src/nepi/util/server.py

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