src/nepi/util/server.py

   1 # -*- coding: utf-8 -*-
   2 # vim:ts=4:sw=4:et:ai:sts=4
   3 import errno
   4 import os
   5 import select
   6 import socket
   7 import sys
   8 import threading
   9
  10 CTRL_SOCK = "ctrl.sock"
  11 STD_ERR = "stderr.log"
  12 MAX_FD = 1024
  13
  14 STOP_MSG = "STOP"
  15
  16 class Server(object):
  17     def __init__(self):
  18         self.stop = False
  19         self.ctrl_sock = None
  20
  21     def run(self):
  22         if self.daemonize():
  23             self.loop()
  24             self.cleanup()
  25
  26     def daemonize(self):
  27         if True:
  28             return 1
  29
  30         pid1 = os.fork()
  31         if pid1 > 0:
  32             return 0
  33
  34         # Decouple from parent environment.
  35         #os.chdir(?)
  36         os.umask(0)
  37         os.setsid()
  38
  39         # fork 2
  40         pid2 = os.fork()
  41         if pid2 > 0:
  42             return 0
  43
  44         # close all open file descriptors.
  45         for fd in range(0, MAX_FD):
  46             try:
  47                 os.close(fd)
  48             except OSError:
  49                 pass
  50
  51         # Redirect standard file descriptors.
  52         stdout = stderr = file(STD_ERR, "a", 0)
  53         stdin = open('/dev/null', 'r')
  54         os.dup2(stdin.fileno(), sys.stdin.fileno())
  55         os.dup2(stdout.fileno(), sys.stdout.fileno())
  56         os.dup2(stderr.fileno(), sys.stderr.fileno())
  57         return 1
  58
  59     def loop(self):
  60         self.ctrl_sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
  61         self.ctrl_sock.bind(CTRL_SOCK)
  62         self.ctrl_sock.listen(0)
  63         while not self.stop:
  64             print 'accept'
  65             conn, addr = self.ctrl_sock.accept()
  66             conn.settimeout(5)
  67             while True:
  68                 try:
  69                     print 'recv'
  70                     data = conn.recv(1024)
  71                 except socket.timeout, e:
  72                     print e
  73                     break
  74
  75                 if data == STOP_MSG:
  76                     self.stop = True
  77                 else:
  78                     conn.send("%s received" % data)
  79             conn.close()
  80
  81     def cleanup(self):
  82         self.ctrl_sock.close()
  83         try:
  84             s.remove(CTRL_SOCK)
  85         except:
  86             pass
  87
  88 class Forwarder(object):
  89     def __init__(self):
  90         self.ctrl_sock = None
  91
  92     def forward(self):
  93         self.connect()
  94         while True:
  95             msg = sys.stdin.readline()
  96             self.send(msg)
  97             reply = self.ctrl_sock.recv(1024)
  98             sys.stdout.write(reply)
  99
 100     def send(self, msg):
 101         try:
 102             self.ctrl_sock.send(msg)
 103         except IOError, e:
 104             if e.errno == errno.EPIPE:
 105                 self.connect()
 106                 self.ctrl_sock.send(msg)
 107             else:
 108                 raise e
 109
 110     def connect(self):
 111         try:
 112             self.ctrl_sock.close()
 113         except:
 114             pass
 115         self.ctrl_sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
 116         self.ctrl_sock.connect(CTRL_SOCK)
 117
 118 # Client
 119 # import subprocess
 120 # s = subprocess.Popen(['python' ,'-c' 'import server;c=server.Forwarder();c.forward()'], stdin = subprocess.PIPE)
 121 # s.stdin.write('aaaa\n')