/// <summary>
/// Prepare WebSocket send frame
/// </summary>
/// <param name="opcode">WebSocket opcode</param>
/// <param name="mask">WebSocket mask</param>
/// <param name="buffer">Buffer to send</param>
/// <param name="offset">Buffer offset</param>
/// <param name="size">Buffer size</param>
/// <param name="status">WebSocket status (default is 0)</param>
public void PrepareSendFrame(byte opcode, bool mask, byte[] buffer, int offset, int size, int status = 0)
{
// Clear the previous WebSocket send buffer
WsSendBuffer.Clear();
// Append WebSocket frame opcode
WsSendBuffer.Add(opcode);
// Append WebSocket frame size
if (size <= 125)
{
WsSendBuffer.Add((byte)((size & 0xFF) | (mask ? 0x80 : 0)));
}
else if (size <= 65535)
{
WsSendBuffer.Add((byte)(126 | (mask ? 0x80 : 0)));
WsSendBuffer.Add((byte)((size >> 8) & 0xFF));
WsSendBuffer.Add((byte)(size & 0xFF));
}
else
{
WsSendBuffer.Add((byte)(127 | (mask ? 0x80 : 0)));
for (int i = 7; i >= 0; i--)
{
WsSendBuffer.Add((byte)((size >> (8 * i)) & 0xFF));
}
}
if (mask)
{
// Append WebSocket frame mask
WsSendBuffer.Add(WsSendMask[0]);
WsSendBuffer.Add(WsSendMask[1]);
WsSendBuffer.Add(WsSendMask[2]);
WsSendBuffer.Add(WsSendMask[3]);
}
// Resize WebSocket frame buffer
int bufferOffset = WsSendBuffer.Count;
WsSendBuffer.AddRange(new byte[size]);
// Mask WebSocket frame content
for (int i = 0; i < size; i++)
{
WsSendBuffer[bufferOffset + i] = (byte)(buffer[offset + i] ^ WsSendMask[i % 4]);
}
}
/// <summary>
/// Clear WebSocket send/receive buffers
/// </summary>
public void ClearWsBuffers()
{
lock (WsReceiveLock)
{
WsReceived = false;
WsHeaderSize = 0;
WsPayloadSize = 0;
WsReceiveBuffer.Clear();
Array.Clear(WsReceiveMask, 0, WsReceiveMask.Length);
}
lock (WsSendLock)
{
WsSendBuffer.Clear();
Array.Clear(WsSendMask, 0, WsSendMask.Length);
}
}
