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

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

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

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

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

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

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