Python 基於Twisted框架的資料夾網路傳輸原始碼

由於資料夾可能有多層目錄，因此需要對其進行遞歸遍歷。

本文採取了簡單的協議定制，定義了五條命令，指令Head如下：
Sync：標識開始同步文件夾
End：標識結束同步
File：標識傳輸的文件名（相對路徑）
Folder：標誌文件夾（相對路徑）
None：檔案內容

每個指令以CMB_BEGIN開始，以CMB_END結束。

客戶端需要對接收緩衝做解析，取出一條一條的指令，然後根據指令的Head做對應的處理，例如建立資料夾、寫入檔案等。

下面是服務端的程式碼：

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的某個訊號之後(此程式碼中，當Client隨便向Server發送任何內容都可)，Server即會呼叫send_file_folder將sever資料夾下的內容全部發送給客戶端。

服務端運作結果如下：

下面是客戶端的程式碼：

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()

客戶端提取出來自Server的指令，當提取出Sync指令時，則將sourceDir目錄清空，然後根據後續的指令跟Server的資料夾進行同步。

客戶端運行結果如下：

需要注意的地方：
Client寫入文件時，需要以二進制的方式打開文件，否則，在傳輸二進位時可能出現錯誤或導致文件損壞。

經過測試，程式碼可以正常的運行，資料夾同步成功，文字檔案、圖像和其他類型的二進位檔案均可正常傳輸。

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