/// <summary>
/// Initializes a new instance.
/// </summary>
public StompErrorFrameException(StompFrame frame) : base(frame, GetErrorMessage(frame))
{
}
/// <summary>
/// Extracts the message from the error frame.
/// </summary>
/// <param name="frame"></param>
/// <returns></returns>
static string GetErrorMessage(StompFrame frame)
{
return(frame.GetHeaderValue("message") ?? GetErrorBody(frame));
}
/// <summary> /// Sends a single STOMP frame to the transport. /// </summary> /// <param name="frame"></param> /// <param name="cancellationToken"></param> /// <returns></returns> public abstract ValueTask SendAsync(StompFrame frame, CancellationToken cancellationToken);
/// <summary>
/// Attempts to parse a single frame from the given sequence.
/// </summary>
/// <param name="sequence"></param>
/// <param name="frame"></param>
/// <returns></returns>
public bool TryReadFrame(ref SequenceReader <byte> sequence, out StompFrame frame)
{
frame = new StompFrame(StompCommand.Unknown, null, null);
StompCommand command;
List <KeyValuePair <string, string> > headers = new List <KeyValuePair <string, string> >();
Memory <byte> body = null;
// attempt to read initial command line
if (TryReadCommand(ref sequence, out command) == false)
{
return(false);
}
// read headers
while (sequence.End == false)
{
// read the current header
if (TryReadHeader(ref sequence, out var header, command != StompCommand.Connect && command != StompCommand.Connected) == false)
{
return(false);
}
// null key indicates end of headers
if (header.Key == null)
{
break;
}
headers.Add(header);
}
// content length header can help us decide how far to read
var contenLengthHeader = headers.FirstOrDefault(i => i.Key == "content-length");
if (contenLengthHeader.Value != null)
{
if (int.TryParse(contenLengthHeader.Value, out var contentLength) == false)
{
throw new StompProtocolException("Invalid 'content-length'. Not an integer.");
}
// allocate new buffer and copy body contents
body = new byte[contentLength];
if (sequence.TryCopyTo(body.Span) == false)
{
return(false);
}
sequence.Advance(contentLength);
// body should be terminated by a null character
if (sequence.TryRead(out var term) == false)
{
return(false);
}
if (term != 0x00)
{
throw new StompProtocolException("Body not terminated by null.");
}
}
else
{
if (sequence.TryReadTo(out ReadOnlySpan <byte> buffer, (byte)0x00) == false)
{
return(false);
}
// allocate new buffer and copy body contents
body = new byte[buffer.Length];
if (buffer.TryCopyTo(body.Span) == false)
{
return(false);
}
}
frame = new StompFrame(command, headers, body);
return(true);
}
/// <summary>
/// Writes the specified frame to the writer.
/// </summary>
/// <param name="writer"></param>
/// <param name="frame"></param>
public void Write(ArrayBufferWriter <byte> writer, StompFrame frame)
{
// write command
switch (frame.Command)
{
case StompCommand.Connect:
writer.Write(COMMAND_CONNECT);
break;
case StompCommand.Stomp:
writer.Write(COMMAND_STOMP);
break;
case StompCommand.Connected:
writer.Write(COMMAND_CONNECTED);
break;
case StompCommand.Send:
writer.Write(COMMAND_SEND);
break;
case StompCommand.Subscribe:
writer.Write(COMMAND_SUBSCRIBE);
break;
case StompCommand.Unsubscribe:
writer.Write(COMMAND_UNSUBSCRIBE);
break;
case StompCommand.Ack:
writer.Write(COMMAND_ACK);
break;
case StompCommand.Nack:
writer.Write(COMMAND_NACK);
break;
case StompCommand.Begin:
writer.Write(COMMAND_BEGIN);
break;
case StompCommand.Disconnect:
writer.Write(COMMAND_DISCONNECT);
break;
case StompCommand.Message:
writer.Write(COMMAND_MESSAGE);
break;
case StompCommand.Receipt:
writer.Write(COMMAND_RECEIPT);
break;
case StompCommand.Error:
writer.Write(COMMAND_ERROR);
break;
default:
throw new StompProtocolException("Unknown command.");
}
// write headers
foreach (var header in frame.Headers)
{
WriteEscapedHeaderValue(writer, header.Key);
writer.Write(BYTE_COLON);
WriteEscapedHeaderValue(writer, header.Value);
writer.Write(BYTE_LF);
}
// headers separated from body by a new line
writer.Write(BYTE_LF);
// body followed by NULL
writer.Write(frame.Body.Span);
writer.Write(BYTE_NULL);
}
/// <summary>
/// Handles outgoing messages to the transport.
/// </summary>
/// <param name="frame"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
async ValueTask OnSendAsync(StompFrame frame, CancellationToken cancellationToken)
{
logger.LogDebug("Sending STOMP frame: {Command}", frame.Command);
await transport.SendAsync(frame, cancellationToken);
}