Gaudi-speak
component: refers to a block of software with a well defined interface and purpose. ex.) an algorithm or a service
Transient Data Store (TDS) a mechanism for shared memory; a tree that stores all data pertinent to a particular execution of the code. Within Gaudi, all algorithms, services, tools, etc., use the data store to
- Retrieve the data needed to do its particular task
- To store any output data
Persistency Service
Converter provides translation between the transient representation to the persistent representation and back again. Converters are part of the persistency service.
Service
Tool
Fermi's Use of Gaudi
Started in 2000 as part of our upgrade of the simulation and reconstruction software named Gleam, now often referred to as GlastRelease. See this diagram from our online workbook.
G4Generator - Algorithm that is our interface to Geant4. G4 generates one event, and the resulting data are then posted to the TDS.
ntupleWriterSvc - rather than utilize Gaudi's historgram service we chose to write our own. Over the years it has been extended to handle not only writing our outupt ROOT ntuples, but also provides a mechanism to read in ntuples for reprocessing.