python网络基础编程笔记(一)

import socket, traceback, os, sys, select

class stateclass:
stdmask = select.POLLERR | select.POLLHUP | select.POLLNVAL

def __init__(self, mastersock):
self.p = select.poll()
self.mastersock = mastersock
self.watchread(mastersock)
self.readbuffers = {}
self.writebuffers = {}
self.sockets = {mastersock.fileno():mastersock}
def fd2socket(self, fd):
return self.sockets[fd]
def watchread(self, fd):
self.p.register(fd, select.POLLIN | self.stdmask)
def watchwrite(self, fd):
self.p.register(fd, select.POLLOUT | self.stdmask)
def watchboth(self, fd):
self.p.register(fd, select.POLLIN | select.POLLOUT | self.stdmask)
def dontwatch(self, fd):
self.p.unregister(fd)
def sendtoall(self, text, originfd):
for line in text.split("\n"):
line = line.strip()
transmittext = str(self.fd2socket(originfd).getpeername()) + \
": " + line + "\n"
for fd in self.writebuffers.keys():
self.writebuffers[fd] += transmittext
self.watchboth(fd)

def newconn(self, sock):
fd = sock.fileno()
self.watchboth(fd)
self.writebuffers[fd] = "Welcome to the chat server, %s\n" % \
str(sock.getpeername())
self.readbuffers[fd] = ""
self.sockets[fd] = sock
def readevent(self, fd):
try:
self.readbuffers[fd] += self.fd2socket(fd).recv(4096)
except:
self.closeout(fd)
parts = self.readbuffers[fd].split("SEND")
if len(parts) < 2:
return
elif parts[-1] == '':
self.readbuffers[fd] = ""
sendlist = parts[:-1]
else:
self.readbuffers[fd] = parts[-1]
sendlist = parts[:-1]

for item in sendlist:
self.sendtoall(item.strip(), fd)
def writeevent(self, fd):
if not len(self.writebuffers[fd]):
self.watchread(fd)
return
try:
byteswritten = self.fd2socket(fd).send(self.writebuffers[fd])
except:
self.closeout(fd)
self.writebuffers[fd] = self.writebuffers[fd][byteswritten:]
if not len(self.writebuffers[fd]):
self.watchread(fd)
def errorevent(self, fd):
self.closeout(fd)
def closeout(self, fd):
self.dontwatch(fd)
try:
self.fd2socket(fd).close()
except:
pass
del self.writebuffers[fd]
del self.sockets[fd]
def loop(self):
while 1:
result = self.p.poll()
for fd, event in result:
if fd == self.mastersock.fileno() and event == select.POLLIN:
try:
newsock, addr = self.fd2socket(fd).accept()
newsock.setblocking(0)
print "Got connection from ", newsock.getpeername()
self.newconn(newsock)
except:
pass
elif event == select.POLLIN:
self.readevent(fd)
elif event == select.POLLOUT:
self.writeevent(fd)
else:
self.errorevent(fd)

host = ''
port = 51423
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.bind((host, port))
s.listen(1)
s.setblocking(0)

state = stateclass(s)
state.loop()