reflection based deserialisation, binary only for now

Author: Angel-foxxo

AttributeList.cs

@@ -9,6 +9,7 @@
 
 using AttrKVP = System.Collections.Generic.KeyValuePair<string, object>;
 using System.Reflection;
+using System.IO;
 
 namespace Datamodel
 {
@@ -243,11 +244,21 @@ public virtual object this[string name]
                     throw new AttributeTypeException("Elements are not supported as prefix attributes.");
 
                 var prop_attr = (PropertyInfo)PropertyInfos[name];
+
                 if (prop_attr != null)
                 {
-                    throw new InvalidOperationException($"Cannot set the value of a property-derived attribute by key. Assign to '{prop_attr.Name}' directly instead.");
-                }
+                    PropertyInfo prop = GetType().GetProperty(prop_attr.Name, BindingFlags.Public | BindingFlags.Instance);
 
+                    if (null != prop && prop.CanWrite)
+                    {
+                        prop.SetValue(this, value);
+                    }
+                    else
+                    {
+                        throw new InvalidDataException("Property of deserialisation class must be writeable, make sure it's public and has a public setter");
+                    }
+                }
+                
                 Attribute old_attr;
                 Attribute new_attr;
                 int old_index = -1;

Codecs/Binary.cs

@@ -5,6 +5,8 @@
 using System.Numerics;
 using System.IO;
 using System.Diagnostics;
+using System.Reflection;
+using System.Runtime.CompilerServices;
 
 namespace Datamodel.Codecs
 {
@@ -344,8 +346,15 @@ object ReadValue(Datamodel dm, Type type, bool raw_string)
             throw new ArgumentException(type == null ? "No type provided to GetValue()" : "Cannot read value of type " + type.Name);
         }
 
-        public Datamodel Decode(string encoding, int encoding_version, string format, int format_version, Stream stream, DeferredMode defer_mode)
+        public Datamodel Decode(string encoding, int encoding_version, string format, int format_version, Stream stream, DeferredMode defer_mode, Assembly callingAssembly, bool attemptReflection)
         {
+            Dictionary<string, Type> callingTypes = new();
+
+            foreach (var classType in callingAssembly.DefinedTypes)
+            {
+                callingTypes.Add(classType.Name, classType);
+            }
+
             stream.Seek(0, SeekOrigin.Begin);
             while (true)
             {
@@ -383,7 +392,39 @@ public Datamodel Decode(string encoding, int encoding_version, string format, in
                 var id_bits = Reader.ReadBytes(16);
                 var id = new Guid(BitConverter.IsLittleEndian ? id_bits : id_bits.Reverse().ToArray());
 
-                var elem = new Element(dm, name, id, type);
+                Element? elem = null;
+                var matchedType = callingTypes.TryGetValue(type, out var classType);
+
+                if(matchedType)
+                {
+                    var isElementDerived = IsElementDerived(classType);
+                    if (isElementDerived && classType.Name == type)
+                    {
+                        Type derivedType = classType;
+                
+                        ConstructorInfo? constructor = typeof(Element).GetConstructor(
+                            BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic,
+                            null,
+                            new Type[] { typeof(Datamodel), typeof(string), typeof(Guid), typeof(string) },
+                            null
+                        );
+                
+                        if (constructor == null)
+                        {
+                            throw new InvalidOperationException("Failed to get constructor while attemption reflection based deserialisation");
+                        }
+                
+                        object uninitializedObject = RuntimeHelpers.GetUninitializedObject(derivedType);
+                        constructor.Invoke(uninitializedObject, new object[] { dm, name, id, type });
+                
+                        elem = (Element?)uninitializedObject;
+                    }
+                }
+                
+                if (elem == null)
+                {
+                    elem = new Element(dm, name, id, type);
+                }
             }
 
