private ObjectReader(IDbCommand command, Type type, IDataReader reader)
{
var provider = InsightDbProvider.For(command);
_columns = new List <ColumnInfo>();
var accessors = new List <Func <object, object> >();
// create a mapping, and only keep mappings that match our modified schema
var sourceMappings = ColumnMapping.MapColumns(type, reader).ToList();
var sourceColumns = ColumnInfo.FromDataReader(reader);
IsAtomicType = TypeHelper.IsAtomicType(type);
if (!IsAtomicType)
{
int columnCount = sourceMappings.Count;
for (int i = 0; i < columnCount; i++)
{
var mapping = sourceMappings[i];
var column = sourceColumns[i];
if (column.IsReadOnly && !column.IsIdentity)
{
continue;
}
_columns.Add(column);
if (mapping == null)
{
accessors.Add(null);
}
else
{
accessors.Add(GenerateAccessor(type, mapping, column));
}
}
}
else
{
var column = sourceColumns.First();
_columns.Add(column);
accessors.Add(GenerateAccessor(type, null, column));
}
_accessors = accessors.ToArray();
}
/// <summary>
/// Maps the columns.
/// </summary>
/// <param name="type">The type being mapped.</param>
/// <param name="reader">The reader being read.</param>
/// <param name="startColumn">The start column index.</param>
/// <param name="columnCount">The number of columns.</param>
/// <param name="structure">The record structure, which may contain custom mapping.</param>
/// <param name="allowBindChild">True if the context allows binding children (e.g. Merge Outputs)</param>
/// <returns>The mapping.</returns>
private static List <FieldMapping> MapColumns(Type type, IDataReader reader, int startColumn, int columnCount, IRecordStructure structure, bool allowBindChild = false)
{
// get the mapping from the reader to the type, excluding deep mappings
var mapping = ColumnMapping.MapColumns(type, reader, startColumn, columnCount, structure);
if (!allowBindChild)
{
for (int i = 0; i < mapping.Count; i++)
{
if (mapping[i] != null && mapping[i].IsDeep)
{
mapping[i] = null;
}
}
}
return(mapping);
}
private ObjectReader(IDbCommand command, Type type, IDataReader reader)
{
var provider = InsightDbProvider.For(command);
// create a mapping, and only keep mappings that match our modified schema
var mappings = ColumnMapping.MapColumns(type, reader).ToList();
// copy the schema and fix it
SchemaTable = reader.GetSchemaTable().Copy();
FixupSchemaNumericScale();
FixupSchemaRemoveReadOnlyColumns(mappings);
IsAtomicType = TypeHelper.IsAtomicType(type);
if (!IsAtomicType)
{
int columnCount = SchemaTable.Rows.Count;
_accessors = new Func <object, object> [columnCount];
_memberTypes = new Type[columnCount];
for (int i = 0; i < columnCount; i++)
{
var mapping = mappings[i];
if (mapping == null)
{
continue;
}
ClassPropInfo propInfo = mapping.Member;
// create a new anonymous method that takes an object and returns the value
var dm = new DynamicMethod(string.Format(CultureInfo.InvariantCulture, "GetValue-{0}-{1}", type.FullName, Guid.NewGuid()), typeof(object), new[] { typeof(object) }, true);
var il = dm.GetILGenerator();
// convert the object reference to the desired type
il.Emit(OpCodes.Ldarg_0);
if (type.IsValueType)
{
// access the field/property of a value type
var valueHolder = il.DeclareLocal(type);
il.Emit(OpCodes.Unbox_Any, type);
il.Emit(OpCodes.Stloc, valueHolder);
il.Emit(OpCodes.Ldloca_S, valueHolder);
}
else
{
il.Emit(OpCodes.Isinst, type); // cast object -> type
}
// get the value from the object
var readyToSetLabel = il.DefineLabel();
ClassPropInfo.EmitGetValue(type, mapping.PathToMember, il, readyToSetLabel);
if (mapping.Member.MemberType.IsValueType)
{
il.Emit(OpCodes.Unbox_Any, mapping.Member.MemberType);
}
// if the type is nullable, handle nulls
Type sourceType = propInfo.MemberType;
Type targetType = (Type)SchemaTable.Rows[i]["DataType"];
Type underlyingType = Nullable.GetUnderlyingType(sourceType);
if (underlyingType != null)
{
// check for not null
Label notNullLabel = il.DefineLabel();
var nullableHolder = il.DeclareLocal(propInfo.MemberType);
il.Emit(OpCodes.Stloc, nullableHolder);
il.Emit(OpCodes.Ldloca_S, nullableHolder);
il.Emit(OpCodes.Call, sourceType.GetProperty("HasValue").GetGetMethod());
il.Emit(OpCodes.Brtrue_S, notNullLabel);
// it's null, just return null
il.Emit(OpCodes.Ldnull);
il.Emit(OpCodes.Ret);
il.MarkLabel(notNullLabel);
// it's not null, so unbox to the underlyingtype
il.Emit(OpCodes.Ldloca, nullableHolder);
il.Emit(OpCodes.Call, sourceType.GetProperty("Value").GetGetMethod());
// at this point we have de-nulled value, so use those converters
sourceType = underlyingType;
}
if (sourceType != targetType && !sourceType.IsValueType && sourceType != typeof(string))
{
il.EmitLoadType(sourceType);
StaticFieldStorage.EmitLoad(il, mapping.Serializer);
il.Emit(OpCodes.Call, typeof(ObjectReader).GetMethod("SerializeObject", BindingFlags.NonPublic | BindingFlags.Static));
}
else
{
// attempt to convert the value
// either way, we are putting it in an object variable, so box it
if (TypeConverterGenerator.EmitConversionOrCoersion(il, sourceType, targetType))
{
il.Emit(OpCodes.Box, targetType);
}
else
{
il.Emit(OpCodes.Box, sourceType);
}
}
il.MarkLabel(readyToSetLabel);
il.Emit(OpCodes.Ret);
_memberTypes[i] = propInfo.MemberType;
_accessors[i] = (Func <object, object>)dm.CreateDelegate(typeof(Func <object, object>));
}
}
else
{
// we are working off a single-column atomic type
_memberTypes = new Type[1] {
type
};
_accessors = new Func <object, object>[] { o => o };
}
}
