public async Task <WSFrame> SendFrame(WSFrame frame, CancellationToken cancellationToken)
{
try {
await semaphore.WaitAsync();
var fragment = frame.Fragment;
var frameHeader = new WSFrameHeader {
Mask = true,
Last = frame.Last,
Code = frame.Code,
Length = fragment.Length,
};
Logger.Debug($"SendFrame");
await SendFrameHeader(frameHeader, cancellationToken);
Logger.Debug($"SendFrame (header complete)", new {
Header = frameHeader,
});
SendPayload(fragment.GetSegment());
return(frame);
}
finally {
semaphore.Release();
}
}
private async Task <WSFrameHeader> ReadFrameHeader(CancellationToken cancellationToken)
{
Array.Clear(frame, 0, 2);
Array.Clear(frameMask, 0, 4);
Array.Clear(frameLength, 0, 8);
await Stream.ReadAsync(frame, 0, 2);
var last = (frame[0] & WSConsts.MSB) != 0;
var mask = (frame[1] & WSConsts.MSB) != 0;
var rsv0 = (frame[0] & WSConsts.RSV0) != 0;
var rsv1 = (frame[0] & WSConsts.RSV1) != 0;
var rsv2 = (frame[0] & WSConsts.RSV2) != 0;
var code = frame[0] & WSConsts.CodeMask;
var length = frame[1] & WSConsts.LengthMask;
ResetMask();
if (mask)
{
await Stream.ReadAsync(frameMask, 0, 4, cancellationToken);
}
switch (length)
{
case WSConsts.UInt16Flag:
await Stream.ReadAsync(frameLength, 6, 2, cancellationToken);
length = 0;
DecodeLength(ref length);
break;
case WSConsts.UInt64Flag:
await Stream.ReadAsync(frameLength, 0, 8, cancellationToken);
length = 0;
DecodeLength(ref length);
break;
}
var header = new WSFrameHeader {
Last = last,
Mask = mask,
Code = code,
RSV0 = rsv0,
RSV1 = rsv1,
RSV2 = rsv2,
Length = length,
};
return(header);
}
private async Task <WSFrameHeader> SendFrameHeader(WSFrameHeader frameHeader, CancellationToken cancellationToken)
{
Array.Clear(frame, 0, 2);
Array.Clear(frameMask, 0, 4);
Array.Clear(frameLength, 0, 8);
var frameHeaderLength = GetLength(frameHeader.Length);
var frame0 = 0;
if (frameHeader.Last)
{
frame0 |= WSConsts.MSB;
}
if (frameHeader.RSV0)
{
frame0 |= WSConsts.RSV0;
}
if (frameHeader.RSV1)
{
frame0 |= WSConsts.RSV1;
}
if (frameHeader.RSV2)
{
frame0 |= WSConsts.RSV2;
}
frame0 |= frameHeader.Code & WSConsts.CodeMask;
var frame1 = 0;
if (frameHeader.Mask)
{
frame1 |= WSConsts.MSB;
}
frame1 |= frameHeaderLength & WSConsts.LengthMask;
frame[0] = (byte)frame0;
frame[1] = (byte)frame1;
await Stream.WriteAsync(frame, 0, 2, cancellationToken);
ResetMask();
if (frameHeader.Mask)
{
CreateMask();
await Stream.WriteAsync(frameMask, 0, 4, cancellationToken);
}
EncodeLength(frameHeader.Length);
switch (frameHeaderLength)
{
case WSConsts.UInt16Flag:
await Stream.WriteAsync(frameLength, 6, 2, cancellationToken);
break;
case WSConsts.UInt64Flag:
await Stream.WriteAsync(frameLength, 0, 8, cancellationToken);
break;
}
return(frameHeader);
}