             // read attributes (or not, if we're deferred)
@@ -396,8 +437,7 @@ public Datamodel Decode(string encoding, int encoding_version, string format, in
                 foreach (var i in Enumerable.Range(0, num_attrs))
                 {
                     var name = StringDict.ReadString();
-
-                    if (defer_mode == DeferredMode.Automatic)
+                    if (defer_mode == DeferredMode.Automatic && attemptReflection == false)
                     {
                         CodecUtilities.AddDeferredAttribute(elem, name, Reader.BaseStream.Position);
                         SkipAttribute();
@@ -408,6 +448,7 @@ public Datamodel Decode(string encoding, int encoding_version, string format, in
                     }
                 }
             }
+
             return dm;
         }
 
@@ -762,6 +803,28 @@ void WriteAttribute(object value, bool in_array)
             }
         }
 
+        bool IsElementDerived(Type type)
+        {
+            var elementType = typeof(Element);
+
+            while (type.BaseType != elementType)
+            {
+                var baseType = type.BaseType;
+
+                if (baseType != null)
+                {
+                    type = baseType;
+                }
+                else
+                {
+                    return type == elementType ? true : false;
+                }
+
+            }
+
+            return type.BaseType == elementType ? true : false;
+        }
+
         class DmxBinaryWriter : BinaryWriter
         {
             public DmxBinaryWriter(Stream output)

Codecs/KeyValues2.cs

@@ -6,6 +6,7 @@
 using System.IO;
 using System.Runtime.CompilerServices;
 using System.Globalization;
+using System.Reflection;
 
 namespace Datamodel.Codecs
 {
@@ -597,7 +598,7 @@ object Decode_ParseValue(Type type, string value)
             else throw new ArgumentException($"Internal error: ParseValue passed unsupported type: {type}.");
         }
 
-        public Datamodel Decode(string encoding, int encoding_version, string format, int format_version, Stream stream, DeferredMode defer_mode)
+        public Datamodel Decode(string encoding, int encoding_version, string format, int format_version, Stream stream, DeferredMode defer_mode, Assembly callingAssembly, bool attemptReflection)
         {
             DM = new Datamodel(format, format_version);
 

Datamodel.NET.csproj

@@ -19,7 +19,7 @@
     <AssemblyOriginatorKeyFile>sgKey.snk</AssemblyOriginatorKeyFile>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All"/>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
   </ItemGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Documentation|AnyCPU'">
     <OutputPath>bin\Documentation\</OutputPath>
@@ -30,10 +30,11 @@
   </PropertyGroup>
   <PropertyGroup>
     <DelaySign>false</DelaySign>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
   <ItemGroup>
-    <None Include="README.md" Pack="true" PackagePath="\"/>
-    <None Include="COPYING" Pack="true" PackagePath="\"/>
+    <None Include="README.md" Pack="true" PackagePath="\" />
+    <None Include="COPYING" Pack="true" PackagePath="\" />
   </ItemGroup>
   <ItemGroup>
     <Compile Remove="DmxPad\**" />

Datamodel.NET.sln

@@ -6,7 +6,10 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Datamodel.NET", "Datamodel.
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Tests", "Tests\Tests.csproj", "{4C928D60-5E48-4C0D-9C7E-C75D9734CD58}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DmxPad", "DmxPad\DmxPad.csproj", "{B49BF0E9-46DB-4BE3-9890-02FF5C098C7C}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ConsoleApp1", "..\ConsoleApp1\ConsoleApp1.csproj", "{B4982001-13F5-4CD3-953E-F438FC42699E}"
+	ProjectSection(ProjectDependencies) = postProject
+		{075743A9-B292-410C-B68F-6E6CF588D60A} = {075743A9-B292-410C-B68F-6E6CF588D60A}
+	EndProjectSection
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -27,6 +30,12 @@ Global
 		{4C928D60-5E48-4C0D-9C7E-C75D9734CD58}.Documentation|Any CPU.Build.0 = Debug|Any CPU
 		{4C928D60-5E48-4C0D-9C7E-C75D9734CD58}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{4C928D60-5E48-4C0D-9C7E-C75D9734CD58}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B4982001-13F5-4CD3-953E-F438FC42699E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B4982001-13F5-4CD3-953E-F438FC42699E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B4982001-13F5-4CD3-953E-F438FC42699E}.Documentation|Any CPU.ActiveCfg = Release|Any CPU
+		{B4982001-13F5-4CD3-953E-F438FC42699E}.Documentation|Any CPU.Build.0 = Release|Any CPU
+		{B4982001-13F5-4CD3-953E-F438FC42699E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B4982001-13F5-4CD3-953E-F438FC42699E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

