protected override Expression VisitStructureExpression(StructureExpression expression)
{
var tupleExpression = GetTupleExpression(expression);
var typeInfo = expression.PersistentType;
var tuplePrototype = typeInfo.TuplePrototype;
var mappingInfo = expression.Fields
.OfType <FieldExpression>()
.Where(f => f.ExtendedType == ExtendedExpressionType.Field)
.OrderBy(f => f.Field.MappingInfo.Offset)
.Select(f => new Pair <int>(f.Field.MappingInfo.Offset, f.Mapping.Offset))
.Distinct()
.ToArray();
int[] columnMap = MaterializationHelper.CreateSingleSourceMap(tuplePrototype.Count, mappingInfo);
var persistentTupleExpression = (Expression)Expression.Call(
BuildPersistentTupleMethod,
tupleExpression,
Expression.Constant(tuplePrototype),
Expression.Constant(columnMap));
return(Expression.Convert(
Expression.Call(
WellKnownMembers.CreateStructure,
Expression.Field(itemMaterializationContextParameter, ItemMaterializationContext.SessionFieldInfo),
Expression.Constant(expression.Type),
persistentTupleExpression),
expression.Type));
}
public TypeMapping GetTypeMapping(int entityIndex, TypeInfo approximateType, int typeId, Pair <int>[] columns)
{
TypeMapping result;
var cache = entityMappings[entityIndex];
if (cache.SingleItem != null)
{
if (typeId != ResolveTypeToNodeSpecificTypeIdentifier(cache.SingleItem.Type))
{
throw new ArgumentOutOfRangeException("typeId");
}
return(cache.SingleItem);
}
if (cache.Items.TryGetValue(typeId, out result))
{
return(result);
}
var type = TypeIdRegistry[typeId];
var keyInfo = type.Key;
var descriptor = type.TupleDescriptor;
var typeColumnMap = columns.ToArray();
if (approximateType.IsInterface)
{
// fixup target index
for (int i = 0; i < columns.Length; i++)
{
var pair = typeColumnMap[i];
var approxTargetIndex = pair.First;
var interfaceField = approximateType.Columns[approxTargetIndex].Field;
var field = type.FieldMap[interfaceField];
var targetIndex = field.MappingInfo.Offset;
typeColumnMap[i] = new Pair <int>(targetIndex, pair.Second);
}
}
int[] allIndexes = MaterializationHelper.CreateSingleSourceMap(descriptor.Count, typeColumnMap);
int[] keyIndexes = allIndexes.Take(keyInfo.TupleDescriptor.Count).ToArray();
var transform = new MapTransform(true, descriptor, allIndexes);
var keyTransform = new MapTransform(true, keyInfo.TupleDescriptor, keyIndexes);
result = new TypeMapping(type, keyTransform, transform, keyIndexes);
if (type.Hierarchy.Root.IsLeaf && approximateType == type)
{
cache.SingleItem = result;
}
else
{
cache.Items.Add(typeId, result);
}
entityMappings[entityIndex] = cache;
return(result);
}