# HG changeset patch
# User Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
# Date 1181213332 -7200
# Node ID 777fcfabc1c8040d0e40893b83b6546f412c9a4b
# Parent  62901fdaeb6826e1f59a6c040e53373550cba066
rename packet-history.h to packet-metadata.h

diff -r 62901fdaeb68 -r 777fcfabc1c8 SConstruct
--- a/SConstruct	Thu Jun 07 12:44:44 2007 +0200
+++ b/SConstruct	Thu Jun 07 12:48:52 2007 +0200
@@ -189,7 +189,7 @@
     'header.cc',
     'trailer.cc',
     'packet-printer.cc',
-    'packet-history.cc',
+    'packet-metadata.cc',
     'packet.cc',
     'tags.cc',
     'pcap-writer.cc',
@@ -212,7 +212,7 @@
     'tags.h',
     'packet.h',
     'packet-printer.h',
-    'packet-history.h',
+    'packet-metadata.h',
     'uv-trace-source.h',
     'sv-trace-source.h',
     'fv-trace-source.h',
diff -r 62901fdaeb68 -r 777fcfabc1c8 src/common/packet-history.cc
--- a/src/common/packet-history.cc	Thu Jun 07 12:44:44 2007 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1631 +0,0 @@
-/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/*
- * Copyright (c) 2006,2007 INRIA
- * All rights reserved.
- *
- * 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 <utility>
-#include <list>
-#include "ns3/assert.h"
-#include "ns3/fatal-error.h"
-#include "ns3/debug.h"
-#include "packet-history.h"
-#include "chunk.h"
-#include "buffer.h"
-
-NS_DEBUG_COMPONENT_DEFINE ("PacketHistory");
-
-namespace ns3 {
-
-bool PacketHistory::m_enable = false;
-uint32_t PacketHistory::m_maxSize = 0;
-uint16_t PacketHistory::m_chunkUid = 0;
-PacketHistory::DataFreeList PacketHistory::m_freeList;
-bool g_optOne = false;
-
-void 
-PacketHistory::Enable (void)
-{
-  m_enable = true;
-}
-
-void 
-PacketHistory::SetOptOne (bool optOne)
-{
-  g_optOne = optOne;
-}
-
-void
-PacketHistory::ReserveCopy (uint32_t size)
-{
-  struct PacketHistory::Data *newData = PacketHistory::Create (m_used + size);
-  memcpy (newData->m_data, m_data->m_data, m_used);
-  newData->m_dirtyEnd = m_used;
-  m_data->m_count--;
-  if (m_data->m_count == 0) 
-    {
-      PacketHistory::Recycle (m_data);
-    }
-  m_data = newData;
-  if (m_head != 0xffff)
-    {
-      uint8_t *start;
-      NS_ASSERT (m_tail != 0xffff);
-      // clear the next field of the tail
-      start = &m_data->m_data[m_tail];
-      Append16 (0xffff, start);
-      // clear the prev field of the head
-      start = &m_data->m_data[m_head] + 2;
-      Append16 (0xffff, start);
-    }
-}
-void
-PacketHistory::Reserve (uint32_t size)
-{
-  NS_ASSERT (m_data != 0);
-  if (m_data->m_size >= m_used + size &&
-      (m_head == 0xffff ||
-       m_data->m_count == 1 ||
-       m_data->m_dirtyEnd == m_used))
-    {
-      /* enough room, not dirty. */
-    }
-  else 
-    {
-      /* (enough room and dirty) or (not enough room) */
-      ReserveCopy (size);
-    }
-}
-
-uint32_t 
-PacketHistory::GetUleb128Size (uint32_t value) const
-{
-  if (value < 0x80)
-    {
-      return 1;
-    }
-  if (value < 0x4000)
-    {
-      return 2;
-    }
-  if (value < 0x200000)
-    {
-      return 3;
-    }
-  if (value < 0x10000000)
-    {
-      return 4;
-    }
-  return 5;
-}
-uint32_t
-PacketHistory::ReadUleb128 (const uint8_t **pBuffer) const
-{
-  const uint8_t *buffer = *pBuffer;
-  uint32_t result = 0;
-  uint8_t byte;
-  result = 0;
-  byte = buffer[0];
-  result = (byte & (~0x80));
-  if (!(byte & 0x80))
-    {
-      *pBuffer = buffer + 1;
-      return result;
-    }
-  byte = buffer[1];
-  result = (byte & (~0x80)) << 7;
-  if (!(byte & 0x80))
-    {
-      *pBuffer = buffer + 2;
-      return result;
-    }
-  byte = buffer[2];
-  result = (byte & (~0x80)) << 14;
-  if (!(byte & 0x80))
-    {
-      *pBuffer = buffer + 3;
-      return result;
-    }
-  byte = buffer[3];
-  result = (byte & (~0x80)) << 21;
-  if (!(byte & 0x80))
-    {
-      *pBuffer = buffer + 4;
-      return result;
-    }
-  byte = buffer[4];
-  result = (byte & (~0x80)) << 28;
-  if (!(byte & 0x80))
-    {
-      *pBuffer = buffer + 5;
-      return result;
-    }
-  /* This means that the LEB128 number was not valid.
