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

/*

 * Copyright (c) 2005,2006 INRIA

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#include "packet.h"

#include "ns3/assert.h"

#include "ns3/log.h"

#include "ns3/test.h"

#include <string>

#include <stdarg.h>

NS_LOG_COMPONENT_DEFINE ("Packet");

namespace ns3 {

uint32_t Packet::m_globalUid = 0;

TypeId 

ByteTagIterator::Item::GetTypeId (void) const

{

  return m_tid;

}

uint32_t 

ByteTagIterator::Item::GetStart (void) const

{

  return m_start;

}

uint32_t 

ByteTagIterator::Item::GetEnd (void) const

{

  return m_end;

}

void 

ByteTagIterator::Item::GetTag (Tag &tag) const

{

  if (tag.GetInstanceTypeId () != GetTypeId ())

    {

      NS_FATAL_ERROR ("The tag you provided is not of the right type.");

    }

  tag.Deserialize (m_buffer);

}

ByteTagIterator::Item::Item (TypeId tid, uint32_t start, uint32_t end, TagBuffer buffer)

  : m_tid (tid),

    m_start (start),

    m_end (end),

    m_buffer (buffer)

{}

bool 

ByteTagIterator::HasNext (void) const

{

  return m_current.HasNext ();

}

ByteTagIterator::Item 

ByteTagIterator::Next (void)

{

  ByteTagList::Iterator::Item i = m_current.Next ();

  return ByteTagIterator::Item (i.tid, 

                                i.start-m_current.GetOffsetStart (), 

                                i.end-m_current.GetOffsetStart (), 

                                i.buf);

}

ByteTagIterator::ByteTagIterator (ByteTagList::Iterator i)

  : m_current (i)

{}

PacketTagIterator::PacketTagIterator (const struct PacketTagList::TagData *head)

  : m_current (head)

{}

bool 

PacketTagIterator::HasNext (void) const

{

  return m_current != 0;

}

PacketTagIterator::Item 

PacketTagIterator::Next (void)

{

  NS_ASSERT (HasNext ());

  const struct PacketTagList::TagData *prev = m_current;

  m_current = m_current->next;

  return PacketTagIterator::Item (prev);

}

PacketTagIterator::Item::Item (const struct PacketTagList::TagData *data)

  : m_data (data)

{}

TypeId 

PacketTagIterator::Item::GetTypeId (void) const

{

  return m_data->tid;

}

void 

PacketTagIterator::Item::GetTag (Tag &tag) const

{

  NS_ASSERT (tag.GetInstanceTypeId () == m_data->tid);

  tag.Deserialize (TagBuffer ((uint8_t*)m_data->data, (uint8_t*)m_data->data+PACKET_TAG_MAX_SIZE));

}

Ptr<Packet> 

Packet::Copy (void) const

{

  // we need to invoke the copy constructor directly

  // rather than calling Create because the copy constructor

  // is private.

  return Ptr<Packet> (new Packet (*this), false);

}

Packet::Packet ()

  : m_buffer (),

    m_byteTagList (),

    m_packetTagList (),

    m_metadata (m_globalUid, 0),

    m_nixVector (0)

{

  m_globalUid++;

}

Packet::Packet (const Packet &o)

  : m_buffer (o.m_buffer),

    m_byteTagList (o.m_byteTagList),

    m_packetTagList (o.m_packetTagList),

    m_metadata (o.m_metadata)

{

  o.m_nixVector ? m_nixVector = o.m_nixVector->Copy () 

                : m_nixVector = 0;

}

Packet &

Packet::operator = (const Packet &o)

{

  if (this == &o)

    {

      return *this;

    }

  m_buffer = o.m_buffer;

  m_byteTagList = o.m_byteTagList;

  m_packetTagList = o.m_packetTagList;

  m_metadata = o.m_metadata;

  o.m_nixVector ? m_nixVector = o.m_nixVector->Copy () 

                : m_nixVector = 0;

  return *this;

