public override ITypeHandler4 ReadCandidateHandler(QueryingReadContext context)
{
int id = 0;
int offset = context.Offset();
try
{
id = context.ReadInt();
}
catch (Exception)
{
}
context.Seek(offset);
if (id != 0)
{
StatefulBuffer reader = context.Container().ReadStatefulBufferById(context.Transaction
(), id);
if (reader != null)
{
ObjectHeader oh = new ObjectHeader(context.Container(), reader);
try
{
if (oh.ClassMetadata() != null)
{
context.Buffer(reader);
return oh.ClassMetadata().SeekCandidateHandler(context);
}
}
catch (Exception e)
{
}
}
}
// TODO: Check Exception Types
// Errors typically occur, if classes don't match
return null;
}
public virtual ITypeHandler4 ReadCandidateHandler(QueryingReadContext context)
{
var payLoadOffSet = context.ReadInt();
if (payLoadOffSet == 0)
{
return null;
}
context.Seek(payLoadOffSet);
var classMetadataID = context.ReadInt();
var classMetadata = context.Container().ClassMetadataForID(classMetadataID
);
if (classMetadata == null)
{
return null;
}
return classMetadata.ReadCandidateHandler(context);
}
public QCandidate ReadSubCandidate(QueryingReadContext context, ITypeHandler4 handler
)
{
ObjectID objectID = ObjectID.NotPossible;
try
{
int offset = context.Offset();
if (handler is IReadsObjectIds)
{
objectID = ((IReadsObjectIds)handler).ReadObjectID(context);
}
if (objectID.IsValid())
{
return new QCandidate(this, null, objectID._id);
}
if (objectID == ObjectID.NotPossible)
{
context.Seek(offset);
object obj = context.Read(handler);
if (obj != null)
{
QCandidate candidate = new QCandidate(this, obj, context.Container().GetID(context
.Transaction(), obj));
candidate.ClassMetadata(context.Container().ClassMetadataForObject(obj));
return candidate;
}
}
}
catch (Exception)
{
}
// FIXME: Catchall
return null;
}
/// <exception cref="Db4objects.Db4o.Ext.Db4oIOException"></exception>
private void CollectIDsByInstantiatingCollection(QueryingReadContext context)
{
var id = context.CollectionID();
if (id == 0)
{
return;
}
var transaction = context.Transaction();
var container = context.Container();
var obj = container.GetByID(transaction, id);
if (obj == null)
{
return;
}
// FIXME: [TA] review activation depth
var depth = DepthUtil.AdjustDepthToBorders(2);
container.Activate(transaction, obj, container.ActivationDepthProvider().ActivationDepth
(depth, ActivationMode.Activate));
Platform4.ForEachCollectionElement(obj, new _IVisitor4_390(context));
}