Methods and systems for compressing and decompressing extensible markup language (XML) data

Abstract

The invention provides a method for compressing extensible markup language (XML) data. The method comprises the following steps of: optimizing an XML schema to remove indirect use between redundant structure information and a node, and storing the optimized schema; extracting a structural information part of the XML data which takes the schema as a specification by using the optimized schema; dividing a data part of the XML data into a plurality of data blocks according to the node of the optimized schema; and respectively compressing the structural information part and the data blocks by using a general compression method, and outputting compression results to a file. Correspondingly, the invention provides a decompression method, a compression system and a decompression system of the XML data. In the invention, the minimum structural information is acquired by simplifying the XML schema, and a packet storage strategy of the data is improved, so that compression rate is improved. Furthermore, the storage of miniature data blocks is optimized, so that the compression rate is further improved.

Description

technical field [0001] The invention relates to the field of XML data processing, in particular to an XML data compression and decompression method and system. Background technique [0002] XML (Extensible Markup Language), as a cross-platform standard data exchange format, is widely used in web services, data exchange and storage, etc. It is a powerful tool for processing structured document information. Since the XML document contains a large number of repeated tags and structural information, there is a large amount of data redundancy in the XML document, so it needs to be compressed in many applications. Commonly used XML compression methods are XMILL, XMLPPM, XWRT and so on. [0003] The XMILL compression method first separates the XML structure information from the XML document through the syntax parser SAX, then reorganizes the XML document data items into different containers according to different semantics, and finally uses GZip to compress each container separate...

AI Technical Summary

Problems solved by technology

[0007] Although the above-mentioned compression methods can better compress some specific XML files, since these compression methods mainly deal with the regular parts of XML documents and most of them use the method of compressing data by node blocks, Without taking into account the irregular structure and the presence of micro-blocks (i.e., blocks of data whose size is small) in the corresponding XML tree of the XML document

Therefore, when the XML document structure is relatively complex, there may be a large number of micro-data blocks, and the existing compression methods often have low compression ratios for such XML documents.

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