A Consistency Model and Supporting Schemes for Real-time Cooperative Editing Systems

C. Sun
School of Computing & Information Technology, Griffith University, Brisbane, Qld 4111, Australia.
C.Sun@cit.gu.edu.au

Y. Yang
CRC for Distributed Systems Technology, Level 7, Gehrmann Labs, University of Queensland, Brisbane, Qld 4072, Australia.
yun@dstc.edu.au

Y. Zhang
Department of Mathematics & Computing, The University of Southern Queensland, Toowoomba, Qld 4350, Australia.
yan@usq.edu.au

D. Chen
School of Computing & Information Technology, Griffith University, Brisbane, Qld 4111, Australia.
D.Chen@cit.gu.edu.au

Abstract

Real-time cooperative editing systems allow multiple users to view and edit the same document at the same time from multiple sites connected by a communication network. Consistency maintenance is one of the most significant challenges in designing and implementing real-time cooperative editing systems. In this paper, three inconsistency problems -- divergence, causality-violation, and intention-violation -- in real-time cooperative editing systems are first identified. Then, a novel consistency model, with properties of convergence, causality-preservation, and intention-preservation, is proposed as a framework for solving these problems. Moreover, an integrated set of schemes and algorithms, which support the proposed consistency model, are defined and discussed in detail. A software simulation system has been built to verify the correctness of the proposed approach. We conclude by summarizing the main results and contributions of this work and listing the major current and future works.

Conference Home Page