public Boolean TryCreateSendBuffer(out WebSocketSendBuffer buffer)
{
lock ( m_lock )
{
if (State >= WebSocketState.Closed)
{
buffer = default;
return(false);
}
if (IsCompressionEnabled())
{
if (m_deflater == null)
{
m_deflater = new ZLibDeflater();
m_deflater.AddRef();
Closed.ContinueWith(x => m_deflater.Release());
}
else
{
m_deflater.AddRef();
}
}
}
buffer = new WebSocketSendBuffer(m_deflater);
return(true);
}
private async Task ClosePrivateAsync(WebSocketCloseStatus status, String description)
{
try
{
if (State == WebSocketState.Closing)
{
// Close payload is two bytes containing the close status followed by a UTF8-encoding of the status description, if it exists.
using (var buffer = new WebSocketSendBuffer())
{
WriteCloseMessage(status, m_closeReceived ? String.Empty : description, buffer);
await SendAsync(buffer.ToMessage(WebSocketMessageType.Close, this));
}
var receiveCloseTask = Task.CompletedTask;
lock ( m_lock )
{
if (!m_closeReceived)
{
receiveCloseTask = ReceiveCloseAsync();
}
}
await receiveCloseTask;
lock ( m_lock )
{
if (State == WebSocketState.Closing)
{
ChangeState(WebSocketState.Closed);
}
}
}
}
catch (Exception ex)
{
Abort(ex);
}
}
public async Task <Boolean> SendAsync(WebSocketMessageType messageType, WebSocketSendBuffer buffer)
{
if (buffer == null)
{
throw new ArgumentNullException(nameof(buffer));
}
try
{
await SendAsync(buffer.ToMessage(messageType, this));
return(true);
}
catch (Exception ex)
{
WebSocketsEventSource.Log.Error(Id, ex);
OnException?.Invoke(ex);
Abort(ex.Message);
return(false);
}
}
private static unsafe void WriteCloseMessage(WebSocketCloseStatus status, String description, WebSocketSendBuffer buffer)
{
var span = buffer.GetSpan(2);
span[0] = (Byte)(((UInt16)status) >> 8);
span[1] = (Byte)(((UInt16)status) & 0xFF);
buffer.Advance(2);
if (!String.IsNullOrWhiteSpace(description))
{
span = buffer.GetSpan(Encoding.GetMaxByteCount(description.Length));
fixed(Byte *fixedSpan = span)
fixed(Char * fixedString = description)
{
var byteCount = Encoding.GetBytes(fixedString, description.Length, fixedSpan, span.Length);
buffer.Advance(byteCount);
}
}
}
