private static ValueTask <int> WritePacketAsync(IByteHandler byteHandler, int sequenceNumber, ArraySegment <byte> contents, IOBehavior ioBehavior)
{
var bufferLength = contents.Count + 4;
var buffer = ArrayPool <byte> .Shared.Rent(bufferLength);
SerializationUtility.WriteUInt32((uint)contents.Count, buffer, 0, 3);
buffer[3] = (byte)sequenceNumber;
Buffer.BlockCopy(contents.Array, contents.Offset, buffer, 4, contents.Count);
var task = byteHandler.WriteBytesAsync(new ArraySegment <byte>(buffer, 0, bufferLength), ioBehavior);
if (task.IsCompletedSuccessfully)
{
ArrayPool <byte> .Shared.Return(buffer);
return(default);
private static ValueTask <Packet> ReadPacketAfterHeader(ArraySegment <byte> headerBytes, BufferedByteReader bufferedByteReader, IByteHandler byteHandler, Func <int> getNextSequenceNumber, ProtocolErrorBehavior protocolErrorBehavior, IOBehavior ioBehavior)
{
if (headerBytes.Count < 4)
{
return(protocolErrorBehavior == ProtocolErrorBehavior.Throw ?
ValueTaskExtensions.FromException <Packet>(new EndOfStreamException("Expected to read 4 header bytes but only received {0}.".FormatInvariant(headerBytes.Count))) :
default(ValueTask <Packet>));
}
var payloadLength = (int)SerializationUtility.ReadUInt32(headerBytes.Array, headerBytes.Offset, 3);
int packetSequenceNumber = headerBytes.Array[headerBytes.Offset + 3];
var expectedSequenceNumber = getNextSequenceNumber() % 256;
if (expectedSequenceNumber != -1 && packetSequenceNumber != expectedSequenceNumber)
{
if (protocolErrorBehavior == ProtocolErrorBehavior.Ignore)
{
return(default(ValueTask <Packet>));
}
var exception = MySqlProtocolException.CreateForPacketOutOfOrder(expectedSequenceNumber, packetSequenceNumber);
return(ValueTaskExtensions.FromException <Packet>(exception));
}
var payloadBytesTask = bufferedByteReader.ReadBytesAsync(byteHandler, payloadLength, ioBehavior);
if (payloadBytesTask.IsCompleted)
{
return(CreatePacketFromPayload(payloadBytesTask.Result, payloadLength, protocolErrorBehavior));
}
return(AddContinuation(payloadBytesTask, payloadLength, protocolErrorBehavior));
// NOTE: use a local function (with no captures) to defer creation of lambda objects
ValueTask <Packet> AddContinuation(ValueTask <ArraySegment <byte> > payloadBytesTask_, int payloadLength_, ProtocolErrorBehavior protocolErrorBehavior_)
=> payloadBytesTask_.ContinueWith(x => CreatePacketFromPayload(x, payloadLength_, protocolErrorBehavior_));
}