private async Task SerializeToStreamAsyncCore(Stream targetStream, bool async, CancellationToken cancellationToken)
{
Encoding?targetEncoding = JsonHelpers.GetEncoding(Headers.ContentType?.CharSet);
// Wrap provided stream into a transcoding stream that buffers the data transcoded from utf-8 to the targetEncoding.
if (targetEncoding != null && targetEncoding != Encoding.UTF8)
{
#if NETCOREAPP
Stream transcodingStream = Encoding.CreateTranscodingStream(targetStream, targetEncoding, Encoding.UTF8, leaveOpen: true);
try
{
if (async)
{
await JsonSerializer.SerializeAsync(transcodingStream, Value, ObjectType, _jsonSerializerOptions, cancellationToken).ConfigureAwait(false);
}
else
{
// Have to use Utf8JsonWriter because JsonSerializer doesn't support sync serialization into stream directly.
// ToDo: Remove Utf8JsonWriter usage after https://github.com/dotnet/runtime/issues/1574
using var writer = new Utf8JsonWriter(transcodingStream);
JsonSerializer.Serialize(writer, Value, ObjectType, _jsonSerializerOptions);
}
}
finally
{
// Dispose/DisposeAsync will flush any partial write buffers. In practice our partial write
// buffers should be empty as we expect JsonSerializer to emit only well-formed UTF-8 data.
if (async)
{
await transcodingStream.DisposeAsync().ConfigureAwait(false);
}
else
{
transcodingStream.Dispose();
}
}
#else
Debug.Assert(async);
using (TranscodingWriteStream transcodingStream = new TranscodingWriteStream(targetStream, targetEncoding))
{
await JsonSerializer.SerializeAsync(transcodingStream, Value, ObjectType, _jsonSerializerOptions, cancellationToken).ConfigureAwait(false);
// The transcoding streams use Encoders and Decoders that have internal buffers. We need to flush these
// when there is no more data to be written. Stream.FlushAsync isn't suitable since it's
// acceptable to Flush a Stream (multiple times) prior to completion.
await transcodingStream.FinalWriteAsync(cancellationToken).ConfigureAwait(false);
}
#endif
}
else
{
if (async)
{
await JsonSerializer.SerializeAsync(targetStream, Value, ObjectType, _jsonSerializerOptions, cancellationToken).ConfigureAwait(false);
}
else
{
#if NETCOREAPP
// Have to use Utf8JsonWriter because JsonSerializer doesn't support sync serialization into stream directly.
// ToDo: Remove Utf8JsonWriter usage after https://github.com/dotnet/runtime/issues/1574
using var writer = new Utf8JsonWriter(targetStream);
JsonSerializer.Serialize(writer, Value, ObjectType, _jsonSerializerOptions);
#else
Debug.Fail("Synchronous serialization is only supported since .NET 5.0");
#endif
}
}
}
public JsonContent(TValue inputValue, JsonTypeInfo <TValue> jsonTypeInfo)
{
_typeInfo = jsonTypeInfo ?? throw new ArgumentNullException(nameof(jsonTypeInfo));
_typedValue = inputValue;
Headers.ContentType = JsonHelpers.GetDefaultMediaType();
}