public static void Sync(Action action) => TaskUtil.Sync(action);
public static T Sync <T>(Func <T> func) => TaskUtil.Sync(func);
async Task RecvLoopAsync()
{
try
{
CancellationToken cancel = this.GrandCancel;
LowerStream.ReadTimeout = Options.TimeoutComm;
MemoryBuffer <byte> currentRecvingMessage = new MemoryBuffer <byte>();
while (true)
{
byte b1 = await LowerStream.ReceiveByteAsync(cancel).FlushOtherStreamIfPending(UpperStream);
WebSocketOpcode opcode = (WebSocketOpcode)(b1 & 0x0f);
byte b2 = await LowerStream.ReceiveByteAsync(cancel);
bool isMasked = (b2 & 0b10000000)._ToBool();
int tmp = (b2 & 0b01111111);
ulong payloadLen64 = 0;
if (tmp <= 125)
{
payloadLen64 = (ulong)tmp;
}
else if (tmp == 126)
{
payloadLen64 = await LowerStream.ReceiveUInt16Async(cancel).FlushOtherStreamIfPending(UpperStream);
}
else if (tmp == 127)
{
payloadLen64 = await LowerStream.ReceiveUInt64Async(cancel).FlushOtherStreamIfPending(UpperStream);
}
if (payloadLen64 > (ulong)Options.RecvMaxPayloadLenPerFrame)
{
throw new ApplicationException($"payloadLen64 {payloadLen64} > Options.RecvMaxPayloadLenPerFrame {Options.RecvMaxPayloadLenPerFrame}");
}
int payloadLen = (int)payloadLen64;
Memory <byte> maskKey = default;
if (isMasked)
{
maskKey = await LowerStream.ReceiveAllAsync(4, cancel).FlushOtherStreamIfPending(UpperStream);
}
Memory <byte> data = await LowerStream.ReceiveAllAsync(payloadLen, cancel).FlushOtherStreamIfPending(UpperStream);
if (isMasked)
{
TaskUtil.Sync(() =>
{
Span <byte> maskKeySpan = maskKey.Span;
Span <byte> dataSpan = data.Span;
for (int i = 0; i < dataSpan.Length; i++)
{
dataSpan[i] = (byte)(dataSpan[i] ^ maskKeySpan[i % 4]);
}
});
}
if (opcode.EqualsAny(WebSocketOpcode.Text, WebSocketOpcode.Bin, WebSocketOpcode.Continue))
{
if (Options.RespectMessageDelimiter == false)
{
if (data.Length >= 1)
{
await UpperStream.WaitReadyToSendAsync(cancel, Timeout.Infinite);
UpperStream.FastSendNonBlock(data, false);
}
}
else
{
bool isFin = (b1 & 0b10000000)._ToBool();
if (isFin && opcode.EqualsAny(WebSocketOpcode.Text, WebSocketOpcode.Bin))
{
// Single message
if (data.Length >= 1)
{
await UpperStream.WaitReadyToSendAsync(cancel, Timeout.Infinite);
UpperStream.FastSendNonBlock(data, false);
}
}
else if (isFin == false && opcode.EqualsAny(WebSocketOpcode.Text, WebSocketOpcode.Bin))
{
// First message
currentRecvingMessage.Clear();
if ((currentRecvingMessage.Length + data.Length) >= Options.RecvMaxTotalFragmentSize)
{
throw new ApplicationException("WebSocket: Exceeding Options.RecvMaxTotalFragmentSize.");
}
currentRecvingMessage.Write(data);
}
else if (isFin && opcode == WebSocketOpcode.Continue)
{
// Final continuous message
if ((currentRecvingMessage.Length + data.Length) >= Options.RecvMaxTotalFragmentSize)
{
throw new ApplicationException("WebSocket: Exceeding Options.RecvMaxTotalFragmentSize.");
}
currentRecvingMessage.Write(data);
if (currentRecvingMessage.Length >= 1)
{
await UpperStream.WaitReadyToSendAsync(cancel, Timeout.Infinite);
UpperStream.FastSendNonBlock(data, false);
}
currentRecvingMessage.Clear();
}
else if (isFin == false && opcode == WebSocketOpcode.Continue)
{
// Intermediate continuous message
if ((currentRecvingMessage.Length + data.Length) >= Options.RecvMaxTotalFragmentSize)
{
throw new ApplicationException("WebSocket: Exceeding Options.RecvMaxTotalFragmentSize.");
}
currentRecvingMessage.Write(data);
}
}
}
else if (opcode == WebSocketOpcode.Pong)
{
lock (this.PongQueueLock)
{
this.PongQueue.Enqueue(data);
}
this.SendPongEvent.Set(true);
}
else if (opcode == WebSocketOpcode.Ping)
{
lock (this.PongQueueLock)
{
this.PongQueue.Enqueue(data);
}
this.SendPongEvent.Set(true);
}
else if (opcode == WebSocketOpcode.Close)
{
throw new DisconnectedException();
}
else
{
throw new ApplicationException($"WebSocket: Unknown Opcode: {(int)opcode}");
}
}
}
catch (Exception ex)
{
this.UpperStream.Disconnect();
await this.CancelAsync(ex);
}
}