Use IQualifiedNameProvider if possible

If possible, do not look for the qualified names in the resource
descriptor, asking the IQualifiedNameProvider for the values is much
faster, as the lookup involve very expensive operations (specially the
second one):
- Create a collection with all the resource descriptions of the
referenced resource (only first lookup).
- Iterate through the list every time and compare the fragments.

Asking the IQualifiedNameProvider has the extra advantage that it can
return a name even the target object has not yet been exported, this
happens in the second phase when:
- a resource is loaded on demand
- liking to an inferred object which was not inferred in the pre-linking
phase is done.
- the resource loaded on demand has not yet been processed in the second
phase

under this circumstances the
IResourceDescriptions.getExportedObjectsByObject will not find the
element we have linked right before.

Author: rubenporras

com.avaloq.tools.ddk.xtext/src/com/avaloq/tools/ddk/xtext/linking/LinkingService.java

@@ -17,9 +17,11 @@
 import org.eclipse.emf.ecore.EClass;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EReference;
+import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.xtext.linking.impl.DefaultLinkingService;
 import org.eclipse.xtext.linking.impl.ImportedNamesAdapter;
 import org.eclipse.xtext.naming.IQualifiedNameConverter;
+import org.eclipse.xtext.naming.IQualifiedNameProvider;
 import org.eclipse.xtext.naming.QualifiedName;
 import org.eclipse.xtext.nodemodel.INode;
 import org.eclipse.xtext.resource.IEObjectDescription;
@@ -82,13 +84,22 @@ private void registerNamedType(final EObject context, final QualifiedName name,
    *          the lookup type, may be {@code null}
    */
   public void importObject(final EObject context, final EObject target, final EClass type) {
-    final IResourceDescriptions resourceDescriptions = provider.getResourceDescriptions(context.eResource());
-    Iterator<IEObjectDescription> exports = resourceDescriptions.getExportedObjectsByObject(target).iterator();
-    if (exports.hasNext()) {
-      QualifiedName targetName = exports.next().getName();
-      if (targetName != null && !targetName.isEmpty()) {
-        registerNamedType(context, targetName.toLowerCase(), type); // NOPMD targetName not a String!
+    Resource eResource = target.eResource();
+    QualifiedName targetName = null;
+    if (eResource instanceof LazyLinkingResource2) {
+      IQualifiedNameProvider nameProvider = ((LazyLinkingResource2) eResource).getService(IQualifiedNameProvider.class);
+      if (nameProvider != null) {
+        targetName = nameProvider.getFullyQualifiedName(target);
       }
+    } else {
+      final IResourceDescriptions resourceDescriptions = provider.getResourceDescriptions(context.eResource());
+      Iterator<IEObjectDescription> exports = resourceDescriptions.getExportedObjectsByObject(target).iterator();
+      if (exports.hasNext()) {
+        targetName = exports.next().getName();
+      }
+    }
+    if (targetName != null && !targetName.isEmpty()) {
+      registerNamedType(context, targetName.toLowerCase(), type); // NOPMD targetName not a String!
     }
   }