Podio event source: Use new, exception-free Emit() callback

src/services/io/podio/JEventSourcePODIO.cc

@@ -69,6 +69,7 @@ struct InsertingVisitor {
 //------------------------------------------------------------------------------
 JEventSourcePODIO::JEventSourcePODIO(std::string resource_name, JApplication* app) : JEventSource(resource_name, app) {
     SetTypeName(NAME_OF_THIS); // Provide JANA with class name
+    SetCallbackStyle(CallbackStyle::ExpertMode); // Use new, exception-free Emit() callback
 
     // Tell JANA that we want it to call the FinishEvent() method.
     // EnableFinishEvent();
@@ -185,7 +186,7 @@ void JEventSourcePODIO::Close() {
 ///
 /// \param event
 //------------------------------------------------------------------------------
-void JEventSourcePODIO::GetEvent(std::shared_ptr<JEvent> event) {
+JEventSourcePODIO::Result JEventSourcePODIO::Emit(JEvent& event) {
 
     /// Calls to GetEvent are synchronized with each other, which means they can
     /// read and write state on the JEventSource without causing race conditions.
@@ -194,10 +195,9 @@ void JEventSourcePODIO::GetEvent(std::shared_ptr<JEvent> event) {
     if( Nevents_read >= Nevents_in_file ) {
         if( m_run_forever ){
             Nevents_read = 0;
-        }else{
-            // m_reader.close();
-            // TODO:: ROOTReader does not appear to have a close() method.
-            throw RETURN_STATUS::kNO_MORE_EVENTS;
+        }
+        else{
+            return Result::FailureFinished;
         }
     }
 
@@ -208,19 +208,20 @@ void JEventSourcePODIO::GetEvent(std::shared_ptr<JEvent> event) {
     if (event_headers.size() != 1) {
         throw JException("Bad event headers: Entry %d contains %d items, but 1 expected.", Nevents_read, event_headers.size());
     }
-    event->SetEventNumber(event_headers[0].getEventNumber());
-    event->SetRunNumber(event_headers[0].getRunNumber());
+    event.SetEventNumber(event_headers[0].getEventNumber());
+    event.SetRunNumber(event_headers[0].getRunNumber());
 
     // Insert contents odf frame into JFactories
     VisitPodioCollection<InsertingVisitor> visit;
     for (const std::string& coll_name : frame->getAvailableCollections()) {
         const podio::CollectionBase* collection = frame->get(coll_name);
-        InsertingVisitor visitor(*event, coll_name);
+        InsertingVisitor visitor(event, coll_name);
         visit(visitor, *collection);
     }
 
-    event->Insert(frame.release()); // Transfer ownership from unique_ptr to JFactoryT<podio::Frame>
+    event.Insert(frame.release()); // Transfer ownership from unique_ptr to JFactoryT<podio::Frame>
     Nevents_read += 1;
+    return Result::Success;
 }
 
 //------------------------------------------------------------------------------

src/services/io/podio/JEventSourcePODIO.h

@@ -30,7 +30,7 @@ class JEventSourcePODIO : public JEventSource {
 
     void Close() override;
 
-    void GetEvent(std::shared_ptr<JEvent>) override;
+    Result Emit(JEvent& event) override;
 
     static std::string GetDescription();