Files
glitchy-engine-beef/ScriptCore/Serialization/DeserializationObject.cs
T

408 lines
12 KiB
C#

using GlitchyEngine.Core;
using GlitchyEngine.Extensions;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Text;
namespace GlitchyEngine.Serialization;
internal class DeserializationObject
{
private class NoObject
{
}
/// <summary>
/// Object used to specify, that no particular value was deserialized for the field and thus the value currently stored shall not be changed.
/// </summary>
private static readonly NoObject NoValueDeserialized = new ();
private IntPtr _internalContext;
private UUID _id;
private Stack<string> _structScope = new();
private string _structScopeName;
public Dictionary<UUID, DeserializationObject> DeserializedClasses;
private object _instance;
public DeserializationObject(IntPtr internalContext, UUID id, Dictionary<UUID, DeserializationObject> deserializedClasses)
{
_internalContext = internalContext;
_id = id;
DeserializedClasses = deserializedClasses;
}
private Dictionary<string, Type> _fullNameToType = new();
private Type FindType(string fullName)
{
foreach (Assembly assembly in AppDomain.CurrentDomain.GetAssemblies().Reverse())
{
Type type = assembly.GetType(fullName);
if (type != null)
return type;
}
return null;
}
private Type GetTypeFromName(string fullName)
{
if (_fullNameToType.TryGetValue(fullName, out Type storedType))
return storedType;
Type type = FindType(fullName);
_fullNameToType.Add(fullName, type);
return type;
}
private DeserializationObject GetDeserializedObject(UUID id)
{
DeserializationObject context;
if (DeserializedClasses.TryGetValue(id, out context))
return context;
ScriptGlue.Serialization_GetObject(_internalContext, id, out IntPtr contextPtr);
context = new DeserializationObject(contextPtr, id, DeserializedClasses);
DeserializedClasses.Add(id, context);
ScriptGlue.Serialization_GetObjectTypeName(context._internalContext, out string fullTypeName);
Type type = GetTypeFromName(fullTypeName);
if (type == null)
return context;
context._instance = ActivatorExtension.CreateInstanceSafe(type);
if (context._instance == null)
return context;
context.DeserializeFields(context._instance);
return context;
}
private void PushScope(string name)
{
_structScope.Push(name);
_structScopeName += $"{name}.";
}
private void PopScope()
{
string scopeToRemove = _structScope.Pop();
_structScopeName = _structScopeName.Remove(_structScopeName.Length - scopeToRemove.Length - 1);
}
[StructLayout(LayoutKind.Explicit)]
private unsafe struct DataHelper
{
[StructLayout(LayoutKind.Sequential)]
public struct EngineObjectReferenceHelper
{
public byte* FullTypeName;
public long FullTypeNameLength;
public UUID Id;
}
[FieldOffset(0)]
public EngineObjectReferenceHelper EngineObjectReference;
}
private unsafe object GetFieldValue(string fieldName, SerializationType serializationType)
{
string completeFieldName = $"{_structScopeName}{fieldName}";
// Decimal is the larges primitive we store so we use a decimal as stack allocated memory (because stackalloc doesn't seem to work :(
//decimal backingFieldOnStack = 0.0m;
byte* rawData = stackalloc byte[sizeof(DataHelper)];
//byte* rawData = (byte*)&backingFieldOnStack;
ref DataHelper dataHelper = ref Unsafe.AsRef<DataHelper>(rawData);
ScriptGlue.Serialization_DeserializeField(_internalContext, serializationType, completeFieldName, rawData);
string GetString()
{
// rawData contains a Pointer and a string length!
byte* utf8Ptr = *(byte**)rawData;
if (utf8Ptr == null)
return null;
ulong length = *(ulong*)(rawData + 8);
if (length == 0)
return string.Empty;
return Encoding.UTF8.GetString(utf8Ptr, (int)length);
}
switch (serializationType)
{
case SerializationType.Bool:
return *(bool*)rawData;
case SerializationType.Char:
return *(char*)rawData;
case SerializationType.String:
return GetString();
case SerializationType.Int8:
return *(sbyte*)rawData;
case SerializationType.Int16:
return *(short*)rawData;
case SerializationType.Int32:
return *(int*)rawData;
case SerializationType.Int64:
return *(long*)rawData;
case SerializationType.UInt8:
return *(byte*)rawData;
case SerializationType.UInt16:
return *(ushort*)rawData;
case SerializationType.UInt32:
return *(uint*)rawData;
case SerializationType.UInt64:
return *(ulong*)rawData;
case SerializationType.Float:
return *(float*)rawData;
case SerializationType.Double:
return *(double*)rawData;
case SerializationType.Decimal:
return *(decimal*)rawData;
case SerializationType.Enum:
return GetString();
case SerializationType.EntityReference:
case SerializationType.ComponentReference:
return dataHelper.EngineObjectReference;
case SerializationType.ObjectReference:
return *(UUID*)rawData;
default:
return NoValueDeserialized;
}
}
public void Deserialize(Entity entity)
{
_instance = entity;
DeserializeFields(entity);
}
private bool DeserializeFields(object obj)
{
Type type = obj.GetType();
bool changed = false;
foreach (FieldInfo field in type.GetFields())
{
if (!EntitySerializer.SerializeField(field))
continue;
changed |= DeserializeField(obj, field);
}
return changed;
}
private bool DeserializeField(object targetInstance, FieldInfo field)
{
Type fieldType = field.FieldType;
object newFieldValue = NoValueDeserialized;
if (fieldType.IsPrimitive)
{
newFieldValue = DeserializePrimitive(field.Name, fieldType);
}
else if (fieldType == typeof(string))
{
newFieldValue = GetFieldValue(field.Name, SerializationType.String);
}
else if (fieldType.IsEnum)
{
newFieldValue = DeserializeEnum(field.Name, fieldType);
}
else if (fieldType.IsArray)
{
// Log.Error($"Array serialization not yet implemented");
}
else if (fieldType.IsGenericType)
{
if (fieldType.GetGenericTypeDefinition() == typeof(List<>))
{
//SerializeList(fieldName, type, o);
Log.Error($"List serialization not yet implemented");
}
//else if (fieldType.GetGenericTypeDefinition() == typeof(Dictionary<,>))
//{
// ImGui.Text($"{fieldName} Dictionary");
//}
else
{
// TODO: what to do?
