Software understanding
in the large
Tudor Gîrba
www.tudorgirba.com

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Systems are large and complex

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… and have many facets

Still, simple tools can get you far

for i in $( ls ); do
echo `wc -l $i` >> temp
done
sort -nr temp | head -10

3
Spinellis 200

Indentation correlates with complexity.
indle e tal 2008
H

Queries reduce the analysis space

Intensional Views ensure rules
acceptsClassOfType(?VisitorClass,?VisitedClass) if
methodWithNameInClass(?Method,?Selector,?VisitorClass),
[’accept*’ match:?Selector asString],
argumentOfMethod(?Argument,?Method),
[’*’,(?VisitedClass name asString),
’*’ match:?Argument asString]
6
Mens etal 200

Visual queries put results in perspective

Every system is special.

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Every system is special.

vs. Live ana
Rep orting lysis

Every system is special.

Every technology is special.

Data Classes are dumb data holders
Interface of class reveals data
rather than offering services
WOC < ONE THIRD
AND Data Class
Class reveals many attributes and is
not complex
006
ari nescu 2
L anza, M

Use a Transfer Object to encapsulate the business data. A
single method call is used to send and retrieve the Transfer
Object.
When the client requests the enterprise bean for the
business data, the enterprise bean can construct the
Transfer Object, populate it with its attribute values, and
pass it by value to the client.
java .sun.com

Every technology is special.

In Java
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In J2EE
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In J2EE
.jsp
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{ = .java
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}
}
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In J2EE
.jsp
{
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{ { }
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{ = .java
} }
}
}
{
.xml

.java we
oking only at rmation
By lo ful info
ould m iss use
w

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/*
*/

7
etal 200
Schreck

7
etal 200
Schreck

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/*
*/

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.pdf } }
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/*
*/ @

MAKAO shows Makefile dependencies
dams e tal 2007
A

The sources can tell you how the system looks like,
but not why.

ugly?

Model

Model
GUI

Model
Helpers GUI

Model
Helpers GUI 5
etal 199
Murphy

Model
Helpers

ann e tal 2008
Brühlm

ann e tal 2008
Brühlm

Put findings in perspective.

It’s not Lupus

You mainly see what you are looking for.

Tudor Gîrba
www.tudorgirba.com
creativecommons.org/licenses/by/3.0/