pyva/src/main/python/pseudoclient/sys_base.py

   1 import threading
   2 import MySQLdb as db
   3
   4 class Subsystem(object):
   5         #--------------------------------------------------------------#
   6         # i'm not entirely sure if this functionality is still
   7         # required, but it seems it was removed from this module
   8         # but not from cmd_admin, so I can only assume the removal
   9         # was not intentional.
  10
  11         db_up = True
  12
  13         @classmethod
  14         def set_db_up(cls, up):
  15                 cls.db_up = up
  16
  17         @classmethod
  18         def get_db_up(cls):
  19                 return cls.db_up
  20
  21         #--------------------------------------------------------------#
  22
  23         def __init__(self, module, options, name):
  24                 self.module = module
  25                 self.__options = options
  26                 self.__lock = threading.Lock()
  27                 self.name = name
  28                 self.__timer = None
  29                 self.conn = None
  30                 self.cursor = None
  31                 self.reload()
  32
  33         def db_open(self):
  34                 self.conn = db.connect(
  35                         host=self.module.config.get('database', 'host'),
  36                         user=self.module.config.get('database', 'user'),
  37                         passwd=self.module.config.get('database', 'passwd'),
  38                         db=self.module.config.get('database', 'db'),
  39                         unix_socket=self.module.config.get('database','sock')
  40                 )
  41                 self.conn.ping(True)
  42                 self.conn.autocommit(True)
  43                 self.cursor = self.conn.cursor()
  44
  45         def db_close(self):
  46                 if self.cursor != None:
  47                         self.cursor.close()
  48                         self.cursor = None
  49
  50                 if self.conn != None:
  51                         self.conn.close()
  52                         self.conn = None
  53
  54         def reload(self):
  55                 self.__delay = self.get_option('update_period', int, 120)
  56
  57                 if self.__timer != None:
  58                         self.stop()
  59                         self.on_reload()
  60                         self.start()
  61                 else:
  62                         self.on_reload()
  63
  64         def on_reload(self):
  65                 pass
  66
  67         def get_option(self, name, type, default):
  68                 return self.__options.get('%s_%s' % (self.name, name), type, default)
  69
  70         def set_option(self, name, value):
  71                 return self.__options.set('%s_%s' % (self.name, name), value)
  72
  73         def start(self):
  74                 self.__timer = threading.Timer(self.__delay, self.worker)
  75                 self.__timer.daemon = True
  76                 self.__timer.start()
  77
  78         def stop(self):
  79                 self.__lock.acquire()
  80
  81                 try:
  82                         if self.__timer != None:
  83                                 self.__timer.cancel()
  84                                 self.__timer = None
  85                 finally:
  86                         self.__lock.release()
  87
  88         def update(self):
  89                 self.__lock.acquire()
  90
  91                 try:
  92                         self.commit()
  93                 finally:
  94                         self.__lock.release()
  95
  96         def force(self):
  97                 self.update()
  98
  99         def commit(self):
 100                 pass
 101
 102         def worker(self):
 103                 try:
 104                         if self.conn != None:
 105                                 self.conn.ping(True)
 106                 finally:
 107                         pass
 108
 109                 if self.__class__.db_up:
 110                         self.update()
 111
 112                 self.__timer = threading.Timer(self.__delay, self.worker)
 113                 self.__timer.daemon = True
 114                 self.__timer.start()
 115