Log.Error($"Generic class serialization not yet implemented");
}
}
else if (fieldType.IsValueType)
{
object structValue = field.GetValue(targetInstance);
newFieldValue = DeserializeStruct(field.Name, structValue);
}
else if (fieldType.IsClass)
{
newFieldValue = DeserializeClass(field.Name, fieldType);
}
else
{
Log.Error($"Encountered unhandled type \"{fieldType}\" while serializing.");
}
if (newFieldValue != NoValueDeserialized)
{
field.SetValue(targetInstance, newFieldValue);
return true;
}
return false;
}
private object DeserializePrimitive(string fieldName, Type fieldType)
{
Debug.Assert(fieldType.IsPrimitive, $"{fieldType} is not a primitive type.");
SerializationType expectedType = SerializationType.None;
if (fieldType == typeof(bool))
expectedType = SerializationType.Bool;
else if (fieldType == typeof(char))
expectedType = SerializationType.Char;
else if (fieldType == typeof(byte))
expectedType = SerializationType.UInt8;
else if (fieldType == typeof(sbyte))
expectedType = SerializationType.Int8;
else if (fieldType == typeof(ushort))
expectedType = SerializationType.UInt16;
else if (fieldType == typeof(short))
expectedType = SerializationType.Int16;
else if (fieldType == typeof(uint))
expectedType = SerializationType.UInt32;
else if (fieldType == typeof(int))
expectedType = SerializationType.Int32;
else if (fieldType == typeof(ulong))
expectedType = SerializationType.UInt64;
else if (fieldType == typeof(long))
expectedType = SerializationType.Int64;
else if (fieldType == typeof(float))
expectedType = SerializationType.Float;
else if (fieldType == typeof(double))
expectedType = SerializationType.Double;
else if (fieldType == typeof(decimal))
expectedType = SerializationType.Decimal;
else
{
Log.Error($"The primitive {fieldType} is not implemented.");
}
return GetFieldValue(fieldName, expectedType);
}
private object DeserializeEnum(string fieldName, Type enumType)
{
if (GetFieldValue(fieldName, SerializationType.Enum) is not string valueName)
return NoValueDeserialized;
try
{
return Enum.Parse(enumType, valueName);
}
catch
{
Log.Error($"Failed to parse \"{valueName}\" as enum-type \"{enumType}\"");
}
return NoValueDeserialized;
}
private object DeserializeStruct(string fieldName, object targetInstance)
{
PushScope(fieldName);
bool changed = DeserializeFields(targetInstance);
PopScope();
return changed ? targetInstance : NoValueDeserialized;
}
private unsafe object DeserializeClass(string fieldName, Type fieldType)
{
bool isEntity = typeof(Entity).IsAssignableFrom(fieldType);
bool isComponent = fieldType.IsSubclassOf(typeof(Component));
if (isEntity || isComponent)
{
var data = (DataHelper.EngineObjectReferenceHelper)GetFieldValue(fieldName, isEntity ? SerializationType.EntityReference : SerializationType.ComponentReference);
UUID id = data.Id;
if (id == UUID.Zero)
return null;
string fullTypeName = Encoding.UTF8.GetString(data.FullTypeName, (int)data.FullTypeNameLength);
Type type = GetTypeFromName(fullTypeName);
if (type == null)
return NoValueDeserialized;
if (isEntity)
{
// We have to differentiate between simple Entity references and script instances
// (because we decided to use the same type for both, so we could have a field Entity which contains a script instance instead of an Entity reference)
if (type == typeof(Entity))
return new Entity(id);
return Entity.GetScriptReference(id, type);
}
else
{
Entity entity = new Entity(id);
return entity.GetComponent(type);
}
}
else
{
UUID id = (UUID)GetFieldValue(fieldName, SerializationType.ObjectReference);
if (id == UUID.Zero)
return null;
DeserializationObject deserializedObject = GetDeserializedObject(id);
return deserializedObject._instance;
}
}
}