Datamodel.cs

@@ -9,6 +9,7 @@
 using System.Security;
 using System.Numerics;
 using CodecRegistration = System.Tuple<string, int>;
+using System.Reflection;
 
 namespace Datamodel
 {
@@ -231,32 +232,32 @@ public void Save(string path, string encoding, int encoding_version)
         /// </summary>
         /// <param name="stream">The input Stream.</param>
         /// <param name="defer_mode">How to handle deferred loading.</param>
-        public static Datamodel Load(Stream stream, DeferredMode defer_mode = DeferredMode.Automatic)
+        public static Datamodel Load(Stream stream, DeferredMode defer_mode = DeferredMode.Automatic, bool attemptReflection = false)
         {
-            return Load_Internal(stream, defer_mode);
+            return Load_Internal(stream, Assembly.GetCallingAssembly(), defer_mode, attemptReflection);
         }
         /// <summary>
         /// Loads a Datamodel from a byte array.
         /// </summary>
         /// <param name="stream">The input Stream.</param>
         /// <param name="defer_mode">How to handle deferred loading.</param>
-        public static Datamodel Load(byte[] data, DeferredMode defer_mode = DeferredMode.Automatic)
+        public static Datamodel Load(byte[] data, DeferredMode defer_mode = DeferredMode.Automatic, bool attemptReflection = false)
         {
-            return Load_Internal(new MemoryStream(data, true), defer_mode);
+            return Load_Internal(new MemoryStream(data, true), Assembly.GetCallingAssembly(), defer_mode, attemptReflection);
         }
 
         /// <summary>
         /// Loads a Datamodel from a file path.
         /// </summary>
         /// <param name="path">The source file path.</param>
         /// <param name="defer_mode">How to handle deferred loading.</param>
-        public static Datamodel Load(string path, DeferredMode defer_mode = DeferredMode.Automatic)
+        public static Datamodel Load(string path, DeferredMode defer_mode = DeferredMode.Automatic, bool attemptReflection = false)
         {
             var stream = File.OpenRead(path);
             Datamodel dm = null;
             try
             {
-                dm = Load_Internal(stream, defer_mode);
+                dm = Load_Internal(stream, Assembly.GetCallingAssembly(), defer_mode, attemptReflection);
                 return dm;
             }
             finally
@@ -265,7 +266,7 @@ public static Datamodel Load(string path, DeferredMode defer_mode = DeferredMode
             }
         }
 
-        private static Datamodel Load_Internal(Stream stream, DeferredMode defer_mode = DeferredMode.Automatic)
+        private static Datamodel Load_Internal(Stream stream, Assembly callingAssembly, DeferredMode defer_mode = DeferredMode.Automatic, bool attemptReflection = false)
         {
             stream.Seek(0, SeekOrigin.Begin);
             var header = string.Empty;
@@ -292,7 +293,7 @@ private static Datamodel Load_Internal(Stream stream, DeferredMode defer_mode =
 
             ICodec codec = GetCodec(encoding, encoding_version);
 
-            var dm = codec.Decode(encoding, encoding_version, format, format_version, stream, defer_mode);
+            var dm = codec.Decode(encoding, encoding_version, format, format_version, stream, defer_mode, callingAssembly, attemptReflection);
             if (defer_mode == DeferredMode.Automatic && codec is IDeferredAttributeCodec deferredCodec)
             {
                 dm.Stream = stream;

Element.cs

@@ -161,6 +161,7 @@ internal set
 
         #region Properties
 
+        // TODO: this could probably be sped up by caching the properties somehow
         protected override ICollection<(string Name, PropertyInfo Property)> GetPropertyDerivedAttributeList()
         {
             var type = GetType();
@@ -176,8 +177,6 @@ internal set
                 if (property.GetIndexParameters().Length == 0 && property.DeclaringType.IsSubclassOf(typeof(Element)))
                 {
                     var name = property.Name;
-                    name = property.DeclaringType.GetCustomAttribute<Format.AttributeNamingConventionAttribute>()?
-                        .GetAttributeName(name, property.PropertyType) ?? name;
                     name = property.GetCustomAttribute<Format.DMProperty>()?.Name ?? name;
 
                     properties.Add((name, property));

