/// <summary>
/// Receive web socket result
/// </summary>
/// <param name="buffer">The buffer to copy data into</param>
/// <param name="cancellationToken">The cancellation token</param>
/// <returns>The web socket result details</returns>
public override async Task <WebSocketReceiveResult> ReceiveAsync(ArraySegment <byte> buffer, CancellationToken cancellationToken)
{
try
{
// we may receive control frames so reading needs to happen in an infinite loop
while (true)
{
// allow this operation to be cancelled from iniside OR outside this instance
using (CancellationTokenSource linkedCts = CancellationTokenSource.CreateLinkedTokenSource(_internalReadCts.Token, cancellationToken))
{
WebSocketFrame frame = null;
try
{
frame = await WebSocketFrameReader.ReadAsync(_stream, buffer, linkedCts.Token);
Events.Log.ReceivedFrame(_guid, frame.OpCode, frame.IsFinBitSet, frame.Count);
}
catch (SocketException)
{
// do nothing, the socket has been disconnected
}
catch (InternalBufferOverflowException ex)
{
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.MessageTooBig, "Frame too large to fit in buffer. Use message fragmentation", ex);
throw;
}
catch (ArgumentOutOfRangeException ex)
{
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.ProtocolError, "Payload length out of range", ex);
throw;
}
catch (EndOfStreamException ex)
{
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.InvalidPayloadData, "Unexpected end of stream encountered", ex);
throw;
}
catch (OperationCanceledException ex)
{
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.EndpointUnavailable, "Operation cancelled", ex);
throw;
}
catch (Exception ex)
{
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.InternalServerError, "Error reading WebSocket frame", ex);
throw;
}
switch (frame.OpCode)
{
case WebSocketOpCode.ConnectionClose:
return(await RespondToCloseFrame(frame, buffer, linkedCts.Token));
case WebSocketOpCode.Ping:
ArraySegment <byte> pingPayload = new ArraySegment <byte>(buffer.Array, buffer.Offset, frame.Count);
await SendPongAsync(pingPayload, linkedCts.Token);
break;
case WebSocketOpCode.Pong:
ArraySegment <byte> pongBuffer = new ArraySegment <byte>(buffer.Array, frame.Count, buffer.Offset);
Pong?.Invoke(this, new PongEventArgs(pongBuffer));
break;
case WebSocketOpCode.TextFrame:
if (!frame.IsFinBitSet)
{
// continuation frames will follow, record the message type Text
_continuationFrameMessageType = WebSocketMessageType.Text;
}
return(new WebSocketReceiveResult(frame.Count, WebSocketMessageType.Text, frame.IsFinBitSet));
case WebSocketOpCode.BinaryFrame:
if (!frame.IsFinBitSet)
{
// continuation frames will follow, record the message type Binary
_continuationFrameMessageType = WebSocketMessageType.Binary;
}
return(new WebSocketReceiveResult(frame.Count, WebSocketMessageType.Binary, frame.IsFinBitSet));
case WebSocketOpCode.ContinuationFrame:
return(new WebSocketReceiveResult(frame.Count, _continuationFrameMessageType, frame.IsFinBitSet));
default:
Exception ex = new NotSupportedException($"Unknown WebSocket opcode {frame.OpCode}");
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.ProtocolError, ex.Message, ex);
throw ex;
}
}
}
}
catch (Exception catchAll)
{
// Most exceptions will be caught closer to their source to send an appropriate close message (and set the WebSocketState)
// However, if an unhandled exception is encountered and a close message not sent then send one here
if (_state == WebSocketState.Open)
{
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.InternalServerError, "Unexpected error reading from WebSocket", catchAll);
}
throw;
}
}
/// <summary>
/// Receive web socket result
/// </summary>
/// <param name="buffer">The buffer to copy data into</param>
/// <param name="cancellationToken">The cancellation token</param>
/// <returns>The web socket result details</returns>
public override async Task <WebSocketReceiveResult> ReceiveAsync(ArraySegment <byte> buffer, CancellationToken cancellationToken)
{
try
{
// we may receive control frames so reading needs to happen in an infinite loop
while (true)
{
// allow this operation to be cancelled from iniside OR outside this instance
using (CancellationTokenSource linkedCts = CancellationTokenSource.CreateLinkedTokenSource(_internalReadCts.Token, cancellationToken))
{
WebSocketFrame frame;
try
{
if (_readCursor.NumBytesLeftToRead > 0)
{
// If the buffer used to read the frame was too small to fit the whole frame then we need to "remember" this frame
// and return what we have. Subsequent calls to the read function will simply continue reading off the stream without
// decoding the first few bytes as a websocket header.
