This package contains TagInfoMgr which is an Athena service that manages detector description tag information. It maintains a TagInfo object in the Detector Store with current tag values.

The tags to fill the TagInfo object may come from a variety of sources: i.e. the tags specified by the GeoModelSvc and IOVDbSvc, or the tags stored in the incoming EventInfo object, or the TagInfo object itself may be in the IOV DB. The TagInfoMgr itself only adds in tags from the incoming event. Others are added by external clients.

The interface provides a 'input' method to allow client to add in their own tags:

virtual StatusCode addTag(const std::string& tagName, const std::string& tagValue) = 0;

The full set of tags in TagInfo are copied each event into EventInfo (specifically EventType) to be written out in the event stream. Currently, the tags are NOT written to the IOV DB via the TagInfoMgr.

Some clients need to know when detector description tags change so that they may update their descriptions, such as the geometry description. These clients need to set up a callback with the IOVSvc, as is done below for this class.

The TagInfoMgr also has a property to add value/tag pairs via jobOptions. This is currently used in standard configurable EventInfoMgtInit.py, to set the release version as a tag/value pair: Release/<version>. The release version is extracted from an environment variable.

Default values of properties of TagInfoMgr

AddEventInfoTags - true OverrideEventInfoTags - true ExtraTagValuePairs - just add in release version TagInfoKey - ProcessingTags