-   * ie: the last (5th) byte did not have the high-order bit zeroed.
-   */
-  NS_ASSERT (false);
-  return 0;
-}
-
-void
-PacketHistory::Append16 (uint16_t value, uint8_t *buffer)
-{
-  buffer[0] = value & 0xff;
-  value >>= 8;
-  buffer[1] = value;
-}
-bool
-PacketHistory::TryToAppendFast (uint32_t value, uint8_t **pBuffer, uint8_t *end)
-{
-  uint8_t *start = *pBuffer;
-  if (value < 0x80 && start < end)
-    {
-      start[0] = value;
-      *pBuffer = start + 1;
-      return true;
-    }
-  if (value < 0x4000 && start + 1 < end)
-    {
-      uint8_t byte = value & (~0x80);
-      start[0] = 0x80 | byte;
-      value >>= 7;
-      start[1] = value;
-      *pBuffer = start + 2;
-      return true;
-    }
-  return false;
-}
-bool
-PacketHistory::TryToAppend16 (uint16_t value,  uint8_t **pBuffer, uint8_t *end)
-{
-  uint8_t *start = *pBuffer;
-  if (start + 1 < end)
-    {
-      start[0] = value & 0xff;
-      start[1] = value >> 8;
-      *pBuffer = start + 2;
-      return true;
-    }
-  return false;
-}
-bool
-PacketHistory::TryToAppend32 (uint32_t value,  uint8_t **pBuffer, uint8_t *end)
-{
-  uint8_t *start = *pBuffer;
-  if (start + 3 < end)
-    {
-      start[0] = value & 0xff;
-      start[1] = (value >> 8) & 0xff;
-      start[2] = (value >> 16) & 0xff;
-      start[3] = (value >> 24) & 0xff;
-      *pBuffer = start + 4;
-      return true;
-    }
-  return false;
-}
-bool
-PacketHistory::TryToAppend (uint32_t value, uint8_t **pBuffer, uint8_t *end)
-{
-  uint8_t *start = *pBuffer;
-  if (value < 0x80 && start < end)
-    {
-      start[0] = value;
-      *pBuffer = start + 1;
-      return true;
-    }
-  if (value < 0x4000 && start + 1 < end)
-    {
-      uint8_t byte = value & (~0x80);
-      start[0] = 0x80 | byte;
-      value >>= 7;
-      start[1] = value;
-      *pBuffer = start + 2;
-      return true;
-    }
-  if (value < 0x200000 && start + 2 < end)
-    {
-      uint8_t byte = value & (~0x80);
-      start[0] = 0x80 | byte;
-      value >>= 7;
-      byte = value & (~0x80);
-      start[1] = 0x80 | byte;
-      value >>= 7;
-      byte = value & (~0x80);
-      start[2] = value;
-      *pBuffer = start + 3;
-      return true;
-    }
-  if (value < 0x10000000 && start + 3 < end)
-    {
-      uint8_t byte = value & (~0x80);
-      start[0] = 0x80 | byte;
-      value >>= 7;
-      byte = value & (~0x80);
-      start[1] = 0x80 | byte;
-      value >>= 7;
-      byte = value & (~0x80);
-      start[2] = 0x80 | byte;
-      value >>= 7;
-      start[3] = value;
-      *pBuffer = start + 4;
-      return true;
-    }
-  if (start + 4 < end)
-    {
-      uint8_t byte = value & (~0x80);
-      start[0] = 0x80 | byte;
-      value >>= 7;
-      byte = value & (~0x80);
-      start[1] = 0x80 | byte;
