class Session(object):
"""
Sessions used to maintain user presence between requests.
Sessions store a unique id as a cookie in the browser and
referenced in a datastore object. This maintains user presence
by validating requests as visits from the same browser.
You can add extra data to the session object by using it
as a dictionary object. Values can be any python object that
can be pickled.
For extra performance, session objects are also store in
memcache and kept consistent with the datastore. This
increases the performance of read requests to session
data.
"""
def __init__(
self,
cookie_path=DEFAULT_COOKIE_PATH,
cookie_name=COOKIE_NAME,
session_expire_time=SESSION_EXPIRE_TIME,
clean_check_percent=CLEAN_CHECK_PERCENT,
integrate_flash=INTEGRATE_FLASH,
check_ip=CHECK_IP,
check_user_agent=CHECK_USER_AGENT,
set_cookie_expires=SET_COOKIE_EXPIRES,
session_token_ttl=SESSION_TOKEN_TTL,
):
"""
Initializer
Args:
cookie_name: The name for the session cookie stored in the browser.
session_expire_time: The amount of time between requests before the
session expires.
clean_check_percent: The percentage of requests the will fire off a
cleaning routine that deletes stale session data.
integrate_flash: If appengine-utilities flash utility should be
integrated into the session object.
check_ip: If browser IP should be used for session validation
check_user_agent: If the browser user agent should be used for
sessoin validation.
set_cookie_expires: True adds an expires field to the cookie so
it saves even if the browser is closed.
session_token_ttl: Number of sessions a session token is valid
for before it should be regenerated.
"""
self.cookie_path = cookie_path
self.cookie_name = cookie_name
self.session_expire_time = session_expire_time
self.clean_check_percent = clean_check_percent
self.integrate_flash = integrate_flash
self.check_user_agent = check_user_agent
self.check_ip = check_ip
self.set_cookie_expires = set_cookie_expires
self.session_token_ttl = session_token_ttl
"""
Check the cookie and, if necessary, create a new one.
"""
self.cache = {}
self.sid = None
self.uid = None # user id.
string_cookie = os.environ.get("HTTP_COOKIE", "")
self.cookie = Cookie.SimpleCookie()
self.cookie.load(string_cookie)
# check for existing cookie
if self.cookie.get(cookie_name):
self.sid = self.cookie[cookie_name].value
# If there isn't a valid session for the cookie sid,
# start a new session.
self.session = self._get_session()
if self.session is None:
self.sid = self.new_sid()
self.session = UserSession()
self.session.ua = os.environ["HTTP_USER_AGENT"]
self.session.ip = os.environ["REMOTE_ADDR"]
self.session.sid = [self.sid]
self.session.uid = None
self.cookie[cookie_name] = self.sid
self.cookie[cookie_name]["path"] = cookie_path
if set_cookie_expires:
self.cookie[cookie_name]["expires"] = self.session_expire_time
else:
# check the age of the token to determine if a new one
# is required
duration = datetime.timedelta(seconds=self.session_token_ttl)
session_age_limit = datetime.datetime.now() - duration
if self.session.last_activity < session_age_limit:
self.sid = self.new_sid()
if len(self.session.sid) > 2:
self.session.sid.remove(self.session.sid[0])
self.session.sid.append(self.sid)
else:
self.sid = self.session.sid[-1]
self.session.login = False # set current user logout
self.cookie[cookie_name] = self.sid
self.cookie[cookie_name]["path"] = cookie_path
if set_cookie_expires:
self.cookie[cookie_name]["expires"] = self.session_expire_time
else:
self.sid = self.new_sid()
self.session = UserSession()
self.session.ua = os.environ["HTTP_USER_AGENT"]
self.session.ip = os.environ["REMOTE_ADDR"]
self.session.sid = [self.sid]
self.cookie[cookie_name] = self.sid
self.cookie[cookie_name]["path"] = cookie_path
if set_cookie_expires:
self.cookie[cookie_name]["expires"] = self.session_expire_time
self.cache["sid"] = pickle.dumps(self.sid)
# update the last_activity field in the datastore every time that
# the session is accessed. This also handles the write for all
# session data above.
self.session.put()
print self.cookie
# fire up a Flash object if integration is enabled
if self.integrate_flash:
import flash
self.flash = flash.Flash(cookie=self.cookie)
# randomly delete old stale sessions in the datastore (see
# CLEAN_CHECK_PERCENT variable)
if random.randint(1, 100) < CLEAN_CHECK_PERCENT:
self._clean_old_sessions()
def new_sid(self):
"""
Create a new session id.
