1. Discussion on managing the coexistence of CDF and XML geometry files
LHCb Software Week
5-7 April 2000
P. Mato / CERN
The following are few slides intended to trigger a discussion/brainstorming with the goal of producing an Architecture for the DCS kernel.
Definition on Architecture: “The architecture of a system is the structure of the system”. Two main ingredients: A set of building blocks, and a set of collaborations that specify how those building blocks cooperate to provide various system functions.
An DCS architecture will allow us to provide set of control applications or control systems that fulfill a range of needs within the DCS domain. An architecture encourages reuse.
Analogies in the real world: Gothic architecture, Lego Basic® architecture, Lego Technique® architecture.
“To be successful, an object-oriented project must craft an architecture that is both coherent and resilient and then must propagate and evolve the vision of this architecture to the entire development team”, G. Booch, Object Solutions.
6/4/2000
Managing the coexistance of CDF and XML geometry files

2. Managing the coexistance of CDF and XML geometry files
Problem Statement
Today’s situation
The geometry information is available to Fortran algorithms from CDF files by specific Fortran detector description code.
Final situation
The geometry information will be made available to GAUDI algorithms from XML files (or database) by a combination of generic and specific converters.
Intermediate situation (hybrid)
Fortran code (in particular Geant 3) will get the geometry from CDF files and C++ algorithms from XML files.
How can we made sure that the two “persistent” geometries are consistent?
Even if BRUNEL is completely in C++, SicbMC will still be in Fortran for a while.
6/4/2000
Managing the coexistance of CDF and XML geometry files

3. Managing the coexistance of CDF and XML geometry files
The Ingredients
Recons
Alg
Geom
Commons
CDF G3
Geant3 Geo
Recons
Alg
XML
Cnv
XML
T.DetStore G4
Cnv G4
G4 Geo
specific
6/4/2000
Managing the coexistance of CDF and XML geometry files

4. Managing the coexistance of CDF and XML geometry files
Option A
Recons
Alg
Geom
Commons
CDF G3
Geant3 Geo
Recons
Alg
XML
Cnv
XML
T.DetStore G4
Cnv G4
The two geometries are
edited by hand, making sure that they are compatible
G4 Geo
6/4/2000
Managing the coexistance of CDF and XML geometry files

5. Managing the coexistance of CDF and XML geometry files
Option B
Recons
Alg
Geom
Commons
CDF G3
Geant3 Geo
CDF to
XML
Recons
Alg
XML
Cnv
XML
T.DetStore G4
Cnv G4
Rewrite specific Fortran routines (based on existing ones) to generate XML from CDF
G4 Geo
6/4/2000
Managing the coexistance of CDF and XML geometry files

6. Managing the coexistance of CDF and XML geometry files
Option C
Recons
Alg
Geom
Commons
CDF G3
Geant3 Geo
XML to
CDF
Recons
Alg
XML
Cnv
XML
T.DetStore G4
Cnv G4
Sections of the XML file contain CDF fragments, which can be extracted.
G4 Geo
6/4/2000
Managing the coexistance of CDF and XML geometry files

7. Managing the coexistance of CDF and XML geometry files
Pros and Cons
Discussion
6/4/2000
Managing the coexistance of CDF and XML geometry files