ITK/Release 4/Modularization

Modularization

Goals

• Organize the continuous growth of the Toolkit
  • Create system with a kernel base code and topic modules
  • Kernel very rigorously supported and developed
  • Possibly two classes of modules: Core and Extra
  • Core modules also rigorously supported
  • Extra modules less so
• Simplify usage for application developers
  • Package manager that allows user to choose exactly what functionality is desired
  • Modules exist along logical boundaries

Issues

Automatic code analysis and initial segmentation

• Develop accurate graph of code dependencies
  • Use "#include" as edge in graph
  • Need to remove unnecessary includes (non-trivial problem)
• Segment the code into a kernel and modules
  • Use graph clustering/segmentation methods
  • Develop good cost function for the segmentation
  • High cost for code in the kernel
  • High cost for weak modular dependencies

Manual segmentation improvement

• Ensure that modules divided logically
• Good granularity so that modules provide a benefit
  • Too many modules is too complex
  • Too few modules is pointless
  • Goal: ~20 modules
• Only logical modular dependencies
  • "Advanced Registration" depends on "Registration" is OK
  • "Segmentation" depends on "Registration" because they share one non-kernel file is BAD

Tools

Ryppl

• http://ryppl.org/
• Package Manager - Multi-Platform
  • Requirements

Source Navigator

• http://sourcenav.berlios.de/
• Static analysis tool
• Builds detailed database of code elements and interactions
• Programmable tcl API (also c++ but less well documents and/or out of date)