public void TestMethod1()
{
var buffer = new byte[1000];
var sendFrame = new DataFrame("abc");
int sendFrameSize;
sendFrame.WriteTo(buffer, out sendFrameSize);
DataFrame receiveFrame;
int receiveFrameSize;
DataFrame.TryReadFrom(buffer, sendFrameSize, out receiveFrame, out receiveFrameSize);
Assert.AreEqual(receiveFrameSize, sendFrameSize);
Assert.AreEqual(receiveFrame.Message, sendFrame.Message);
}
public static bool TryReadFrom(byte[] buffer, int size, out DataFrame frame, out int consumedBytes)
{
frame = null;
consumedBytes = 0;
if (size < 2)
{
return false;
}
var stream = new BitReader(buffer, size);
int fragmented = stream.ReadBit();
if (fragmented == 0)
{
throw new NotSupportedException("Fragmented messages are currently not supported");
}
// Reserved
stream.ReadBits(3);
// Op code
var operationCode = (OpCode)stream.ReadBits(4);
if (operationCode != OpCode.Text)
{
throw new NotSupportedException("Only text frames are currently supported");
}
// Masking
bool isMasked = stream.ReadBit() != 0;
if (!isMasked)
{
throw new NotSupportedException("Only masked frames are supported");
}
// Payload
var payloadSize = (ulong)stream.ReadBits(7);
consumedBytes = 2;
if (payloadSize == 126)
{
byte[] payloadBytes = stream.ReadBytes(2);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(payloadBytes);
}
payloadSize = BitConverter.ToUInt16(payloadBytes, 0);
consumedBytes = 4;
}
else if (payloadSize == 127)
{
byte[] payloadSizeBytes = stream.ReadBytes(4);
if (BitConverter.IsLittleEndian)
{
Array.Reverse(payloadSizeBytes);
}
payloadSize = BitConverter.ToUInt64(payloadSizeBytes, 0);
consumedBytes = 10;
}
if (payloadSize > int.MaxValue)
{
throw new NotSupportedException("Only frames with a payload smaller than int.MaxValue are currently supported");
}
byte[] maskBytes = stream.ReadBytes(4);
consumedBytes += 4;
for (int i = 0; i < (int)payloadSize; i++)
{
buffer[consumedBytes + i] = (byte)(buffer[consumedBytes + i] ^ maskBytes[i % 4]);
}
consumedBytes += (int)payloadSize;
string message = Encoding.UTF8.GetString(buffer, consumedBytes - (int)payloadSize, (int)payloadSize);
frame = new DataFrame(message);
return true;
}
private void WriteSendBuffer(string message)
{
var dataFrame = new DataFrame(message);
int frameSize;
dataFrame.WriteTo(outputBuffer, out frameSize);
sendBufferOffset = 0;
sendBufferSize = frameSize;
}