}

Packet::Packet (uint32_t size)

  : m_buffer (size),

    m_byteTagList (),

    m_packetTagList (),

    m_metadata (m_globalUid, size),

    m_nixVector (0)

{

  m_globalUid++;

}

Packet::Packet (uint8_t const*buffer, uint32_t size)

  : m_buffer (),

    m_byteTagList (),

    m_packetTagList (),

    m_metadata (m_globalUid, size),

    m_nixVector (0)

{

  m_globalUid++;

  m_buffer.AddAtStart (size);

  Buffer::Iterator i = m_buffer.Begin ();

  i.Write (buffer, size);

}

Packet::Packet (const Buffer &buffer,  const ByteTagList &byteTagList, 

                const PacketTagList &packetTagList, const PacketMetadata &metadata)

  : m_buffer (buffer),

    m_byteTagList (byteTagList),

    m_packetTagList (packetTagList),

    m_metadata (metadata),

    m_nixVector (0)

{}

Ptr<Packet>

Packet::CreateFragment (uint32_t start, uint32_t length) const

{

  NS_LOG_FUNCTION (this << start << length);

  Buffer buffer = m_buffer.CreateFragment (start, length);

  NS_ASSERT (m_buffer.GetSize () >= start + length);

  uint32_t end = m_buffer.GetSize () - (start + length);

  PacketMetadata metadata = m_metadata.CreateFragment (start, end);

  // again, call the constructor directly rather than

  // through Create because it is private.

  return Ptr<Packet> (new Packet (buffer, m_byteTagList, m_packetTagList, metadata), false);

}

void

Packet::SetNixVector (Ptr<NixVector> nixVector)

{

  m_nixVector = nixVector;

}

Ptr<NixVector>

Packet::GetNixVector (void) const

{

  return m_nixVector;

} 

uint32_t 

Packet::GetSize (void) const

{

  return m_buffer.GetSize ();

}

void

Packet::AddHeader (const Header &header)

{

  uint32_t size = header.GetSerializedSize ();

  NS_LOG_FUNCTION (this << header.GetInstanceTypeId ().GetName () << size);

  uint32_t orgStart = m_buffer.GetCurrentStartOffset ();

  bool resized = m_buffer.AddAtStart (size);

  if (resized)

    {

      m_byteTagList.AddAtStart (m_buffer.GetCurrentStartOffset () + size - orgStart,

                                m_buffer.GetCurrentStartOffset () + size);

    }

  header.Serialize (m_buffer.Begin ());

  m_metadata.AddHeader (header, size);

}

uint32_t

Packet::RemoveHeader (Header &header)

{

  uint32_t deserialized = header.Deserialize (m_buffer.Begin ());

  NS_LOG_FUNCTION (this << header.GetInstanceTypeId ().GetName () << deserialized);

  m_buffer.RemoveAtStart (deserialized);

  m_metadata.RemoveHeader (header, deserialized);

  return deserialized;

}

uint32_t

Packet::PeekHeader (Header &header) const

{

  uint32_t deserialized = header.Deserialize (m_buffer.Begin ());

  NS_LOG_FUNCTION (this << header.GetInstanceTypeId ().GetName () << deserialized);

  return deserialized;

}

void

Packet::AddTrailer (const Trailer &trailer)

{

  uint32_t size = trailer.GetSerializedSize ();

  NS_LOG_FUNCTION (this << trailer.GetInstanceTypeId ().GetName () << size);

  uint32_t orgStart = m_buffer.GetCurrentStartOffset ();

  bool resized = m_buffer.AddAtEnd (size);

  if (resized)

    {

      m_byteTagList.AddAtEnd (m_buffer.GetCurrentStartOffset () - orgStart,

                              m_buffer.GetCurrentEndOffset () - size);

    }

  Buffer::Iterator end = m_buffer.End ();

  trailer.Serialize (end);

  m_metadata.AddTrailer (trailer, size);

}

uint32_t

Packet::RemoveTrailer (Trailer &trailer)

