IndexesConfig.java

package pt.ist.fenixframework.indexes;

import java.util.List;
import java.util.Set;

import pt.ist.fenixframework.Atomic;
import pt.ist.fenixframework.DomainRoot;
import pt.ist.fenixframework.FenixFramework;
import pt.ist.fenixframework.adt.bplustree.BPlusTree;
import pt.ist.fenixframework.dml.AnnotatedSlot;
import pt.ist.fenixframework.dml.Annotation;
import pt.ist.fenixframework.hibernatesearch.HibernateSearchConfig;

public abstract class IndexesConfig extends HibernateSearchConfig {


    /* See comment on updateIndexes() */
    @Override
    protected void init() {
        updateIndexes();
        super.init();
    }

    /*
     *  This method uses the TransactionManager, so make sure that it is already initialized when
     *  this method is called.
     */
    @Atomic
    private void updateIndexes() {
	// Ensure the root index tree exists
	DomainRoot domRoot = FenixFramework.getDomainRoot();
	BPlusTree<BPlusTree> rootIndex = domRoot.getIndexRoot();
	if (rootIndex == null) {
	    rootIndex = new BPlusTree<BPlusTree>();
	    domRoot.setIndexRoot(rootIndex);
	}
	
	// Now check for new and unused slot indexes
	List<AnnotatedSlot> indexedSlots = FenixFramework.getDomainModel().getAnnotatedSlots().get(Annotation.INDEX_ANNOTATION);
	Set<? extends Comparable> persistedIndexedSlots = rootIndex.getKeys();

        if (indexedSlots != null) {
            for (AnnotatedSlot annSlot : indexedSlots) {
                String key = annSlot.getDomainClass().getFullName() + "." + annSlot.getSlot().getName();
                BPlusTree slotIndexTree = rootIndex.get(key);
                if (slotIndexTree == null) {
                    slotIndexTree = new BPlusTree();
                    rootIndex.insert(key, slotIndexTree);
                }

                // Remove this slots' key from the known ones, meaning its still being used
                persistedIndexedSlots.remove(key);
            }
        }
	// For each key left out, we know that the corresponding slot is no longer annotated. Thus, delete its index tree.
	for (Comparable key : persistedIndexedSlots) {
	    rootIndex.remove(key);
	}
	
    }
    
}