public static ValueTask <Packet> ReadPacketAsync(BufferedByteReader bufferedByteReader, IByteHandler byteHandler, Func <int> getNextSequenceNumber, ProtocolErrorBehavior protocolErrorBehavior, IOBehavior ioBehavior)
{
return(bufferedByteReader.ReadBytesAsync(byteHandler, 4, ioBehavior)
.ContinueWith(headerBytes =>
{
if (headerBytes.Count < 4)
{
return protocolErrorBehavior == ProtocolErrorBehavior.Throw ?
ValueTaskExtensions.FromException <Packet>(new EndOfStreamException()) :
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 (packetSequenceNumber != expectedSequenceNumber)
{
if (protocolErrorBehavior == ProtocolErrorBehavior.Ignore)
{
return default(ValueTask <Packet>);
}
var exception = new InvalidOperationException("Packet received out-of-order. Expected {0}; got {1}.".FormatInvariant(expectedSequenceNumber, packetSequenceNumber));
return ValueTaskExtensions.FromException <Packet>(exception);
}
return bufferedByteReader.ReadBytesAsync(byteHandler, payloadLength, ioBehavior)
.ContinueWith(payloadBytes =>
{
if (payloadBytes.Count < payloadLength)
{
return protocolErrorBehavior == ProtocolErrorBehavior.Throw ?
ValueTaskExtensions.FromException <Packet>(new EndOfStreamException()) :
default(ValueTask <Packet>);
}
return new ValueTask <Packet>(new Packet(packetSequenceNumber, payloadBytes));
});
}));
}
public static ValueTask <Packet> ReadPacketAsync(BufferedByteReader bufferedByteReader, IByteHandler byteHandler, Func <int> getNextSequenceNumber, ProtocolErrorBehavior protocolErrorBehavior, IOBehavior ioBehavior)
{
var headerBytesTask = bufferedByteReader.ReadBytesAsync(byteHandler, 4, ioBehavior);
if (headerBytesTask.IsCompleted)
{
return(ReadPacketAfterHeader(headerBytesTask.Result, bufferedByteReader, byteHandler, getNextSequenceNumber, protocolErrorBehavior, ioBehavior));
}
return(AddContinuation(headerBytesTask, bufferedByteReader, byteHandler, getNextSequenceNumber, protocolErrorBehavior, ioBehavior));
// NOTE: use a local function (with no captures) to defer creation of lambda objects
ValueTask <Packet> AddContinuation(ValueTask <ArraySegment <byte> > headerBytes_, BufferedByteReader bufferedByteReader_, IByteHandler byteHandler_, Func <int> getNextSequenceNumber_, ProtocolErrorBehavior protocolErrorBehavior_, IOBehavior ioBehavior_) =>
headerBytes_.ContinueWith(x => ReadPacketAfterHeader(x, bufferedByteReader_, byteHandler_, getNextSequenceNumber_, protocolErrorBehavior_, ioBehavior_));
}
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()) :
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_));
}