asyncore : Python裡面的非同步Socket

 

MFC裡面有個Class叫做CAsyncsocket, 它是用實作非同步的socket.

在實際的應用裡面, 一個應用程式很少會固定等待socket連線, 或是傳送資料, 通常都是在突然的情況下一個socket要進行連線, 或是要傳送資料. 所以非同步的socket的好處就在這裡, 你可以指定在socket發生連線或是傳送資料的時候進行某個動作, 而CAsyncsocket就是把這樣的非同步行為包成一個class讓我們只要繼承它就能達到這樣的效果.

而在Python裡面也有個 非同步的module叫做asyncore. 我們實作的socket只要繼承asyncore.dispatcher就能進行非同步的 socket運作.

下面就有Client和Server的範例code, 主要用途在於Client能連上Server, 然後Client和Server之間就能進行非同步的溝通, Client可以輸入訊息給Server, Server也能輸入訊息給Client.

Server 程式 :

# -*- coding: cp950 -*-import socketimport asyncoreimport threadingMAX_RECV = 4096#負責接受client socket連線class AgentServer(asyncore.dispatcher):      def __init__(self, port):       #asyncore.dispatcher的constructor       asyncore.dispatcher.__init__(self)       #client socket       self.clientSocket = None       #server port       self.port = port       #建立等待的socket       self.create_socket(socket.AF_INET, socket.SOCK_STREAM)       self.bind(('', self.port))       self.listen(5)     def handle_accept(self):       #接受client socket的連線       self.clientSocket, address = self.accept()       print 'New client from : ' + address[0]       #將和client連線的socket加上一些功能 (自訂socket)       self.clientSocket = ClientAgent(self.clientSocket)#自訂的client連線socketclass ClientAgent(asyncore.dispatcher):   def __init__(self, socket):       asyncore.dispatcher.__init__(self, socket)       #要送出的data       self.SendData = ""   #從client收到的data   def handle_read(self):       self.RecvData = self.recv(MAX_RECV)       if len(self.RecvData) > 0:           print "recv : " + self.RecvData   #送出data到client   def handle_write(self):       send_byte = self.send(self.SendData)       #一次可能不會全部送完(一次最多送出512 bytes ?)       if send_byte > 0:           send_out = self.SendData[:send_byte]           self.SendData = self.SendData[send_byte:]           self.handle_write()       else:           print "send all!!"           self.SendData = ""   #不自動執行handle_write   def writable(self):       return False     def handle_close(self):       print "close connection : " + self.getpeername()[0]       self.close()#產生等待client連線的threadclass listen_client_thread(threading.Thread):   def __init__(self,port):       self.agentServer = AgentServer(port)       threading.Thread.__init__ ( self )         def run(self):       print "Listen Client ..."       asyncore.loop()#產生處理輸入的thread       class input_thread(threading.Thread):   def __init__(self,listen_thread):       self.listen_thread = listen_thread       threading.Thread.__init__ ( self )   def run(self):       while 1:           send_data = raw_input()           self.listen_thread.agentServer.clientSocket.SendData = send_data           self.listen_thread.agentServer.clientSocket.handle_write()if __name__ == "__main__":   #產生等待client連線的thread   listen_thread = listen_client_thread(111)   listen_thread.start()   #產生處理輸入的thread   input_thread(listen_thread).start()Client 程式 :# -*- coding: cp950 -*-import asyncore, socketimport threading#收到data最大長度MAX_RECV = 4096#連線server的socketclass client(asyncore.dispatcher):   def __init__(self, host, port):       asyncore.dispatcher.__init__(self)       self.SendData = ""       self.RecvData = ""       #和server建立連線       self.create_socket(socket.AF_INET, socket.SOCK_STREAM)       self.connect( (host, port) )   def handle_connect(self):       print 'connect!!'   def handle_close(self):       print "disconnection : " + self.getpeername()[0]       self.close()   #收到的data   def handle_read(self):       self.RecvData = self.recv(MAX_RECV)       if len(self.RecvData) > 0:           print "recv : " + self.RecvData   #送出data   def handle_write(self):       send_byte = self.send(self.SendData)       if send_byte > 0:           send_out = self.SendData[:send_byte]           self.SendData = self.SendData[send_byte:]           print "send : " + send_out           self.handle_write()       else:           print "send all!!"           self.SendData = ""   #自動偵測送出永遠失敗   def writable(self):       return False  #等待server傳送訊息的threadclass send_server_thread(threading.Thread):   def __init__(self,host,port):       self.client = client(host, port)       threading.Thread.__init__ ( self )   def run(self):       try:           asyncore.loop()       except:           pass#等待user input的thread       class input_thread(threading.Thread):   def __init__(self,client_thread):       self.client_thread = client_thread       threading.Thread.__init__ ( self )   def run(self):       while 1:           send_data = raw_input()           self.client_thread.client.SendData = send_data           self.client_thread.client.handle_write()#主程式if __name__ == "__main__":   #建立和server連線, 並且等待溝通   client_thread = send_server_thread("localhost",111)   client_thread.start()   #等待user input   input_thread(client_thread).start()