Don't allocate strings for property key lookups

src/Discord.Net.Rest/Serialization/JsonConverters/EntityOrIdPropertyConverter.cs

@@ -28,7 +28,7 @@ namespace Discord.Serialization.Json.Converters
             else
             {
                 if (isTopLevel)
-                    writer.WriteAttribute(map.Key, value.Id);
+                    writer.WriteAttribute(map.Utf16Key, value.Id);
                 else
                     writer.WriteValue(value.Id);
             }

src/Discord.Net.Rest/Serialization/JsonConverters/Int53PropertyConverter.cs

@@ -15,7 +15,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, long value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value);
+                writer.WriteAttribute(map.Utf16Key, value);
             else
                 writer.WriteValue(value.ToString());
         }

src/Discord.Net.Rest/Serialization/JsonConverters/UInt53PropertyConverter.cs

@@ -15,7 +15,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, ulong value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value);
+                writer.WriteAttribute(map.Utf16Key, value);
             else
                 writer.WriteValue(value.ToString());
         }

src/Discord.Net.Serialization/ConverterCollection.cs

@@ -65,42 +65,48 @@ namespace Discord.Serialization
         
         public object Get<TType>(PropertyInfo propInfo = null)
         {
-            return _cache.GetOrAdd(typeof(TType), _ =>
+            if (!_cache.TryGetValue(typeof(TType), out var result))
             {
-                TypeInfo typeInfo = typeof(TType).GetTypeInfo();
+                object converter = Create(typeof(TType), propInfo);
+                result = _cache.GetOrAdd(typeof(TType), converter);
+            }
+            return result;
+        }
+        private object Create(Type type, PropertyInfo propInfo)
+        {
+            TypeInfo typeInfo = type.GetTypeInfo();
 
-                //Mapped generic converters (List<T> -> CollectionPropertyConverter<T>)
-                if (typeInfo.IsGenericType)
+            //Mapped generic converters (List<T> -> CollectionPropertyConverter<T>)
+            if (typeInfo.IsGenericType)
+            {
+                var converterType = FindConverterType(typeInfo.GetGenericTypeDefinition(), _mappedGenericTypes, typeInfo, propInfo);
+                if (converterType != null)
                 {
-                    var converterType = FindConverterType(typeInfo.GetGenericTypeDefinition(), _mappedGenericTypes, typeInfo, propInfo);
-                    if (converterType != null)
-                    {
-                        var innerType = typeInfo.GenericTypeArguments[0];
-                        converterType = converterType.MakeGenericType(innerType);
-                        object innerConverter = GetInnerConverter(innerType, propInfo);
-                        return Activator.CreateInstance(converterType, innerConverter);
-                    }
+                    var innerType = typeInfo.GenericTypeArguments[0];
+                    converterType = converterType.MakeGenericType(innerType);
+                    object innerConverter = GetInnerConverter(innerType, propInfo);
+                    return Activator.CreateInstance(converterType, innerConverter);
                 }
+            }
 
-                //Normal converters (bool -> BooleanPropertyConverter)
-                {
-                    var converterType = FindConverterType(typeof(TType), _types, typeInfo, propInfo);
-                    if (converterType != null)
-                        return Activator.CreateInstance(converterType);
-                }
+            //Normal converters (bool -> BooleanPropertyConverter)
+            {
+                var converterType = FindConverterType(type, _types, typeInfo, propInfo);
+                if (converterType != null)
+                    return Activator.CreateInstance(converterType);
+            }
 
-                //Generic converters (Model -> ObjectPropertyConverter<Model>)
+            //Generic converters (Model -> ObjectPropertyConverter<Model>)
+            {
+                var converterType = FindConverterType(_genericTypes, typeInfo, propInfo);
+                if (converterType != null)
                 {
-                    var converterType = FindConverterType(_genericTypes, typeInfo, propInfo);
-                    if (converterType != null)
-                    {
-                        converterType = converterType.MakeGenericType(typeof(TType));
-                        return Activator.CreateInstance(converterType);
-                    }
+                    converterType = converterType.MakeGenericType(type);
+                    return Activator.CreateInstance(converterType);
                 }
+            }
 
-                throw new InvalidOperationException($"Unsupported model type: {typeof(TType).Name}");
-            });
+            throw new InvalidOperationException($"Unsupported model type: {type.Name}");
         }
         private object GetInnerConverter(Type type, PropertyInfo propInfo)
             => _getConverterMethod.MakeGenericMethod(type).Invoke(this, new object[] { propInfo });

src/Discord.Net.Serialization/Json/Converters/Collections.cs

@@ -26,7 +26,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, List<T> value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteArrayStart(map.Key);
+                writer.WriteArrayStart(map.Utf16Key);
             else
                 writer.WriteArrayStart();
             for (int i = 0; i < value.Count; i++)

