C++ NS3记录时间精度

我正在使用NS3.20来查找从一个节点发送到FAT树拓扑中另一个节点的数据包的时间戳

NS_LOG= "*=level_info|prefix_func|prefix_time|prefix_node" ./waf --run scratch/fat-tree &> save-log.txt

将包含pkt 196相关信息的几行选定行灰显后。输出为

时间戳，Nodeid，Functioncalled，DevNo，pktid

示例行如下所示

1.74547s 34 CsmaChannel:TransmitStart(): UID is 196)
1.74548s 34 CsmaChannel:TransmitEnd(): UID is 196)
1.74548s 23 Node:ReceiveFromDevice(): Node 23 ReceiveFromDevice:  dev 2 (type=ns3::CsmaNetDevice) Packet UID 196
1.74548s 23 BridgeNetDevice:ReceiveFromDevice(): UID is 196
1.74548s 23 CsmaChannel:TransmitStart(): UID is 196)
1.74548s 34 CsmaChannel:PropagationCompleteEvent(): UID is 196)
.
.
.

为了我的研究，我需要时间戳以纳秒为单位。有没有办法进行配置？ 注意：我在函数中尝试了cout和fout，但它只是打印时间而没有节点id，这对我来说是无用的

---

请帮助

首先，我建议使用最新版本的ns-3，ns-3.30.1。一般来说，保持最新是个好主意。也就是说，我的解决方案是使用ns-3.30.1进行测试的，所以很可能它不适用于ns-3.20。如果不起作用，请参阅中的注释

我引用了第11.3条，该条为我指明了示例。基于该示例，这里是您所需输出的最小可复制示例

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
// set the time format and precision of LOG macros
// https://stackoverflow.com/questions/60148908
// this example is adapted from ./src/core/examples/sample-log-time-format.cc

#include "ns3/simulator.h"
#include "ns3/log.h"
#include "ns3/random-variable-stream.h"

using namespace ns3;

void
ReplacementTimePrinter (std::ostream &os)
{
    os << Simulator::Now ().GetNanoSeconds () << " ns";
}

void
ReplaceTimePrinter (void)
{
    std::cout << "Replacing time printer function after Simulator::Run ()" << std::endl;
    LogSetTimePrinter (&ReplacementTimePrinter);
}

int
main (int argc, char *argv[])
{
    LogComponentEnable ("RandomVariableStream", LOG_LEVEL_ALL);
    LogComponentEnableAll (LOG_PREFIX_TIME);
    Ptr<UniformRandomVariable> uniformRv = CreateObject<UniformRandomVariable> ();
    Simulator::Schedule (Seconds (0), &ReplaceTimePrinter);

    // schedule some bogus events to demonstrate the new TimePrinter
    Simulator::Schedule (NanoSeconds (1), &UniformRandomVariable::SetAntithetic, uniformRv, false);
    Simulator::Schedule (NanoSeconds (123), &UniformRandomVariable::SetAntithetic, uniformRv, false);
    Simulator::Schedule (NanoSeconds (123456), &UniformRandomVariable::SetAntithetic, uniformRv, false);
    Simulator::Schedule (NanoSeconds (123456789), &UniformRandomVariable::SetAntithetic, uniformRv, false);

    Simulator::Run ();
    Simulator::Destroy ();
}

请注意，我们没有在模拟器代码中直接调用

LogSetTimePrinter

，而是安排了一个事件来调用

LogSetTimePrinter

Simulator::Schedule (Seconds (0), &ReplaceTimePrinter);

---

我不确定为什么会出现这种情况，但进一步检查后，似乎

GetImpl（）

调用了

LogSetTimePrinter

GetImpl（）

由

Simulator:：Run（）

调用，这意味着

Simulator:：Run（）

将在调用

Simulator:：Run（）

之前“覆盖”对

LogSetTimePrinter的任何调用。因此，我们需要创建一个事件，在创建
SimulatorImpl
之后设置
TimePrinter
 您可以基于此链接为数据包添加时间戳
RandomVariableStream:RandomVariableStream(0x7fc0aee287d0)
RandomVariableStream:UniformRandomVariable(0x7fc0aee287d0)
RandomVariableStream:SetStream(0x7fc0aee287d0, -1)
RandomVariableStream:SetAntithetic(0x7fc0aee287d0, 0)
Replacing time printer function after Simulator::Run ()
1 ns RandomVariableStream:SetAntithetic(0x7fc0aee287d0, 0)
123 ns RandomVariableStream:SetAntithetic(0x7fc0aee287d0, 0)
123456 ns RandomVariableStream:SetAntithetic(0x7fc0aee287d0, 0)
123456789 ns RandomVariableStream:SetAntithetic(0x7fc0aee287d0, 0)
RandomVariableStream:~RandomVariableStream(0x7fc0aee287d0)

Simulator::Schedule (Seconds (0), &ReplaceTimePrinter);