def wrapper(*args, **kwargs):
d = Deferred()
try:
d.resolve(func(*args, **kwargs))
except Exception as e:
d.reject(exception=e)
return d.promise()
class CollectionSaveHelper(six.Iterator):
def __init__(self, manager, new_collection):
self.deferred = Deferred()
self._manager = manager
self.new_collection = new_collection
self.old_collection = None
self.items = iter(new_collection)
def __next__(self):
return next(self.items)
def save(self):
# read current state of collection (it`s items)
# if collection exists - go to next step
# otherwise create new collection
self._manager.storage.read_collection(self.new_collection.id)\
.done(partial(self._collection_found))\
.fail(partial(self._collection_not_found))
return self.deferred.promise()
def _collection_found(self, old_collection):
self.old_collection = self._manager.collection_factory.discover(old_collection)
self._add_items()
def _collection_not_found(self, exception):
self._manager.storage.create_collection(self.new_collection.id)\
.done(partial(self._collection_created))\
.fail(self.deferred.reject)
def _collection_created(self, collection_id):
self.new_collection.id = collection_id
# lie that old collection was just empty
self._collection_found([])
def _add_items(self):
try:
self._manager.add_item_to_collection(self.new_collection,
next(self)).done(self._item_added)\
.fail(self.deferred.reject)
except StopIteration:
self._del_items()
def _item_added(self, item_id):
try:
del self.old_collection[item_id]
except:
pass
self._add_items()
def _del_items(self, deleted_item_id=None):
try:
self._manager.remove_item_from_collection(
self.new_collection, next(self.old_collection))\
.done(partial(self._del_items))\
.fail(self.deferred.reject)
except StopIteration:
self.deferred.resolve(self.new_collection.id)