"""
sid = sha.new(repr(time.time()) + os.environ["REMOTE_ADDR"] + str(random.random())).hexdigest()
return sid
def _get_session(self):
"""
Get the user's session from the datastore
"""
query = UserSession.all()
query.filter("sid", self.sid)
if self.check_user_agent:
query.filter("ua", os.environ["HTTP_USER_AGENT"])
if self.check_ip:
query.filter("ip", os.environ["REMOTE_ADDR"])
results = query.fetch(1)
if len(results) is 0:
return None
else:
sessionAge = datetime.datetime.now() - results[0].last_activity
if sessionAge.seconds > self.session_expire_time:
results[0].delete()
return None
return results[0]
def _get(self, keyname=None):
"""
Return all of the SessionData object unless keyname is specified, in
which case only that instance of SessionData is returned.
Important: This does not interact with memcache and pulls directly
from the datastore.
Args:
keyname: The keyname of the value you are trying to retrieve.
"""
query = UserSessionData.all()
query.filter("session", self.session)
if keyname != None:
query.filter("keyname =", keyname)
results = query.fetch(1000)
if len(results) is 0:
return None
if keyname != None:
return results[0]
return results
def _validate_key(self, keyname):
"""
Validate the keyname, making sure it is set and not a reserved name.
"""
if keyname is None:
raise ValueError("You must pass a keyname for the session" + " data content.")
elif keyname in ("sid", "flash"):
raise ValueError(keyname + " is a reserved keyname.")
if type(keyname) != type([str, unicode]):
return str(keyname)
return keyname
def _put(self, keyname, value):
"""
Insert a keyname/value pair into the datastore for the session.
Args:
keyname: The keyname of the mapping.
value: The value of the mapping.
"""
keyname = self._validate_key(keyname)
if value is None:
raise ValueError("You must pass a value to put.")
sessdata = self._get(keyname=keyname)
if sessdata is None:
sessdata = UserSessionData()
sessdata.session = self.session
sessdata.keyname = keyname
sessdata.content = pickle.dumps(value)
self.cache[keyname] = pickle.dumps(value)
sessdata.put()
self._set_memcache()
def _delete_session(self):
"""
Delete the session and all session data for the sid passed.
"""
sessiondata = self._get()
# delete from datastore
if sessiondata is not None:
for sd in sessiondata:
sd.delete()
# delete from memcache
memcache.delete("sid-" + str(self.session.key()))
# delete the session now that all items that reference it are deleted.
self.session.delete()
# if the event class has been loaded, fire off the sessionDeleted event
if "AEU_Events" in __main__.__dict__:
__main__.AEU_Events.fire_event("sessionDelete")
def delete(self):
"""
Delete the current session and start a new one.
This is useful for when you need to get rid of all data tied to a
current session, such as when you are logging out a user.
"""
self._delete_session()
def delete_all_sessions(self):
"""
Deletes all sessions and session data from the data store and memcache.
"""
all_sessions_deleted = False
all_data_deleted = False
while not all_sessions_deleted:
query = UserSession.all()
results = query.fetch(1000)
if len(results) is 0:
all_sessions_deleted = True
else:
for result in results:
result.delete()
while not all_data_deleted:
query = UserSessionData.all()
results = query.fetch(1000)
if len(results) is 0:
all_data_deleted = True
else:
for result in results:
result.delete()
def _clean_old_sessions(self):
"""
Delete expired sessions from the datastore.
This is only called for CLEAN_CHECK_PERCENT percent of requests because
it could be rather intensive.
