Source Code for Module turbogears.visit.savisit

  1  from datetime import datetime 
  2   
  3  from sqlalchemy import Table, Column, String, DateTime 
  4  from sqlalchemy.orm import class_mapper, mapper 
  5  try: 
  6      from sqlalchemy.orm.exc import UnmappedClassError 
  7  except ImportError: # SQLAlchemy < 0.5 
  8      from sqlalchemy.exceptions import InvalidRequestError as UnmappedClassError 
  9   
 10  from turbogears import config 
 11  from turbogears.database import bind_metadata, metadata, session 
 12  from turbogears.util import load_class 
 13  from turbogears.visit.api import BaseVisitManager, Visit 
 14   
 15  import logging 
 16  log = logging.getLogger("turbogears.identity.savisit") 
 17   
 18  visit_class = None 
 19   
 20   
 21 -class SqlAlchemyVisitManager(BaseVisitManager): 
 22   
 23 -    def __init__(self, timeout): 
 24          global visit_class 
 25          visit_class_path = config.get("visit.saprovider.model", 
 26              "turbogears.visit.savisit.TG_Visit") 
 27          visit_class = load_class(visit_class_path) 
 28          if visit_class is None: 
 29              msg = 'No visit class found for %s' % visit_class_path 
 30              msg += ', did you run setup.py develop?' 
 31              log.error(msg) 
 32          else: 
 33              log.info('Successfully loaded "%s"', visit_class_path) 
 34   
 35          if visit_class is TG_Visit: 
 36              # Handle it gracefully when TG_Visit is already mapped. 
 37              # May happen, when the visit manager is shutdown and started again 
 38              try: 
 39                  class_mapper(visit_class) 
 40              except UnmappedClassError: 
 41                  mapper(visit_class, visits_table) 
 42          # base-class' __init__ triggers self.create_model, so mappers need to 
 43          # be initialized before. 
 44          super(SqlAlchemyVisitManager, self).__init__(timeout) 
 45   
 46 -    def create_model(self): 
 47          """Create the Visit table if it doesn't already exist.""" 
 48          bind_metadata() 
 49          class_mapper(visit_class).local_table.create(checkfirst=True) 
 50          log.debug("Visit model database table(s) created.") 
 51   
 52 -    def new_visit_with_key(self, visit_key): 
 53          """Return a new Visit object with the given key.""" 
 54          created = datetime.now() 
 55          visit = visit_class() 
 56          visit.visit_key = visit_key 
 57          visit.created = created 
 58          visit.expiry = created + self.timeout 
 59          session.add(visit) 
 60          session.flush() 
 61          return Visit(visit_key, True) 
 62   
 63 -    def visit_for_key(self, visit_key): 
 64          """Return the visit (tg api Visit) for this key. 
 65   
 66          Returns None if the visit doesn't exist or has expired. 
 67   
 68          """ 
 69          try: 
 70              expiry = self.queue[visit_key] 
 71          except KeyError: 
 72              visit = visit_class.lookup_visit(visit_key) 
 73              if not visit: 
 74                  return None 
 75              expiry = visit.expiry 
 76          now = datetime.now(expiry.tzinfo) 
 77          if expiry < now: 
 78              return None 
 79          # Visit hasn't expired, extend it 
 80          self.update_visit(visit_key, now + self.timeout) 
 81          return Visit(visit_key, False) 
 82   
 83 -    def update_queued_visits(self, queue): 
 84          # TODO this should be made transactional 
 85          table = class_mapper(visit_class).mapped_table 
 86          engine = table.bind 
 87          # Now update each of the visits with the most recent expiry 
 88          for visit_key, expiry in queue.items(): 
 89              log.info("updating visit (%s) to expire at %s", visit_key, expiry) 
 90              engine.execute(table.update(table.c.visit_key == visit_key, 
 91                  values=dict(expiry=expiry))) 
 92   
 93   
 94  # The Visit table 
 95   
 96  visits_table = Table('tg_visit', metadata, 
 97      Column('visit_key', String(40), primary_key=True), 
 98      Column('created', DateTime, nullable=False, default=datetime.now), 
 99      Column('expiry', DateTime) 
100  ) 
101   
102   
103 -class TG_Visit(object): 
104   
105      @classmethod 
106 -    def lookup_visit(cls, visit_key): 
107          return session.query(cls).get(visit_key) 
108