CSC305 Lecture 07

Individual Software Design and Development
Structural Metrics
(202410)

Transcript

1. Dr. Javier Gonzalez-Sanchez javiergs@calpoly.edu www.javiergs.info o ffi ce: 14 -227 CSC 305 Individual Software Design and Development Lecture 07. Structural Metrics
2. Code Metrics 2
3. Complexity Number Meaning 1-10 Structured and well written code High Testability Cost and Effort is less 10-20 Complex Code Medium Testability Cost and effort is Medium 20-40 Very complex Code Low Testability Cost and Effort are high >40 Not at all testable Very high Cost and Effort Cyclomatic Complexity 3
4. Structural Metrics Abstractness Instability
5. Is this a good design? 5
6. Relationships 6 Association Directed Association Reflexive Association Multiplicity Aggregation Composition Generalization Realization
7. Abstractness of a Package • It is the degree to which a cl a ss or p a ck a ge emph a sizes a bstr a ction over concrete implement a tion • It is a v a lue 0 to 1: • For p a ck a ges, It is the r a tio of a bstr a ct cl a sses or interf a ces to the tot a l number of cl a sses within a p a ck a ge. • For cl a sses, It is 0 for a concrete cl a ss a nd 1 for a n interf a ce or a bstr a ct cl a sses 7
8. Instability • Indic a tes whether: ( a ) the item is m a inly used by others (st a ble – h a rd to ch a nge); or (b) it m a inly depends on other items (in-st a ble – ch a nge a ble). • It is a v a lue between 0 a nd 1: • 0 only incoming dependencies to • 1 (only outgoing dependencies). 8
9. Structural Metrics Distance
10. Distance • Dist a nce: how f a r a p a ck a ge is a w a y from the M a in Sequence • D = A + I – 1 • V a lues -1 to 1 • Absolute Dist a nce |D| 10
11. Distance 11 Abstract Concrete Stable Hard to Change Only incoming dependencies Unstable Changeable Only outgoing dependencies the m ain sequence Painful Useless 0 1 1 0 Instability Abstractness
12. project3.common.model project3.client.UI project3.server.controller
13. Test Yourselves
15. Is this a good design? 15
16. Questions 16
17. Lab 05 Software Metrics
18. Reminder 18 Calculate metrics (A, I) for the kappa version of my Paint App https://github.com/CSC3100/App-Paint/tree/main/ src/main/java/javiergs/paint/Kappa
19. Let’s Work 19
20. CSC 305 Individual Software Design and Development Javier Gonzalez-Sanchez, Ph.D. javiergs@calpoly.edu Summer 2024 Copyright. These slides can only be used as study material for the class CSC305 at Cal Poly. They cannot be distributed or used for another purpose.