using System.Buffers; namespace System.Text.Json { internal static class Utf8JsonWriterCache { private sealed class ThreadLocalState { public readonly PooledByteBufferWriter BufferWriter; public readonly Utf8JsonWriter Writer; public int RentedWriters; public ThreadLocalState() { BufferWriter = PooledByteBufferWriter.CreateEmptyInstanceForCaching(); Writer = Utf8JsonWriter.CreateEmptyInstanceForCaching(); } } [ThreadStatic] private static ThreadLocalState t_threadLocalState; public static Utf8JsonWriter RentWriterAndBuffer(JsonSerializerOptions options, out PooledByteBufferWriter bufferWriter) { return RentWriterAndBuffer(options.GetWriterOptions(), options.DefaultBufferSize, out bufferWriter); } public static Utf8JsonWriter RentWriterAndBuffer(JsonWriterOptions options, int defaultBufferSize, out PooledByteBufferWriter bufferWriter) { ThreadLocalState threadLocalState = t_threadLocalState ?? (t_threadLocalState = new ThreadLocalState()); Utf8JsonWriter utf8JsonWriter; if (threadLocalState.RentedWriters++ == 0) { bufferWriter = threadLocalState.BufferWriter; utf8JsonWriter = threadLocalState.Writer; bufferWriter.InitializeEmptyInstance(defaultBufferSize); utf8JsonWriter.Reset(bufferWriter, options); } else { bufferWriter = new PooledByteBufferWriter(defaultBufferSize); utf8JsonWriter = new Utf8JsonWriter(bufferWriter, options); } return utf8JsonWriter; } public static Utf8JsonWriter RentWriter(JsonSerializerOptions options, IBufferWriter<byte> bufferWriter) { ThreadLocalState threadLocalState = t_threadLocalState ?? (t_threadLocalState = new ThreadLocalState()); Utf8JsonWriter utf8JsonWriter; if (threadLocalState.RentedWriters++ == 0) { utf8JsonWriter = threadLocalState.Writer; utf8JsonWriter.Reset(bufferWriter, options.GetWriterOptions()); } else utf8JsonWriter = new Utf8JsonWriter(bufferWriter, options.GetWriterOptions()); return utf8JsonWriter; } public static void ReturnWriterAndBuffer(Utf8JsonWriter writer, PooledByteBufferWriter bufferWriter) { ThreadLocalState threadLocalState = t_threadLocalState; writer.ResetAllStateForCacheReuse(); bufferWriter.ClearAndReturnBuffers(); int num = --threadLocalState.RentedWriters; } public static void ReturnWriter(Utf8JsonWriter writer) { ThreadLocalState threadLocalState = t_threadLocalState; writer.ResetAllStateForCacheReuse(); int num = --threadLocalState.RentedWriters; } } }