Format/Attribute.cs

@@ -3,67 +3,12 @@
 
 namespace Datamodel.Format;
 
-/// <summary>
-/// Subclass this attribute to define a custom attribute name convention.
-/// </summary>
-[AttributeUsage(AttributeTargets.Class, Inherited = false, AllowMultiple = false)]
-public abstract class AttributeNamingConventionAttribute : System.Attribute
-{
-    public abstract string GetAttributeName(string propertyName, Type propertyType);
-}
-
-/// <summary>
-/// This class' property names are mostly lowercase.
-/// </summary>
-public class LowercasePropertiesAttribute : AttributeNamingConventionAttribute
-{
-    public override string GetAttributeName(string propertyName, Type _)
-        => propertyName.ToLower();
-}
-
-/// <summary>
-/// This class' property names are mostly camelCase.
-/// </summary>
-public class CamelCasePropertiesAttribute : AttributeNamingConventionAttribute
-{
-    public override string GetAttributeName(string propertyName, Type _)
-        => char.ToLowerInvariant(propertyName.AsSpan()[0]) + propertyName[1..];
-}
-
-/// <summary>
-/// This class' property names are mostly m_hungarian.
-/// </summary>
-public class HungarianPropertiesAttribute : CamelCasePropertiesAttribute
-{
-    public override string GetAttributeName(string propertyName, Type propertyType)
-    {
-        var typeAnnotation = propertyType switch
-        {
-            _ when propertyType == typeof(int) => "n",
-            _ when propertyType == typeof(float) => "fl",
-            _ when propertyType == typeof(bool) => "b",
-            _ when propertyType == typeof(Vector2) => "v",
-            _ when propertyType == typeof(Vector3) => "v",
-            _ when propertyType == typeof(Vector4) => "v",
-            _ when propertyType == typeof(Matrix4x4) => "mat",
-            _ => string.Empty,
-        };
-
-        if (typeAnnotation == string.Empty)
-        {
-            return "m_" + base.GetAttributeName(propertyName, propertyType);
-        }
-
-        return "m_" + typeAnnotation + propertyName;
-    }
-}
-
 [AttributeUsage(AttributeTargets.Property, Inherited = true, AllowMultiple = false)]
 public sealed class DMProperty : System.Attribute
 {
     /// <param name="name">The name to use for serialization.</param>
     /// <param name="optional">Ignore serialization if property is on the default value.</param>
-    public DMProperty(string name = null, bool optional = false)
+    public DMProperty(string name = "", bool optional = false)
     {
         Name = name;
         Optional = optional;

ICodec.cs

@@ -2,6 +2,7 @@
 using System.Linq;
 using System.IO;
 using System.Numerics;
+using System.Reflection;
 
 namespace Datamodel.Codecs
 {
@@ -29,7 +30,7 @@ public interface ICodec
         /// <param name="stream">The input stream. Its position will always be 0. Do not dispose.</param>
         /// <param name="defer_mode">The deferred loading mode specified by the caller. Only relevant to implementers of <see cref="IDeferredAttributeCodec"/></param>
         /// <returns></returns>
-        Datamodel Decode(string encoding, int encoding_version, string format, int format_version, Stream stream, DeferredMode defer_mode);
+        Datamodel Decode(string encoding, int encoding_version, string format, int format_version, Stream stream, DeferredMode defer_mode, Assembly callingAssembly, bool attemptReflection);
     }
 
     /// <summary>

Tests/Resources/cs2_map.vmap.txt

@@ -91,7 +91,7 @@
 
 		"nextDecalID" "int" "0"
 		"fixupEntityNames" "bool" "1"
-		"mapUsageType" "string" "standard"
+		"mapUsageType" "string" "hellyea"
 		"origin" "vector3" "0 0 0"
 		"angles" "qangle" "0 0 0"
 		"scales" "vector3" "1 1 1"