The Study Of Parallel Algorithm For XML Processing

The large-scale electronic publishing and the exchange of a wide variety of data on the Web need a language that has good description ability and dealing with ability. The HyperText Markup Language that has made the outstanding contributions for the development of Internet and Web can't already be suitable for the needs of above-mentioned business because of its own defect. The World Wide Web Consortium(W3C) has developed and issued a new generation markup language - Extensible Markup Language(XML). With the issued of the XML, each manufacturer and company developed their own XML parser one after another. These XML parser support the Simple API for XML (SAX) and/or DOM API. The parser that use the SAX deal with the XML file in sequence, the data was not in the memory after operated and it can't modify the file, so it can't do random access to the file and is difficult to realize complex query. The scope of application of SAX is small. The parser that use the DOM can avoid some disadvantages of using SAX. But the DOM is a kind of operation of consuming memory. It regard the element, attribute, character data, processing instruction and comment as a node object to deal with. The document object tree that made up of this node object need to take up a large amount of memory. For some large-scale files which include many nodes if processed with the DOM parser would needed high performance computer otherwise the processing speeds would be reduced even couldn't go on because of consumed system resources in a large amount.With the development of computer technology and network technology, the distributed parallel computation environment that based on network become a new high performance calculation environment because of its high cost performance and big range, largequantity heterogeneous cluster system parallel computation. The XML and DOM has good parallel structure. Based on the distributed parallel computation environment that based on network, this paper study the parallel processing of XML. Programmed by the JAVA , utilizing the multi-thread technology of JAVA to realize parallel processing and the socket technology of JAVA to realize communications, we developed a parallel XML parser. The parallel processing of XML mainly is the parallel processing of data. We study the dealing with of prolog, the recognition of character encoding, the cutting apart of data, the parallel parser and carry on the experiment. The experiment has proved that the parallel XML parser which developed and implemented by this paper has made the anticipated result.