""" Copyright (c) 2008, appengine-utilities project All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: - Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. - Neither the name of the appengine-utilities project nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. """ # main python imports import os import time import datetime import random import sha import Cookie import pickle import __main__ # google appengine imports from google.appengine.ext import db from google.appengine.api import memcache #django simplejson import, used for flash from django.utils import simplejson # settings, if you have these set elsewhere, such as your django settings file, # you'll need to adjust the values to pull from there. COOKIE_NAME = 'appengine-utilities-session-sid' DEFAULT_COOKIE_PATH = '/' SESSION_EXPIRE_TIME = 7200 # sessions are valid for 7200 seconds (2 hours) CLEAN_CHECK_PERCENT = 15 # 15% of all requests will clean the database INTEGRATE_FLASH = True # integrate functionality from flash module? CHECK_IP = True # validate sessions by IP CHECK_USER_AGENT = True # validate sessions by user agent SET_COOKIE_EXPIRES = True # Set to True to add expiration field to cookie SESSION_TOKEN_TTL = 5 # Number of seconds a session token is valid for. class _AppEngineUtilities_Session(db.Model): """ Model for the sessions in the datastore. This contains the identifier and validation information for the session. """ sid = db.StringListProperty() ip = db.StringProperty() ua = db.StringProperty() last_activity = db.DateTimeProperty(auto_now=True) class _AppEngineUtilities_SessionData(db.Model): """ Model for the session data in the datastore. """ session = db.ReferenceProperty(_AppEngineUtilities_Session) keyname = db.StringProperty() content = db.BlobProperty() 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 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 = _AppEngineUtilities_Session() if 'HTTP_USER_AGENT' in os.environ: self.session.ua = os.environ['HTTP_USER_AGENT'] else: self.session.ua = None if 'REMOTE_ADDR' in os.environ: self.session.ip = os.environ['REMOTE_ADDR'] else: self.session.ip = None 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 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.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 = _AppEngineUtilities_Session() 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 = _AppEngineUtilities_Session.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 = _AppEngineUtilities_SessionData.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 = _AppEngineUtilities_SessionData() 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 = _AppEngineUtilities_Session.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 = _AppEngineUtilities_SessionData.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 = _AppEngineUtilities_Session.all() query.filter('last_activity <', session_age) results = query.fetch(1000) for result in results: data_query = _AppEngineUtilities_SessionData.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__()