{

  uint32_t deserialized = trailer.Deserialize (m_buffer.End ());

  NS_LOG_FUNCTION (this << trailer.GetInstanceTypeId ().GetName () << deserialized);

  m_buffer.RemoveAtEnd (deserialized);

  m_metadata.RemoveTrailer (trailer, deserialized);

  return deserialized;

}

uint32_t

Packet::PeekTrailer (Trailer &trailer)

{

  uint32_t deserialized = trailer.Deserialize (m_buffer.End ());

  NS_LOG_FUNCTION (this << trailer.GetInstanceTypeId ().GetName () << deserialized);

  return deserialized;

}

void 

Packet::AddAtEnd (Ptr<const Packet> packet)

{

  NS_LOG_FUNCTION (this << packet << packet->GetSize ());

  uint32_t aStart = m_buffer.GetCurrentStartOffset ();

  uint32_t bEnd = packet->m_buffer.GetCurrentEndOffset ();

  m_buffer.AddAtEnd (packet->m_buffer);

  uint32_t appendPrependOffset = m_buffer.GetCurrentEndOffset () - packet->m_buffer.GetSize ();

  m_byteTagList.AddAtEnd (m_buffer.GetCurrentStartOffset () - aStart, 

                          appendPrependOffset);

  ByteTagList copy = packet->m_byteTagList;

  copy.AddAtStart (m_buffer.GetCurrentEndOffset () - bEnd,

                   appendPrependOffset);

  m_byteTagList.Add (copy);

  m_metadata.AddAtEnd (packet->m_metadata);

}

void

Packet::AddPaddingAtEnd (uint32_t size)

{

  NS_LOG_FUNCTION (this << size);

  uint32_t orgEnd = m_buffer.GetCurrentEndOffset ();

  bool resized = m_buffer.AddAtEnd (size);

  if (resized)

    {

      m_byteTagList.AddAtEnd (m_buffer.GetCurrentEndOffset () - orgEnd,

                              m_buffer.GetCurrentEndOffset () - size);

    }

  m_metadata.AddPaddingAtEnd (size);

}

void 

Packet::RemoveAtEnd (uint32_t size)

{

  NS_LOG_FUNCTION (this << size);

  m_buffer.RemoveAtEnd (size);

  m_metadata.RemoveAtEnd (size);

}

void 

Packet::RemoveAtStart (uint32_t size)

{

  NS_LOG_FUNCTION (this << size);

  m_buffer.RemoveAtStart (size);

  m_metadata.RemoveAtStart (size);

}

void 

Packet::RemoveAllByteTags (void)

{

  NS_LOG_FUNCTION (this);

  m_byteTagList.RemoveAll ();

}

uint8_t const *

Packet::PeekData (void) const

{

  NS_LOG_FUNCTION (this);

  uint32_t oldStart = m_buffer.GetCurrentStartOffset ();

  uint8_t const * data = m_buffer.PeekData ();

  uint32_t newStart = m_buffer.GetCurrentStartOffset ();

  // Update tag offsets if buffer offsets were changed

  const_cast<ByteTagList &>(m_byteTagList).AddAtStart (newStart - oldStart, newStart);

  return data;

}

uint32_t 

Packet::CopyData (uint8_t *buffer, uint32_t size) const

{

  Buffer::Iterator i = m_buffer.Begin ();

  uint32_t cur = 0;

  while (!i.IsEnd () && cur < size)

    {

      buffer[cur] = i.ReadU8 ();

      cur++;

    }

  return cur;

}

void

Packet::CopyData(std::ostream *os, uint32_t size) const

{

  return m_buffer.CopyData (os, size);

}

uint32_t 

Packet::GetUid (void) const

{

  return m_metadata.GetUid ();

}

void 

Packet::PrintByteTags (std::ostream &os) const

{

  ByteTagIterator i = GetByteTagIterator ();

  while (i.HasNext ())

