Fedora Repository Views
...
But the angle one views the repository might also affect the number of entries seen. The above, recursive approach will always lead to one entry per data object. The remedy for this is to mark some classes as Entries for a certain view angle. This means that to compute the records for a given view angle, the view of all objects of a class that is an Entry should be computed. This is the view of the repository.
Fedora Implementation
This section describes how the above could be implemented in Fedora.
...
| Code Block | ||
|---|---|---|
| ||
Set<Object> visitedObjects;
List<Object> CalculateView(Object o) {
List<Objects> view = new List<Objects>();
if (visitedObjects.contain(o){
return view;
}
visitedObjects.add(o);
if (o.isDeleted){
return view;
}
ContentModel c = o.getContentModel();
List<Relation> view-rels = c.getViewRelations();
List<Relation> object-rels = o.getRelations();
for (Relation r : object-rels){
if (view-rels.contain(r)){
view.addAll(CalculateView(r.getObject());
}
}
List<Relation> view-invrels = c.getInverseViewRelations();
List<Relation> object-invrels = o.getInverseRelations();
for (Relation r : object-invrels){
if (view-invrels.contain(r)){
view.addAll(CalculateView(r.getSubject());
}
}
return view;
} |
...