Event format meta data

Picking up from the discussion at !33803 (closed)

@akraszna implemented a very nice start to handling xAOD::EventFormat metadata in athenaMT. @gemmeren Pointed out that we should adopt a uniform approach to handling EventStreamInfo and xAOD::EventFormat. This leaves some approaches:

• Write multithreaded service maintaining one shared EventStreamInfo object in a thread-safe manner.
• Maintain a xAOD::EventFormat object for each output stream.
• Something we have not yet thought of Here we choose the second, i.e. maintain a xAOD::EventFormat object for each output stream. That means the key of the xAOD::EventFormat object now is a function of the stream name. Trying to adopt the EventStreamInfo style I went for something like:

AthenaOutputStream(
    name=name,
    HelperTools=[
        CfgMgr.xAODMaker__EventFormatStreamHelperTool(
            name="EventFormatStreamHelper"
            Key='Format{}'.format(name),
        ),
    ],
)

Of course any client looking up xAOD::EventFormat by key will have to adjust for that, as you can see in the read test. How much of a nightmare will this be?

I have not yet included recording and retrieving xAOD::EventFormat though the MetaDataSvc as implemented for EventStreamInfo. Is that desirable @mnowak

As you can see by the hacky approach and the title this is still a construction site and needs cleaning up.

Thoughts?

@tsulaia

Event/xAOD/xAODEventFormatCnv/src/EventFormatStreamHelperTool.cxx

@@ -10,7 +10,6 @@ namespace xAODMaker {
    StatusCode EventFormatStreamHelperTool::initialize() {
 
       // Retrieve all needed components.
-      ATH_CHECK( m_evtStore.retrieve() );
       ATH_CHECK( m_evFormatSvc.retrieve() );
 
       // Return gracefully.
@@ -21,7 +20,7 @@ namespace xAODMaker {
 
       // Notify the event format service that it should collect the metadata
       // that it needs.
-      ATH_CHECK( m_evFormatSvc->collectFormatMetadata( *m_evtStore ) );
+      ATH_CHECK( m_evFormatSvc->collectFormatMetadata( *( evtStore() ) ) );
       ATH_MSG_VERBOSE( "Triggered metadata collection on: " << m_evFormatSvc );
 
       // Return gracefully.