/// <summary>
/// Initializes the state for polymorphic cases and returns the appropriate converter.
/// </summary>
public JsonConverter?ResolvePolymorphicConverter(object value, Type typeToConvert, JsonSerializerOptions options)
{
Debug.Assert(value != null);
Debug.Assert(PolymorphicSerializationState != PolymorphicSerializationState.PolymorphicReEntryStarted);
if (PolymorphicSerializationState == PolymorphicSerializationState.PolymorphicReEntrySuspended)
{
// Quickly retrieve the polymorphic converter in case of a re-entrant continuation
Debug.Assert(PolymorphicJsonTypeInfo != null && value.GetType() == PolymorphicJsonTypeInfo.PropertyType);
return(PolymorphicJsonTypeInfo.ConverterBase);
}
Type runtimeType = value.GetType();
if (runtimeType == typeToConvert)
{
return(null);
}
// For perf, avoid the dictionary lookup in GetOrAddJsonTypeInfo() for every element of a collection
// if the current element is the same type as the previous element.
if (PolymorphicJsonTypeInfo?.PropertyType != runtimeType)
{
JsonTypeInfo typeInfo = options.GetOrAddJsonTypeInfo(runtimeType);
PolymorphicJsonTypeInfo = typeInfo.PropertyInfoForTypeInfo;
}
return(PolymorphicJsonTypeInfo.ConverterBase);
}
/// <summary>
/// Initializes the state for polymorphic cases and returns the appropriate converter.
/// </summary>
public JsonConverter InitializeReEntry(Type type, JsonSerializerOptions options)
{
// For perf, avoid the dictionary lookup in GetOrAddClass() for every element of a collection
// if the current element is the same type as the previous element.
if (PolymorphicJsonPropertyInfo?.PropertyType != type)
{
JsonTypeInfo typeInfo = options.GetOrAddJsonTypeInfo(type);
PolymorphicJsonPropertyInfo = typeInfo.PropertyInfoForTypeInfo;
}
return(PolymorphicJsonPropertyInfo.ConverterBase);
}
/// <summary>
/// Configures the next stack frame for a polymorphic converter.
/// </summary>
public JsonConverter InitializePolymorphicReEntry(Type runtimeType, JsonSerializerOptions options)
{
Debug.Assert(PolymorphicSerializationState == PolymorphicSerializationState.None);
// For perf, avoid the dictionary lookup in GetOrAddJsonTypeInfo() for every element of a collection
// if the current element is the same type as the previous element.
if (PolymorphicJsonTypeInfo?.PropertyType != runtimeType)
{
JsonTypeInfo typeInfo = options.GetOrAddJsonTypeInfo(runtimeType);
PolymorphicJsonTypeInfo = typeInfo.PropertyInfoForTypeInfo;
}
PolymorphicSerializationState = PolymorphicSerializationState.PolymorphicReEntryStarted;
return(PolymorphicJsonTypeInfo.ConverterBase);
}
