private static bool HasReadPayload(ArraySegmentHolder <byte> previousPayloads, Packet packet, ProtocolErrorBehavior protocolErrorBehavior, out ValueTask <ArraySegment <byte> > result)
{
if (previousPayloads.Count == 0 && packet.Contents.Count < MaxPacketSize)
{
result = new ValueTask <ArraySegment <byte> >(packet.Contents);
return(true);
}
var previousPayloadsArray = previousPayloads.Array;
if (previousPayloadsArray == null)
{
previousPayloadsArray = new byte[ProtocolUtility.MaxPacketSize + 1];
}
else if (previousPayloads.Offset + previousPayloads.Count + packet.Contents.Count > previousPayloadsArray.Length)
{
Array.Resize(ref previousPayloadsArray, previousPayloadsArray.Length * 2);
}
Buffer.BlockCopy(packet.Contents.Array, packet.Contents.Offset, previousPayloadsArray, previousPayloads.Offset + previousPayloads.Count, packet.Contents.Count);
previousPayloads.ArraySegment = new ArraySegment <byte>(previousPayloadsArray, previousPayloads.Offset, previousPayloads.Count + packet.Contents.Count);
if (packet.Contents.Count < ProtocolUtility.MaxPacketSize)
{
result = new ValueTask <ArraySegment <byte> >(previousPayloads.ArraySegment);
return(true);
}
result = default(ValueTask <ArraySegment <byte> >);
return(false);
}
private static ValueTask <ArraySegment <byte> > DoReadPayloadAsync(BufferedByteReader bufferedByteReader, IByteHandler byteHandler, Func <int> getNextSequenceNumber, ArraySegmentHolder <byte> previousPayloads, ProtocolErrorBehavior protocolErrorBehavior, IOBehavior ioBehavior)
{
var readPacketTask = ReadPacketAsync(bufferedByteReader, byteHandler, getNextSequenceNumber, protocolErrorBehavior, ioBehavior);
while (readPacketTask.IsCompleted)
{
if (HasReadPayload(previousPayloads, readPacketTask.Result, protocolErrorBehavior, out var result))
{
return(result);
}
readPacketTask = ReadPacketAsync(bufferedByteReader, byteHandler, getNextSequenceNumber, protocolErrorBehavior, ioBehavior);
}
return(AddContinuation(readPacketTask, bufferedByteReader, byteHandler, getNextSequenceNumber, previousPayloads, protocolErrorBehavior, ioBehavior));
// NOTE: use a local function (with no captures) to defer creation of lambda objects
ValueTask <ArraySegment <byte> > AddContinuation(ValueTask <Packet> readPacketTask_, BufferedByteReader bufferedByteReader_, IByteHandler byteHandler_, Func <int> getNextSequenceNumber_, ArraySegmentHolder <byte> previousPayloads_, ProtocolErrorBehavior protocolErrorBehavior_, IOBehavior ioBehavior_)
{
return(readPacketTask_.ContinueWith(packet =>
HasReadPayload(previousPayloads_, packet, protocolErrorBehavior_, out var result_) ? result_ :
DoReadPayloadAsync(bufferedByteReader_, byteHandler_, getNextSequenceNumber_, previousPayloads_, protocolErrorBehavior_, ioBehavior_)));
}
}
public static ValueTask <ArraySegment <byte> > ReadPayloadAsync(BufferedByteReader bufferedByteReader, IByteHandler byteHandler, Func <int> getNextSequenceNumber, ArraySegmentHolder <byte> cache, ProtocolErrorBehavior protocolErrorBehavior, IOBehavior ioBehavior)
{
cache.Clear();
return(DoReadPayloadAsync(bufferedByteReader, byteHandler, getNextSequenceNumber, cache, protocolErrorBehavior, ioBehavior));
}