Source Code for Module ZenUtils.NJobs

 1  ########################################################################### 
 2  # 
 3  # This program is part of Zenoss Core, an open source monitoring platform. 
 4  # Copyright (C) 2007, Zenoss Inc. 
 5  # 
 6  # This program is free software; you can redistribute it and/or modify it 
 7  # under the terms of the GNU General Public License version 2 as published by 
 8  # the Free Software Foundation. 
 9  # 
10  # For complete information please visit: http://www.zenoss.com/oss/ 
11  # 
12  ########################################################################### 
13  #! /usr/bin/env python  
14   
15  __doc__='''NJobs 
16   
17  Run a list of jobs in parallel, limited to N at a time. 
18   
19  $Id$ 
20  ''' 
21   
22  __version__ = "$Revision$"[11:-2] 
23   
24  from twisted.internet import defer 
25   
26   
27 -class NJobs: 
28      "Run a list of jobs in parallel, limited to N at a time." 
29       
30 -    def __init__(self, max, callable, data): 
31          self.defer = defer.Deferred() 
32          self.results = [] 
33          self.max = max 
34          self.callable = callable 
35          self.workQueue = data 
36          self.running = 0 
37   
38 -    def start(self): 
39          self._runSome() 
40          return self.defer 
41   
42 -    def status(self): 
43          return self.running, len(self.workQueue), len(self.results) 
44   
45 -    def _runSome(self): 
46          while self.running < self.max and self.workQueue: 
47              self.running += 1 
48              try: 
49                  d = self.callable(self.workQueue.pop()) 
50              except Exception, ex: 
51                  self._finished(ex) 
52              else: 
53                  d.addBoth(self._finished) 
54          if self.running == 0 and not self.workQueue and not self.defer.called: 
55              self.defer.callback(self.results) 
56   
57 -    def _finished(self, result): 
58          self.running -= 1 
59          self.results.append(result) 
60          self._runSome() 
61