/// <summary>
/// Each of the specialized 'peek' methods copies the appropriate field value of an instance of T
/// into the provided buffer. So, the call is 'peek(userObject, ref destination)' and the logic is
/// indentical to 'destination = userObject.##FIELD##', where ##FIELD## is defined per peek method.
/// </summary>
internal static Delegate GeneratePeek <TOwn, TRow>(InternalSchemaDefinition.Column column)
{
switch (column.MemberInfo)
{
case FieldInfo fieldInfo:
Type fieldType = fieldInfo.FieldType;
var assignmentOpCode = GetAssignmentOpCode(fieldType);
Func <FieldInfo, OpCode, Delegate> func = GeneratePeek <TOwn, TRow, int>;
var methInfo = func.GetMethodInfo().GetGenericMethodDefinition()
.MakeGenericMethod(typeof(TOwn), typeof(TRow), fieldType);
return((Delegate)methInfo.Invoke(null, new object[] { fieldInfo, assignmentOpCode }));
case PropertyInfo propertyInfo:
Type propertyType = propertyInfo.PropertyType;
var assignmentOpCodeProp = GetAssignmentOpCode(propertyType);
Func <PropertyInfo, OpCode, Delegate> funcProp = GeneratePeek <TOwn, TRow, int>;
var methInfoProp = funcProp.GetMethodInfo().GetGenericMethodDefinition()
.MakeGenericMethod(typeof(TOwn), typeof(TRow), propertyType);
return((Delegate)methInfoProp.Invoke(null, new object[] { propertyInfo, assignmentOpCodeProp }));
default:
Contracts.Assert(false);
throw Contracts.ExceptNotSupp("Expected a FieldInfo or a PropertyInfo");
}
}
private static OpCode GetAssignmentOpCode(Type t)
{
// REVIEW: This should be a Dictionary<Type, OpCode> based solution.
// DvTypes, strings, arrays, all nullable types, VBuffers and RowId.
if (t == typeof(ReadOnlyMemory <char>) || t == typeof(string) || t.IsArray ||
(t.IsGenericType && t.GetGenericTypeDefinition() == typeof(VBuffer <>)) ||
(t.IsGenericType && t.GetGenericTypeDefinition() == typeof(Nullable <>)) ||
t == typeof(DateTime) || t == typeof(DateTimeOffset) || t == typeof(TimeSpan) || t == typeof(RowId))
{
return(OpCodes.Stobj);
}
// Simple primitive types.
if (t == typeof(Single))
{
return(OpCodes.Stind_R4);
}
if (t == typeof(Double))
{
return(OpCodes.Stind_R8);
}
if (t == typeof(sbyte) || t == typeof(byte) || t == typeof(bool))
{
return(OpCodes.Stind_I1);
}
if (t == typeof(short) || t == typeof(ushort))
{
return(OpCodes.Stind_I2);
}
if (t == typeof(int) || t == typeof(uint))
{
return(OpCodes.Stind_I4);
}
if (t == typeof(long) || t == typeof(ulong))
{
return(OpCodes.Stind_I8);
}
throw Contracts.ExceptNotSupp("Type '{0}' is not supported.", t.FullName);
}