Visual Exploration of Large-Scale System Evolution

Visual Exploration of Large-Scale

System EvolutionRichard Wettel and Michele Lanza

REVEAL group, Faculty of InformaticsUniversity of Lugano, Switzerland

Software systems as citiesPhoto: SkyShaper (Flickr)

Richard Wettel and Michele Lanza Visual Exploration of Large-Scale System Evolution

The city metaphor

3


The city metaphor

3

domain mapping

class building

package district

system city


The city metaphor

3

domain mapping

class building

package district

system city


The city metaphor

3

domain mapping

class building

package district

system city


The city metaphor

3

domain mapping

class building

package district

system city


The city metaphor

3

domain mapping

class building

package district

system city

number of methods (NOM) height

number of attributes (NOA) base size


The city metaphor

3

domain mapping

class building

package district

system city

nesting level color


number of attributes (NOA) base size


The city metaphor

3

domain mapping

class building

package district

system city

nesting level color


number of attributes (NOA) base size [Wettel & Lanza, ICPC 2007]

[Wettel & Lanza, VISSOFT 2007]


Decoding a city: ArgoUML

4



4

skyscrapers(NOM, NOA)



4


parking lots(NOM, NOA)



4


parking lots(NOM, NOA)

office buildings(NOM, NOA)


Code cities

5


Code cities

5

System Language NOP NOC kLOC

Azureus Java 457 4734 274

ArgoUML Java 144 2542 137

JHotDraw Java 72 998 30

iText Java 149 1250 80

Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160

Moose Smalltalk 278 961 32

Jun Smalltalk 288 2236 351

CodeCity Smalltalk 129 291 18

ScumVM C++ 18 1331 105


Code cities

5






Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160




ScumVM C++ 18 1331 105


Code cities

5






Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160




ScumVM C++ 18 1331 105


Code cities

5






Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160




ScumVM C++ 18 1331 105


Code cities

5






Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160




ScumVM C++ 18 1331 105


Code cities

5






Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160




ScumVM C++ 18 1331 105


Code cities

5






Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160




ScumVM C++ 18 1331 105


Code cities

5






Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160




ScumVM C++ 18 1331 105


Code cities

5






Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160




ScumVM C++ 18 1331 105


Code cities

5






Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160




ScumVM C++ 18 1331 105


Code cities

5






Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160




ScumVM C++ 18 1331 105


Code cities

5






Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160




ScumVM C++ 18 1331 105


Code cities

5






Jmol Java 105 1032 85

JDK 1.5 Java 137 4715 160




ScumVM C++ 18 1331 105

1.25 million LOC

Software in time...

Richard Wettel and Michele Lanza Visual Exploration of Large-Scale System Evolution 7

Numbers on the history data

System ArgoUML JHotDraw Jmol

Packages 144 72 105

Classes 2,542 998 1,032

Lines of code 137,000 30,000 85,000

Sampling start Oct. 2002 Oct. 2000 Jan. 2000

Sampling end Feb. 2007 Apr. 2005 Aug. 2007

Revisions 15,535 267 8,065

Sampling period release-based 1 week 6 months 8 weeks

Samples 9 57 8 50


Evolution of a code city: ArgoUML

8


Evolution of a code city: ArgoUML

8



1. Age map


1. Age map 2. Time travel


1. Age map 2. Time travel 3. Timeline

Age map


Principle of age map

11


Glimpse in the pastentities colored according to age


11




11

1Nnew-bornveteran




11

1Nnew-bornveteran




11

1N

age (number of survived versions)

new-bornveteran


Coarse-grained age map: ArgoUML

12



12

org.argouml.language. java.generator

JavaTokenTypes

146 attributes

0 methods

JavaRecognizer

24 attributes

91 methods



12

org.argouml.language. java.generator

JavaTokenTypes

173 attributes

0 methods

JavaRecognizer

79 attributes

176 methods

org.argouml.uml.reveng.java

JavaTokenTypes

146 attributes

0 methods

JavaRecognizer

24 attributes

91 methods


Refining the granularity

13

NO

M =

7

NOA

= 2

NOA = 2

class C



13

NO

M =

7

NOA

= 2

NOA = 2

class C



13

NO

M =

7

NOA

= 2

NOA = 2

class C

class Cm4

m1m3

m5 m7

m6

m2

old

new


Fine-grained age map: JHotDraw

14

library packages:

java

javax

junit

org.w3c.dom

(classes) AllTests

CH.ifa.draw.standard

CH.ifa.draw.frameworkCH.ifa.draw.figures

CH.ifa.draw.test

class DrawApplication

in CH.ifa.draw.application

class StandardDrawingView

in CH.ifa.draw.standard.