    {

      ByteTagIterator::Item item = i.Next ();

      os << item.GetTypeId ().GetName () << " [" << item.GetStart () << "-" << item.GetEnd () << "]";

      Callback<ObjectBase *> constructor = item.GetTypeId ().GetConstructor ();

      if (constructor.IsNull ())

        {

          if (i.HasNext ())

            {

              os << " ";

            }

          continue;

        }

      Tag *tag = dynamic_cast<Tag *> (constructor ());

      NS_ASSERT (tag != 0);

      os << " ";

      item.GetTag (*tag);

      tag->Print (os);

      if (i.HasNext ())

        {

          os << " ";

        }

      delete tag;

    }

}

void 

Packet::Print (std::ostream &os) const

{

  PacketMetadata::ItemIterator i = m_metadata.BeginItem (m_buffer);

  while (i.HasNext ())

    {

      PacketMetadata::Item item = i.Next ();

      if (item.isFragment)

        {

          switch (item.type) {

          case PacketMetadata::Item::PAYLOAD:

            os << "Payload";

            break;

          case PacketMetadata::Item::HEADER:

          case PacketMetadata::Item::TRAILER:

            os << item.tid.GetName ();

            break;

          }

          os << " Fragment [" << item.currentTrimedFromStart<<":"

             << (item.currentTrimedFromStart + item.currentSize) << "]";

        }

      else

        {

          switch (item.type) {

          case PacketMetadata::Item::PAYLOAD:

            os << "Payload (size=" << item.currentSize << ")";

            break;

          case PacketMetadata::Item::HEADER:

          case PacketMetadata::Item::TRAILER:

            os << item.tid.GetName () << " (";

            {

              NS_ASSERT (item.tid.HasConstructor ());

              Callback<ObjectBase *> constructor = item.tid.GetConstructor ();

              NS_ASSERT (!constructor.IsNull ());

              ObjectBase *instance = constructor ();

              NS_ASSERT (instance != 0);

              Chunk *chunk = dynamic_cast<Chunk *> (instance);

              NS_ASSERT (chunk != 0);

              chunk->Deserialize (item.current);

              chunk->Print (os);

              delete chunk;

            }

            os << ")";

            break;

          }          

        }

      if (i.HasNext ())

        {

          os << " ";

        }

    }

#if 0

  // The code below will work only if headers and trailers

  // define the right attributes which is not the case for

  // now. So, as a temporary measure, we use the 

  // headers' and trailers' Print method as shown above.

  PacketMetadata::ItemIterator i = m_metadata.BeginItem (m_buffer);

  while (i.HasNext ())

    {

      PacketMetadata::Item item = i.Next ();

      if (item.isFragment)

        {

          switch (item.type) {

          case PacketMetadata::Item::PAYLOAD:

            os << "Payload";

            break;

          case PacketMetadata::Item::HEADER:

          case PacketMetadata::Item::TRAILER:

            os << item.tid.GetName ();

            break;

          }

          os << " Fragment [" << item.currentTrimedFromStart<<":"

             << (item.currentTrimedFromStart + item.currentSize) << "]";

        }

      else

        {

          switch (item.type) {

          case PacketMetadata::Item::PAYLOAD:

            os << "Payload (size=" << item.currentSize << ")";

            break;

          case PacketMetadata::Item::HEADER:

          case PacketMetadata::Item::TRAILER:

            os << item.tid.GetName () << "(";

            {

              NS_ASSERT (item.tid.HasConstructor ());

              Callback<ObjectBase *> constructor = item.tid.GetConstructor ();

              NS_ASSERT (constructor.IsNull ());

              ObjectBase *instance = constructor ();

              NS_ASSERT (instance != 0);

              Chunk *chunk = dynamic_cast<Chunk *> (instance);

              NS_ASSERT (chunk != 0);

              chunk->Deserialize (item.current);

              for (uint32_t j = 0; j < item.tid.GetAttributeN (); j++)

                {

                  std::string attrName = item.tid.GetAttributeName (j);

                  std::string value;

                  bool ok = chunk->GetAttribute (attrName, value);

