocol):

    def connectionMade(self):
        print 'Connection received from tcp..'
        client_list.append(self)

    def dataReceived(self, data):
        print 'Command receive', repr(data)
        #Build command, if ok, send to serial port
        #????
    def connectionLost(self, reason):
        print 'Connection lost', reason
        if self in client_list:
            print "Removing " + str(self)
            client_list.remove(self)

    def notifyClient(self, data):
        self.transport.write(data)

class CommandRxFactory(Factory):
    protocol = CommandRx
    def __init__(self):
        client_list = []

if __name__ == '__main__':
    reactor.listenTCP(8000, CommandRxFactory())
    SerialPort(USBClient(), 'COM8', reactor, baudrate='19200')
    reactor.run()

Answer 1

谢谢，我搞定了。之前无法让def notifyAll把数据发送到我的调制解调器……我这样做的：对每个客户端列表中的cli，cli.transport.write(data)
这是新代码：

import sys

from twisted.internet import reactor
from twisted.internet.protocol import Factory
from twisted.internet.protocol import Protocol
from twisted.internet.serialport import SerialPort
from twisted.python import log

log.startLogging(sys.stdout)
client_list = []#TCP clients connecting to me
usb_list = []

class USBClient(Protocol):

    def __init__(self, network):
        self.network = network
        self.usb_list = []

    def connectionFailed(self):
        print "Connection Failed:", self
        reactor.stop()

    def connectionMade(self):
        usb_list.append(self)
        print 'Connected to USB modem'
        USBClient.sendLine(self, 'AT\r\n')

    def dataReceived(self, data):
        print "Data received", repr(data)
        print "Data received! with %d bytes!" % len(data)

        for cli in client_list:
            cli.transport.write(data)
        #self.network.notifyAll(data)# !!AArgh..!Could not get this to work
        pass

    def lineReceived(self, line):
        print "Line received", repr(line)

    def sendLine(self, cmd):
        print cmd
        self.transport.write(cmd + "\r\n")

    def outReceived(self, data):
        print "outReceived! with %d bytes!" % len(data)
        self.data = self.data + data

class CommandRx(Protocol):


    def connectionMade(self):
        print 'Connection received from tcp..'
        client_list.append(self)

    def dataReceived(self, data):
        print 'Command receive', repr(data)
        for usb in usb_list:
            usb.transport.write(data)

    def connectionLost(self, reason):
        print 'Connection lost', reason
        if self in client_list:
            print "Removing " + str(self)
            client_list.remove(self)

class CommandRxFactory(Factory):
    protocol = CommandRx
    def __init__(self):
        self.client_list = []

    def notifyAll(self, data):
        for cli in self.client_list:
            cli.transport.write('yipee')

if __name__ == '__main__':

    tcpfactory = CommandRxFactory()
    reactor.listenTCP(8000, tcpfactory)
    SerialPort(USBClient(tcpfactory), '/dev/ttyUSB4', reactor, baudrate='19200')
    reactor.run()

Answer 2

你的问题其实跟Twisted没关系，而是跟Python有关。可以看看这个常见问题的解答：

如何让一个连接的输入在另一个连接上输出？

简单来说，如果你想在通过TCP连接的客户端发送数据，而你的协议是串行连接的，只需要把工厂的引用传给协议，这样你就可以用这个引用来建立连接。

下面是一些示例代码，大致展示了这个过程：

class USBClient(Protocol):
    def __init__(self, network):
        self.network = network
    def dataReceived(self, data):
        print "Data received", repr(data)
        #check & perhaps modify response and return to client
        self.network.notifyAll(data)
    #...    

class CommandRx(Protocol):
    def connectionMade(self):
        self.factory.client_list.append(self)
    def connectionLost(self, reason):
        if self in self.factory.client_list:
            self.factory.client_list.remove(self)

class CommandRxFactory(Factory):
    protocol = CommandRx
    def __init__(self):
        self.client_list = []

    def notifyAll(self, data):
        for cli in self.client_list:
            cli.transport.write(data)

在初始化时，传入这个引用：

tcpfactory = CommandRxFactory()
reactor.listenTCP(8000, tcpfactory)
SerialPort(USBClient(tcpfactory), 'COM8', reactor, baudrate='19200')
reactor.run()