palm/lib/child.py

   1 # Copyright (C) 2008-2009, Eduardo Silva <edsiper@gmail.com>
   2 #
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation; either version 2 of the License, or
   6 # (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program; if not, write to the Free Software
  15 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  16
  17 import os
  18 import sys
  19 import time
  20 import signal
  21 from epoll import *
  22
  23 class Child:
  24     def __init__(self, s, conf):
  25         self._s = s
  26         self.conf = conf
  27         self.split_conf()
  28
  29         # On child end, re-create it
  30         signal.signal(signal.SIGCHLD, self._child_exit)
  31
  32         # Start our child
  33         self._create()
  34
  35     def split_conf(self):
  36         try:
  37             opts = self.conf.opts.split()
  38         except:
  39             opts = []
  40
  41         self.c = {'bin': self.conf.bin, 'opts': opts}
  42
  43     def _create(self):
  44         # Creating pipes
  45         [self.ext_r, self.int_w] = os.pipe()
  46         [self.int_r, self.ext_w] = os.pipe()
  47
  48         # Fork process
  49         pid = os.fork()
  50         if pid:
  51             self._pid = pid
  52             print "My PID " + str(pid)
  53             # Close unused pipe ends
  54             os.close(self.int_w)
  55             os.close(self.int_r)
  56         else:
  57             # Close unused pipe ends
  58             os.close(self.ext_r)
  59             os.close(self.ext_w)
  60
  61             # Start child loop
  62             self.start_child()
  63
  64     def _child_exit(self,a, b):
  65         os.close(self.ext_r)
  66         os.close(self.ext_w)
  67         self._create()
  68
  69     def write_to_child(self, message):
  70         os.write(self.ext_w, message)
  71
  72     def read(self, fd):
  73         buf = ""
  74         while 1:
  75             data = fd.recv(4096)
  76             if len(data) == 0:
  77                 break
  78             else:
  79                 buf += data
  80                 if buf[-4:] == '\r\n\r\n':
  81                     break;
  82
  83         try:
  84             if os.environ['PALM_DEBUG'] is not None:
  85                 print buf
  86         except:
  87             pass
  88
  89         return buf
  90
  91     def parse_request(self, data):
  92         arr = data.split('\r\n')
  93         for line in arr[:-2]:
  94             # print line
  95             if line == arr[0]:
  96                 request = Request(line)
  97                 continue
  98
  99             sep = line.find('=')
 100             if sep < 0:
 101                 continue
 102
 103             key = line[:sep]
 104             val = line[sep+1:]
 105
 106             request.add_header(key, val)
 107
 108         try:
 109             if os.environ['PALM_DEBUG'] is not None:
 110                 for h in request.headers:
 111                     print h + ' = \'' + request.headers[h] + '\''
 112         except:
 113             pass
 114
 115         return request
 116
 117     def start_child(self):
 118         # Creating epoll for read pipe side
 119         while 1:
 120             remote, info = self._s.accept()
 121             # print "Got connection! I won! ->", os.getpid()
 122             buf = self.read(remote)
 123             #print "reading, ", buf
 124
 125             request = self.parse_request(buf)
 126
 127             if self.c['bin'] is None:
 128                 bin = request.resource
 129             else:
 130                 bin = self.c['bin']
 131
 132             if self.c['opts'] is None and bin != request.resource:
 133                 opts = [request.resource]
 134             else:
 135                 opts = self.c['opts']
 136                 opts.append(request.resource)
 137
 138             os.dup2(remote.fileno(), sys.stdout.fileno())
 139             try:
 140                 os.execve(bin, opts, request.headers)
 141             except:
 142                 exit(1)
 143
 144
 145     def write_to_parent(self, message):
 146         time.sleep(1)
 147         n = os.write(self.int_w, message)
 148         print "Child wrote: ", n
 149
 150     def read_data(self, fd):
 151         buf = os.read(fd, 1024)
 152         os.write(self.int_w, buf)
 153         print "Child got: ", buf
 154
 155     def get_pid(self):
 156         return self._pid
 157
 158     def kill(self):
 159         os.kill(self._pid, signal.SIGKILL)
 160
 161 class Request:
 162     def __init__(self, resource):
 163         self.resource = resource
 164         self.headers = {}
 165
 166     def add_header(self, key, val):
 167         self.headers[key] = val
 168         # print self.headers
 169