                  NS_ASSERT (ok);

                  os << attrName << "=" << value;

                  if ((j + 1) < item.tid.GetAttributeN ())

                    {

                      os << ",";

                    }

                }

            }

            os << ")";

            break;

          }          

        }

      if (i.HasNext ())

        {

          os << " ";

        }

    }

#endif   

}

PacketMetadata::ItemIterator 

Packet::BeginItem (void) const

{

  return m_metadata.BeginItem (m_buffer);

}

void

Packet::EnablePrinting (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  PacketMetadata::Enable ();

}

void

Packet::EnableChecking (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  PacketMetadata::EnableChecking ();

}

Buffer 

Packet::Serialize (void) const

{

  NS_LOG_FUNCTION (this);

  Buffer buffer;

  uint32_t reserve;

  // write metadata

  reserve = m_metadata.GetSerializedSize ();

  buffer.AddAtStart (reserve);

  m_metadata.Serialize (buffer.Begin (), reserve);

  // write tags

  //XXX

  //reserve = m_tags.GetSerializedSize ();

  //buffer.AddAtStart (reserve);

  //m_tags.Serialize (buffer.Begin (), reserve);

  // aggregate byte buffer, metadata, and tags

  Buffer tmp = m_buffer.CreateFullCopy ();

  tmp.AddAtEnd (buffer);

  // write byte buffer size.

  tmp.AddAtStart (4);

  tmp.Begin ().WriteU32 (m_buffer.GetSize ());

  return tmp;

}

void 

Packet::Deserialize (Buffer buffer)

{

  NS_LOG_FUNCTION (this);

  Buffer buf = buffer;

  // read size

  uint32_t packetSize = buf.Begin ().ReadU32 ();

  buf.RemoveAtStart (4);

  // read buffer.

  buf.RemoveAtEnd (buf.GetSize () - packetSize);

  m_buffer = buf;

  buffer.RemoveAtStart (4 + packetSize);

  // read tags

  //XXX

  //uint32_t tagsDeserialized = m_tags.Deserialize (buffer.Begin ());

  //buffer.RemoveAtStart (tagsDeserialized);

  // read metadata

  uint32_t metadataDeserialized = 

    m_metadata.Deserialize (buffer.Begin ());

  buffer.RemoveAtStart (metadataDeserialized);

}

void 

Packet::AddByteTag (const Tag &tag) const

{

  NS_LOG_FUNCTION (this << tag.GetInstanceTypeId ().GetName () << tag.GetSerializedSize ());

  ByteTagList *list = const_cast<ByteTagList *> (&m_byteTagList);

  TagBuffer buffer = list->Add (tag.GetInstanceTypeId (), tag.GetSerializedSize (), 

                                m_buffer.GetCurrentStartOffset (),

                                m_buffer.GetCurrentEndOffset ());

  tag.Serialize (buffer);

}

ByteTagIterator 

Packet::GetByteTagIterator (void) const

{

  return ByteTagIterator (m_byteTagList.Begin (m_buffer.GetCurrentStartOffset (), m_buffer.GetCurrentEndOffset ()));

}

bool 

Packet::FindFirstMatchingByteTag (Tag &tag) const

{

  TypeId tid = tag.GetInstanceTypeId ();

  ByteTagIterator i = GetByteTagIterator ();

  while (i.HasNext ())

    {

      ByteTagIterator::Item item = i.Next ();

      if (tid == item.GetTypeId ())

        {

          item.GetTag (tag);

          return true;

        }

    }

  return false;

}

void 

Packet::AddPacketTag (const Tag &tag) const

{

  NS_LOG_FUNCTION (this << tag.GetInstanceTypeId ().GetName () << tag.GetSerializedSize ());

  m_packetTagList.Add (tag);

}

bool 

Packet::RemovePacketTag (Tag &tag)

