dorsal/arxiv
View SchemaEvent Data Definition in LHCb
| Authors | Marco Cattaneo, Gloria Corti, Markus Frank, Pere Mato Vila, Silvia Miksch, Stefan Roiser |
|---|---|
| Categories | |
| ArXiv ID | physics/0306104 |
| URL | https://arxiv.org/abs/physics/0306104 |
Abstract
We present the approach used for defining the event object model for the LHCb experiment. This approach is based on a high level modelling language, which is independent of the programming language used in the current implementation of the event data processing software. The different possibilities of object modelling languages are evaluated, and the advantages of a dedicated model based on XML over other possible candidates are shown. After a description of the language itself, we explain the benefits obtained by applying this approach in the description of the event model of an experiment such as LHCb. Examples of these benefits are uniform and coherent mapping of the object model to the implementation language across the experiment software development teams, easy maintenance of the event model, conformance to experiment coding rules, etc. The description of the object model is parsed by means of a so called front-end which allows to feed several back-ends. We give an introduction to the model itself and to the currently implemented back-ends which produce information like programming language specific implementations of event objects or meta information about these objects. Meta information can be used for introspection of objects at run-time which is essential for functionalities like object persistency or interactive analysis. This object introspection package for C++ has been adopted by the LCG project as the starting point for the LCG object dictionary that is going to be developed in common for the LHC experiments. The current status of the event object modelling and its usage in LHCb are presented and the prospects of further developments are discussed.
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"abstract": "We present the approach used for defining the event object model for the LHCb\nexperiment. This approach is based on a high level modelling language, which is\nindependent of the programming language used in the current implementation of\nthe event data processing software. The different possibilities of object\nmodelling languages are evaluated, and the advantages of a dedicated model\nbased on XML over other possible candidates are shown. After a description of\nthe language itself, we explain the benefits obtained by applying this approach\nin the description of the event model of an experiment such as LHCb. Examples\nof these benefits are uniform and coherent mapping of the object model to the\nimplementation language across the experiment software development teams, easy\nmaintenance of the event model, conformance to experiment coding rules, etc.\n The description of the object model is parsed by means of a so called\nfront-end which allows to feed several back-ends. We give an introduction to\nthe model itself and to the currently implemented back-ends which produce\ninformation like programming language specific implementations of event objects\nor meta information about these objects. Meta information can be used for\nintrospection of objects at run-time which is essential for functionalities\nlike object persistency or interactive analysis. This object introspection\npackage for C++ has been adopted by the LCG project as the starting point for\nthe LCG object dictionary that is going to be developed in common for the LHC\nexperiments.\n The current status of the event object modelling and its usage in LHCb are\npresented and the prospects of further developments are discussed.",
"arxiv_id": "physics/0306104",
"authors": [
"Marco Cattaneo",
"Gloria Corti",
"Markus Frank",
"Pere Mato Vila",
"Silvia Miksch",
"Stefan Roiser"
],
"categories": [
"physics.comp-ph"
],
"title": "Event Data Definition in LHCb",
"url": "https://arxiv.org/abs/physics/0306104"
},
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