Loosely Coupling Java Algorithms and XML Parsers: a Performance-Oriented Study

The adoption of XML to represent any kind of data and documents, even complex and huge, is becoming a matter of fact. However, interfacing algorithms and applications with XML Parsers requires to adapt algorithms and applications: event-based SAX Parsers need algorithms that react to events generated by the parser. But parsing/loading XML documents provides poor performance (if compared to reading flat files): therefore, several researches are trying to address this problem by improving the parsing phase, e.g., by adopting condensed or binary representations of XML documents. This paper deals with the other side of the coin, i.e., the problem of coupling algorithms with XML Parsers, in a way that does not require to change the active (polling-based) nature of many algorithms and provides acceptable performance during execution; this problem becomes even more important when we consider Java algorithms, that usually are less efficient than C or C++ algorithms. This paper presents a study about the problem of loosely coupling Java algorithms with XML Parsers. The coupling is loose because the algorithm should be unaware of the particular interface provided by parsers. We consider several coupling techniques, and we compare them by analyzing their performance. The evaluation leads us to identify the coupling techniques that perform better, depending on the specific algorithm’s needs and application scenario.