def create_multi(cls, values):
"""Creates multiple unique values at once.
:param values:
A sequence of values to be unique. See :meth:`create`.
:returns:
A tuple (bool, list_of_keys). If all values were created, bool is
True and list_of_keys is empty. If one or more values weren't
created, bool is False and the list contains all the values that
already existed in datastore during the creation attempt.
"""
# Maybe do a preliminary check, before going for transactions?
# entities = model.get_multi(keys)
# existing = [entity.key.id() for entity in entities if entity]
# if existing:
# return False, existing
# Create all records transactionally.
keys = [model.Key(cls, value) for value in values]
entities = [cls(key=key) for key in keys]
func = lambda e: e.put() if not e.key.get() else None
created = [model.transaction(lambda: func(e)) for e in entities]
if created != keys:
# A poor man's "rollback": delete all recently created records.
model.delete_multi(k for k in created if k)
return False, [k.id() for k in keys if k not in created]
return True, []
def create_multi(cls, values):
"""Creates multiple unique values at once.
:param values:
A sequence of values to be unique. See :meth:`create`.
:returns:
A tuple (bool, list_of_keys). If all values were created, bool is
True and list_of_keys is empty. If one or more values weren't
created, bool is False and the list contains all the values that
already existed in datastore during the creation attempt.
"""
# Maybe do a preliminary check, before going for transactions?
# entities = model.get_multi(keys)
# existing = [entity.key.id() for entity in entities if entity]
# if existing:
# return False, existing
# Create all records transactionally.
keys = [model.Key(cls, value) for value in values]
entities = [cls(key=key) for key in keys]
func = lambda e: e.put() if not e.key.get() else None
created = [model.transaction(lambda: func(e)) for e in entities]
if created != keys:
# A poor man's "rollback": delete all recently created records.
model.delete_multi(k for k in created if k)
return False, [k.id() for k in keys if k not in created]
return True, []
def delete_multi(cls, values):
"""Deletes multiple unique values at once.
:param values:
A sequence of values to be deleted.
"""
return model.delete_multi(model.Key(cls, v) for v in values)
def delete_multi(cls, values):
"""Deletes multiple unique values at once.
:param values:
A sequence of values to be deleted.
"""
return model.delete_multi(model.Key(cls, v) for v in values)
def delete_all(cls):
return model.delete_multi(cls.query().fetch(keys_only = True))