Recommending Refactorings to Reverse Software Architecture Erosion (CSMR 2012)

Architectural erosion is a recurrent problem faced by software architects. Despite this fact, the process is usually tackled in ad hoc way, without adequate tool support at the architecture level. To address this issue, we describe the preliminary design of a recommendation system whose main purpose is to provide refactoring guidelines for developers and maintainers during the task of reversing an architectural erosion process. The paper formally describes first recommendations proposed in our current research and results of their application in a web-based application.

Transcript

1. Recommending Refactorings to Reverse Software
   Architecture Erosion
   Ricardo Terra
   Marco Túlio Valente Krzysztof Czarnecki
   Roberto S. Bigonha
   {terra,bigonha,mtov}@dcc.ufmg.br kczarnec@gsd.uwaterloo.ca
   CSMR ERA, 2012
   CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 1 / 10
   

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2. Introduction
   CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 2 / 10
   Intended
   

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3. Introduction
   CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 2 / 10
   Intended Implemented
   

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4. Introduction
   CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 2 / 10
   Intended Implemented
   

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5. Introduction
   CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 2 / 10
   Intended Implemented
   

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6. Introduction
   CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 2 / 10
   Intended Implemented
   

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7. Motivation
   CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 3 / 10
   Detecting...
   

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8. Motivation
   CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 3 / 10
   Detecting...
   But...
   ?
   expertise
   waste of time
   ad hoc procedures
   

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9. Architectural Recommendation Engine – Overview
   Architectural Recommendation Engine
   Architectural_Rule
   Code_With_Violation =⇒ Recommendation,
   if Preconditions
   CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 4 / 10
   

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10. Architectural Recommendation Engine – Overview
    Architectural Recommendation Engine
    Architectural_Rule
    Code_With_Violation =⇒ Recommendation,
    if Preconditions
    Sounds like?
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 4 / 10
    

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11. Architectural Recommendation Engine – Overview
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 5 / 10
    Exactly! However, focus on the architectural level
    DCL
    

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12. Architectural Recommendation Engine – Overview
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 5 / 10
    Exactly! However, focus on the architectural level
    DCL
    only FactoryB can-create B
    

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13. Architectural Recommendation Engine – Overview
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 5 / 10
    Exactly! However, focus on the architectural level
    DCL
    only FactoryB can-create B
    

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14. Architectural Recommendation Engine – Overview
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 5 / 10
    Exactly! However, focus on the architectural level
    DCL
    only FactoryB can-create B
    

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15. Architectural Recommendation Engine – Overview
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 5 / 10
    Exactly! However, focus on the architectural level
    DCL
    only FactoryB can-create B
    

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16. Architectural Recommendation Engine – Overview
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 5 / 10
    Exactly! However, focus on the architectural level
    DCL
    only FactoryB can-create B
    

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17. Architectural Recommendation Engine – Overview
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 5 / 10
    Exactly! However, focus on the architectural level
    DCL
    only FactoryB can-create B
    analyzes the violation
    

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18. Architectural Recommendation Engine – Overview
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 5 / 10
    Exactly! However, focus on the architectural level
    DCL
    only FactoryB can-create B
    analyzes the violation
    A /
    ∈ FactoryB
    A cannot-create B
    

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19. Architectural Recommendation Engine – Overview
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 5 / 10
    Exactly! However, focus on the architectural level
    DCL
    only FactoryB can-create B
    analyzes the violation
    checks constraints
    A /
    ∈ FactoryB
    A cannot-create B
    

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20. Architectural Recommendation Engine – Overview
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 5 / 10
    Exactly! However, focus on the architectural level
    DCL
    only FactoryB can-create B
    analyzes the violation
    checks constraints
    A /
    ∈ FactoryB
    A cannot-create B
    

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21. Architectural Recommendation Engine – Overview
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 5 / 10
    Exactly! However, focus on the architectural level
    DCL
    only FactoryB can-create B
    analyzes the violation
    checks constraints
    performs SCA
    A /
    ∈ FactoryB
    A cannot-create B
    

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22. Architectural Recommendation Engine – Overview
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 5 / 10
    Exactly! However, focus on the architectural level
    DCL
    only FactoryB can-create B
    analyzes the violation
    checks constraints
    performs SCA
    A /
    ∈ FactoryB
    A cannot-create B
    + getB() : B
    

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23. Architectural Recommendation Engine – Overview
    Bingo!
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 6 / 10
    

