The Design And Implementation Of A Structural Document Version Management System For A Cooperative Editing System

This paper introduces a design of structural document version management system which implements in a real cooperative editor (Z-Office).The main purposes of version management of XML documents are to efficiently store a frequently modified XML document, reduce the storage costs, retrieve previous versions of the XML document with quick response, and provide mechanism querying Multi-Version XML documents. Z-Office provides its document format which instantiates XML specification. This paper therefore presents a solution to versionize such documents.Firstly, this paper studies and analyzes algorithm X-Diff, and the related SPaR numbering schema for version control mechanism are analyzed. Secondly, an improvement in document node numbering is presented. Both temporal and spatial views are taken account into creating sparse position number, lifespan and other node properties for every document node in the tree document structures of Z-Office. And a new algorithm based document update maintenance is proposed and implemented in the system. With the support of these works, Z-Office can retrieve all versions efficiently and quickly. Therefore Z-Office needs not to restore the version forward and backward. Finally, for the Multi-Version document query, this paper makes use of text search technology and structural join algorithm so as to support search based on key words, accurate search and comparative search. All the work above realizes a complete version management system for a real cooperative editor.