Source Code for Module npsgd.confirmation_map

 1  # Author: Thomas Dimson [tdimson@gmail.com] 
 2  # Date:   January 2011 
 3  # For distribution details, see LICENSE 
 4  """Module used within the queue daemon for keeping track of confirmation codes.""" 
 5  import random 
 6  import string 
 7  import logging 
 8  import threading 
 9  from datetime import datetime 
10  from config import config 
11   
12 -class ConfirmationEntry(object): 
13 -    def __init__(self, request): 
14          self.timestamp  = datetime.now() 
15          self.expiryTime = datetime.now() + config.confirmTimeout 
16          self.request    = request 
17   
18 -    def expired(self): 
19          return datetime.now() >= self.expiryTime 
20   
21 -class ExistingCodeError(RuntimeError): pass 
22 -class ConfirmationMap(object): 
23      """Confirmation code map (thread safe).  
24   
25      Essentially this is a wrapped hash from code string -> request with some 
26      helper methods to expire old confirmation entries. 
27      """ 
28 -    def __init__(self): 
29          self.codeToRequest = {} 
30          self.codeLength    = 16 
31          self.lock          = threading.RLock() 
32   
33 -    def getRequestsWithCodes(self): 
34          return [(code,c.request) for code,c in self.codeToRequest.iteritems()] 
35   
36 -    def putRequestWithCode(self, request, code): 
37          with self.lock: 
38              if code in self.codeToRequest: 
39                  raise ExistingCodeError("%s already exists in map", code) 
40   
41              self.codeToRequest[code] = ConfirmationEntry(request) 
42       
43 -    def putRequest(self, request): 
44          code = self.generateCode() 
45          with self.lock: 
46              self.codeToRequest[code] = ConfirmationEntry(request) 
47   
48          return code 
49   
50 -    def getRequest(self, code): 
51          with self.lock: 
52              if code in self.codeToRequest: 
53                  request = self.codeToRequest[code].request 
54                  del self.codeToRequest[code] 
55                  return request 
56              else: 
57                  raise KeyError("Code does not exist") 
58   
59 -    def expireConfirmations(self): 
60          """Expire old confirmations - meant to be called at a regular rate.""" 
61   
62          with self.lock: 
63              delKeys = [k for (k,v) in self.codeToRequest.iteritems() if v.expired()] 
64              if len(delKeys) > 0: 
65                  logging.info("Expiring %d confirmations" % (len(delKeys))) 
66                  for k in delKeys: 
67                      del self.codeToRequest[k] 
68   
69 -    def generateCode(self): 
70          return "".join(random.choice(string.letters + string.digits)\ 
71                  for i in xrange(self.codeLength)) 
72