LLamaSharp/LLama/Common/PolymorphicJSONConverter.cs

58 lines
2.2 KiB
C#

using LLama.Abstractions;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Text.Json;
using System.Text.Json.Serialization;
namespace LLama.Common
{
internal class PolymorphicJSONConverter<T> : JsonConverter<T>
{
public override T? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
{
if (reader.TokenType != JsonTokenType.StartObject)
throw new JsonException();
reader.Read();
if (reader.TokenType != JsonTokenType.PropertyName)
throw new JsonException();
string? propertyName = reader.GetString();
if (propertyName != "Name")
return default;
reader.Read();
if (reader.TokenType != JsonTokenType.String)
throw new JsonException();
string? name = reader.GetString() ?? throw new JsonException();
var inheritedTypes = Assembly.GetExecutingAssembly().GetTypes().Where(
t => typeof(T).IsAssignableFrom(t) && !t.IsAbstract && !t.IsInterface
);
var type = inheritedTypes.FirstOrDefault(t => t.Name == name);
if (type == null)
throw new JsonException();
reader.Read();
if (reader.TokenType != JsonTokenType.PropertyName)
throw new JsonException();
propertyName = reader.GetString();
if (propertyName != "Data")
throw new JsonException();
var data = JsonSerializer.Deserialize(ref reader, type, options);
if (data == null)
throw new JsonException();
reader.Read();
reader.Read();
return (T)data;
}
public override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions options)
{
writer.WriteStartObject();
writer.WriteString("Name", value.GetType().Name);
writer.WritePropertyName("Data");
JsonSerializer.Serialize(writer, value, value.GetType(), options);
writer.WriteEndObject();
}
}
}