-      value >>= 7;
-      byte = value & (~0x80);
-      start[2] = 0x80 | byte;
-      value >>= 7;
-      byte = value & (~0x80);
-      start[3] = 0x80 | byte;
-      value >>= 7;
-      start[4] = value;
-      *pBuffer = start + 5;
-      return true;
-    }
-  return false;
-}
-
-void
-PacketHistory::AppendValueExtra (uint32_t value, uint8_t *buffer)
-{
-  if (value < 0x200000)
-    {
-      uint8_t byte = value & (~0x80);
-      buffer[0] = 0x80 | byte;
-      value >>= 7;
-      byte = value & (~0x80);
-      buffer[1] = 0x80 | byte;
-      value >>= 7;
-      byte = value & (~0x80);
-      buffer[2] = value;
-      return;
-    }
-  if (value < 0x10000000)
-    {
-      uint8_t byte = value & (~0x80);
-      buffer[0] = 0x80 | byte;
-      value >>= 7;
-      byte = value & (~0x80);
-      buffer[1] = 0x80 | byte;
-      value >>= 7;
-      byte = value & (~0x80);
-      buffer[2] = 0x80 | byte;
-      value >>= 7;
-      buffer[3] = value;
-      return;
-    }
-  {
-    uint8_t byte = value & (~0x80);
-    buffer[0] = 0x80 | byte;
-    value >>= 7;
-    byte = value & (~0x80);
-    buffer[1] = 0x80 | byte;
-    value >>= 7;
-    byte = value & (~0x80);
-    buffer[2] = 0x80 | byte;
-    value >>= 7;
-    byte = value & (~0x80);
-    buffer[3] = 0x80 | byte;
-    value >>= 7;
-    buffer[4] = value;
-  }
-}
-
-void
-PacketHistory::AppendValue (uint32_t value, uint8_t *buffer)
-{
-  if (value < 0x80)
-    {
-      buffer[0] = value;
-      return;
-    }
-  if (value < 0x4000)
-    {
-      uint8_t byte = value & (~0x80);
-      buffer[0] = 0x80 | byte;
-      value >>= 7;
-      buffer[1] = value;
-      return;
-    }
-  AppendValueExtra (value, buffer);
-}
-
-void
-PacketHistory::UpdateTail (uint16_t written)
-{
-  if (m_head == 0xffff)
-    {
-      NS_ASSERT (m_tail == 0xffff);
-      m_head = m_used;
-      m_tail = m_used;
-    } 
-  else
-    {
-      NS_ASSERT (m_tail != 0xffff);
-      // overwrite the next field of the previous tail of the list.
-      uint8_t *previousTail = &m_data->m_data[m_tail];
-      Append16 (m_used, previousTail);
-      // update the tail of the list to the new node.
-      m_tail = m_used;
-    }
-  NS_ASSERT (m_tail != 0xffff);
-  NS_ASSERT (m_head != 0xffff);
-  m_used += written;
-  m_data->m_dirtyEnd = m_used;
-}
-
-
-void
-PacketHistory::UpdateHead (uint16_t written)
-{
-  if (m_head == 0xffff)
-    {
-      NS_ASSERT (m_tail == 0xffff);
-      m_head = m_used;
-      m_tail = m_used;
-    } 
-  else
-    {
-      NS_ASSERT (m_head != 0xffff);
-      // overwrite the prev field of the previous head of the list.
-      uint8_t *previousHead = &m_data->m_data[m_head + 2];
-      Append16 (m_used, previousHead);
-      // update the head of list to the new node.