src/Discord.Net.Serialization/Json/Converters/Nullable.cs

@@ -28,7 +28,7 @@ namespace Discord.Serialization.Json.Converters
             else
             {
                 if (isTopLevel)
-                    writer.WriteAttributeNull(map.Key);
+                    writer.WriteAttributeNull(map.Utf16Key);
                 else
                     writer.WriteNull();
             }

src/Discord.Net.Serialization/Json/Converters/Object.cs

@@ -1,4 +1,5 @@
 using System.Text.Json;
+using System.Text.Utf8;
 
 namespace Discord.Serialization.Json.Converters
 {
@@ -19,9 +20,8 @@ namespace Discord.Serialization.Json.Converters
                     return model;
                 if (reader.TokenType != JsonTokenType.PropertyName)
                     throw new SerializationException("Bad input, expected PropertyName");
-
-                string key = reader.ParseString();                
-                if (_map.PropertiesByKey.TryGetValue(key, out var property))
+                
+                if (_map.PropertiesByKey.TryGetValue(reader.Value, out var property))
                     (property as IJsonPropertyMap<T>).Read(model, ref reader);
                 else
                     reader.Skip(); //Unknown property, skip
@@ -31,7 +31,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, T value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteObjectStart(map.Key);
+                writer.WriteObjectStart(map.Utf16Key);
             else
                 writer.WriteObjectStart();
             for (int i = 0; i < _map.Properties.Length; i++)

src/Discord.Net.Serialization/Json/Converters/Primitives.DateTime.cs

@@ -16,7 +16,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, DateTime value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value);
+                writer.WriteAttribute(map.Utf16Key, value);
             else
                 writer.WriteValue(value);
         }
@@ -35,7 +35,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, DateTimeOffset value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value);
+                writer.WriteAttribute(map.Utf16Key, value);
             else
                 writer.WriteValue(value);
         }

src/Discord.Net.Serialization/Json/Converters/Primitives.Float.cs

@@ -15,7 +15,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, float value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value.ToString());
+                writer.WriteAttribute(map.Utf16Key, value.ToString());
             else
                 writer.WriteValue(value.ToString());
         }
@@ -34,7 +34,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, double value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value.ToString());
+                writer.WriteAttribute(map.Utf16Key, value.ToString());
             else
                 writer.WriteValue(value.ToString());
         }
@@ -53,7 +53,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, decimal value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value.ToString());
+                writer.WriteAttribute(map.Utf16Key, value.ToString());
             else
                 writer.WriteValue(value.ToString());
         }

src/Discord.Net.Serialization/Json/Converters/Primitives.Other.cs

@@ -19,7 +19,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, bool value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value);
+                writer.WriteAttribute(map.Utf16Key, value);
             else
                 writer.WriteValue(value);
         }
@@ -33,12 +33,12 @@ namespace Discord.Serialization.Json.Converters
                 reader.Read();
             if (reader.ValueType != JsonValueType.String)
                 throw new SerializationException("Bad input, expected String");
-            return Guid.Parse(reader.ParseString());
+            return Guid.Parse(reader.ParseString()); //TODO: Causes allocs
         }
         public void Write(PropertyMap map, ref JsonWriter writer, Guid value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value.ToString());
+                writer.WriteAttribute(map.Utf16Key, value.ToString());
             else
                 writer.WriteValue(value.ToString());
         }

src/Discord.Net.Serialization/Json/Converters/Primitives.Signed.cs

@@ -15,7 +15,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, sbyte value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value);
+                writer.WriteAttribute(map.Utf16Key, value);
             else
                 writer.WriteValue(value);
         }
@@ -34,7 +34,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, short value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value);
+                writer.WriteAttribute(map.Utf16Key, value);
             else
                 writer.WriteValue(value);
         }
@@ -53,7 +53,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, int value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value);
+                writer.WriteAttribute(map.Utf16Key, value);
             else
                 writer.WriteValue(value);
         }
@@ -72,7 +72,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, long value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value.ToString());
+                writer.WriteAttribute(map.Utf16Key, value.ToString());
             else
                 writer.WriteValue(value.ToString());
         }

src/Discord.Net.Serialization/Json/Converters/Primitives.String.cs

@@ -34,7 +34,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, string value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value);
+                writer.WriteAttribute(map.Utf16Key, value);
             else
                 writer.WriteValue(value);
         }

src/Discord.Net.Serialization/Json/Converters/Primitives.Unsigned.cs

@@ -15,7 +15,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, byte value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value);
+                writer.WriteAttribute(map.Utf16Key, value);
             else
                 writer.WriteValue(value);
         }
@@ -34,7 +34,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, ushort value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value);
+                writer.WriteAttribute(map.Utf16Key, value);
             else
                 writer.WriteValue(value);
         }
@@ -53,7 +53,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, uint value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value);
+                writer.WriteAttribute(map.Utf16Key, value);
             else
                 writer.WriteValue(value);
         }
@@ -72,7 +72,7 @@ namespace Discord.Serialization.Json.Converters
         public void Write(PropertyMap map, ref JsonWriter writer, ulong value, bool isTopLevel)
         {
             if (isTopLevel)
-                writer.WriteAttribute(map.Key, value.ToString());
+                writer.WriteAttribute(map.Utf16Key, value.ToString());
             else
                 writer.WriteValue(value.ToString());
         }

