Python 基于Twisted框架的文件夹网络传输源码

由于文件夹可能有多层目录，因此需要对其进行递归遍历。

本文采取了简单的协议定制，定义了五条命令，指令Head如下：
Sync：标识开始同步文件夹
End：标识结束同步
File：标识传输的文件名（相对路径）
Folder：标志文件夹（相对路径）
None：文件内容

每条命令以CMB_BEGIN开始，以CMB_END结束。

客户端需要对接收缓冲做解析，取出一条一条的指令，然后根据指令的Head做相应的处理，比如创建文件夹、写入文件等。

下面是服务端的代码：

    from twisted.internet import reactor
    from twisted.internet.protocol import Protocol,Factory
    from twisted.protocols.basic import LineReceiver
    import os
    import struct

    BUFSIZE = 4096

    class SimpleLogger(Protocol):
      def connectionMade(self):
        print 'Got connection from', self.transport.client

      def connectionLost(self, reason):
        print self.transport.client, 'disconnected'

      def dataReceived(self, line):
        print line
        self.transport.write("Hello Client, I am the Server!\r\n")

        self.transport.write("CMB_BEGIN")
        self.transport.write("Sync")
        self.transport.write("CMB_END")
        self.send_file_folder('server')

      def send_file_folder(self,folder):
        '''send folder to the client'''
        for f in os.listdir(folder):
          sourceF = os.path.join(folder, f)
          if os.path.isfile(sourceF):      
            print 'File:',sourceF[7:]
            self.transport.write("CMB_BEGIN")
            self.transport.write("File:" + sourceF[7:])
            self.transport.write("CMB_END")
            fp = open(sourceF,'rb')
            while 1:
              filedata = fp.read(BUFSIZE)
              if not filedata: break
              else:
                self.transport.write("CMB_BEGIN")
                self.transport.write(filedata)
                print 'send size:::::::::',len(filedata)
                self.transport.write("CMB_END")
            fp.close()
            self.transport.write("CMB_BEGIN")
            self.transport.write("End")
            self.transport.write("CMB_END")
          if os.path.isdir(sourceF):
            print 'Folder:',sourceF[7:]
            self.transport.write("CMB_BEGIN")
            self.transport.write("Folder:" + sourceF[7:])
            self.transport.write("CMB_END")
            self.send_file_folder(sourceF)

    factory = Factory()
    factory.protocol = SimpleLogger
    reactor.listenTCP(1234, factory)
    reactor.run()

Server在收到Client的某个信号之后(此代码中，当Client随便向Server发送任何内容都可)，Server即会调用send_file_folder将sever文件夹下的内容全部发送给客户端。

服务端运行结果如下：

下面是客户端的代码：

    from twisted.internet.selectreactor import SelectReactor
    from twisted.internet.protocol import Protocol,ClientFactory
    from twisted.protocols.basic import LineReceiver
    import os
    from struct import *

    reactor = SelectReactor()
    protocol = Protocol()
    prepare = 0
    filename = ""
    sourceDir = 'client'
    recvBuffer = ''

    def delete_file_folder(src):
      '''delete files and folders'''
      if os.path.isfile(src):
        try:
          os.remove(src)
        except:
          pass
      elif os.path.isdir(src):
        for item in os.listdir(src):
          itemsrc = os.path.join(src,item)
          delete_file_folder(itemsrc) 
        try:
          os.rmdir(src)
        except:
          pass

    def clean_file_folder(src):
      '''delete files and child folders'''
      delete_file_folder(src)
      os.mkdir(src)

    def writefile(filename,data):
      print 'write file size:::::::::',len(data)
      fp = open(filename,'a+b')
      fp.write(data)
      fp.close()

    class QuickDisconnectedProtocol(Protocol):
      def connectionMade(self):
        print "Connected to %s."%self.transport.getPeer().host
        self.transport.write("Hello server, I am the client!\r\n")
      def dataReceived(self, line):
        global prepare
        global filename
        global sourceDir
        global recvBuffer

        recvBuffer = recvBuffer + line
        self.processRecvBuffer()

      def processRecvBuffer(self):
        global prepare
        global filename
        global sourceDir
        global recvBuffer

        while len(recvBuffer) > 0 :
          index1 = recvBuffer.find('CMB_BEGIN')
          index2 = recvBuffer.find('CMB_END')

          if index1 >= 0 and index2 >= 0:
            line = recvBuffer[index1+9:index2]
            recvBuffer = recvBuffer[index2+7:]

            if line == 'Sync':
              clean_file_folder(sourceDir)

            if line[0:3] == "End":
              prepare = 0
            elif line[0:5] == "File:":
              name = line[5:]
              filename = os.path.join(sourceDir, name)
              print 'mk file:',filename
              prepare = 1
            elif line[0:7] == "Folder:":
              name = line[7:]
              filename = os.path.join(sourceDir, name)
              print 'mkdir:',filename
              os.mkdir(filename)
            elif prepare == 1:
              writefile(filename,line)
          else:
            break 

    class BasicClientFactory(ClientFactory):
      protocol=QuickDisconnectedProtocol
      def clientConnectionLost(self,connector,reason):
        print 'Lost connection: %s'%reason.getErrorMessage()
        reactor.stop()
      def clientConnectionFailed(self,connector,reason):
        print 'Connection failed: %s'%reason.getErrorMessage()
        reactor.stop()

    reactor.connectTCP('localhost',1234,BasicClientFactory())
    reactor.run()

客户端提取出来自Server的指令，当提取出Sync指令时，则将sourceDir目录清空，然后根据后续的指令，跟Server的文件夹进行同步。

客户端运行结果如下：

需要注意的地方：
Client写入文件时，需要以二进制的方式打开文件，否则，在传输二进制文件时可能出现错误或导致文件损坏。

经过测试，代码可以正常的运行，文件夹同步成功，文本文件、图像和其他类型的二进制文件均可正常传输。