-      m_head = m_used;
-    }
-  NS_ASSERT (m_tail != 0xffff);
-  NS_ASSERT (m_head != 0xffff);
-  m_used += written;
-  m_data->m_dirtyEnd = m_used;
-}
-
-uint16_t
-PacketHistory::AddSmall (const struct PacketHistory::SmallItem *item)
-{
-  NS_ASSERT (m_data != 0);
-  if (g_optOne)
-    {
-      uint32_t typeUidSize = GetUleb128Size (item->typeUid);
-      uint32_t sizeSize = GetUleb128Size (item->size);
-      uint32_t n = typeUidSize + sizeSize + 2 + 2 + 2;
-    restart:
-      if (m_used + n <= m_data->m_size &&
-      (m_head == 0xffff ||
-       m_data->m_count == 1 ||
-       m_used == m_data->m_dirtyEnd))
-        {
-          uint8_t *buffer = &m_data->m_data[m_used];
-          Append16 (item->next, buffer);
-          buffer += 2;
-          Append16 (item->prev, buffer);
-          buffer += 2;
-          AppendValue (item->typeUid, buffer);
-          buffer += typeUidSize;
-          AppendValue (item->size, buffer);
-          buffer += sizeSize;
-          Append16 (item->chunkUid, buffer);
-        }
-      else
-        {
-          ReserveCopy (n);
-          goto restart;
-        }
-      return n;
-    }
- append:
-  uint8_t *start = &m_data->m_data[m_used];
-  uint8_t *end = &m_data->m_data[m_data->m_size];
-  if (end - start >= 8 &&
-      (m_head == 0xffff ||
-       m_data->m_count == 1 ||
-       m_used == m_data->m_dirtyEnd))
-    {
-      uint8_t *buffer = start;
-
-      Append16 (item->next, buffer);
-      buffer += 2;
-      Append16 (item->prev, buffer);
-      buffer += 2;
-      if (TryToAppendFast (item->typeUid, &buffer, end) &&
-          TryToAppendFast (item->size, &buffer, end) &&
-          TryToAppend16 (item->chunkUid, &buffer, end))
-        {
-          uintptr_t written = buffer - start;
-          NS_ASSERT (written <= 0xffff);
-          return written;
-        }
-    }
-  uint32_t n = GetUleb128Size (item->typeUid);
-  n += GetUleb128Size (item->size);
-  n += 2;
-  n += 2 + 2;
-  Reserve (n);
-  goto append;
-}
-
-uint16_t
-PacketHistory::AddBig (uint32_t next, uint32_t prev, 
-                       const PacketHistory::SmallItem *item, 
-                       const PacketHistory::ExtraItem *extraItem)
-{
-  NS_ASSERT (m_data != 0);
-  uint32_t typeUid = ((item->typeUid & 0x1) == 0x1)?item->typeUid:item->typeUid+1;
- append:
-  uint8_t *start = &m_data->m_data[m_used];
-  uint8_t *end = &m_data->m_data[m_data->m_size];
-  if (end - start >= 14 &&
-      (m_head == 0xffff ||
-       m_data->m_count == 1 ||
-       m_used == m_data->m_dirtyEnd))
-    {
-      uint8_t *buffer = start;
-
-      Append16 (next, buffer);
-      buffer += 2;
-      Append16 (prev, buffer);
-      buffer += 2;
-      if (TryToAppend (typeUid, &buffer, end) &&
-          TryToAppend (item->size, &buffer, end) &&
-          TryToAppend16 (item->chunkUid, &buffer, end) &&
-          TryToAppend (extraItem->fragmentStart, &buffer, end) &&
-          TryToAppend (extraItem->fragmentEnd, &buffer, end) &&
-          TryToAppend32 (extraItem->packetUid, &buffer, end))
-        {
-          uintptr_t written = buffer - start;
-          NS_ASSERT (written <= 0xffff);
-          return written;
-        }
-    }
-
-  uint32_t n = GetUleb128Size (typeUid);
-  n += GetUleb128Size (item->size);
-  n += 2;
-  n += GetUleb128Size (extraItem->fragmentStart);
-  n += GetUleb128Size (extraItem->fragmentEnd);
-  n += 4;
-  n += 2 + 2;
-  ReserveCopy (n);
-  goto append;
-}
-
-void
-PacketHistory::ReplaceTail (PacketHistory::SmallItem *item, 
-                            PacketHistory::ExtraItem *extraItem,
-                            uint32_t available)
-{
-  NS_ASSERT (m_data != 0);  
-  if (available >= 14 &&
-      m_data->m_count == 1)
-    {
-      uint8_t *buffer = &m_data->m_data[m_tail];
-      uint8_t *end = buffer + available;
-
-      Append16 (item->next, buffer);
-      buffer += 2;
-      Append16 (item->prev, buffer);
-      buffer += 2;
-      if (TryToAppend (item->typeUid, &buffer, end) &&
-          TryToAppend (item->size, &buffer, end) &&
-          TryToAppend16 (item->chunkUid, &buffer, end) &&
-          TryToAppend (extraItem->fragmentStart, &buffer, end) &&
-          TryToAppend (extraItem->fragmentEnd, &buffer, end) &&
-          TryToAppend32 (extraItem->packetUid, &buffer, end))
-        {
-          m_used = buffer - &m_data->m_data[0];
-          m_data->m_dirtyEnd = m_used;
-          return;
-        }
-    }
-  
-  // create a copy of the packet.
