public static SaiFrame Parse(byte[] bytes)
{
SaiFrame theFrame = null;
var theFrameType = (SaiFrameType)bytes[0];
if (theFrameType == SaiFrameType.TTS_OffsetStart)
{
theFrame = new SaiTtsFrameOffsetStart();
}
else if (theFrameType == SaiFrameType.TTS_OffsetAnswer1)
{
theFrame = new SaiTtsFrameOffsetAnswer1();
}
else if (theFrameType == SaiFrameType.TTS_OffsetAnswer2)
{
theFrame = new SaiTtsFrameOffsetAnswer2();
}
else if (theFrameType == SaiFrameType.TTS_OffsetEstimate)
{
theFrame = new SaiTtsFrameEstimate();
}
else if (theFrameType == SaiFrameType.TTS_OffsetEnd)
{
theFrame = new SaiTtsFrameOffsetEnd();
}
else if (theFrameType == SaiFrameType.TTS_AppData)
{
theFrame = new SaiTtsFrameAppData();
}
else if (theFrameType == SaiFrameType.EC_Start)
{
theFrame = new SaiEcFrameStart();
}
else if (theFrameType == SaiFrameType.EC_AppData)
{
theFrame = new SaiEcFrameApplication();
}
else if (theFrameType == SaiFrameType.EC_AppDataAskForAck)
{
theFrame = new SaiEcFrameAskForAck();
}
else if (theFrameType == SaiFrameType.EC_AppDataAcknowlegment)
{
theFrame = new SaiEcFrameAcknowlegment();
}
else
{
throw new InvalidOperationException(string.Format("无法解析指定的Sai帧，不可识别的类型{0}。", theFrameType));
}
theFrame.ParseBytes(bytes);
return(theFrame);
}
public void Test1()
{
var frameInital = new SaiTtsFrameEstimate();
frameInital.SequenceNo = 100;
frameInital.SenderTimestamp = 1000;
frameInital.SenderLastRecvTimestamp = 900;
frameInital.ReceiverLastSendTimestamp = 800;
frameInital.OffsetMax = -3000;
frameInital.OffsetMin = -3100;
var bytes = frameInital.GetBytes();
var actual = SaiFrame.Parse(bytes) as SaiTtsFrameEstimate;
Assert.AreEqual(frameInital.FrameType, actual.FrameType);
Assert.AreEqual(frameInital.SequenceNo, actual.SequenceNo);
Assert.AreEqual(frameInital.SenderTimestamp, actual.SenderTimestamp);
Assert.AreEqual(frameInital.SenderLastRecvTimestamp, actual.SenderLastRecvTimestamp);
Assert.AreEqual(frameInital.ReceiverLastSendTimestamp, actual.ReceiverLastSendTimestamp);
Assert.AreEqual(frameInital.OffsetMax, actual.OffsetMax);
Assert.AreEqual(frameInital.OffsetMin, actual.OffsetMin);
}
protected override void HandleTtsOffsetAnswer2Frame(Frames.SaiTtsFrameOffsetAnswer2 answer2)
{
// 收到Answer2，停止计时器
this.Context.StopHandshakeTimer();
LogUtility.Info(string.Format("{0}: 收到OffsetAnswer2报文，停止Tres_start计时器。",
this.Context.RsspEP.ID));
// 更新时间戳
this.Calculator.ResTimestamp3 = this.TTS.LocalLastRecvTimeStamp;
this.Calculator.InitTimestamp2 = answer2.SenderLastRecvTimestamp;
this.Calculator.InitTimestamp3 = answer2.SenderTimestamp;
// 应答方计算时钟偏移
this.Calculator.EstimateResOffset();
LogUtility.Info(string.Format("{0}: 应答方估算的时钟偏移，OffsetMin = {1}, OffsetMax = {2}",
this.Context.RsspEP.ID, this.Calculator.ResMinOffset, this.Calculator.ResMaxOffset));
// 发送OffsetEst
var seq = (ushort)this.Context.SeqNoManager.GetAndUpdateSendSeq();
var estimateFrame = new SaiTtsFrameEstimate(seq,
TripleTimestamp.CurrentTimestamp, TTS.RemoteLastSendTimestamp, TTS.LocalLastRecvTimeStamp,
this.Calculator.ResMinOffset,
this.Calculator.ResMaxOffset);
this.Context.NextLayer.SendUserData(estimateFrame.GetBytes());
LogUtility.Info(string.Format("{0}: 发送OffsetEst。", this.Context.RsspEP.ID));
// 启动计时器，等待OffsetEnd报文。
LogUtility.Info(string.Format("{0}: 启动计时器，等待OffsetEnd报文。",
this.Context.RsspEP.ID));
this.Context.StartHandshakeTimer();
// 更新状态。
this.Context.CurrentState = new TtsWaitingforEndState(this);
}
protected override void HandleTtsEstimateFrame(SaiTtsFrameEstimate estimateFrame)
{
// 收到OffsetEst，停止计时器
LogUtility.Info(string.Format("{0}: 收到OffsetEst报文，停止Tint_start计时器。", this.Context.RsspEP.ID));
this.Context.StopHandshakeTimer();
// 更新时间戳
this.Calculator.ResMinOffset = estimateFrame.OffsetMin;
this.Calculator.ResMaxOffset = estimateFrame.OffsetMax;
// 检查估算值
var valid = this.Calculator.IsEstimationValid();
// 更新连接状态。
this.Context.Connected = valid;
// 发送OffsetEnd。
var seq = (ushort)this.Context.SeqNoManager.GetAndUpdateSendSeq();
var offsetEndFrame = new SaiTtsFrameOffsetEnd(seq,
TripleTimestamp.CurrentTimestamp, TTS.RemoteLastSendTimestamp, TTS.LocalLastRecvTimeStamp, valid);
this.Context.NextLayer.SendUserData(offsetEndFrame.GetBytes());
//
if (valid)
{
LogUtility.Info(string.Format("{0}: 发送OffsetEnd，时钟偏移验证通过，SAI层连接成功。", this.Context.RsspEP.ID));
}
else
{
throw new Exception(string.Format("{0}: 时钟偏移估算无效，SAI层连接失败。", this.Context.RsspEP.ID));
}
// 更新状态。
this.Context.CurrentState = new TtsConnectedState(this);
}
protected virtual void HandleTtsEstimateFrame(SaiTtsFrameEstimate frame)
{
LogUtility.Error(string.Format("{0}: {1}.{2} not implement!",
this.Context.RsspEP.ID, this.GetType().Name,
new StackFrame(0).GetMethod().Name.Split('.').Last()));
}
