Feature/system.text.json (#192)

Initial support for System.Text.Json and some refactoring
2026-08-18 11:52:54 +00:00 · 2024-03-16 14:45:36 +01:00
parent 462c857bba
commit 2fb3442800
66 changed files with 2318 additions and 1095 deletions
@@ -0,0 +1,133 @@
+using System;
+using System.Collections.Concurrent;
+using System.Globalization;
+using System.Linq;
+using System.Reflection;
+using System.Text.Json.Serialization;
+using System.Text.Json;
+using CryptoExchange.Net.Attributes;
+using System.Collections.Generic;
+
+namespace CryptoExchange.Net.Converters.SystemTextJson
+{
+    /// <summary>
+    /// Converter for arrays to objects. Can deserialize data like [0.1, 0.2, "test"] to an object. Mapping is done by marking the class with [JsonConverter(typeof(ArrayConverter))] and the properties
+    /// with [ArrayProperty(x)] where x is the index of the property in the array
+    /// </summary>
+    public class ArrayConverter : JsonConverterFactory
+    {
+        /// <inheritdoc />
+        public override bool CanConvert(Type typeToConvert) => true;
+
+        /// <inheritdoc />
+        public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options)
+        {
+            Type converterType = typeof(ArrayConverterInner<>).MakeGenericType(typeToConvert);
+            return (JsonConverter)Activator.CreateInstance(converterType);
+        }
+
+        private class ArrayPropertyInfo
+        {
+            public PropertyInfo PropertyInfo { get; set; } = null!;
+            public ArrayPropertyAttribute ArrayProperty { get; set; } = null!;
+            public Type? JsonConverterType { get; set; }
+            public bool DefaultDeserialization { get; set; }
+        }
+
+        private class ArrayConverterInner<T> : JsonConverter<T>
+        {
+            private static readonly ConcurrentDictionary<Type, List<ArrayPropertyInfo>> _typeAttributesCache = new ConcurrentDictionary<Type, List<ArrayPropertyInfo>>();
+
+
+            public override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions options)
+            {
+                // TODO
+                throw new NotImplementedException();
+            }
+
+            /// <inheritdoc />
+            public override T? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+            {
+                if (reader.TokenType == JsonTokenType.Null)
+                    return default;
+
+                var result = Activator.CreateInstance(typeToConvert);
+                return (T)ParseObject(ref reader, result, typeToConvert);
+            }
+
+            private static List<ArrayPropertyInfo> CacheTypeAttributes(Type type)
+            {
+                var attributes = new List<ArrayPropertyInfo>();
+                var properties = type.GetProperties();
+                foreach (var property in properties)
+                {
+                    var att = property.GetCustomAttribute<ArrayPropertyAttribute>();
+                    if (att == null)
+                        continue;
+
+                    attributes.Add(new ArrayPropertyInfo
+                    {
+                        ArrayProperty = att,
+                        PropertyInfo = property,
+                        DefaultDeserialization = property.GetCustomAttribute<JsonConversionAttribute>() != null,
+                        JsonConverterType = property.GetCustomAttribute<JsonConverterAttribute>()?.ConverterType
+                    });
+                }
+
+                _typeAttributesCache.TryAdd(type, attributes);
+                return attributes;
+            }
+
+            private static object ParseObject(ref Utf8JsonReader reader, object result, Type objectType)
+            {
+                if (reader.TokenType != JsonTokenType.StartArray)
+                    throw new Exception("1");
+
+                if (!_typeAttributesCache.TryGetValue(objectType, out var attributes))
+                    attributes = CacheTypeAttributes(objectType);
+
+                int index = 0;
+                while (reader.Read())
+                {
+                    if (reader.TokenType == JsonTokenType.EndArray)
+                        break;
+
+                var attribute = attributes.SingleOrDefault(a => a.ArrayProperty.Index == index);
+                var targetType = attribute.PropertyInfo.PropertyType;
+
+                    object? value = null;
+                    if (attribute.JsonConverterType != null)
+                    {
+                        // Has JsonConverter attribute
+                        var options = new JsonSerializerOptions();
+                        options.Converters.Add((JsonConverter)Activator.CreateInstance(attribute.JsonConverterType));
+                        value = JsonDocument.ParseValue(ref reader).Deserialize(targetType, options);
+                    }
+                    else if (attribute.DefaultDeserialization)
+                    {
+                        // Use default deserialization
+                        value = JsonDocument.ParseValue(ref reader).Deserialize(targetType);
+                    }
+                    else
+                    {
+                        value = reader.TokenType switch
+                        {
+                            JsonTokenType.Null => null,
+                            JsonTokenType.False => false,
+                            JsonTokenType.True => true,
+                            JsonTokenType.String => reader.GetString(),
+                            JsonTokenType.Number => reader.GetDecimal(),
+                            _ => throw new NotImplementedException($"Array deserialization of type {reader.TokenType} not supported"),
+                        };
+                    }
+
+                    attribute.PropertyInfo.SetValue(result, value == null ? null : Convert.ChangeType(value, attribute.PropertyInfo.PropertyType, CultureInfo.InvariantCulture));
+                    
+                    index++;
+                }
+
+                return result;
+            }
+        }
+    }
+}