def create_sharing_record(user_id, collection_name, callback):
"""
Returns:
-The sharing secret key for the create sharing record
"""
#check to see whether that particular collection has been shared before
exsisting_sharing_secret = yield gen.Task(SharingController.get_sharing_secret_from_subscriber_info,
user_id, collection_name)
if exsisting_sharing_secret is not None:
SharingController.__log.info('SharingController - exsiting sharing record found for user %s and collection %s' % (user_id, collection_name))
callback(exsisting_sharing_secret)
#we couldn't find the sharing secret so create a new sharing record
else:
sharing_secret = SharingController.__generate_sharing_secret()
sharing_collection = DatabaseFactory.get_sharing_collection()
sharing_record = {SharingRecord.SECRET_KEY : sharing_secret,
SharingRecord.OWNER_KEY : user_id,
SharingRecord.COLLECTION_NAME_KEY : collection_name,
SharingRecord.SUBSCIRBERS_KEY : [(user_id,collection_name)]}
#add sharing record to the cache
yield gen.Task(sharing_collection.insert, sharing_record)
yield gen.Task(SharingController.add_subscriber, user_id, collection_name,
sharing_secret)
#cache both the subscription info and the sharing record itself
sharing_record_json = json.dumps(sharing_record)
yield gen.Task(SharingController.__cache.set_sharing_record,
sharing_secret, sharing_record_json)
callback(sharing_secret)
def remove_all_subscribers(sharing_secret, callback):
"""
Removes all the subscribers to a sharing space identified by
a sharing_secret
implementation detail, does not gurantee sharing record updates.
do not use for logic
"""
subscriber_collection = DatabaseFactory.get_subscribers_collection()
query = {SharingController.SHARING_SPACE_SECRET_KEY: sharing_secret}
#first get the sharing record
sharing_record = yield gen.Task(SharingController.get_sharing_record_by_secret,
sharing_secret)
if sharing_record is None:
SharingController.__log.info('SharingController - Sharing record is None for secret %s' % sharing_secret)
callback(None)
else:
subscribers_list = sharing_record.get_subscribers()
for subscriber_info in subscribers_list:
subscriber_id = subscriber_info[0]
subscriber_collection_name = subscriber_info[1]
#just remove it from the cache
SharingController.__cache.remove_subscriber_info(subscriber_id,
subscriber_collection_name, callback=None)
#remove everything from the db in one shot
yield gen.Task(subscriber_collection.remove, query)
callback()
def get_sharing_record_by_secret(sharing_secret, callback):
"""
Returns:
-A Sharing record object containing information of the
sharing space with the sharing_secret and None if the
sharing record for the specified sharing secret does not
exist
"""
#try the cache
sharing_record_json_str = yield gen.Task(SharingController.__cache.get_sharing_record,
sharing_secret)
#cache hit
if sharing_record_json_str is not None:
if sharing_record_json_str == 'false':
callback(None)
else:
sharing_record_obj = json.loads(sharing_record_json_str)
sharing_record = SharingRecord(
sharing_record_obj[SharingRecord.SECRET_KEY],
sharing_record_obj[SharingRecord.OWNER_KEY],
sharing_record_obj[SharingRecord.COLLECTION_NAME_KEY],
sharing_record_obj[SharingRecord.SUBSCIRBERS_KEY])
callback(sharing_record)
#cache miss
else:
sharing_collection = DatabaseFactory.get_sharing_collection()
query = {SharingRecord.SECRET_KEY : sharing_secret}
sharing_records_cursor = yield gen.Task(sharing_collection.find, query)
result_count = len(sharing_records_cursor[0][0])
#if we have more sharing spaces with this sharing secret
#something is horribly wrong
if result_count >= 2:
SharingController.__log.warning('SharingController - More than two sharing info found for: %s' % sharing_secret)
yield gen.Task(SharingController.__cache.set_sharing_record, sharing_secret, 'false')
callback(None)
if not result_count:
SharingController.__log.warning('SharingController - no sharing info found for: %s' % sharing_secret)
yield gen.Task(SharingController.__cache.set_sharing_record, sharing_secret, 'false')
callback(None)
else:
#FIXME: is there a better way to these in asyncMongo other
#than these ugly indicies
sharing_record_bson = sharing_records_cursor[0][0][0]
try:
sharing_record = SharingRecord(
sharing_record_bson[SharingRecord.SECRET_KEY],
sharing_record_bson[SharingRecord.OWNER_KEY],
sharing_record_bson[SharingRecord.COLLECTION_NAME_KEY],
sharing_record_bson[SharingRecord.SUBSCIRBERS_KEY])
callback(sharing_record)
except Exception:
SharingController.__log.warning('SharingController - corrupted sharing info found for: %s' % sharing_secret)
yield gen.Task(SharingController.__cache.set_sharing_record, sharing_secret, 'false')
callback(None)
def get_sharing_secret_from_subscriber_info(user_id, collection_name, callback):
"""
Retrieves the sharing secret of a sharing space, uniquely identified
by the user_id and collection name.