Buildings in age maps

15

age: 1 2 3 4 5 6 7 8



15

age: 1 2 3 4 5 6 7 8

stable

very old



15

age: 1 2 3 4 5 6 7 8

stable

oldvery old

rarely updated



15

age: 1 2 3 4 5 6 7 8

stable

youngoldvery old

rarely updated

highly unstable



15

age: 1 2 3 4 5 6 7 8

stable

youngoldvery old

rarely updated

highly unstable

very old

updated often,

rather unstable

Time travel


Travelling through ArgoUML’s time

17

0.10.1

0.12

0.14

0.16

0.18.1

0.20

0.22

0.23.4

0.24



17

0.10.1

0.12

0.14

0.16

0.18.1

0.20

0.22

0.23.4

0.24



17

ModelFacadeNOM: 184, NOA: 60

0.10.1

0.12

0.14

0.16

0.18.1

0.20

0.22

0.23.4

0.24



17

0.10.1

0.12

0.14

0.16

0.18.1

0.20

0.22

0.23.4

0.24

ModelFacadeNOM: 435, NOA: 108



17

0.10.1

0.12

0.14

0.16

0.18.1

0.20

0.22

0.23.4

0.24

NSUMLModelFacadeNOM: 319, NOA: 2

FacadeNOM: 306, NOA: 1


FacadeMDRImplNOM: 329, NOA: 2


17

0.10.1

0.12

0.14

0.16

0.18.1

0.20

0.22

0.23.4

0.24

NSUMLModelFacadeNOM: 334, NOA: 2



FacadeMDRImplNOM: 340, NOA: 3


17

0.10.1

0.12

0.14

0.16

0.18.1

0.20

0.22

0.23.4

0.24




17

0.10.1

0.12

0.14

0.16

0.18.1

0.20

0.22

0.23.4

0.24



17

0.10.1

0.12

0.14

0.16

0.18.1

0.20

0.22

0.23.4

0.24


Reality check no. 1

18


Reality check no. 1

18

L.T., main developer of ArgoUML:“ModelFacade was an implementation of the model subsystem using NSUML repository. When the change was made to MDR we turned this to a regular interface allowing for several different repositories.”

“The attributes in the ModelFacade are not attributes but constant tokens used in the NSUML repository implementation.”


Example of system getting old

19

JHotDraw



19

JHotDraw



19

JHotDraw



19

JHotDraw



19

JHotDraw



19

JHotDraw



19

JHotDraw



19

JHotDraw


Reality check no. 2

20


Reality check no. 2

20

W.K., developer of JHotDraw:“I used a JavaDoc-based code generator to automatically generate test cases for the JHotDraw. Therefore, the test methods are still not implemented and only the work to do is outlined.“


Story of Jmol’s evolution

21

Timeline

1887 Sep. 1887 Dec. 1888 Mar. 1888 Jun. 1888 Sep. 1888 Dec. 1889 Mar.


Timeline principles

23

History of class C


Timeline principles

23

time (versions)m3

m5

History of class C

V1


Timeline principles

23

time (versions)m3

m5 m8

m12

m3

History of class C

V1

V2


Timeline principles

23

time (versions)m3

m5 m8

m12

m3

History of class C

V1

V2


Timeline principles

23

time (versions)m3

m5 m8

m12

m3

m12

m18

History of class C

V1

V2

V3


Timeline principles

23

time (versions)m3

m5 m8

m12

m3

m12

m18

History of class C

V1

V2

V3


Code decays...

24

StandardDrawingView(JHotDraw)

GeneratorJava(ArgoUML)

Eval(Jmol)


Color anomalies reveal restores

25

forcePixeldisappears after v1

reappears in v9

applyBlueAnaglyphdisappears after v10

reappears in v18

fillTriangledisappears after v5

reappears in v21

Graphics3D


Contemporary methods have the same color.


25


reappears in v9


reappears in v18


reappears in v21

Graphics3D


Contemporary methods have the same color.

Contemporary methods are also neighbors.


25


reappears in v9


reappears in v18


reappears in v21

Graphics3D


Similar pattern in Jmol timelines

TransformManager

JmolViewer

Eval

Viewer


Similar pattern in Jmol timelines

TransformManager

JmolViewer

Eval

Viewer


Reality check no. 3

27


Reality check no. 3

27

Subversion logs:

r5091: “No more javax.vecmath.Point3f in g3d shape drawing routines. There were some cases where screen coordinates were being passed in as Point3f objects ... not a good thing.”

r5579: “Revert of vecmathlib change”.


Reality check no. 3

27

Subversion logs:



N.V., developer: “Your hypothesis is probably correct. We found some major problems, and diagnostic was too difficult, so we reverted to a stable version and tried to apply patches in small batch.”


Reality check no. 3

27

Subversion logs:



N.V., developer: “Your hypothesis is probably correct. We found some major problems, and diagnostic was too difficult, so we reverted to a stable version and tried to apply patches in small batch.”

B.H., developer: “It was quite a nightmare for everyone involved. The issue was that I was new to the project and had committed quite a few additions to Jmol thinking that M. was monitoring; as it turned out he found my additions too much too fast, and because there was a problem with the graphics display module g3d that resulted in some slow performance, he opted to revert to an earlier state. In the end it turned out to be a recent addition to transparency in the graphics, not anything I had done, that caused the problem. In any case, we did sort of start over -- or at least I did.”


Closing remarks

28


Closing remarks

28


Closing remarks

28

Our visualizations techniques for software evolution reveal insights unavailable outside the historical context.


Closing remarks

28

Our visualizations techniques for software evolution reveal insights unavailable outside the historical context.

http://www.inf.unisi.ch/phd/wettel/codecity.html



Richard Wettelhttp://www.inf.unisi.ch/phd/wettel

http://creativecommons.org/licenses/by/3.0/

http://www.inf.unisi.ch/phd/wettel

http://www.inf.unisi.ch/phd/wettel



Technology

Visual Exploration of Large-Scale System Evolution