LargeObjectWithParameterizedConstructorConverter.cs

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using System.Buffers;
using System.Collections.Generic;
using System.Text.Json.Serialization.Metadata;
 
namespace System.Text.Json.Serialization.Converters;
 
internal class LargeObjectWithParameterizedConstructorConverter<T> : ObjectWithParameterizedConstructorConverter<T>
{
    protected sealed override bool ReadAndCacheConstructorArgument(ref ReadStack state, ref Utf8JsonReader reader, JsonParameterInfo jsonParameterInfo)
    {
        object value;
        bool flag = jsonParameterInfo.ConverterBase.TryReadAsObject(ref reader, jsonParameterInfo.Options, ref state, out value);
        if (flag && (value != null || !jsonParameterInfo.IgnoreDefaultValuesOnRead))
        {
            ((object[])state.Current.CtorArgumentState.Arguments)[jsonParameterInfo.ClrInfo.Position] = value;
        }
        return flag;
    }
 
    protected sealed override object CreateObject(ref ReadStackFrame frame)
    {
        object[] array = (object[])frame.CtorArgumentState.Arguments;
        frame.CtorArgumentState.Arguments = null;
        Func<object[], T> func = (Func<object[], T>)frame.JsonTypeInfo.CreateObjectWithArgs;
        if (func == null)
        {
            ThrowHelper.ThrowNotSupportedException_ConstructorMaxOf64Parameters(TypeToConvert);
        }
        object result = func(array);
        ArrayPool<object>.Shared.Return(array, clearArray: true);
        return result;
    }
 
    protected sealed override void InitializeConstructorArgumentCaches(ref ReadStack state, JsonSerializerOptions options)
    {
        JsonTypeInfo jsonTypeInfo = state.Current.JsonTypeInfo;
        if (jsonTypeInfo.ParameterCache == null)
        {
            jsonTypeInfo.InitializePropCache();
        }
        List<KeyValuePair<string, JsonParameterInfo>> list = jsonTypeInfo.ParameterCache.List;
        object[] array = ArrayPool<object>.Shared.Rent(list.Count);
        for (int i = 0; i < jsonTypeInfo.ParameterCount; i++)
        {
            JsonParameterInfo value = list[i].Value;
            array[value.ClrInfo.Position] = value.DefaultValue;
        }
        state.Current.CtorArgumentState.Arguments = array;
    }
}