python实战--Http代理服务器
fmwg
10年前
最近打算好好深入研究下python的socket编程， 于是打算学习下，仿写了一下，发现写好还真不容易，中途出现很多问题，果真是看的容易，做起来难啊
import socket import thread import urlparse import select BUFLEN=8192 class Proxy(object): def __init__(self,conn,addr): self.source=conn self.request="" self.headers={} self.destnation=socket.socket(socket.AF_INET,socket.SOCK_STREAM) self.run() def get_headers(self): header='' while True: header+=self.source.recv(BUFLEN) index=header.find('\n') if index >0: break #firstLine,self.request=header.split('\r\n',1) firstLine=header[:index] self.request=header[index+1:] self.headers['method'],self.headers['path'],self.headers['protocol']=firstLine.split() def conn_destnation(self): url=urlparse.urlparse(self.headers['path']) hostname=url[1] port="80" if hostname.find(':') >0: addr,port=hostname.split(':') else: addr=hostname port=int(port) ip=socket.gethostbyname(addr) print ip,port self.destnation.connect((ip,port)) data="%s %s %s\r\n" %(self.headers['method'],self.headers['path'],self.headers['protocol']) self.destnation.send(data+self.request) print data+self.request def renderto(self): readsocket=[self.destnation] while True: data='' (rlist,wlist,elist)=select.select(readsocket,[],[],3) if rlist: data=rlist[0].recv(BUFLEN) if len(data)>0: self.source.send(data) else: break def run(self): self.get_headers() self.conn_destnation() self.renderto() class Server(object): def __init__(self,host,port,handler=Proxy): self.host=host self.port=port self.server=socket.socket(socket.AF_INET,socket.SOCK_STREAM) self.server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) self.server.bind((host,port)) self.server.listen(5) self.handler=handler def start(self): while True: try: conn,addr=self.server.accept() thread.start_new_thread(self.handler,(conn,addr)) except: pass if __name__=='__main__': s=Server('127.0.0.1',8080) s.start() import socket import thread import urlparse import select BUFLEN=8192 class Proxy(object): def __init__(self,conn,addr): self.source=conn self.request="" self.headers={} self.destnation=socket.socket(socket.AF_INET,socket.SOCK_STREAM) self.run() def get_headers(self): header='' while True: header+=self.source.recv(BUFLEN) index=header.find('\n') if index >0: break #firstLine,self.request=header.split('\r\n',1) firstLine=header[:index] self.request=header[index+1:] self.headers['method'],self.headers['path'],self.headers['protocol']=firstLine.split() def conn_destnation(self): url=urlparse.urlparse(self.headers['path']) hostname=url[1] port="80" if hostname.find(':') >0: addr,port=hostname.split(':') else: addr=hostname port=int(port) ip=socket.gethostbyname(addr) print ip,port self.destnation.connect((ip,port)) data="%s %s %s\r\n" %(self.headers['method'],self.headers['path'],self.headers['protocol']) self.destnation.send(data+self.request) print data+self.request def renderto(self): readsocket=[self.destnation] while True: data='' (rlist,wlist,elist)=select.select(readsocket,[],[],3) if rlist: data=rlist[0].recv(BUFLEN) if len(data)>0: self.source.send(data) else: break def run(self): self.get_headers() self.conn_destnation() self.renderto() class Server(object): def __init__(self,host,port,handler=Proxy): self.host=host self.port=port self.server=socket.socket(socket.AF_INET,socket.SOCK_STREAM) self.server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) self.server.bind((host,port)) self.server.listen(5) self.handler=handler def start(self): while True: try: conn,addr=self.server.accept() thread.start_new_thread(self.handler,(conn,addr)) except: pass if __name__=='__main__': s=Server('127.0.0.1',8080) s.start() 其实Http代理服务器本身不难，但写出来还是挺费事的，这里就不细说源代码了，很简单。主要说说，我遇到的问题。
一： 我本来只知道，thread.start_new_thread的第一个参数是函数对象，但当我看到上面的博文时，心里一愣，这样也可以，于是我迅速的测试了一下：
import thread class Hello: def __init__(self,content): print content def cs(): thread.start_new_thread(Hello, ("Hello World",)) if __name__=='__main__': cs() import thread class Hello: def __init__(self,content): print content def cs(): thread.start_new_thread(Hello, ("Hello World",)) if __name__=='__main__': cs() Unhandled exception in thread started by
Error in sys.excepthook:
Original exception was:
Unhandled exception in thread started by
Error in sys.excepthook:
Original exception was:
一看，我说嘛，第一个参数怎么可以是对象，我呵呵一笑，稍微鄙视了一下作者。于是，我洗洗睡了，第二天，我还是不死心，于是把代码下下来，本地实验了一下，可以的，立马意识到是我2了，于是立马百度。
原来thread模块中，主线程如果比子线程先结束，就会抛出这个异常，所以我们必须让子线程先结束，最简单的方法就是让主线程sleep足够长的时间，至于多长时间，貌似不知道，那到底怎么解决呢？
比较好的解决办法就是，主线程给每个子线程都加一把锁，子线程在结束前将锁释放掉，主线程一直循环检查锁的状态。代码如下：
import thread class Hello: def __init__(self,content,lock): print content """ do something .... At the end,release the lock """ lock.release() def cs(): lock=thread.allocate_lock() lock.acquire() thread.start_new_thread(Hello, ("Hello World",lock)) while True: if not lock.locked(): break print "lock release" if __name__=='__main__': cs() import thread class Hello: def __init__(self,content,lock): print content """ do something .... At the end,release the lock """ lock.release() def cs(): lock=thread.allocate_lock() lock.acquire() thread.start_new_thread(Hello, ("Hello World",lock)) while True: if not lock.locked(): break print "lock release" if __name__=='__main__': cs() 二.第二个错误就是比较2的了
self.source.send[data]
peError: 'builtin_function_or_method' object is unsubscriptable
self.source.send[data]
TypeError: 'builtin_function_or_method' object is unsubscriptable
主要意思就是说，内置函数或方法无法拥有下标，你懂的