{

  NS_LOG_FUNCTION (this << tag.GetInstanceTypeId ().GetName () << tag.GetSerializedSize ());

  bool found = m_packetTagList.Remove (tag);

  return found;

}

bool 

Packet::PeekPacketTag (Tag &tag) const

{

  bool found = m_packetTagList.Peek (tag);

  return found;

}

void 

Packet::RemoveAllPacketTags (void)

{

  NS_LOG_FUNCTION (this);

  m_packetTagList.RemoveAll ();

}

void 

Packet::PrintPacketTags (std::ostream &os) const

{

  PacketTagIterator i = GetPacketTagIterator ();

  while (i.HasNext ())

    {

      PacketTagIterator::Item item = i.Next ();

      NS_ASSERT (item.GetTypeId ().HasConstructor ());

      Callback<ObjectBase *> constructor = item.GetTypeId ().GetConstructor ();

      NS_ASSERT (!constructor.IsNull ());

      ObjectBase *instance = constructor ();

      Tag *tag = dynamic_cast<Tag *> (instance);

      NS_ASSERT (tag != 0);

      item.GetTag (*tag);

      tag->Print (os);

      delete tag;

      if (i.HasNext ())

        {

          os << " ";

        }

    }

}

PacketTagIterator 

Packet::GetPacketTagIterator (void) const

{

  return PacketTagIterator (m_packetTagList.Head ());

}

std::ostream& operator<< (std::ostream& os, const Packet &packet)

{

  packet.Print (os);

  return os;

}

//-----------------------------------------------------------------------------

// Unit tests

//-----------------------------------------------------------------------------

namespace {

class ATestTagBase : public Tag

{

public:

  ATestTagBase () : m_error (false) {}

  bool m_error;

};

template <int N>

class ATestTag : public ATestTagBase

{

public:

  static TypeId GetTypeId (void) {

    std::ostringstream oss;

    oss << "anon::ATestTag<" << N << ">";

    static TypeId tid = TypeId (oss.str ().c_str ())

      .SetParent<Tag> ()

      .AddConstructor<ATestTag<N> > ()

      .HideFromDocumentation ()

      ;

    return tid;

  }

  virtual TypeId GetInstanceTypeId (void) const {

    return GetTypeId ();

  }

  virtual uint32_t GetSerializedSize (void) const {

    return N;

  }

  virtual void Serialize (TagBuffer buf) const {

    for (uint32_t i = 0; i < N; ++i)

      {

        buf.WriteU8 (N);

      }

  }

  virtual void Deserialize (TagBuffer buf) {

    for (uint32_t i = 0; i < N; ++i)

      {

        uint8_t v = buf.ReadU8 ();

        if (v != N)

          {

            m_error = true;

          }

      }

  }

  virtual void Print (std::ostream &os) const {

    os << N;

  }

  ATestTag ()

    : ATestTagBase () {}

};

class ATestHeaderBase : public Header

{

public:

  ATestHeaderBase () : Header (), m_error (false) {}

  bool m_error;

};

template <int N>

class ATestHeader : public ATestHeaderBase

{

public:

  static TypeId GetTypeId (void) {

    std::ostringstream oss;

    oss << "anon::ATestHeader<" << N << ">";

    static TypeId tid = TypeId (oss.str ().c_str ())

      .SetParent<Header> ()

      .AddConstructor<ATestHeader<N> > ()

      .HideFromDocumentation ()

      ;

    return tid;

  }

  virtual TypeId GetInstanceTypeId (void) const {

    return GetTypeId ();

  }

  virtual uint32_t GetSerializedSize (void) const {

    return N;

  }

  virtual void Serialize (Buffer::Iterator iter) const {

    for (uint32_t i = 0; i < N; ++i)

      {

        iter.WriteU8 (N);

      }

  }

  virtual uint32_t Deserialize (Buffer::Iterator iter) {

    for (uint32_t i = 0; i < N; ++i)

      {

        uint8_t v = iter.ReadU8 ();

        if (v != N)

          {

            m_error = true;

          }

      }

    return N;

