/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

#include "ns3/packet.h"

#include "ns3/header.h"

#include <iostream>

using namespace ns3;

/* A sample Header implementation

 */

class MyHeader : public Header 

{

public:

  static const char *GetUid (void);

  MyHeader ();

  virtual ~MyHeader ();

  void SetData (uint16_t data);

  uint16_t GetData (void) const;

private:

  virtual std::string DoGetName (void) const;

  virtual void PrintTo (std::ostream &os) const;

  virtual void SerializeTo (Buffer::Iterator start) const;

  virtual uint32_t DeserializeFrom (Buffer::Iterator start);

  virtual uint32_t GetSerializedSize (void) const;

  uint16_t m_data;

};

MyHeader::MyHeader ()

{

  // we must provide a public default constructor, 

  // implicit or explicit, but never private.

}

MyHeader::~MyHeader ()

{}

const char *

MyHeader::GetUid (void)

{

  // This string is used by the internals of the packet

  // code to keep track of the packet metadata.

  // You need to make sure that this string is absolutely

  // unique. The code will detect any duplicate string.

  return "MyHeader.test.nsnam.org";

}

std::string 

MyHeader::DoGetName (void) const

{

  // This string is used to identify the type of 

  // my header by the packet printing routines.

  return "MYHEADER";

}

void 

MyHeader::PrintTo (std::ostream &os) const

{

  // This method is invoked by the packet printing

  // routines to print the content of my header.

  os << "data=" << m_data << std::endl;

}

uint32_t

MyHeader::GetSerializedSize (void) const

{

  // we reserve 2 bytes for our header.

  return 2;

}

void

MyHeader::SerializeTo (Buffer::Iterator start) const

{

  // we can serialize two bytes at the start of the buffer.

  // we write them in network byte order.

  start.WriteHtonU16 (m_data);

}

uint32_t

MyHeader::DeserializeFrom (Buffer::Iterator start)

{

  // we can deserialize two bytes from the start of the buffer.

  // we read them in network byte order and store them

  // in host byte order.

  m_data = start.ReadNtohU16 ();

  // we return the number of bytes effectively read.

  return 2;

}

void 

MyHeader::SetData (uint16_t data)

{

  m_data = data;

}

uint16_t 

MyHeader::GetData (void) const

{

  return m_data;

}

int main (int argc, char *argv[])

{

  // instantiate a header.

  MyHeader sourceHeader;

  sourceHeader.SetData (2);

  // instantiate a packet

  Packet p;

  // and store my header into the packet.

  p.AddHeader (sourceHeader);

  // print the content of my packet on the standard output.

  p.Print (std::cout);

  // you can now remove the header from the packet:

  MyHeader destinationHeader;

  p.RemoveHeader (destinationHeader);

  // and check that the destination and source

  // headers contain the same values.

  NS_ASSERT (sourceHeader.GetData () == destinationHeader.GetData ());

  return 0;

}