src/python/osrf/system.py

   1 # -----------------------------------------------------------------------
   2 # Copyright (C) 2007  Georgia Public Library Service
   3 # Bill Erickson <billserickson@gmail.com>
   4 #
   5 # This program is free software; you can redistribute it and/or
   6 # modify it under the terms of the GNU General Public License
   7 # as published by the Free Software Foundation; either version 2
   8 # of the License, or (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 # -----------------------------------------------------------------------
  15
  16 import osrf.conf
  17 from osrf.net import Network, set_network_handle, get_network_handle
  18 import osrf.stack, osrf.log, osrf.set, osrf.cache
  19 import sys, os
  20
  21 class System(object):
  22
  23     config_file = None
  24     config_context = None
  25
  26     @staticmethod
  27     def net_connect(**kwargs):
  28         if get_network_handle():
  29             ''' This thread already has a handle '''
  30             return
  31
  32         config_file = kwargs.get('config_file') or System.config_file
  33         config_context = kwargs.get('config_context') or System.config_context
  34
  35         # store the last config file info for later
  36         System.config_file = config_file
  37         System.config_context = config_context
  38
  39         # parse the config file
  40         config_parser = osrf.conf.Config(config_file, config_context)
  41         config_parser.parse_config()
  42
  43         # set up logging
  44         osrf.log.initialize(
  45             osrf.conf.get('loglevel'),
  46             osrf.conf.get_no_ex('syslog'),
  47             osrf.conf.get_no_ex('logfile'),
  48             osrf.conf.get_no_ex('client') == 'true',
  49             kwargs.get('service'))
  50
  51         # connect to the opensrf network
  52         network = Network(
  53             host = osrf.conf.get('domain'),
  54             port = osrf.conf.get('port'),
  55             username = osrf.conf.get('username'),
  56             password = osrf.conf.get('passwd'),
  57             resource = kwargs.get('resource'))
  58
  59         network.set_receive_callback(osrf.stack.push)
  60         osrf.net.set_network_handle(network)
  61         network.connect()
  62
  63         return network
  64
  65     @staticmethod
  66     def net_disconnect():
  67         network = osrf.net.get_network_handle()
  68         network.disconnect()
  69
  70     @staticmethod
  71     def connect(**kwargs):
  72         """ Connects to the opensrf network
  73             Options:
  74                 config_file
  75                 config_context
  76                 connect_cache
  77                 resource
  78         """
  79
  80         network = System.net_connect(**kwargs)
  81
  82         # load the domain-wide settings file
  83         osrf.set.load(osrf.conf.get('domain'))
  84
  85         if kwargs.get('connect_cache'):
  86             System.connect_cache()
  87
  88         return network
  89
  90
  91     @staticmethod
  92     def connect_cache():
  93         ''' Initializes the cache connections '''
  94         cache_servers = osrf.set.get('cache.global.servers.server')
  95         if cache_servers:
  96             if not isinstance(cache_servers, list):
  97                 cache_servers = [cache_servers]
  98             if not osrf.cache.CacheClient.get_client():
  99                 osrf.cache.CacheClient.connect(cache_servers)
 100
 101     '''
 102     @return 0 if child, pid if parent
 103     '''
 104     @staticmethod
 105     def daemonize(parent_exit=True):
 106         pid = os.fork()
 107         if pid == 0:
 108             try:
 109                 os.chdir('/')
 110                 os.setsid()
 111                 sys.stdin.close()
 112                 sys.stdin = open(os.devnull)
 113                 sys.stdout.close()
 114                 sys.stdout = open(os.devnull)
 115                 sys.stderr.close()
 116                 sys.stderr = open(os.devnull)
 117             except (OSError, ValueError):
 118                 pass
 119         elif parent_exit:
 120             os._exit(0)
 121
 122         return pid
 123
 124