A Fast Operational Transformation Algorithm for Mobile and Asynchronous Collaboration

In a mobile collaboration environment, the shared files are often replicated so that the users can work in parallel during periods of disconnection. When reconnected, sequences of updates made by different users are merged to produce a consistent view of shared files. This paper presents a novel transformation-based merging algorithm for supporting mobile collaboration. Compared to alternative optimistic consistency control methods, it can merge any updates to the same file automatically at the finest granularity without causing loss of work. Moreover, it improves the time complexity of the state-of-the-art transformation-based merging algorithms from O(n³) to O(n), where n is the size of either sequence when their sizes are comparable. This improvement is drastic and important especially for mobile devices that run on batteries and have limited processing power.