Analyzing web service similarity using contextual clones

Abstract

There are several tools and techniques developed over the past decade for detecting duplicated code in software. However, there exists a class of languages for which clone detection is ill-suited. We discovered one of these languages when we attempted to use clone detection to find similar web service operations in service descriptions written in the Web Service Description Language (WSDL). WSDL is structured in such a way that identifying units for comparison becomes a challenge. WSDL service descriptions contain specifications of one or more operations that are divided into pieces and intermingled throughout the description. In this paper, we describe a method of reorganizing them in order to leverage clone detection technology to identify similar services. We introduce the idea of contextual clones -- clones that can only be found by augmenting code fragments with related information referenced by the fragment to give it context. We demonstrate this idea for WSDL and propose other languages and situations for which contextual clones may be of interest.