src/Discord.Net.Serialization/Json/IJsonPropertyMap.cs

@@ -1,10 +1,12 @@
 using System.Text.Json;
+using System.Text.Utf8;
 
 namespace Discord.Serialization
 {
     internal interface IJsonPropertyMap<TModel>
     {
-        string Key { get; }
+        string Utf16Key { get; }
+        Utf8String Utf8Key { get; }
 
         void Write(TModel model, ref JsonWriter writer);
         void Read(TModel model, ref JsonReader reader);

src/Discord.Net.Serialization/ModelMap.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 
 namespace Discord.Serialization
@@ -7,9 +8,9 @@ namespace Discord.Serialization
         where TModel : class, new()
     {
         public readonly PropertyMap[] Properties;
-        public readonly Dictionary<string, PropertyMap> PropertiesByKey;
+        public readonly Dictionary<ReadOnlySpan<byte>, PropertyMap> PropertiesByKey;
 
-        public ModelMap(Dictionary<string, PropertyMap> properties)
+        public ModelMap(Dictionary<ReadOnlySpan<byte>, PropertyMap> properties)
         {
             PropertiesByKey = properties;
             Properties = PropertiesByKey.Values.ToArray();

src/Discord.Net.Serialization/PropertyMap.cs

@@ -1,17 +1,20 @@
 using System.Reflection;
+using System.Text.Utf8;
 
 namespace Discord.Serialization
 {
     public abstract class PropertyMap
     {
-        public string Key { get; }
+        public string Utf16Key { get; }
+        public Utf8String Utf8Key { get; }
         public bool ExcludeNull { get; }
 
         public PropertyMap(PropertyInfo propInfo)
         {
             var jsonProperty = propInfo.GetCustomAttribute<ModelPropertyAttribute>();
 
-            Key = jsonProperty?.Key ?? propInfo.Name;
+            Utf16Key = jsonProperty?.Key ?? propInfo.Name;
+            Utf8Key = new Utf8String(Utf16Key);
             ExcludeNull = jsonProperty?.ExcludeNull ?? false;
         }
     }

src/Discord.Net.Serialization/SerializationFormat.cs

@@ -25,17 +25,15 @@ namespace Discord.Serialization
             return _maps.GetOrAdd(typeof(TModel), _ =>
             {
                 var type = typeof(TModel).GetTypeInfo();
-                var properties = new Dictionary<string, PropertyMap>();
+                var propInfos = type.DeclaredProperties
+                    .Where(x => x.CanRead && x.CanWrite)
+                    .ToArray();
 
-                var propInfos = type.DeclaredProperties.ToArray();
+                var properties = new Dictionary<ReadOnlySpan<byte>, PropertyMap>(propInfos.Length, Utf8SpanComparer.Instance);
                 for (int i = 0; i < propInfos.Length; i++)
                 {
-                    var propInfo = propInfos[i];
-                    if (!propInfo.CanRead || !propInfo.CanWrite)
-                        continue;
-
-                    var propMap = MapProperty<TModel>(propInfo);
-                    properties.Add(propMap.Key, propMap);
+                    var propMap = MapProperty<TModel>(propInfos[i]);
+                    properties.Add(propMap.Utf8Key, propMap);
                 }
                 return new ModelMap<TModel>(properties);
             }) as ModelMap<TModel>;

src/Discord.Net.Serialization/Utf8SpanComparer.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+
+namespace Discord.Serialization
+{
+    internal class Utf8SpanComparer : IEqualityComparer<ReadOnlySpan<byte>>
+    {
+        public static readonly Utf8SpanComparer Instance = new Utf8SpanComparer();
+
+        public bool Equals(ReadOnlySpan<byte> x, ReadOnlySpan<byte> y) => x.SequenceEqual(y);
+        public int GetHashCode(ReadOnlySpan<byte> obj)
+        {
+            //From Utf8String
+            //TODO: Replace when they do
+            unchecked
+            {
+                if (obj.Length <= 4)
+                {
+                    int hash = obj.Length;
+                    for (int i = 0; i < obj.Length; i++)
+                    {
+                        hash <<= 8;
+                        hash ^= obj[i];
+                    }
+                    return hash;
+                }
+                else
+                {
+                    int hash = obj.Length;
+                    hash ^= obj[0];
+                    hash <<= 8;
+                    hash ^= obj[1];
+                    hash <<= 8;
+                    hash ^= obj[obj.Length - 2];
+                    hash <<= 8;
+                    hash ^= obj[obj.Length - 1];
+                    return hash;
+                }
+            }
+        }
+    }
+}