Research on the Algorithm for Coarse-Grained Web Program Slicing

Abstract

A novel approach based on constructing coarse-grained system dependence is proposed to compute web program slicing. The method perfects web program semantics and reduces the computation complexity through expanding the signification of coarse-grained and analyzing the dependence among semantic units. Program semantic units are described in detail. The expression of dependence includes data dependence, control dependence and transfer dependence. At length, two algorithms for constructing system dependence graph and computing coarse-grained program slicing are designed. Introduction Program slicing is a technique for simplifying programs by focusing on selected aspects of semantics unit. The process of slicing deletes those parts of the program which can be determined to have no effect upon the semantics of interest. As a valid method to restrict the focus of a task to specific sub-components of a program, program slicing has extensive applications in software engineering [1]. The applications include program debugging, program testing, software metrics and software maintenance [2].Web program is a special kind of web application for releasing information and accepting input through web pages. With the rapid development of internet technology and www technology, Web application relates to different fields more widely. Recent years have witnessed the increasing of web applications with the advent of .net, J2EE and other new web integration framework [3]. Meanwhile, the size and complexity of web applications are also increasing. Web’s rapid build features present the understanding, analysis and testing of the programs with difficulties.Program slicing technology is applied to web application analysis in this paper. Developers can focus on only those procedures associated with certain web pages or achieving a particular function, thus the reliability and validity of web program are improved. This paper aims to compute coarse-grained web program slicing for obtaining interest points and hierarchy information of web application through analyzing the dependencies between web programs. The program slicing in the paper based on the dependency analysis of program’s dataflow, control flow and interaction between the server application and client application. Simplifying System Dependence Graph In order to understand web program, analyzing the interaction relationships among multiple units is better than analyzing single statement. The definition of coarse-grained is enlarged in order to make the size of grain come up to the web program’s semantic unit. Coarse-grained is defined as follows. Definition.1 Coarse-grained: The graph G which meets the following characters is defined as coarse-grained. (1) Graph G contains the following units which include statement and predicate in the main, class, instance, member method and member variable. (2) In the member method M, if a statement belongs to G, then M also belongs to G. (3) If the member method, member variable and instance in the class A belongs to G, then class A also belongs to G. 2nd International Conference on Electrical, Computer Engineering and Electronics (ICECEE 2015) © 2015. The authors Published by Atlantis Press 1260 System dependence graph is simplified on the basis of above definition of the coarse-grained. Take the following graph for example, fig.1 is a traditional system dependence graph, fig.2 shows the meaning of edges in the graph, and fig.3 is the simplified result.