Supporting Incremental Changes in Large Models by Jannik Laval, Simon Denier, Stephane Ducasse and Andy Kellens, ESUG09, Brest, France.

1. SUPPORTING INCREMENTAL
CHANGES IN LARGE MODELS
Jannik Laval, Simon Denier, Stéphane Ducasse
RMod Team - INRIA
Andy Kellens
Software Languages Lab - VUB

2. ROADMAP
• Problem
• Different naive approaches
• copy
• delta
• lookup
• Our proposal

3. PROBLEM
• How to predict impact of changes ?
• How to predict and compare different
futures ?
• In large models.

4. EXAMPLE
• move mB1() in classA.
• remove classC.
Pack1 Pack1'
classA classA'
mA1() mA1'()
mA2() mA2'()
mB1'()
classB
mB1() classB'
mB2() mB2'()
classC

5. DIFFERENT NAIVE
APPROACHES
• Copy
• Delta
• LookUp

6. COPY
Model 1
Pack1
parentPackage
classC
classA
classB
parentClass
parentClass
mA1() mA2() mB1() mB2()
to from to from
anInvocation anInvocation
Model 2
Pack1'
parentPackage
classA'
classB'
parentClass
parentClass
mA1'() mA2'() mB1'() mB2'()
to from to from
anInvocation' anInvocation'

7. COPY
• Pros
• each version is complete
• easy to use and to transform
• Cons
• high creation time
• high memory usage

8. DELTA
Model 1
Pack1
parentPackage
classC
classA Model 2
classB
parentClass - removeLinkBetween: classB and: mB1()
parentClass - createLinkBetween: classA and: mB1()
- removeClass: classC
mA1() mA2() mB1() mB2()
to from to from
anInvocation anInvocation

9. DELTA
• Pros
• each version is represented by its changes
• fast to create a version
• Cons
• slow to access a version

10. Model 1
LOOKUP
Pack1
parentPackage
classC
classA
classB
parentClass
parentClass
mA1() mA2() mB1() mB2()
to from to from
anInvocation anInvocation
Model 2 LookUp
Pack1'
removedClass
C
classA'
classB'
parentClass
mB1'()

11. LOOKUP
• Pros
• only changed entities are copied
• Cons
• time for lookUp
• what about removed elements ?

12. LOOKUP Model 1
Pack1
parentPackage
classC
classA
classB
parentClass
parentClass
mA1() mA2() mB1() mB2()
to from to from
•a problem: anInvocation anInvocation
Model 2 LookUp
• mB2() parentClass ? Pack1'
removedClass
C
classA'
classB'
parentClass
mB1'()

13. PERFORMANCES
cost of cost of memory
Approach
creation access cost
copy ++++ 1 ++++
delta + ++++ +
lookUp + ++++ +

14. ORION APPROACH Model 1
Pack1
parentPackage
classC
classA
classB
parentClass
parentClass
• pointers approach mA1() mA2() mB1()
to
mB2()
to from from
anInvocation anInvocation
• access to updated elements
Model 2
Pack1'
• by an ID
classA'
• mB2() parentClass ?
classB'
mB1()'

15. ORION APPROACH
• Pros
• fastcreation and low memory usage: only
changed elements
• fast access: with the ID or pointers
• Cons
•a model depends on its predecessors

16. PERFORMANCES
Approach cost of cost of memory
creation access cost
copy ++++ 1 ++++
delta + ++++ +
lookUp + ++++ +
Orion + + +

17. ITS FUTURE
• Useit to make manual and automatic
prediction changes
• Comparing different changes
• Coupling with analysis tools (Famix)

18. THANKS
SUPPORTING INCREMENTAL CHANGES IN
LARGE MODELS
Jannik Laval, Simon Denier, Stéphane Ducasse
RMod Team - INRIA
Andy Kellens
Software Languages Lab - VUB