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          if visit_class is TG_Visit: 
 35              try: 
 36                  class_mapper(visit_class) 
 37              except UnmappedClassError: 
 38                  visit_class._map() 
 39          # base-class' __init__ triggers self.create_model, 
 40          # so mappers need to be initialized before. 
 41          super(SqlAlchemyVisitManager, self).__init__(timeout) 
 42   
 43 -    def create_model(self): 
 44          """Create the Visit table if it doesn't already exist.""" 
 45          bind_metadata() 
 46          class_mapper(visit_class).local_table.create(checkfirst=True) 
 47          log.debug("Visit model database table(s) created.") 
 48   
 49 -    def new_visit_with_key(self, visit_key): 
 50          """Return a new Visit object with the given key.""" 
 51          created = datetime.now() 
 52          visit = visit_class() 
 53          visit.visit_key = visit_key 
 54          visit.created = created 
 55          visit.expiry = created + self.timeout 
 56          session.add(visit) 
 57          session.flush() 
 58          return Visit(visit_key, True) 
 59   
 60 -    def visit_for_key(self, visit_key): 
 61          """Return the visit (tg api Visit) for this key. 
 62   
 63          Returns None if the visit doesn't exist or has expired. 
 64   
 65          """ 
 66          try: 
 67              expiry = self.queue[visit_key] 
 68          except KeyError: 
 69              visit = visit_class.lookup_visit(visit_key) 
 70              if not visit: 
 71                  return None 
 72              expiry = visit.expiry 
 73          now = datetime.now(expiry.tzinfo) 
 74          if expiry < now: 
 75              return None 
 76          # Visit hasn't expired, extend it 
 77          self.update_visit(visit_key, now + self.timeout) 
 78          return Visit(visit_key, False) 
 79   
 80 -    def update_queued_visits(self, queue): 
 81          if not visit_class: 
 82              return # if VisitManager extension wasn't shutted down cleanly 
 83          # TODO this should be made transactional 
 84          table = class_mapper(visit_class).mapped_table 
 85          engine = table.bind 
 86          # Now update each of the visits with the most recent expiry 
 87          for visit_key, expiry in queue.items(): 
 88              log.info("updating visit (%s) to expire at %s", visit_key, expiry) 
 89              engine.execute(table.update(table.c.visit_key == visit_key, 
 90                  values=dict(expiry=expiry))) 
 91   
 92   
 93  # The default Visit model class 
 94   
 95 -class TG_Visit(object): 
 96   
 97      @classmethod 
 98 -    def lookup_visit(cls, visit_key): 
 99          return session.query(cls).get(visit_key) 
100   
101      @classmethod 
102 -    def _map(cls): 
103          cls._table = Table('visit', metadata, 
104              Column('visit_key', String(40), primary_key=True), 
105              Column('created', DateTime, nullable=False, default=datetime.now), 
106              Column('expiry', DateTime)) 
107          cls._mapper = mapper(cls, cls._table) 
108