private ObjectReader GetFieldsReader([NotNull] Serializer serializer, [NotNull] FieldInfo[] fields,
[NotNull] Type type)
{
var c = new Compiler <ObjectReader>();
var stream = c.Parameter <Stream>("stream");
var session = c.Parameter <DeserializerSession>("session");
var newExpression = c.NewObject(type);
var target = c.Variable <object>("target");
var assignNewObjectToTarget = c.WriteVar(target, newExpression);
c.Emit(assignNewObjectToTarget);
if (serializer.Options.PreserveObjectReferences)
{
var trackDeserializedObjectMethod =
typeof(DeserializerSession).GetTypeInfo().GetMethod(nameof(DeserializerSession.TrackDeserializedObject));
c.EmitCall(trackDeserializedObjectMethod, session, target);
}
//for (var i = 0; i < storedFieldCount; i++)
//{
// var fieldName = stream.ReadLengthEncodedByteArray(session);
// if (!Utils.Compare(fieldName, fieldNames[i]))
// {
// //TODO: field name mismatch
// //this should really be a compare less equal or greater
// //to know if the field is added or removed
// //1) if names are equal, read the value and assign the field
// //2) if the field is less than the expected field, then this field is an unknown new field
// //we need to read this object and just ignore its content.
// //3) if the field is greater than the expected, we need to check the next expected until
// //the current is less or equal, then goto 1)
// }
//}
var typedTarget = c.CastOrUnbox(target, type);
var serializers = fields.Select(field => serializer.GetSerializerByType(field.FieldType)).ToArray();
var preallocatedBufferSize = serializers.Length != 0 ? serializers.Max(s => s.PreallocatedByteBufferSize) : 0;
if (preallocatedBufferSize > 0)
{
EmitPreallocatedBuffer(c, preallocatedBufferSize, session,
typeof(DeserializerSession).GetTypeInfo().GetMethod(nameof(DeserializerSession.GetBuffer)));
}
for (var i = 0; i < fields.Length; i++)
{
var field = fields[i];
var s = serializers[i];
int read;
if (!serializer.Options.VersionTolerance && field.FieldType.IsHyperionPrimitive())
{
//Only optimize if property names are not included.
//if they are included, we need to be able to skip past unknown property data
//e.g. if sender have added a new property that the receiveing end does not yet know about
//which we cannot do w/o a manifest
read = s.EmitReadValue(c, stream, session, field);
}
else
{
var method = typeof(StreamEx).GetTypeInfo().GetMethod(nameof(StreamEx.ReadObject));
read = c.StaticCall(method, stream, session);
read = c.Convert(read, field.FieldType);
}
var assignReadToField = c.WriteField(field, typedTarget, target, read);
c.Emit(assignReadToField);
}
c.Emit(target);
var readAllFields = c.Compile();
return(readAllFields);
}
//this generates a FieldWriter that writes all fields by unrolling all fields and calling them individually
//no loops involved
private ObjectWriter GetFieldsWriter([NotNull] Serializer serializer, [NotNull] IEnumerable <FieldInfo> fields,
out int preallocatedBufferSize)
{
var c = new Compiler <ObjectWriter>();
var stream = c.Parameter <Stream>("stream");
var target = c.Parameter <object>("target");
var session = c.Parameter <SerializerSession>("session");
var preserveReferences = c.Constant(serializer.Options.PreserveObjectReferences);
if (serializer.Options.PreserveObjectReferences)
{
var method =
typeof(SerializerSession).GetTypeInfo().GetMethod(nameof(SerializerSession.TrackSerializedObject));
c.EmitCall(method, session, target);
}
var fieldsArray = fields.ToArray();
var serializers = fieldsArray.Select(field => serializer.GetSerializerByType(field.FieldType)).ToArray();
preallocatedBufferSize = serializers.Length != 0 ? serializers.Max(s => s.PreallocatedByteBufferSize) : 0;
if (preallocatedBufferSize > 0)
{
EmitPreallocatedBuffer(c, preallocatedBufferSize, session,
typeof(SerializerSession).GetTypeInfo().GetMethod("GetBuffer"));
}
for (var i = 0; i < fieldsArray.Length; i++)
{
var field = fieldsArray[i];
//get the serializer for the type of the field
var valueSerializer = serializers[i];
//runtime Get a delegate that reads the content of the given field
var cast = c.CastOrUnbox(target, field.DeclaringType);
var readField = c.ReadField(field, cast);
//if the type is one of our special primitives, ignore manifest as the content will always only be of this type
if (!serializer.Options.VersionTolerance && field.FieldType.IsHyperionPrimitive())
{
//primitive types does not need to write any manifest, if the field type is known
valueSerializer.EmitWriteValue(c, stream, readField, session);
}
else
{
var converted = c.Convert <object>(readField);
var valueType = field.FieldType;
if (field.FieldType.IsNullable())
{
var nullableType = field.FieldType.GetNullableElement();
valueSerializer = serializer.GetSerializerByType(nullableType);
valueType = nullableType;
}
var vs = c.Constant(valueSerializer);
var vt = c.Constant(valueType);
var method = typeof(StreamEx).GetTypeInfo().GetMethod(nameof(StreamEx.WriteObject));
c.EmitStaticCall(method, stream, converted, vt, vs, preserveReferences, session);
}
}
return(c.Compile());
}
