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             # Close unused pipe ends
  53             os.close(self.int_w)
  54             os.close(self.int_r)
  55         else:
  56             # Close unused pipe ends
  57             os.close(self.ext_r)
  58             os.close(self.ext_w)
  59
  60             # Start child loop
  61             self.start_child()
  62
  63     def _child_exit(self,a, b):
  64         os.close(self.ext_r)
  65         os.close(self.ext_w)
  66         self._create()
  67
  68     def write_to_child(self, message):
  69         os.write(self.ext_w, message)
  70
  71     def read(self, fd):
  72         buf = ""
  73         while 1:
  74             data = fd.recv(4096)
  75             if len(data) == 0:
  76                 break
  77             else:
  78                 buf += data
  79                 if buf[-4:] == '\r\n\r\n':
  80                     break;
  81
  82         try:
  83             if os.environ['PALM_DEBUG'] is not None:
  84                 print buf
  85         except:
  86             pass
  87
  88         return buf
  89
  90     def parse_request(self, data):
  91         arr = data.split('\r\n')
  92         for line in arr[:-2]:
  93             # print line
  94             if line == arr[0]:
  95                 request = Request(line)
  96                 continue
  97
  98             sep = line.find('=')
  99             if sep < 0:
 100                 continue
 101
 102             key = line[:sep]
 103             val = line[sep+1:]
 104
 105             request.add_header(key, val)
 106
 107         try:
 108             if os.environ['PALM_DEBUG'] is not None:
 109                 for h in request.headers:
 110                     print h + ' = \'' + request.headers[h] + '\''
 111         except:
 112             pass
 113
 114         return request
 115
 116     def start_child(self):
 117         # Creating epoll for read pipe side
 118         while 1:
 119             remote, info = self._s.accept()
 120             # print "Got connection! I won! ->", os.getpid()
 121             buf = self.read(remote)
 122             #print "reading, ", buf
 123
 124             request = self.parse_request(buf)
 125
 126             if self.c['bin'] is None:
 127                 bin = request.resource
 128             else:
 129                 bin = self.c['bin']
 130
 131             if self.c['opts'] is None and bin != request.resource:
 132                 opts = [request.resource]
 133             else:
 134                 opts = self.c['opts']
 135                 opts.append(request.resource)
 136
 137             os.dup2(remote.fileno(), sys.stdout.fileno())
 138             try:
 139                 os.execve(bin, opts, request.headers)
 140             except:
 141                 exit(1)
 142
 143
 144     def write_to_parent(self, message):
 145         time.sleep(1)
 146         n = os.write(self.int_w, message)
 147         print "Child wrote: ", n
 148
 149     def read_data(self, fd):
 150         buf = os.read(fd, 1024)
 151         os.write(self.int_w, buf)
 152         print "Child got: ", buf
 153
 154     def get_pid(self):
 155         return self._pid
 156
 157     def kill(self):
 158         os.kill(self._pid, signal.SIGKILL)
 159
 160 class Request:
 161     def __init__(self, resource):
 162         self.resource = resource
 163         self.headers = {}
 164
 165     def add_header(self, key, val):
 166         self.headers[key] = val
 167         # print self.headers
 168