/// <summary>
/// Attempts to read an entire frame. Only finishes when a whole frame is read or an exception is encountered
/// </summary>
/// <returns>The status of the read operation</returns>
/// <param name="frame">The parsed frame (on success)</param>
public async Task<Tuple<DataStatus, WebSocketFrame>> ReadFrameAsync()
{
WebSocketFrame frame = new WebSocketFrame();
DataStatus readStatus = DataStatus.Complete;
WebSocketHeader header = null;
byte[] message = null;
Func<DataStatus, Tuple<DataStatus,WebSocketFrame>> FramePackage = x => Tuple.Create(x, frame);
Func<bool> NoFrameInBuffer = () => (header == null || messageBufferSize < header.FrameSize);
//Continue reading until we get a full frame. If the result is ever NOT complete
//(as in no read was performed), we should get the hell outta here
do
{
//Note: we START with parsing the header just in case we have a leftover frame in the buffer.
//We don't want to read more messages until all frames in the buffer have been parsed.
//Console.WriteLine("Trying to read whole frame. Buffer: " + messageBufferSize);
//Oh good, there's at least enough to know the header size.
if(messageBufferSize >= 2)
{
message = messageBuffer.Take(messageBufferSize).ToArray();
//OK we KNOW we read a whole header at this point.
if(messageBufferSize >= WebSocketHeader.FullHeaderSize(message))
{
//If we can't parse the header at this point, we have some serious issues.
if (!WebSocketHeader.TryParse(message, out header))
return FramePackage(DataStatus.InternalError);
//Too much data
if (header.FrameSize > MaxReceiveSize)
return FramePackage(DataStatus.OversizeError);
}
}
//Only read if there's no full frame in the buffer.
if(NoFrameInBuffer())
readStatus = await GenericReadAsync();
//If there was an error (anything other than "completion" or waiting), return the error.
if (readStatus != DataStatus.Complete)
return FramePackage(readStatus);
}while(NoFrameInBuffer());
//Oh, we have the whole message. Uhh ok then, let's make sure the header fields are correct
//before continuing. RSV needs to be 0 (may change later) and all client messages must be masked.
if (!header.Masked || header.RSV != 0)
return FramePackage(DataStatus.DataFormatError);
//Oh is this... a binary frame? Dawg... don't gimme that crap.
if (header.Opcode == HeaderOpcode.BinaryFrame)
return FramePackage(DataStatus.UnsupportedError);
//Initialize a frame with our newly parsed data
frame = new WebSocketFrame(header, messageBuffer.Take(header.FrameSize).ToArray());
//Remove the message data from the buffer
MessageBufferPop(header.FrameSize);
return FramePackage(DataStatus.Complete);
}
/// <summary>
/// Process given frame. Returns true if the connection can continue
/// </summary>
/// <returns><c>true</c> if everything was fine, <c>false</c> otherwise.</returns>
/// <param name="readFrame">Read frame.</param>
public bool ProcessFrame(WebSocketFrame readFrame, out byte[] outputBytes, out string message)
{
outputBytes = null;
message = "";
//If it's a message frame or PART of a message frame, we should add the payload to the
//fragment buffer. The fragment buffer will be complete if this is a fin frame (see next statement)
if (readFrame.Header.Opcode == HeaderOpcode.ContinueFrame || readFrame.Header.Opcode == HeaderOpcode.TextFrame)
{
if (readFrame.Header.Opcode == HeaderOpcode.ContinueFrame)
Log("Received fragmented frame.", LogLevel.SuperDebug);
Array.Copy(readFrame.PayloadData, 0, fragmentBuffer, fragmentBufferSize, readFrame.Header.PayloadSize);
fragmentBufferSize += readFrame.Header.PayloadSize;
}
//Only convert fragment buffer into message if this is the final frame and it's a text frame
if (readFrame.Header.Fin && (readFrame.Header.Opcode == HeaderOpcode.TextFrame || readFrame.Header.Opcode == HeaderOpcode.ContinueFrame))
{
message = System.Text.Encoding.UTF8.GetString(fragmentBuffer, 0, fragmentBufferSize);
fragmentBufferSize = 0;
Log("Received message: " + message, LogLevel.SuperDebug);
//User.ReceivedMessage(message);
}
else if (readFrame.Header.Opcode == HeaderOpcode.PingFrame)
{
Log("Client ping. Sending pong", LogLevel.SuperDebug);
outputBytes = WebSocketFrame.GetPongFrame().GetRawBytes();
}
//Oh they're disconnecting? OK then, we need to finish up. Do NOT send more data.
else if (readFrame.Header.Opcode == HeaderOpcode.CloseConnectionFrame)
{
Log("Client is disconnecting: " + readFrame.CloseCode, LogLevel.Debug);
readFrame.Header.Masked = false;
outputBytes = readFrame.GetRawBytes();
return false;
}
return true;
}
/// <summary>
/// Attempts to read an entire frame. Returns the frame if one was successfully read.
/// </summary>
/// <returns>The status of the read operation</returns>
/// <param name="frame">The parsed frame (on success)</param>
public DataStatus TryReadFrame(out WebSocketFrame frame)
{
frame = new WebSocketFrame();
//Pull a chunk of data (as much as we can) from the stream and store it in our internal buffer.
DataStatus readStatus = GenericRead();
//If there was an error (anything other than "completion" or waiting), return the error.
if (readStatus != DataStatus.Complete)
return readStatus;
//We MAY have read more than one frame at a time! Wowie...
// while (messageBufferSize > 0)
// {
//We need at least 2 bytes to complete the header.
if (messageBufferSize < 2)
return DataStatus.WaitingOnData;
byte[] message = messageBuffer.Take(messageBufferSize).ToArray();
//If the complete header hasn't been read yet, we're still waiting for it.
if (messageBufferSize < WebSocketHeader.FullHeaderSize(message))
return DataStatus.WaitingOnData;
WebSocketHeader header = new WebSocketHeader();
//If we can't parse the header at this point, we have some serious issues.
if (!WebSocketHeader.TryParse(message, out header))
return DataStatus.InternalError;
//Too much data
if (header.FrameSize > MaxReceiveSize)
{
return DataStatus.OversizeError;
}
//We have the whole header, but do we have the whole message? if not, we're still waiting on data.
if (messageBufferSize < header.FrameSize)
return DataStatus.WaitingOnData;
//Oh, we have the whole message. Uhh ok then, let's make sure the header fields are correct
//before continuing. RSV needs to be 0 (may change later) and all client messages must be masked.
if (!header.Masked || header.RSV != 0)
return DataStatus.DataFormatError;
//Oh is this... a binary frame? Dawg... don't gimme that crap.
if (header.Opcode == HeaderOpcode.BinaryFrame)
return DataStatus.UnsupportedError;
//Initialize a frame with our newly parsed data
frame = new WebSocketFrame(header, messageBuffer.Take(header.FrameSize).ToArray());
//Remove the message data from the buffer
MessageBufferPop(header.FrameSize);
// messageBuffer.TruncateBeginning(header.FrameSize, messageBufferSize);
// messageBufferSize -= header.FrameSize;
//}
return DataStatus.Complete;
}
