using System.Collections; using System.Collections.Generic; using System.Runtime.CompilerServices; using System.Runtime.InteropServices; namespace System.Text.Json.Serialization.Converters { internal sealed class IEnumerableConverter<TCollection> : JsonCollectionConverter<TCollection, object> where TCollection : IEnumerable { private readonly bool _isDeserializable = typeof(TCollection).IsAssignableFrom(typeof(List<object>)); internal override bool SupportsCreateObjectDelegate => false; protected override void Add([In] [IsReadOnly] object value, ref ReadStack state) { ((List<object>)state.Current.ReturnValue).Add(value); } protected override void CreateCollection(ref Utf8JsonReader reader, [ScopedRef] ref ReadStack state, JsonSerializerOptions options) { if (!_isDeserializable) ThrowHelper.ThrowNotSupportedException_CannotPopulateCollection(Type, ref reader, ref state); state.Current.ReturnValue = new List<object>(); } protected 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> elementConverter = JsonCollectionConverter<TCollection, object>.GetElementConverter(ref state); do { if (JsonConverter.ShouldFlush(ref state, writer)) return false; object value2 = enumerator.Current; if (!elementConverter.TryWrite(writer, ref value2, options, ref state)) return false; state.Current.EndCollectionElement(); } while (enumerator.MoveNext()); return true; } } }