_readCursor = await WebSocketFrameReader.ReadFromCursorAsync(_stream, buffer, _readCursor, linkedCts.Token);
frame = _readCursor.WebSocketFrame;
}
else
{
_readCursor = await WebSocketFrameReader.ReadAsync(_stream, buffer, linkedCts.Token);
frame = _readCursor.WebSocketFrame;
Events.Log.ReceivedFrame(_guid, frame.OpCode, frame.IsFinBitSet, frame.Count);
}
}
catch (InternalBufferOverflowException ex)
{
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.MessageTooBig, "Frame too large to fit in buffer. Use message fragmentation", ex);
throw;
}
catch (ArgumentOutOfRangeException ex)
{
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.ProtocolError, "Payload length out of range", ex);
throw;
}
catch (EndOfStreamException ex)
{
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.InvalidPayloadData, "Unexpected end of stream encountered", ex);
throw;
}
catch (OperationCanceledException ex)
{
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.EndpointUnavailable, "Operation cancelled", ex);
throw;
}
catch (Exception ex)
{
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.InternalServerError, "Error reading WebSocket frame", ex);
throw;
}
var endOfMessage = frame.IsFinBitSet && _readCursor.NumBytesLeftToRead == 0;
switch (frame.OpCode)
{
case WebSocketOpCode.ConnectionClose:
return(await RespondToCloseFrame(frame, buffer, linkedCts.Token));
case WebSocketOpCode.Ping:
ArraySegment <byte> pingPayload = new ArraySegment <byte>(buffer.Array, buffer.Offset, _readCursor.NumBytesRead);
await SendPongAsync(pingPayload, linkedCts.Token);
break;
case WebSocketOpCode.Pong:
ArraySegment <byte> pongBuffer = new ArraySegment <byte>(buffer.Array, _readCursor.NumBytesRead, buffer.Offset);
Pong?.Invoke(this, new PongEventArgs(pongBuffer));
break;
case WebSocketOpCode.TextFrame:
if (!frame.IsFinBitSet)
{
// continuation frames will follow, record the message type Text
_continuationFrameMessageType = WebSocketMessageType.Text;
}
return(new WebSocketReceiveResult(_readCursor.NumBytesRead, WebSocketMessageType.Text, endOfMessage));
case WebSocketOpCode.BinaryFrame:
if (!frame.IsFinBitSet)
{
// continuation frames will follow, record the message type Binary
_continuationFrameMessageType = WebSocketMessageType.Binary;
}
return(new WebSocketReceiveResult(_readCursor.NumBytesRead, WebSocketMessageType.Binary, endOfMessage));
case WebSocketOpCode.ContinuationFrame:
return(new WebSocketReceiveResult(_readCursor.NumBytesRead, _continuationFrameMessageType, endOfMessage));
default:
Exception ex = new NotSupportedException($"Unknown WebSocket opcode {frame.OpCode}");
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.ProtocolError, ex.Message, ex);
throw ex;
}
}
}
}
catch (Exception catchAll)
{
// Most exceptions will be caught closer to their source to send an appropriate close message (and set the WebSocketState)
// However, if an unhandled exception is encountered and a close message not sent then send one here
if (_state == WebSocketState.Open)
{
await CloseOutputAutoTimeoutAsync(WebSocketCloseStatus.InternalServerError, "Unexpected error reading from WebSocket", catchAll);
}
throw;
}
}
