public static ControlFrame.Type ToControlFrameType(this FrameOpcode opcode)
{
switch (opcode)
{
case FrameOpcode.Close:
return(ControlFrame.Type.Close);
case FrameOpcode.Ping:
return(ControlFrame.Type.Ping);
case FrameOpcode.Pong:
return(ControlFrame.Type.Pong);
default:
throw new InvalidOperationException("that opcode is not for a control frame!");
}
}
private static async Task SendFixedFrame(Synchronized <Stream> sStream, FrameOpcode opcode, int appDataLength, bool masking, Action <byte[], int> dataWriter)
{
int appDataOffset;
byte[] buffer, maskData;
BuildFrameHeader(opcode, appDataLength, masking, out maskData, out buffer, out appDataOffset, bareHeader: false);
dataWriter(buffer, appDataOffset);
if (masking)
{
for (int i = 0; i < appDataLength; i++)
{
buffer[i + appDataOffset] ^= maskData[i % 4];
}
}
using (var streamHolder = await sStream)
await streamHolder.LockedObject.WriteAsync(buffer, 0, buffer.Length);
}
private static void BuildFrameHeader(FrameOpcode opcode, int appDataLength, bool masking, out byte[] maskData, out byte[] buffer, out int appDataOffset, bool bareHeader)
{
PayloadLengthMode plm;
if (appDataLength < 126)
{
plm = PayloadLengthMode.Short;
}
else if (appDataLength <= UInt16.MaxValue)
{
plm = PayloadLengthMode.Medium;
}
else
{
plm = PayloadLengthMode.Long;
}
// TODO: implement extensions
int bufferLength = 2 + (((int)plm) / 8) + (masking ? 4 : 0) + (bareHeader ? 0 : appDataLength);
buffer = new byte[bufferLength];
buffer[0] = (byte)((byte)opcode | FLAG1_FIN);
switch (plm)
{
case PayloadLengthMode.Short:
buffer[1] = (byte)appDataLength;
appDataOffset = 2;
break;
case PayloadLengthMode.Medium:
buffer[1] = 126;
var shortLength = Util.ReverseArray(BitConverter.GetBytes(checked ((UInt16)appDataLength)));
Array.Copy(shortLength, 0, buffer, 2, shortLength.Length);
appDataOffset = 4;
break;
case PayloadLengthMode.Long:
buffer[1] = 127;
var longLength = Util.ReverseArray(BitConverter.GetBytes(checked ((UInt64)appDataLength)));
Array.Copy(longLength, 0, buffer, 2, longLength.Length);
appDataOffset = 10;
break;
default:
throw new InvalidOperationException("Either the string is impossibly large (HI FUTURE! :D) or the selection loop (or the switch) has failed.");
}
if (masking)
{
maskData = new byte[4];
if (CSPRNG == null)
{
CSPRNG = System.Security.Cryptography.RandomNumberGenerator.Create();
}
CSPRNG.GetBytes(maskData);
buffer[1] |= FLAG2_MASK;
Array.Copy(maskData, 0, buffer, appDataOffset, maskData.Length);
appDataOffset += 4;
}
else
{
maskData = null;
}
}
/// <summary>
/// Gets the frame from opcode.
/// </summary>
/// <param name="protocolVersion">the version of the cql binary protocol in use</param>
/// <param name="opcode">The opcode.</param>
/// <returns></returns>
/// <exception cref="ProtocolException">Unexpected OpCode received.</exception>
private static Frame GetFrameFromOpcode(byte protocolVersion, FrameOpcode opcode)
{
Frame frame;
switch(opcode)
{
case FrameOpcode.Error:
frame = new ErrorFrame();
break;
case FrameOpcode.Ready:
frame = new ReadyFrame();
break;
case FrameOpcode.Authenticate:
frame = new AuthenticateFrame();
break;
case FrameOpcode.AuthChallenge:
frame = new AuthChallengeFrame();
break;
case FrameOpcode.AuthSuccess:
frame = new AuthSuccessFrame();
break;
case FrameOpcode.Supported:
frame = new SupportedFrame();
break;
case FrameOpcode.Result:
frame = new ResultFrame();
break;
case FrameOpcode.Event:
frame = new EventFrame();
break;
default:
throw new ProtocolException(protocolVersion, 0, string.Format("Unexpected OpCode {0:X} received.", opcode));
}
return frame;
}
