Source Code for Module ganeti.config.utils

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29   
30   
31  """Utilities used by the config module.""" 
32   
33   
34  import logging 
35   
36   
37 -def ConfigSync(shared=0): 
38    """Configuration synchronization decorator. 
39   
40    """ 
41    def wrap(fn): 
42      def sync_function(*args, **kwargs): 
43        with args[0].GetConfigManager(shared): 
44          return fn(*args, **kwargs) 
45      return sync_function 
46    return wrap 
47   
48   
49 -class ConfigManager(object): 
50    """Locks the configuration and exposes it to be read or modified. 
51   
52    """ 
53 -  def __init__(self, config_writer, shared=False, forcelock=False): 
54      assert hasattr(config_writer, '_ConfigData'), \ 
55             "invalid argument: Not a ConfigWriter" 
56      self._config_writer = config_writer 
57      self._shared = shared 
58      self._forcelock = forcelock 
59   
60 -  def __enter__(self): 
61      try: 
62        self._config_writer._OpenConfig(# pylint: disable=W0212 
63                                        self._shared, 
64                                        force=self._forcelock) 
65      except Exception: 
66        logging.debug("Opening configuration failed") 
67        try: 
68          self._config_writer._CloseConfig(False) # pylint: disable=W0212 
69        except Exception: # pylint: disable=W0703 
70          logging.debug("Closing configuration failed as well") 
71        raise 
72   
73 -  def __exit__(self, exc_type, exc_value, traceback): 
74      # save the configuration, if this was a write opreration that succeeded 
75      if exc_type is not None: 
76        logging.debug("Configuration operation failed," 
77                      " the changes will not be saved") 
78      # pylint: disable=W0212 
79      self._config_writer._CloseConfig(not self._shared and exc_type is None) 
80      return False 
81