-  PacketHistory h (m_packetUid, 0);
-  uint16_t current = m_head;
-  while (current != 0xffff && current != m_tail)
-    {
-      struct PacketHistory::SmallItem tmpItem;
-      PacketHistory::ExtraItem tmpExtraItem;
-      ReadItems (current, &tmpItem, &tmpExtraItem);
-      uint16_t written = h.AddBig (0xffff, h.m_tail, 
-                                   &tmpItem, &tmpExtraItem);
-      h.UpdateTail (written);
-    }
-  // append new tail.
-  uint16_t written = h.AddBig (0xffff, h.m_tail, item, extraItem);
-  h.UpdateTail (written);
-
-  *this = h;
-}
-
-uint32_t
-PacketHistory::ReadItems (uint16_t current, 
-                          struct PacketHistory::SmallItem *item,
-                          struct PacketHistory::ExtraItem *extraItem) const
-{
-  const uint8_t *buffer = &m_data->m_data[current];
-  item->next = buffer[0];
-  item->next |= (buffer[1]) << 8;
-  item->prev = buffer[2];
-  item->prev |= (buffer[3]) << 8;
-  buffer += 4;
-  item->typeUid = ReadUleb128 (&buffer);
-  item->size = ReadUleb128 (&buffer);
-  item->chunkUid = buffer[0];
-  item->chunkUid |= (buffer[1]) << 8;
-  buffer += 2;
-
-  bool isExtra = (item->typeUid & 0x1) == 0x1;
-  if (isExtra)
-    {
-      extraItem->fragmentStart = ReadUleb128 (&buffer);
-      extraItem->fragmentEnd = ReadUleb128 (&buffer);
-      extraItem->packetUid = buffer[0];
-      extraItem->packetUid |= buffer[1] << 8;
-      extraItem->packetUid |= buffer[2] << 16;
-      extraItem->packetUid |= buffer[3] << 24;
-      buffer += 4;
-    }
-  else
-    {
-      extraItem->fragmentStart = 0;
-      extraItem->fragmentEnd = item->size;
-      extraItem->packetUid = m_packetUid;
-    }
-  NS_ASSERT (buffer <= &m_data->m_data[m_data->m_size]);
-  return buffer - &m_data->m_data[current];
-}
-
-struct PacketHistory::Data *
-PacketHistory::Create (uint32_t size)
-{
-  NS_DEBUG ("create size="<<size<<", max="<<m_maxSize);
-  if (size > m_maxSize)
-    {
-      m_maxSize = size;
-    }
-  while (!m_freeList.empty ()) 
-    {
-      struct PacketHistory::Data *data = m_freeList.back ();
-      m_freeList.pop_back ();
-      if (data->m_size >= size) 
-        {
-          NS_DEBUG ("create found size="<<data->m_size);
-          data->m_count = 1;
-          return data;
-        }
-      PacketHistory::Deallocate (data);
-      NS_DEBUG ("create dealloc size="<<data->m_size);
-    }
-  NS_DEBUG ("create alloc size="<<m_maxSize);
-  return PacketHistory::Allocate (m_maxSize);
-}
-
-void
-PacketHistory::Recycle (struct PacketHistory::Data *data)
-{
-  NS_DEBUG ("recycle size="<<data->m_size<<", list="<<m_freeList.size ());
-  NS_ASSERT (data->m_count == 0);
-  if (m_freeList.size () > 1000 ||
-      data->m_size < m_maxSize) 
-    {
-      PacketHistory::Deallocate (data);
-    } 
-  else 
-    {
-      m_freeList.push_back (data);
-    }
-}
-
-struct PacketHistory::Data *
-PacketHistory::Allocate (uint32_t n)
-{
-  uint32_t size = sizeof (struct Data);
-  if (n <= 10)
-    {
-      n = 10;
-    }
-  size += n - 10;
-  uint8_t *buf = new uint8_t [size];
-  struct PacketHistory::Data *data = (struct PacketHistory::Data *)buf;
-  data->m_size = n;
-  data->m_count = 1;
-  data->m_dirtyEnd = 0;
-  return data;
-}
-void 
-PacketHistory::Deallocate (struct PacketHistory::Data *data)
-{
-  uint8_t *buf = (uint8_t *)data;
-  delete [] buf;
-}
-
-
-PacketHistory 