"""
duration = datetime.timedelta(seconds=self.session_expire_time)
session_age = datetime.datetime.now() - duration
query = UserSession.all()
query.filter("last_activity <", session_age)
results = query.fetch(1000)
for result in results:
data_query = UserSessionData.all()
query.filter("session", result)
data_results = data_query.fetch(1000)
for data_result in data_results:
data_result.delete()
memcache.delete("sid-" + str(result.key()))
result.delete()
# Implement Python container methods
def __getitem__(self, keyname):
"""
Get item from session data.
keyname: The keyname of the mapping.
"""
# flash messages don't go in the datastore
if self.integrate_flash and (keyname == "flash"):
return self.flash.msg
if keyname in self.cache:
return pickle.loads(str(self.cache[keyname]))
mc = memcache.get("sid-" + str(self.session.key()))
if mc is not None:
if keyname in mc:
return mc[keyname]
data = self._get(keyname)
if data:
self.cache[keyname] = data.content
self._set_memcache()
return pickle.loads(data.content)
else:
raise KeyError(str(keyname))
def __setitem__(self, keyname, value):
"""
Set item in session data.
Args:
keyname: They keyname of the mapping.
value: The value of mapping.
"""
# if type(keyname) is type(''):
# flash messages don't go in the datastore
if self.integrate_flash and (keyname == "flash"):
self.flash.msg = value
else:
keyname = self._validate_key(keyname)
self.cache[keyname] = value
self._set_memcache()
return self._put(keyname, value)
# else:
# raise TypeError('Session data objects are only accessible by' + \
# ' string keys, not numerical indexes.')
def __delitem__(self, keyname):
"""
Delete item from session data.
Args:
keyname: The keyname of the object to delete.
"""
sessdata = self._get(keyname=keyname)
if sessdata is None:
raise KeyError(str(keyname))
sessdata.delete()
if keyname in self.cache:
del self.cache[keyname]
self._set_memcache()
def __len__(self):
"""
Return size of session.
"""
# check memcache first
mc = memcache.get("sid-" + str(self.session.key()))
if mc is not None:
return len(mc)
results = self._get()
return len(results)
def __contains__(self, keyname):
"""
Check if an item is in the session data.
Args:
keyname: The keyname being searched.
"""
try:
r = self.__getitem__(keyname)
except KeyError:
return False
return True
def __iter__(self):
"""
Iterate over the keys in the session data.
"""
# try memcache first
mc = memcache.get("sid-" + str(self.session.key()))
if mc is not None:
for k in mc:
yield k
else:
for k in self._get():
yield k.keyname
def __str__(self):
"""
Return string representation.
"""
return ", ".join(['("%s" = "%s")' % (k, self[k]) for k in self])
def _set_memcache(self):
"""
Set a memcache object with all the session date. Optionally you can
add a key and value to the memcache for put operations.
"""
# Pull directly from the datastore in order to ensure that the
# information is as up to date as possible.
data = {}
sessiondata = self._get()
if sessiondata is not None:
for sd in sessiondata:
data[sd.keyname] = pickle.loads(sd.content)
memcache.set("sid-" + str(self.session.key()), data, self.session_expire_time)
def cycle_key(self):
self.sid = self.new_sid()
if len(self.session.sid) > 2:
self.session.sid.remove(self.session.sid[0])
self.session.sid.append(self.sid)
def flush(self):
self._delete_session()
self.__init__()
# add for cpedialog
def login_user(self, user):
"""
associate the sesion object with user.
"""
self.session.user = user
self.session.login = True
self.session.put()
def logout_user(self):
"""
unassociate the sesion object with user(model.User).
"""
session = self.session
session.user = None
self.session.login = False
session.put()
def login_google_user(self):
"""
associate the sesion object with google user object.
"""
session = self.session
google_user = users.get_current_user()
if google_user and (session.user is None):
users_ = User.all().filter("email", google_user.email())
if users_.count() == 0:
user = User()
user.email = google_user.email()
user.username = google_user.nickname()
user.put()
else:
user = users_[0]
self.login_user(user)
def get_current_user(self):
session = self.session
return session.user