Tree Automata for Extracting Consensus from Partial Replicas of a Structured Document

TL;DR

This paper introduces a method using tree automata to merge partial, potentially conflicting replicas of a structured document in asynchronous collaborative editing, ensuring a consistent consensus document.

Contribution

It proposes a novel approach leveraging tree automata to extract consensus documents from partial replicas in asynchronous editing workflows.

Findings

Automata-based merging guarantees conflict-free consensus documents.

The method efficiently identifies maximum conflict-free prefixes.

It enhances confidentiality by working with partial replicas.

Abstract

In an asynchronous cooperative editing workflow of a structured document, each of the co-authors receives in the different phases of the editing process, a copy of the document to insert its contribution. For confidentiality reasons, this copy may be only a partial replica containing only parts of the (global) document which are of demonstrated interest for the considered co-author. Note that some parts may be a demonstrated interest over a co-author; they will therefore be accessible concurrently. When it's synchronization time (e.g. at the end of an asynchronous editing phase of the process), we want to merge all contributions of all authors in a single document. Due to the asynchronism of edition and to the potential existence of the document parts offering concurrent access, conflicts may arise and make partial replicas unmergeable in their entirety: they are inconsistent, meaning that they contain conflictual parts. The purpose of this paper is to propose a merging approach said by consensus of such partial replicas using tree automata. Specifically, from the partial replicas updates, we build a tree automaton that accepts exactly the consensus documents. These documents are the maximum prefixes containing no conflict of partial replicas merged.