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24. Architectural Recommendation Engine – Overview
    Bingo!
    Triggered Refactoring Recommendation
    A cannot-create B
    new B(exp) =⇒ replace( [new B(exp)], [FB.getB(exp)] ),
    if FB = factory(B, [exp] ) ∧ can(A, access, FB)
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 6 / 10
    

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25. Refactoring Recommendations – Table
    A cannot-create B, where A ∈ MA ∧ B ∈ MB
    new B(exp) =
    ⇒ replace( [new B(exp)], [FB.getB(exp)] ), if FB = factory(B, [exp] ) ∧
    can(A, access, FB)
    new B(exp) =
    ⇒ replace( [new B(exp)], [FB.getB(exp)] ), if FB = gen_factory(B, [exp] ) ∧
    can(A, access, FB)
    A cannot-declare B
    B b; S =
    ⇒ replace( [B], [B ] ), if B ∈ super(B) ∧ typecheck( [B b ; S] ) ∧ B /
    ∈ MB
    B b = exp; S =
    ⇒ propagate( [exp], b, [S] ), if can(A, access, B)
    A cannot-access B
    b.f =
    ⇒ replace( [b.f], [D; c.g] ), if g = delegate(f) ∧ D = gen_decl(type(c), g) ∧
    type(c) /
    ∈ MB
    b.f =
    ⇒ g = extract( [b.f] ), move(g, C), if C = suitable_class(g) ∧
    can(A, access, C)
    g { T v = exp_b } =
    ⇒ promote(g, v, [exp_b] ), if ∀C ∈ call_sites(g), can(C, access, B)
    A cannot-throw B
    g (p) throws B { S } =
    ⇒ remove( [throws B] ), if typecheck( [g (p) { S }] )
    g (p) throws B { S } =
    ⇒ remove( [throws B] ), replace( [S], [try {S} catch (B b){S }] ),
    if can(A, declare, B) ∧ S = user_code()
    A cannot-derive B
    A extends | implements B =
    ⇒ move(A, M), if M = suitable_module(A) ∧ can(A, extends | implements, B)
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 7 / 10
    We have formalized a set of more than 20 refactoring recommendations!
    

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26. Preliminary Evaluation
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 8 / 10
    MyWebMarket
    simple web-based e-commerce system
    

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27. Preliminary Evaluation
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 8 / 10
    MyWebMarket
    simple web-based e-commerce system
    mirrors architecture, constraints,
    and violations from a previously
    evaluated system
    

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28. Preliminary Evaluation
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 8 / 10
    MyWebMarket
    simple web-based e-commerce system
    mirrors architecture, constraints,
    and violations from a previously
    evaluated system
    #1: only DAOFactory can-create HibernateDAO
    #2: Controller cannot-handle HibernateDAO
    #3: Model can-only-throw DAOException
    #4: only SystemScheduling can-depend QuartzAPI
    

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29. Preliminary Evaluation
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 8 / 10
    MyWebMarket
    simple web-based e-commerce system
    mirrors architecture, constraints,
    and violations from a previously
    evaluated system
    #1: only DAOFactory can-create HibernateDAO
    #2: Controller cannot-handle HibernateDAO
    #3: Model can-only-throw DAOException
    #4: only SystemScheduling can-depend QuartzAPI
    Constraint # Violations # Recs. # Violations
    before after
    #1 21 21 0
    #2 43 15 12
    #3 44 44 0
    #4 9 9 0
    

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30. Preliminary Evaluation
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 8 / 10
    MyWebMarket
    simple web-based e-commerce system
    mirrors architecture, constraints,
    and violations from a previously
    evaluated system
    #1: only DAOFactory can-create HibernateDAO
    #2: Controller cannot-handle HibernateDAO
    #3: Model can-only-throw DAOException
    #4: only SystemScheduling can-depend QuartzAPI
    Constraint # Violations # Recs. # Violations
    before after
    #1 21 21 0
    #2 43 15 12
    #3 44 44 0
    #4 9 9 0
    ∼90%!
    

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31. Ongoing work
    Evaluation in real systems (in progress)
    Medium-size (30KLOC)
    Large-size (750KLOC)
    More refactoring recommendations (in progress)
    Divergences and also absences
    The dclsuite tool (in progress)
    dclcheck + dclfix
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 9 / 10
    

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32. Thanks!!!
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 10 / 10
    

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33. CSMR 2012
    Presentation: Thursday, March 29, 2012, at 11am
    Poster Session: On the Afternoon of the same day
    CSMR ERA, 2012 Recommending Refactorings to Reverse Software Architecture Erosion 10 / 10
    

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