Source Code for Module gozerbot.persist

 1  # gozerbot/persist.py 
 2  # 
 3  # 
 4   
 5  """ allow data to be pickled to disk .. creating the persisted object 
 6      restores data 
 7  """ 
 8   
 9  __copyright__ = 'this file is in the public domain' 
10   
11  from gozerbot.generic import rlog 
12  import pickle, thread, os, copy 
13   
14  saving = [] 
15  stopsave = 0 
16   
17 -class Persist(object): 
18   
19      """ persist data attribute to pickle file """ 
20   
21 -    def __init__(self, filename, default=None): 
22          rlog(1, 'persist', 'reading %s' % filename) 
23          self.fn = filename 
24          self.lock = thread.allocate_lock() 
25          self.data = None 
26          # load data from pickled file 
27          try: 
28              datafile = open(filename, 'r') 
29          except IOError: 
30              if default != None: 
31                  self.data = copy.deepcopy(default) 
32              return 
33          try: 
34              self.data = pickle.load(datafile) 
35              datafile.close() 
36          except: 
37              if default != None: 
38                  self.data = copy.deepcopy(default) 
39              else: 
40                  rlog(100, 'persist', 'ERROR: %s' % filename) 
41                  raise 
42   
43 -    def save(self): 
44          """ save persist data """ 
45          if stopsave: 
46              rlog(100, 'persist', 'stopping mode .. not saving %s' % self.fn) 
47              return 
48          try: 
49              saving.append(str(self.fn)) 
50              self.lock.acquire() 
51              # first save to temp file and when done rename 
52              tmp = self.fn + '.tmp' 
53              try: 
54                  datafile = open(tmp, 'w') 
55              except IOError: 
56                  rlog(100, 'persist', "can't save %s" % self.fn) 
57                  return 
58              pickle.dump(self.data, datafile) 
59              datafile.close() 
60              os.rename(tmp, self.fn) 
61              rlog(2, 'persist', '%s saved' % self.fn) 
62          finally: 
63              saving.remove(self.fn) 
64              self.lock.release() 
65