Source Code for Module AccessEngine.AEMonitor.MonitorCollection

  1  ''' 
  2  Defines a convenience collection that can be used to notify all L{AEMonitor}s 
  3  of a certain event. 
  4   
  5  @author: Peter Parente 
  6  @organization: IBM Corporation 
  7  @copyright: Copyright (c) 2005, 2007 IBM Corporation 
  8  @license: The BSD License 
  9   
 10  All rights reserved. This program and the accompanying materials are made  
 11  available under the terms of the BSD license which accompanies 
 12  this distribution, and is available at 
 13  U{http://www.opensource.org/licenses/bsd-license.php} 
 14  ''' 
 15  import logging 
 16  import Base 
 17  from AccessEngine.AEAccInterfaces import implements 
 18   
 19  log = logging.getLogger('Monitor') 
 20   
 21 -class MonitorCollection(object): 
 22    ''' 
 23    Collection of known monitors. Defines methods for informing all elements about 
 24    about information to be buffered. 
 25     
 26    @ivar monitors: list of L{AEMonitor}s that will be notified of events 
 27    @type monitors: list of L{AEMonitor}s 
 28    '''  
 29 -  def __init__(self): 
 30      '''Initializes the monitor list.''' 
 31      self.monitors = [] 
 32   
 33 -  def __iter__(self): 
 34      ''' 
 35      @return: Iterator over the list of L{AEMonitor}s 
 36      @rtype: iterator 
 37      ''' 
 38      return iter(self.monitors) 
 39     
 40 -  def __len__(self): 
 41      ''' 
 42      @return: Number of monitors in the collection 
 43      @rtype: integer 
 44      ''' 
 45      return len(self.monitors) 
 46     
 47 -  def __contains__(self, val): 
 48      ''' 
 49      Checks if the given monitor class name or instance is in the monitor 
 50      collection. 
 51       
 52      @param val: Instance of a monitor or a string representing its class name 
 53      @type val: string or L{AEMonitor} 
 54      @return: Is the monitor in the collection? 
 55      @rtype: boolean 
 56      ''' 
 57      if isinstance(val, str): 
 58        for mon in self.monitors: 
 59          if mon.getClassName() == val: 
 60            return True 
 61        return False 
 62      else: 
 63        return val in self.monitors 
 64       
 65 -  def clear(self): 
 66      '''Closes all monitors in L{monitors}.''' 
 67      for m in self.monitors: 
 68        try: 
 69          m.close() 
 70        except Exception, e: 
 71          pass 
 72         
 73 -  def removeByClassName(self, name): 
 74      ''' 
 75      Removes one L{AEMonitor} instance given its class name from the collection. 
 76       
 77      @param name: Class name of the monitor to remove 
 78      @type name: string 
 79      ''' 
 80      for m in self.monitors: 
 81        if m.getClassName() == name: 
 82          m.close() 
 83          # only one possible based on UIE naming convention, so this is safe 
 84          self.monitors.remove(m) 
 85          return 
 86   
 87 -  def remove(self, *mons): 
 88      ''' 
 89      Removes one or more L{AEMonitor} instances from the collection. 
 90       
 91      @param mons: Monitors to remove 
 92      @type mons: list of L{AEMonitor} 
 93      ''' 
 94      for mon in mons: 
 95        self.monitors.remove(mon) 
 96        try: 
 97          mon.close() 
 98        except Exception: 
 99          pass 
100       
101 -  def add(self, kind, monitors): 
102      '''  
103      Adds one or more L{AEMonitor}s to the list of monitors to be notified. 
104      Filters the list of monitors based on the kind of events in which they are  
105      interested. 
106       
107      @param kind: Kind of event of interest to the monitor 
108      @type kind: class 
109      @param monitors: L{AEMonitor}s to notify 
110      @type monitors: tuple of L{AEMonitor}s 
111      ''' 
112      for m in monitors: 
113        if implements(m, Base.AEMonitor) and (implements(m.getEventType(), kind)  
114                                          or implements(kind, m.getEventType())): 
115          # store only the desired kind of monitors 
116          self.monitors.append(m) 
117          # make sure the monitor isn't already initialized 
118          if not m.isInitialized(): 
119            # initialize each monitor so it is displayed 
120            m.init() 
121   
122 -  def show(self, *args, **kwargs): 
123      ''' 
124      Informs L{AEMonitor}s added via L{add} of information to be buffered. Calls 
125      L{Base.AEMonitor.show} on all monitors. Monitors raising IOError in show  
126      are removed from the L{monitors} list and are no longer notified of events. 
127       
128      @param args: Information to buffer 
129      @type args: list 
130      @param kwargs: Information to buffer 
131      @type kwargs: dictionary 
132      ''' 
133      i = 0 
134      # can't use a for loop here because we're removing elements along the way 
135      while i < len(self.monitors): 
136        m = self.monitors[i] 
137        try: 
138          # buffer the given information 
139          m.show(*args, **kwargs) 
140        except IOError: 
141          # remove any monitors that have indicated that want no more events 
142          del self.monitors[i] 
143          continue 
144        except Exception: 
145          # log all exceptions other than IO 
146          log.exception('Monitor exception') 
147        i += 1 
148