/// <summary>
/// Receive frames from <paramref name="socket"/>, blocking until a valid signal arrives.
/// </summary>
/// <param name="socket">The socket to receive from.</param>
/// <returns><c>true</c> if the received signal was zero, otherwise <c>false</c>.</returns>
public static bool ReceiveSignal([NotNull] this IReceivingSocket socket)
{
var msg = new Msg();
msg.InitEmpty();
while (true)
{
socket.Receive(ref msg);
var isMultiFrame = msg.HasMore;
while (msg.HasMore)
{
socket.Receive(ref msg);
}
if (isMultiFrame || msg.Size != 8)
{
continue;
}
var signalValue = NetworkOrderBitsConverter.ToInt64(msg.Data);
if ((signalValue & 0x7FFFFFFFFFFFFF00L) == 0x7766554433221100L)
{
msg.Close();
return((signalValue & 255) == 0);
}
}
}
/// <summary>
/// Attempt to receive a valid signal from <paramref name="socket"/>.
/// If no message is available within <paramref name="timeout"/>, return <c>false</c>.
/// </summary>
/// <param name="socket">The socket to receive from.</param>
/// <param name="timeout">The maximum period of time to wait for a message to become available.</param>
/// <param name="signal"><c>true</c> if the received signal was zero, otherwise <c>false</c>. If no signal received, <c>false</c>.</param>
/// <returns><c>true</c> if a valid signal was observed, otherwise <c>false</c>.</returns>
public static bool TryReceiveSignal([NotNull] this IReceivingSocket socket, TimeSpan timeout, out bool signal)
{
var msg = new Msg();
msg.InitEmpty();
// TODO use clock to enforce timeout across multiple loop iterations — if invalid messages are received regularly, the method may not return once the timeout elapses
while (true)
{
if (!socket.TryReceive(ref msg, timeout))
{
signal = false;
msg.Close();
return(false);
}
var isMultiFrame = msg.HasMore;
while (msg.HasMore)
{
socket.Receive(ref msg);
}
if (isMultiFrame || msg.Size != 8)
{
continue;
}
var signalValue = NetworkOrderBitsConverter.ToInt64(msg.Data);
if ((signalValue & 0x7FFFFFFFFFFFFF00L) == 0x7766554433221100L)
{
signal = (signalValue & 255) == 0;
msg.Close();
return(true);
}
}
}
/// <summary>
/// Convert the buffer to long in network byte order (Big endian)
/// </summary>
/// <returns></returns>
public long ConvertToInt64()
{
return(NetworkOrderBitsConverter.ToInt64(Buffer));
}
