DANA

1
DANA

• David Lawrence
• Oct. 21, 2005

2
Outline

• Requirements
• Philosophy
• Overview of Features
• Open Questions

3
Requirements

• Modular Reconstruction
• Allow independent development of reconstruction
  code for independent detector systems
• Easy to make customized programs that do only
  partial reconstruction
• Consistency
• Single mechanism for database access
• Calibration constants
• Parameters
• Geometry Information
• Interface for passing data between modules
• Multi-threading
• Shallow Learning Curve - Are we there?

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Factory Paradigm
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Event Loops and Threads
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Event Sources and Sinks

• The API for dealing with event sources is defined
  by the DEventSource base class
• The API for dealing with event sinks (files) is
  defined by the DEventSink base class
• New sources and sinks can be added at any time
  without affecting user code

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Data Objects

• All data objects inherit from DObject
• DObject provides the object with an identifier
  that, unlike pointers, can be used outside the
  context of the program
• class DHit public DObject
• public
• float x,y,z
• HDCLASSDEF(DHit)

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DANA Features
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DANA uses Templates

• Templates add better type checking while
  relieving the programmer of some responsibility
• vectorltconst DTrackgt tracks
• loop-gtGet(tracks)

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Factory Tags

• Tags are free-form strings that allow more than
  one factory to produce the same class of data
  objects. Factory tags are specified as an
  optional 2nd argument to DEventLoopGet()
• vectorltconst DTrackgt tracks
• loop-gtGet(tracks, LowResolution)

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Configuration Parameters

• Parameters are simple key/value pairs.
• Database of parameters built up from factories at
  run time
• maxhits10 // int
• dparms.SetDefaultParameter(TRKmaxhits,
  maxhits)
• Parameters can be modified at program startup and
  the database can be recorded in output

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Other DANA Features

• Data on demand
• Shared Objects
• Universal treatment of DObjects
• Uses STL vectors for passing const pointers
• Optional filter routine argument

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Open Questions

• Are any major changes needed?
• What do we put in DObject? (toString(), isA(), )
• How to implement identifiers
• Introspection and I/O
• 4-vector class? Histogram classes?
• Move headers out of src/libraries/include e.g.
  include FDC/DFactory_DFDCHit.h
• Access to auxiliary information