How Scale Affects Structure in Java Programs

Many internal software metrics and external quality attributes of Java programs correlate strongly with program size. This knowledge has been used pervasively in quantitative studies of software through practices such as normalization on size metrics. This paper reports size-related super- and sublinear effects that have not been known before. Findings obtained on a very large collection of Java programs -- 30,911 projects hosted at Google Code as of Summer 2011 -- unveils how certain characteristics of programs vary disproportionately with program size, sometimes even non-monotonically. Many of the specific parameters of nonlinear relations are reported. This result gives further insights for the differences of "programming in the small" vs. "programming in the large." The reported findings carry important consequences for OO software metrics, and software research in general: metrics that have been known to correlate with size can now be properly normalized so that all the information that is left in them is size-independent.Comment: ACM Conference on Object-Oriented Programming, Systems, Languages and Applications (OOPSLA), October 2015. (Preprint

A test-driven approach to code search and its application to the reuse of auxiliary functionality

Context: Software developers spend considerable effort implementing auxiliary functionality used by the main features of a system (e.g., compressing/decompressing files, encryption/decription of data, scaling/rotating images). With the increasing amount of open source code available on the Internet, time and effort can be saved by reusing these utilities through informal practices of code search and reuse. However, when this type of reuse is performed in an ad hoc manner, it can be tedious and error-prone: code results have to be manually inspected and integrated into the workspace.Objective: in this paper we introduce and evaluate the use of test cases as an interface for automating code search and reuse. We call our approach Test-Driven Code Search (TDCS). Test cases serve two purposes: (1) they define the behavior of the desired functionality to be searched; and (2) they test the matching results for suitability in the local context. We also describe CodeGenie, an Eclipse plugin we have developed that performs TDCS using a code search engine called Sourcerer.Method: Our evaluation consists of two studies: an applicability study with 34 different features that were searched using CodeGenie; and a performance study comparing CodeGenie, Google Code Search, and a manual approach.Results: Both studies present evidence of the applicability and good performance of TDCS in the reuse of auxiliary functionality.Conclusion: This paper presents an approach to source code search and its application to the reuse of auxiliary functionality. Our exploratory evaluation shows promising results, which motivates the use and further investigation of TDCS. (C) 2010 Elsevier B.V. All rights reserved.Universidade Federal de São Paulo, Dept Sci & Technol, Sao Jose Dos Campos, SP, BrazilUSP, ICMC, Comp Syst Dept, BR-13560970 Sao Carlos, SP, BrazilUniv Calif Irvine, Donald Bren Sch Informat & Comp Sci, Irvine, CA USAUniversidade Federal de São Paulo, Dept Sci & Technol, Sao Jose Dos Campos, SP, BrazilWeb of Scienc