4 1 views

1
41 views

• Architectural Blueprints The 41 View Model of
  Software Architecture
• Philippe Kruchten
• Software Architecture Elements Forms
  Rationales/Constraints
• Organize description of software architecture
  using several concurrent views, each describing a
  different perspective

2
41 views

• 4 views
• Logical
• Process concurrency and synchronization
• Physical map to hardware
• Development organization in development
  environment
• And use cases

3
Mail Transport Agent
4
The Mail Queue
5
qmail
qmail- lspawn
qmail- local
qmail- inject
qmail- send
qmail- queue
mail queue
qmail- smptd
qmail- rspawn
qmail- remote
6
Architecture, Design, Implementation

• Amnon Eden, Rick Kazman
• Architecture and Design are both things that can
  have an infinite number of implementations
• If a system has a particular design (pattern?),
  adding stuff wont change that fact.
• If a system has a particular architecture, adding
  stuff might change that fact.

7
Three Styles in One System

• Layers
• Dataflow (Pipes and Filters)
• Object-Oriented

8
The System

• Framework for music improvisation
• Bill Walker
• Two applications
• Jazz piano duets
• Extreme modern electronic improvisation
• http//www.shout.net/walker/papers.html

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The Layers
Control
Music transformation
Hardware
Music Representation
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Pipes and Filters

• Components are filters
• Filters transform input to output
• Filters dont
• share state
• know identity of input or output
• Example Streams

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Advantages

• Easy to understand
• Easy to change
• Easty to maintain
• Components are reusable
• Handle parallelism well

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Disadvantages

• Not good for interactive processing
• Doesnt handle separate but related streams very
  well.
• Doesnt model state very well.

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Music Improvisor
Chord Finder
Sequence Finder
MIDI
chords
Keyboard
sequences
Transformer
chords
Chord Builder
MIDI out
sequences
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Data Representation
MusicalObject



Chord
Sequence
Note
Midi Event
15
Dataflow
Stream
Chord Builder
Retrograde
Keyboard
Chord Finder
Sequence Finder
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The Layers
Control
Music transformation
Hardware
Music Representation
17
Use of OO Techniques

• Polymorphism makes it easy to make new
  combination of components
• At runtime!
• Inheritance makes it easier to make new component

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Summary 3 styles

• Layers divides system into three parts
• Pipes and Filters organizes one layer
• OOP is used to describe data (bottom layer),
  provide reusable components for pipes and filters
  system (middle layer) and to implement the
  control system (top layer).

19
Conclusion

• Is it really true that architectural styles must
  hold for entire system?
• Theory must be based on facts.
• Facts come from experience.
• We need to document more architectures and to
  study them.