-PacketHistory::CreateFragment (uint32_t start, uint32_t end) const
-{
-  PacketHistory fragment = *this;
-  fragment.RemoveAtStart (start);
-  fragment.RemoveAtEnd (end);
-  return fragment;
-}
-
-void 
-PacketHistory::DoAddHeader (uint32_t uid, uint32_t size)
-{
-  if (!m_enable)
-    {
-      return;
-    }
-  struct PacketHistory::SmallItem item;
-  item.next = m_head;
-  item.prev = 0xffff;
-  item.typeUid = uid;
-  item.size = size;
-  item.chunkUid = m_chunkUid;
-  m_chunkUid++;
-  uint16_t written = AddSmall (&item);
-  UpdateHead (written);
-}
-void 
-PacketHistory::DoRemoveHeader (uint32_t uid, uint32_t size)
-{
-  if (!m_enable) 
-    {
-      return;
-    }
-  struct PacketHistory::SmallItem item;
-  struct PacketHistory::ExtraItem extraItem;
-  ReadItems (m_head, &item, &extraItem);
-  if ((item.typeUid & 0xfffffffe) != uid ||
-      item.size != size)
-    {
-      NS_FATAL_ERROR ("Removing unexpected header.");
-    }
-  else if (item.typeUid != uid &&
-           (extraItem.fragmentStart != 0 ||
-            extraItem.fragmentEnd != size))
-    {
-      NS_FATAL_ERROR ("Removing incomplete header.");
-    }
-  m_head = item.next;
-  if (m_head > m_tail)
-    {
-      m_used = m_head;
-    }
-}
-void 
-PacketHistory::DoAddTrailer (uint32_t uid, uint32_t size)
-{
-  if (!m_enable)
-    {
-      return;
-    }
-  struct PacketHistory::SmallItem item;
-  item.next = 0xffff;
-  item.prev = m_tail;
-  item.typeUid = uid;
-  item.size = size;
-  item.chunkUid = m_chunkUid;
-  m_chunkUid++;
-  uint16_t written = AddSmall (&item);
-  UpdateTail (written);
-}
-void 
-PacketHistory::DoRemoveTrailer (uint32_t uid, uint32_t size)
-{
-  if (!m_enable) 
-    {
-      return;
-    }
-  struct PacketHistory::SmallItem item;
-  struct PacketHistory::ExtraItem extraItem;
-  ReadItems (m_tail, &item, &extraItem);
-  if ((item.typeUid & 0xfffffffe) != uid ||
-      item.size != size)
-    {
-      NS_FATAL_ERROR ("Removing unexpected trailer.");
-    }
-  else if (item.typeUid != uid &&
-           (extraItem.fragmentStart != 0 ||
-            extraItem.fragmentEnd != size))
-    {
-      NS_FATAL_ERROR ("Removing incomplete trailer.");
-    }
-  m_tail = item.prev;
-  if (m_tail > m_head)
-    {
-      m_used = m_tail;
-    }
-}
-void
-PacketHistory::AddAtEnd (PacketHistory const&o)
-{
-  if (!m_enable) 
-    {
-      return;
-    }
-  if (m_tail == 0xffff)
-    {
-      *this = o;
-      return;
-    }
-  NS_ASSERT (m_head != 0xffff && m_tail != 0xffff);
-
-  uint16_t lastTail;
-  lastTail = m_tail;
-  struct PacketHistory::SmallItem lastItem;
-  PacketHistory::ExtraItem lastExtraItem;
-  uint32_t lastTailSize = ReadItems (m_tail, &lastItem, &lastExtraItem);
-  if (m_tail + lastTailSize == m_used &&
-      m_used == m_data->m_dirtyEnd)
-    {
-      lastTailSize = m_data->m_size - m_tail;
-    }
-
-  uint16_t current = o.m_head;
-  while (current != 0xffff)
-    {
-      struct PacketHistory::SmallItem item;
-      PacketHistory::ExtraItem extraItem;
-      o.ReadItems (current, &item, &extraItem);
-      if (extraItem.packetUid == lastExtraItem.packetUid &&
-          item.typeUid == lastItem.typeUid &&
-          item.chunkUid == lastItem.chunkUid &&
-          item.size == lastItem.size &&
-          extraItem.fragmentStart == lastExtraItem.fragmentEnd)
-        {
-          // replace previous tail.
