GRACE TECHNICAL REPORTS Beanbag: Operation-based Synchronization with Intra-relations

Modern development environment often involves data with complex relationships. When users update some part of the data, we need to synchronize the update to make all data consistent. Bidirectional transformation supports synchronization by propagating updates between two replicas, from one replica to the other or vice versa. However, replicas are often constrained with intra-relations, and we may have to propagate updates within one replica. Such kind of propagation is not well supported by current bidirectional transformation. In this paper we propose Beanbag, a new language for operation-based synchronization of data with intra-relations. Beanbag treats inter-relations and intra-relations in a unified way, and allows users to define these relations declaratively. A Beanbag program can be compiled into a synchronizer, which takes user updates as input and produces new updates to make all data consistent. We have implemented Beanbag in Java, applied it to several applications and tested its performance by experiments.