Event Data Service                

Purpose and Functionality

The event data service manages the transient event data store. The service interacts mainly with two components: algorithms and the application manager.

• The event data service is used by the algorithms as an input/output channel of data objects:
  • The event data service delivers references to event data objects on request. If the requested data objects are not present, the event data service asks the event persistency service to deliver the objects and makes them availible to the algorithm.
  • Event data objects meant to be available to (other) algorithms must be registered to the event data service.
  • Once event data objects are registered to the event data service, the algorithm gives up ownership. The event data service releases the objects on request of the application manager.
• Event data objects must be identifiable in order to be added to the data store.
• The registration of data must follow the hierarchy of the event data objects. This means starting from an event root object, navigation in the data store is like travelling through the delivered event by the use of pointers. The registration of event data objects will be tree like, similar to a file system.

• The application manager tells the event data service which event to deal with in case of a request.
• Clients of the event data service can decide which data should be made persistent:
  • Clients may decide to discard partially or completely the data objects managed by the service.
  • The event data service must be able to deliver transient data objects to the services in charge of creating other data representations like the persistency service or the service responsible for creating graphical representations.

Interfaces

The event data service implements the following interfaces:

• IDataManagerSvc: This interface allows settings necessary to deliver event data like declaring the event root etc. This interface is used by the Application manager. Through this interface actions necessary to manilpulate the scope of event related data like requests to initialize a new event, discard the objects owned by the service etc. are handled.
• IDataProviderSvc: The interface used by the algorithms to request or register event data objects.

Known clients

• Application manager
• Event persistency service
• Graphical representation service
• Algorithms

Dependencies

• Organisation of the transient detector data store
• Generic service,
• Interface of the event data persistency service
• Data item selector
• Standard Templarte Library.