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);
}
private bool CreateChildForDescendable(QCandidates parentCandidates, ITypeHandler4
handler, QueryingReadContext queryingReadContext, ITypeHandler4 arrayElementHandler
)
{
int offset = queryingReadContext.Offset();
bool outerRes = true;
// The following construct is worse than not ideal. For each constraint it completely reads the
// underlying structure again. The structure could be kept fairly easy. TODO: Optimize!
IEnumerator i = parentCandidates.IterateConstraints();
while (i.MoveNext())
{
QCon qcon = (QCon)i.Current;
QField qf = qcon.GetField();
if (qf != null && !qf.Name().Equals(_fieldMetadata.GetName()))
{
continue;
}
QCon tempParent = qcon.Parent();
qcon.SetParent(null);
QCandidates candidates = new QCandidates(parentCandidates.i_trans, null, qf, false
);
candidates.AddConstraint(qcon);
qcon.SetCandidates(candidates);
ReadArrayCandidates(handler, queryingReadContext.Buffer(), arrayElementHandler, candidates
);
queryingReadContext.Seek(offset);
bool isNot = qcon.IsNot();
if (isNot)
{
qcon.RemoveNot();
}
candidates.Evaluate();
ByRef pending = ByRef.NewInstance();
BooleanByRef innerRes = new BooleanByRef(isNot);
candidates.Traverse(new QCandidate.CreateDescendChildTraversingVisitor(pending, innerRes
, isNot));
if (isNot)
{
qcon.Not();
}
// In case we had pending subresults, we need to communicate them up to our root.
if (((Tree)pending.value) != null)
{
((Tree)pending.value).Traverse(new _IVisitor4_168(this));
}
if (!innerRes.value)
{
// Again this could be double triggering.
//
// We want to clean up the "No route" at some stage.
qcon.Visit(GetRoot(), qcon.Evaluator().Not(false));
outerRes = false;
}
qcon.SetParent(tempParent);
}
return(outerRes);
}
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);
}
internal virtual bool CreateChild(QCandidates a_candidates)
{
if (!_include)
{
return(false);
}
if (_fieldMetadata != null)
{
ITypeHandler4 handler = _fieldMetadata.GetHandler();
if (handler != null)
{
QueryingReadContext queryingReadContext = new QueryingReadContext(Transaction(),
MarshallerFamily().HandlerVersion(), _bytes, _key);
ITypeHandler4 arrayElementHandler = Handlers4.ArrayElementHandler(handler, queryingReadContext
);
if (arrayElementHandler != null)
{
int offset = queryingReadContext.Offset();
bool outerRes = true;
// The following construct is worse than not ideal.
// For each constraint it completely reads the
// underlying structure again. The structure could b
// kept fairly easy. TODO: Optimize!
IEnumerator i = a_candidates.IterateConstraints();
while (i.MoveNext())
{
QCon qcon = (QCon)i.Current;
QField qf = qcon.GetField();
if (qf == null || qf.Name().Equals(_fieldMetadata.GetName()))
{
QCon tempParent = qcon.Parent();
qcon.SetParent(null);
QCandidates candidates = new QCandidates(a_candidates.i_trans, null, qf);
candidates.AddConstraint(qcon);
qcon.SetCandidates(candidates);
ReadArrayCandidates(handler, queryingReadContext.Buffer(), arrayElementHandler, candidates
);
queryingReadContext.Seek(offset);
bool isNot = qcon.IsNot();
if (isNot)
{
qcon.RemoveNot();
}
candidates.Evaluate();
ByRef pending = ByRef.NewInstance();
bool[] innerRes = new bool[] { isNot };
candidates.Traverse(new _IVisitor4_160(innerRes, isNot, pending));
// Collect all pending subresults.
// We need to change
// the
// constraint here, so
// our
// pending collector
// uses
// the right
// comparator.
// We only keep one
// pending result
// for
// all array
// elements.
// and memorize,
// whether we had a
// true or a false
// result.
// or both.
if (isNot)
{
qcon.Not();
}
// In case we had pending subresults, we
// need to communicate
// them up to our root.
if (((Tree)pending.value) != null)
{
((Tree)pending.value).Traverse(new _IVisitor4_229(this));
}
if (!innerRes[0])
{
// Again this could be double triggering.
//
// We want to clean up the "No route"
// at some stage.
qcon.Visit(GetRoot(), qcon.Evaluator().Not(false));
outerRes = false;
}
qcon.SetParent(tempParent);
}
}
return(outerRes);
}
// We may get simple types here too, if the YapField was null
// in the higher level simple evaluation. Evaluate these
// immediately.
if (Handlers4.IsQueryLeaf(handler))
{
a_candidates.i_currentConstraint.Visit(this);
return(true);
}
}
}
if (_fieldMetadata == null)
{
return(false);
}
if (_fieldMetadata is NullFieldMetadata)
{
return(false);
}
_classMetadata.SeekToField(Transaction(), _bytes, _fieldMetadata);
Db4objects.Db4o.Internal.Query.Processor.QCandidate candidate = ReadSubCandidate(
a_candidates);
if (candidate == null)
{
return(false);
}
// fast early check for ClassMetadata
if (a_candidates.i_classMetadata != null && a_candidates.i_classMetadata.IsStronglyTyped
())
{
ITypeHandler4 handler = _fieldMetadata.GetHandler();
if (Handlers4.IsUntyped(handler))
{
handler = TypeHandlerFor(candidate);
}
if (handler == null)
{
return(false);
}
}
AddDependant(a_candidates.Add(candidate));
return(true);
}
