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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.Collections;
using System.Diagnostics;
using System.Text.Json.Serialization.Metadata;
namespace System.Text.Json.Serialization.Converters
{
internal class StackOrQueueConverter<TCollection>
: JsonCollectionConverter<TCollection, object?>
where TCollection : IEnumerable
{
internal override bool CanPopulate => true;
protected sealed override void Add(in object? value, ref ReadStack state)
{
var addMethodDelegate = ((Action<TCollection, object?>?)state.Current.JsonTypeInfo.AddMethodDelegate);
Debug.Assert(addMethodDelegate != null);
addMethodDelegate((TCollection)state.Current.ReturnValue!, value);
}
protected sealed override void CreateCollection(ref Utf8JsonReader reader, scoped ref ReadStack state, JsonSerializerOptions options)
{
if (state.ParentProperty?.TryGetPrePopulatedValue(ref state) == true)
{
return;
}
JsonTypeInfo typeInfo = state.Current.JsonTypeInfo;
Func<object>? constructorDelegate = typeInfo.CreateObject;
if (constructorDelegate == null)
{
ThrowHelper.ThrowNotSupportedException_CannotPopulateCollection(Type, ref reader, ref state);
}
state.Current.ReturnValue = constructorDelegate();
Debug.Assert(typeInfo.AddMethodDelegate != null);
}
protected sealed override bool OnWriteResume(Utf8JsonWriter writer, TCollection value, JsonSerializerOptions options, ref WriteStack state)
{
IEnumerator enumerator;
if (state.Current.CollectionEnumerator == null)
{
enumerator = value.GetEnumerator();
state.Current.CollectionEnumerator = enumerator;
if (!enumerator.MoveNext())
{
return true;
}
}
else
{
enumerator = state.Current.CollectionEnumerator;
}
JsonConverter<object?> converter = GetElementConverter(ref state);
do
{
if (ShouldFlush(ref state, writer))
{
return false;
}
object? element = enumerator.Current;
if (!converter.TryWrite(writer, element, options, ref state))
{
return false;
}
state.Current.EndCollectionElement();
} while (enumerator.MoveNext());
return true;
}
}
}
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