/**
* INTERNAL: Execute the query. Get the rows and build the object from the rows.
*
* @exception DatabaseException - an error has occurred on the database
* @return java.lang.Object collection of objects resulting from execution of query.
*/
protected Object executeObjectLevelReadQuery() throws DatabaseException {
Object result = null;
if (getContainerPolicy().overridesRead()) {
return getContainerPolicy().execute();
}
if (this.descriptor.isDescriptorForInterface()) {
Object returnValue =
this.descriptor.getInterfacePolicy().selectAllObjectsUsingMultipleTableSubclassRead(this);
setExecutionTime(System.currentTimeMillis());
return returnValue;
}
List rows = getQueryMechanism().selectAllRows();
setExecutionTime(System.currentTimeMillis());
// If using 1-m joins, must set all rows.
if (hasJoining() && this.joinedAttributeManager.isToManyJoin()) {
this.joinedAttributeManager.setDataResults(rows, this.session);
}
if (this.session.isUnitOfWork()) {
result =
registerResultInUnitOfWork(
rows, (UnitOfWorkImpl) this.session, this.translationRow, true); //
} else {
result = getContainerPolicy().containerInstance(rows.size());
this.descriptor.getObjectBuilder().buildObjectsInto(this, rows, result);
}
if (this.shouldIncludeData) {
ComplexQueryResult complexResult = new ComplexQueryResult();
complexResult.setResult(result);
complexResult.setData(rows);
return complexResult;
}
// Add the other (already registered) results and return them.
if (getDescriptor().hasTablePerClassPolicy()) {
result =
containerPolicy.concatenateContainers(
result,
getDescriptor()
.getTablePerClassPolicy()
.selectAllObjectsUsingMultipleTableSubclassRead(this));
}
return result;
}
/**
* INTERNAL: All objects queried via a UnitOfWork get registered here. If the query went to the
* database.
*
* <p>Involves registering the query result individually and in totality, and hence refreshing /
* conforming is done here.
*
* @param result may be collection (read all) or an object (read one), or even a cursor. If in
* transaction the shared cache will be bypassed, meaning the result may not be originals from
* the parent but raw database rows.
* @param unitOfWork the unitOfWork the result is being registered in.
* @param arguments the original arguments/parameters passed to the query execution. Used by
* conforming
* @param buildDirectlyFromRows If in transaction must construct a registered result from raw
* database rows.
* @return the final (conformed, refreshed, wrapped) UnitOfWork query result
*/
public Object registerResultInUnitOfWork(
Object result,
UnitOfWorkImpl unitOfWork,
AbstractRecord arguments,
boolean buildDirectlyFromRows) {
// For bug 2612366: Conforming results in UOW extremely slow.
// Replacing results with registered versions in the UOW is a part of
// conforming and is now done while conforming to maximize performance.
if (shouldConformResultsInUnitOfWork()
|| this.descriptor.shouldAlwaysConformResultsInUnitOfWork()) {
return conformResult(result, unitOfWork, arguments, buildDirectlyFromRows);
}
// When building directly from rows, one of the performance benefits
// is that we no longer have to wrap and then unwrap the originals.
// result is just a vector, not a collection of wrapped originals.
// Also for cursors the initial connection is automatically registered.
if (buildDirectlyFromRows) {
List<AbstractRecord> rows = (List<AbstractRecord>) result;
ContainerPolicy cp = getContainerPolicy();
int size = rows.size();
Object clones = cp.containerInstance(size);
for (int index = 0; index < size; index++) {
AbstractRecord row = rows.get(index);
// null is placed in the row collection for 1-m joining to filter duplicate rows.
if (row != null) {
Object clone = buildObject(row);
cp.addInto(clone, clones, unitOfWork, row, this);
}
}
return clones;
}
ContainerPolicy cp;
Cursor cursor = null;
// If the query is redirected then the collection returned might no longer
// correspond to the original container policy. CR#2342-S.M.
if (getRedirector() != null) {
cp = ContainerPolicy.buildPolicyFor(result.getClass());
} else {
cp = getContainerPolicy();
}
// In the case of cursors just register the initially read collection.
if (cp.isCursorPolicy()) {
cursor = (Cursor) result;
// In nested UnitOfWork session might have been session of the parent.
cursor.setSession(unitOfWork);
cp = ContainerPolicy.buildPolicyFor(ClassConstants.Vector_class);
result = cursor.getObjectCollection();
}
Object clones = cp.containerInstance(cp.sizeFor(result));
AbstractSession sessionToUse = unitOfWork.getParent();
for (Object iter = cp.iteratorFor(result); cp.hasNext(iter); ) {
Object object = cp.next(iter, sessionToUse);
Object clone = registerIndividualResult(object, unitOfWork, this.joinedAttributeManager);
cp.addInto(clone, clones, unitOfWork);
}
if (cursor != null) {
cursor.setObjectCollection((Vector) clones);
return cursor;
} else {
return clones;
}
}