-Returns:
- The secret is passed to the callback. If there is no such
subscriber then None is passed
"""
#first look up in the cache
sharing_secret = yield gen.Task(SharingController.__cache.get_subscriber_info,
user_id, collection_name)
if sharing_secret is not None:
#this means we have looked up in the DB before and the sharing secret wasn't there
if sharing_secret == 'false':
callback(None)
else:
callback(sharing_secret)
#if cache miss it look up in the DB
else:
subscriber_collection = DatabaseFactory.get_subscribers_collection()
query = {SharingController.SUBSCRIBER_ID_KEY : user_id,
SharingController.SUBSCRIBER_COLLECTION_NAME_KEY : collection_name}
subscriber_record_cursor = yield gen.Task(subscriber_collection.find, query)
result_count = len(subscriber_record_cursor[0][0])
#if user_id and collection_name are not uniquely identifying the
#share space then we are in trouble
if result_count >= 2:
SharingController.__log.warning('SharingController - More than two sharing info found for: ' + user_id + ' - ' + collection_name)
result_count = 0
if not result_count:
SharingController.__log.info('SharingController - No sharing record found for user %s and collection %s' % (user_id, collection_name))
#cache the lack of info so we don't hit the DB every time we ask for a non existing sharing record
yield gen.Task(SharingController.__cache.set_subscriber_info, user_id, collection_name, 'false')
callback(None)
else:
subscriber_record_bson = subscriber_record_cursor[0][0][0]
sharing_secret = subscriber_record_bson[SharingController.SHARING_SPACE_SECRET_KEY]
if sharing_secret is None or not len(sharing_secret):
SharingController.__log.info('SharingController - Sharing secret is None or Empty for user %s and collection %s' % (user_id, collection_name))
yield gen.Task(SharingController.__cache.set_subscriber_info, user_id, collection_name, 'false')
callback(None)
else:
#set the cache for future usage
yield gen.Task(SharingController.__cache.set_subscriber_info,
user_id, collection_name, sharing_secret)
#now call back to the user
callback(sharing_secret)
def remove_sharing_record_by_secret(sharing_secret, callback):
"""
Removes a sharing record identified by the sharing_secret
Returns:
- void. The callback will be called
"""
sharing_collection = DatabaseFactory.get_sharing_collection()
query = {SharingRecord.SECRET_KEY : sharing_secret}
#first remove subscribers
yield gen.Task(SharingController.remove_all_subscribers, sharing_secret)
#the collection itself
yield gen.Task(sharing_collection.remove, query)
#remove the record from the cache too
yield gen.Task(SharingController.__cache.remove_sharing_record, sharing_secret)
callback()
def remove_subscriber(user_id, collection_name, callback):
"""
Removes the subscriber from the subscribers collection.
user_id and collection_name identify a sharing space uniquely.
This is implementation detail. Do not use for actual logic, does
not guarauntee updates to sharing record
"""
subscriber_collection = DatabaseFactory.get_subscribers_collection()
query = {SharingController.SUBSCRIBER_ID_KEY : user_id,
SharingController.SUBSCRIBER_COLLECTION_NAME_KEY : collection_name}
yield gen.Task(subscriber_collection.remove, query)
#remove from cache too
yield gen.Task(SharingController.__cache.remove_subscriber_info,
user_id, collection_name)
if callback is not None:
callback()
def __update_sharing_record(sharing_record, callback):
"""
updates the sharing recrod in the mongoDB database.
The passed in sharing record will replace the one
in the db
This method is very dangerous as the user must make sure that
they also update the subscribers collection in mongo
"""
sharing_collection = DatabaseFactory.get_sharing_collection()
doc_key = {SharingRecord.SECRET_KEY: sharing_record.get_sharing_secret()}
doc_content = sharing_record.toDictionary()
sharing_record_json = sharing_record.to_json_str()
yield gen.Task(sharing_collection.update, doc_key, doc_content)
#update the cache
yield gen.Task(SharingController.__cache.set_sharing_record,
sharing_record.get_sharing_secret(), sharing_record_json)
callback()
def __rename_subscriber_collection_name(user_id, old_collection_name,
new_collection_name, sharing_secret,
callback):
"""
Updates the subscriber table for the user with user_id with the new name
for its collection
"""
sharing_collection = DatabaseFactory.get_subscribers_collection()
key = {SharingController.SUBSCRIBER_ID_KEY : user_id,
SharingController.SUBSCRIBER_COLLECTION_NAME_KEY : old_collection_name}
new_content = {SharingController.SUBSCRIBER_ID_KEY : user_id,
SharingController.SUBSCRIBER_COLLECTION_NAME_KEY : new_collection_name,
SharingController.SHARING_SPACE_SECRET_KEY : sharing_secret}
yield gen.Task(sharing_collection.update, key, new_content)
#remove the old content from cache
yield gen.Task(SharingController.__cache.remove_subscriber_info,
user_id, old_collection_name)
#add new content to the cache
yield gen.Task(SharingController.__cache.set_subscriber_info,
user_id, new_collection_name, sharing_secret)
#TODO I can probalby use the replace cmd in memcache to reduce these two calls to one
callback()
def add_subscriber(user_id, collection_name, sharing_secret, callback):
"""
Adds a subscriber with user id and collection and sharing secret
to the subscribers db. user_id and collection_name uniquely identify
the subscriber and maps it to the sharing_secret of the sharing space
This is implementation detail. Do not use for actual logic
"""
if sharing_secret is None or user_id is None or collection_name is None:
SharingController.__log.warning('Sharing Controller - A value was none in add subscriber')
callback()
else:
subscriber_collection = DatabaseFactory.get_subscribers_collection()
subscriber_record = {SharingController.SUBSCRIBER_ID_KEY : user_id,
SharingController.SUBSCRIBER_COLLECTION_NAME_KEY : collection_name,
SharingController.SHARING_SPACE_SECRET_KEY : sharing_secret}
yield gen.Task(subscriber_collection.insert, subscriber_record)
#add it to the cache to, since we get synchronization for free. this should be
#optimal
yield gen.Task(SharingController.__cache.set_subscriber_info,
user_id, collection_name, sharing_secret)
callback()
def __get_collection():
return DatabaseFactory.get_accounts_collection()
