Python folder network transmission source code based on Twisted framework

Since a folder may have multiple levels of directories, it needs to be traversed recursively.

This article adopts a simple protocol customization and defines five commands. The command Head is as follows:
Sync: identifies the start synchronization folder
End: identifies the end of synchronization
File: identifies the transferred file Name (relative path)
Folder: Flag folder (relative path)
None: File content

Each command starts with CMB_BEGIN and ends with CMB_END.

The client needs to parse the receiving buffer, take out the instructions one by one, and then perform corresponding processing according to the Head of the instruction, such as creating folders, writing files, etc.

The following is the server code:

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()

After Server receives a signal from Client (in this code, when Client sends any content to Server, Server will call send_file_folder sends all the contents of the sever folder to the client.

The running results of the server are as follows:

The following is the code of the client:

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()

The client extracts the instructions from the Server. When the Sync command is extracted, the sourceDir directory is cleared, and then synchronized with the Server folder according to subsequent instructions.

The client running results are as follows:

Things to note:
When Client writes a file, it needs to open the file in binary mode, otherwise , errors may occur when transferring binary files or cause file corruption.

After testing, the code can run normally, folder synchronization is successful, and text files, images and other types of binary files can be transferred normally.

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