Files
Umbraco-CMS/src/Umbraco.Core/Serialization/AutoInterningStringConverter.cs

39 lines
1.6 KiB
C#

using System;
using System.Collections;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
namespace Umbraco.Core.Serialization
{
/// <summary>
/// When applied to a string or string collection field will ensure the deserialized strings are interned
/// </summary>
/// <remarks>
/// Borrowed from https://stackoverflow.com/a/34906004/694494
/// On the same page an interesting approach of using a local intern pool https://stackoverflow.com/a/39605620/694494 which re-uses .NET System.Xml.NameTable
/// </remarks>
internal class AutoInterningStringConverter : JsonConverter
{
public override bool CanConvert(Type objectType)
{
// CanConvert is not called when a converter is applied directly to a property.
throw new NotImplementedException($"{nameof(AutoInterningStringConverter)} should not be used globally");
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (reader.TokenType == JsonToken.Null)
return null;
// Check is in case the value is a non-string literal such as an integer.
var s = reader.TokenType == JsonToken.String
? string.Intern((string)reader.Value)
: string.Intern((string)JToken.Load(reader));
return s;
}
public override bool CanWrite => false;
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) => throw new NotImplementedException();
}
}