public override int Encode(Span <byte> buffer)
{
if (ProtocolString is null || InfoHash is null || PeerId is null)
{
throw new InvalidOperationException();
}
int written = buffer.Length;
Write(ref buffer, (byte)ProtocolString.Length);
WriteAscii(ref buffer, ProtocolString);
Span <byte> supports = stackalloc byte[8];
supports.Clear();
if (SupportsExtendedMessaging)
{
supports[5] |= ExtendedMessagingFlag;
}
if (SupportsFastPeer)
{
supports[7] |= FastPeersFlag;
}
supports.CopyTo(buffer);
buffer = buffer.Slice(supports.Length);
Write(ref buffer, InfoHash.Truncate().Span);
Write(ref buffer, PeerId.Span);
return(written - buffer.Length);
}