  }

  virtual void Print (std::ostream &os) const {

  }

  ATestHeader ()

    : ATestHeaderBase () {}

};

class ATestTrailerBase : public Trailer

{

public:

  ATestTrailerBase () : Trailer (), m_error (false) {}

  bool m_error;

};

template <int N>

class ATestTrailer : public ATestTrailerBase

{

public:

  static TypeId GetTypeId (void) {

    std::ostringstream oss;

    oss << "anon::ATestTrailer<" << N << ">";

    static TypeId tid = TypeId (oss.str ().c_str ())

      .SetParent<Header> ()

      .AddConstructor<ATestTrailer<N> > ()

      .HideFromDocumentation ()

      ;

    return tid;

  }

  virtual TypeId GetInstanceTypeId (void) const {

    return GetTypeId ();

  }

  virtual uint32_t GetSerializedSize (void) const {

    return N;

  }

  virtual void Serialize (Buffer::Iterator iter) const {

    iter.Prev (N);

    for (uint32_t i = 0; i < N; ++i)

      {

        iter.WriteU8 (N);

      }

  }

  virtual uint32_t Deserialize (Buffer::Iterator iter) {

    iter.Prev (N);

    for (uint32_t i = 0; i < N; ++i)

      {

        uint8_t v = iter.ReadU8 ();

        if (v != N)

          {

            m_error = true;

          }

      }

    return N;

  }

  virtual void Print (std::ostream &os) const {

  }

  ATestTrailer ()

    : ATestTrailerBase () {}

};

struct Expected

{

  Expected (uint32_t n_, uint32_t start_, uint32_t end_)

    : n (n_), start (start_), end (end_) {}

  uint32_t n;

  uint32_t start;

  uint32_t end;

};

}

// tag name, start, end

#define E(a,b,c) a,b,c

#define CHECK(p, n, ...)                                \

  DoCheck (p, __FILE__, __LINE__, n, __VA_ARGS__)

class PacketTest: public TestCase 

{

public:

  PacketTest ();

  virtual bool DoRun (void);

private:

  void DoCheck (Ptr<const Packet> p, const char *file, int line, uint32_t n, ...);

};

PacketTest::PacketTest ()

  : TestCase ("Packet") {}

void

PacketTest::DoCheck (Ptr<const Packet> p, const char *file, int line, uint32_t n, ...)

{

  std::vector<struct Expected> expected;

  va_list ap;

  va_start (ap, n);

  for (uint32_t k = 0; k < n; ++k)

    {

      uint32_t N = va_arg (ap, uint32_t);

      uint32_t start = va_arg (ap, uint32_t);

      uint32_t end = va_arg (ap, uint32_t);

      expected.push_back (Expected (N, start, end));

    }

  va_end (ap);

  ByteTagIterator i = p->GetByteTagIterator ();

  uint32_t j = 0;

  while (i.HasNext () && j < expected.size ())

    {

      ByteTagIterator::Item item = i.Next ();

      struct Expected e = expected[j];

      std::ostringstream oss;

      oss << "anon::ATestTag<" << e.n << ">";

      NS_TEST_EXPECT_MSG_EQ_INTERNAL (item.GetTypeId ().GetName (), oss.str (), "trivial", file, line);

      NS_TEST_EXPECT_MSG_EQ_INTERNAL (item.GetStart (), e.start, "trivial", file, line);

      NS_TEST_EXPECT_MSG_EQ_INTERNAL (item.GetEnd (), e.end, "trivial", file, line);

      ATestTagBase *tag = dynamic_cast<ATestTagBase *> (item.GetTypeId ().GetConstructor () ());

      NS_TEST_EXPECT_MSG_NE (tag, 0, "trivial");

      item.GetTag (*tag);

      NS_TEST_EXPECT_MSG_EQ (tag->m_error, false, "trivial");

      delete tag;

      j++;

    }

  NS_TEST_EXPECT_MSG_EQ (i.HasNext (), false, "Nothing left");

