ObjectWriter CreateWriter(Type type)
{
if (type == typeof(string)) {
// String contents are written in the object creation section,
// not into the field value section.
return delegate {};
}
bool isArray = type.IsArray;
if (isArray) {
if (type.GetArrayRank() != 1)
throw new NotSupportedException();
type = type.GetElementType();
if (!type.IsValueType) {
return delegate (SerializationContext context, object array) {
foreach (object val in (object[])array) {
context.WriteObjectID(val);
}
};
} else if (type == typeof(byte)) {
return delegate (SerializationContext context, object array) {
context.writer.Write((byte[])array);
};
}
}
List<FieldInfo> fields = GetSerializableFields(type);
if (fields.Count == 0) {
// The writer has nothing to do for this object.
return delegate { };
}
DynamicMethod dynamicMethod = new DynamicMethod(
(isArray ? "WriteArray_" : "Write_") + type.Name,
typeof(void), new [] { typeof(SerializationContext), typeof(object) },
true);
ILGenerator il = dynamicMethod.GetILGenerator();
var writer = il.DeclareLocal(typeof(BinaryWriter));
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Ldfld, writerField);
il.Emit(OpCodes.Stloc, writer); // writer = context.writer;
if (isArray) {
var instance = il.DeclareLocal(type.MakeArrayType());
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCodes.Castclass, type.MakeArrayType());
il.Emit(OpCodes.Stloc, instance); // instance = (type[])arg_1;
// for (int i = 0; i < instance.Length; i++) write instance[i];
var loopStart = il.DefineLabel();
var loopHead = il.DefineLabel();
var loopVariable = il.DeclareLocal(typeof(int));
il.Emit(OpCodes.Ldc_I4_0);
il.Emit(OpCodes.Stloc, loopVariable); // loopVariable = 0
il.Emit(OpCodes.Br, loopHead); // goto loopHead;
il.MarkLabel(loopStart);
if (type.IsEnum || type.IsPrimitive) {
if (type.IsEnum) {
type = type.GetEnumUnderlyingType();
}
Debug.Assert(type.IsPrimitive);
il.Emit(OpCodes.Ldloc, writer); // writer
il.Emit(OpCodes.Ldloc, instance); // writer, instance
il.Emit(OpCodes.Ldloc, loopVariable); // writer, instance, loopVariable
switch (Type.GetTypeCode(type)) {
case TypeCode.Boolean:
case TypeCode.SByte:
case TypeCode.Byte:
il.Emit(OpCodes.Ldelem_I1); // writer, instance[loopVariable]
il.Emit(callVirt, writeByte); // writer.Write(instance[loopVariable]);
break;
case TypeCode.Char:
case TypeCode.Int16:
case TypeCode.UInt16:
il.Emit(OpCodes.Ldelem_I2); // writer, instance[loopVariable]
il.Emit(callVirt, writeShort); // writer.Write(instance[loopVariable]);
break;
case TypeCode.Int32:
case TypeCode.UInt32:
il.Emit(OpCodes.Ldelem_I4); // writer, instance[loopVariable]
il.Emit(callVirt, writeInt); // writer.Write(instance[loopVariable]);
break;
case TypeCode.Int64:
case TypeCode.UInt64:
il.Emit(OpCodes.Ldelem_I8); // writer, instance[loopVariable]
il.Emit(callVirt, writeLong); // writer.Write(instance[loopVariable]);
break;
case TypeCode.Single:
il.Emit(OpCodes.Ldelem_R4); // writer, instance[loopVariable]
il.Emit(callVirt, writeFloat); // writer.Write(instance[loopVariable]);
break;
case TypeCode.Double:
il.Emit(OpCodes.Ldelem_R8); // writer, instance[loopVariable]
il.Emit(callVirt, writeDouble); // writer.Write(instance[loopVariable]);
break;
default:
throw new NotSupportedException("Unknown primitive type " + type);
}
} else {
il.Emit(OpCodes.Ldloc, instance); // instance
il.Emit(OpCodes.Ldloc, loopVariable); // instance, loopVariable
il.Emit(OpCodes.Ldelem, type); // instance[loopVariable]
EmitWriteValueType(il, writer, type);
}
il.Emit(OpCodes.Ldloc, loopVariable); // loopVariable
il.Emit(OpCodes.Ldc_I4_1); // loopVariable, 1
il.Emit(OpCodes.Add); // loopVariable+1
il.Emit(OpCodes.Stloc, loopVariable); // loopVariable++;
il.MarkLabel(loopHead);
il.Emit(OpCodes.Ldloc, loopVariable); // loopVariable
il.Emit(OpCodes.Ldloc, instance); // loopVariable, instance
il.Emit(OpCodes.Ldlen); // loopVariable, instance.Length
il.Emit(OpCodes.Conv_I4);
il.Emit(OpCodes.Blt, loopStart); // if (loopVariable < instance.Length) goto loopStart;
} else if (type.IsValueType) {
// boxed value type
if (type.IsEnum || type.IsPrimitive) {
il.Emit(OpCodes.Ldloc, writer);
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCodes.Unbox_Any, type);
WritePrimitiveValue(il, type);
} else {
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCodes.Unbox_Any, type);
EmitWriteValueType(il, writer, type);
}
} else {
// reference type
var instance = il.DeclareLocal(type);
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCodes.Castclass, type);
il.Emit(OpCodes.Stloc, instance); // instance = (type)arg_1;
foreach (FieldInfo field in fields) {
EmitWriteField(il, writer, instance, field); // write instance.Field
}
}
il.Emit(OpCodes.Ret);
return (ObjectWriter)dynamicMethod.CreateDelegate(typeof(ObjectWriter));
}