private async Task ReceivePayloadAsync(WebSocketReceiveBuffer buffer, Int32 payloadLength)
{
var offset = 0;
while (payloadLength > 0)
{
var memory = buffer.GetMemory(Math.Min(payloadLength, DefaultSegmentSize));
var receiveByteCount = await ReceiveBufferAsync(memory.Slice(0, Math.Min(memory.Length, payloadLength)));
if (m_receiveHeader.Mask != 0) // Apply the mask to the payload we received so far
{
ApplyMask(m_receiveHeader.Mask, memory.Slice(0, receiveByteCount).Span, offset);
}
buffer.Advance(receiveByteCount);
payloadLength -= receiveByteCount;
offset += receiveByteCount;
}
}
private async Task ReceiveHeaderAsync(WebSocketReceiveBuffer buffer)
{
var memory = buffer.GetMemory(MaxHeaderSize).Slice(0, MaxHeaderSize);
var receivedSize = 0;
var remainingSize = 2;
Receive:
while (remainingSize > 0)
{
var byteCount = await ReceiveBufferAsync(memory.Slice(receivedSize, remainingSize));
remainingSize -= byteCount;
receivedSize += byteCount;
}
var headerSize = 2;
var masked = (memory.Span[1] & 0b1000_0000) != 0;
m_receiveHeader.Mask = 0;
m_receiveHeader.Fin = (memory.Span[0] & 0b1000_0000) != 0;
m_receiveHeader.Compressed = (memory.Span[0] & 0b0100_0000) != 0;
m_receiveHeader.Opcode = (MessageOpcode)(memory.Span[0] & 0b0000_1111);
m_receiveHeader.PayloadLength = memory.Span[1] & 0b0111_1111;
buffer.Compressed = m_receiveHeader.Compressed;
buffer.Type = (WebSocketMessageType)m_receiveHeader.Opcode;
if (masked)
{
headerSize += 4;
}
if (m_receiveHeader.PayloadLength == 126)
{
headerSize += 2;
}
else if (m_receiveHeader.PayloadLength == 127)
{
headerSize += 8;
}
if (receivedSize < headerSize)
{
remainingSize = headerSize - receivedSize;
goto Receive; // More data is needed
}
// Read the remainder of the payload length, if necessary
if (m_receiveHeader.PayloadLength == 126)
{
m_receiveHeader.PayloadLength = (memory.Span[2] << 8) | memory.Span[3];
}
else if (m_receiveHeader.PayloadLength == 127)
{
m_receiveHeader.PayloadLength = 0;
for (var i = 0; i < 8; i++)
{
m_receiveHeader.PayloadLength = (m_receiveHeader.PayloadLength << 8) | memory.Span[2 + i];
}
}
if (masked)
{
m_receiveHeader.Mask = Unsafe.As <Byte, Int32>(ref memory.Span[headerSize - 4]);
}
WebSocketsEventSource.Log.Receive(Id,
m_receiveHeader.Opcode,
m_receiveHeader.PayloadLength,
m_receiveHeader.Compressed,
m_receiveHeader.Fin);
}