  NS_TEST_EXPECT_MSG_EQ (j, expected.size (), "Size match");

}

bool

PacketTest::DoRun (void)

{

  Ptr<Packet> pkt1 = Create<Packet> (reinterpret_cast<const uint8_t*> ("hello"), 5);

  Ptr<Packet> pkt2 = Create<Packet> (reinterpret_cast<const uint8_t*> (" world"), 6);

  Ptr<Packet> packet = Create<Packet> ();

  packet->AddAtEnd (pkt1);

  packet->AddAtEnd (pkt2);

  NS_TEST_EXPECT_MSG_EQ (packet->GetSize (), 11, "trivial");

  std::string msg = std::string (reinterpret_cast<const char *>(packet->PeekData ()),

                                 packet->GetSize ());

  NS_TEST_EXPECT_MSG_EQ (msg, "hello world", "trivial");

  Ptr<const Packet> p = Create<Packet> (1000);

  p->AddByteTag (ATestTag<1> ());

  CHECK (p, 1, E (1, 0, 1000));

  Ptr<const Packet> copy = p->Copy ();

  CHECK (copy, 1, E (1, 0, 1000));

  p->AddByteTag (ATestTag<2> ());

  CHECK (p, 2, E (1, 0, 1000), E(2, 0, 1000));

  CHECK (copy, 1, E (1, 0, 1000));

  {

    Packet c0 = *copy;

    Packet c1 = *copy;

    c0 = c1;

    CHECK (&c0, 1, E (1, 0, 1000));

    CHECK (&c1, 1, E (1, 0, 1000));

    CHECK (copy, 1, E (1, 0, 1000));

    c0.AddByteTag (ATestTag<10> ());

    CHECK (&c0, 2, E (1, 0, 1000), E (10, 0, 1000));

    CHECK (&c1, 1, E (1, 0, 1000));

    CHECK (copy, 1, E (1, 0, 1000));

  }

  Ptr<Packet> frag0 = p->CreateFragment (0, 10);

  Ptr<Packet> frag1 = p->CreateFragment (10, 90);

  Ptr<const Packet> frag2 = p->CreateFragment (100, 900);

  frag0->AddByteTag (ATestTag<3> ());

  CHECK (frag0, 3, E (1, 0, 10), E(2, 0, 10), E (3, 0, 10));

  frag1->AddByteTag (ATestTag<4> ());

  CHECK (frag1, 3, E (1, 0, 90), E(2, 0, 90), E (4, 0, 90));

  frag2->AddByteTag (ATestTag<5> ());

  CHECK (frag2, 3, E (1, 0, 900), E(2, 0, 900), E (5, 0, 900));

  frag1->AddAtEnd (frag2);

  CHECK (frag1, 6, E (1, 0, 90), E(2, 0, 90), E (4, 0, 90), E (1, 90, 990), E(2, 90, 990), E (5, 90, 990));

  CHECK (frag0, 3, E (1, 0, 10), E(2, 0, 10), E (3, 0, 10));

  frag0->AddAtEnd (frag1);

  CHECK (frag0, 9, 

         E (1, 0, 10), E(2, 0, 10), E (3, 0, 10),

         E (1, 10, 100), E(2, 10, 100), E (4, 10, 100), 

         E (1, 100, 1000), E(2, 100, 1000), E (5, 100, 1000));

  // force caching a buffer of the right size.

  frag0 = Create<Packet> (1000);

  frag0->AddHeader (ATestHeader<10> ());

  frag0 = 0;

  p = Create<Packet> (1000);

  p->AddByteTag (ATestTag<20> ());

  CHECK (p, 1, E (20, 0, 1000));

  frag0 = p->CreateFragment (10, 90);

  CHECK (p, 1, E (20, 0, 1000));

  CHECK (frag0, 1, E (20, 0, 90));

  p = 0;

  frag0->AddHeader (ATestHeader<10> ());

  CHECK (frag0, 1, E (20, 10, 100));