-          lastExtraItem.fragmentEnd = extraItem.fragmentEnd;
-          NS_ASSERT (m_tail == lastTail);
-          ReplaceTail (&lastItem, &lastExtraItem, lastTailSize);
-        }
-      else
-        {
-          // append the extra items.
-          uint16_t written = AddBig (0xffff, m_tail, &item, &extraItem);
-          UpdateTail (written);
-        }
-      if (current == o.m_tail)
-        {
-          break;
-        }
-      current = item.next;
-    }
-}
-void
-PacketHistory::AddPaddingAtEnd (uint32_t end)
-{
-  if (!m_enable)
-    {
-      return;
-    }
-}
-void 
-PacketHistory::RemoveAtStart (uint32_t start)
-{
-  if (!m_enable) 
-    {
-      return;
-    }
-  NS_ASSERT (m_data != 0);
-  uint32_t leftToRemove = start;
-  uint16_t current = m_head;
-  while (current != 0xffff && leftToRemove > 0)
-    {
-      struct PacketHistory::SmallItem item;
-      PacketHistory::ExtraItem extraItem;
-      ReadItems (current, &item, &extraItem);
-      uint32_t itemRealSize = extraItem.fragmentEnd - extraItem.fragmentStart;
-      if (itemRealSize <= leftToRemove)
-        {
-          // remove from list.
-          m_head = item.next;
-          leftToRemove -= itemRealSize;
-        }
-      else
-        {
-          // fragment the list item.
-          PacketHistory fragment (m_packetUid, 0);
-          extraItem.fragmentStart += leftToRemove;
-          leftToRemove = 0;
-          uint16_t written = fragment.AddBig (0xffff, fragment.m_tail,
-                                              &item, &extraItem);
-          fragment.UpdateTail (written);
-          current = item.next;
-          while (current != 0xffff)
-            {
-              ReadItems (current, &item, &extraItem);
-              written = fragment.AddBig (0xffff, fragment.m_tail,
-                                         &item, &extraItem);
-              fragment.UpdateTail (written);
-              if (current == m_tail)
-                {
-                  break;
-                }
-              current = item.next;
-            }
-          *this = fragment;
-        }
-      NS_ASSERT (item.size >= extraItem.fragmentEnd - extraItem.fragmentStart &&
-                 extraItem.fragmentStart <= extraItem.fragmentEnd);
-      if (current == m_tail)
-        {
-          break;
-        }
-      current = item.next;
-    }
-  NS_ASSERT (leftToRemove == 0);
-}
-void 
-PacketHistory::RemoveAtEnd (uint32_t end)
-{
-  if (!m_enable) 
-    {
-      return;
-    }
-  NS_ASSERT (m_data != 0);
-
-  uint32_t leftToRemove = end;
-  uint16_t current = m_tail;
-  while (current != 0xffff && leftToRemove > 0)
-    {
-      struct PacketHistory::SmallItem item;
-      PacketHistory::ExtraItem extraItem;
-      ReadItems (current, &item, &extraItem);
-      uint32_t itemRealSize = extraItem.fragmentEnd - extraItem.fragmentStart;
-      if (itemRealSize <= leftToRemove)
-        {
-          // remove from list.
-          m_tail = item.prev;
-          leftToRemove -= itemRealSize;
-        }
-      else
-        {
-          // fragment the list item.
-          PacketHistory fragment (m_packetUid, 0);
-          NS_ASSERT (extraItem.fragmentEnd > leftToRemove);
-          extraItem.fragmentEnd -= leftToRemove;
-          leftToRemove = 0;
-          uint16_t written = fragment.AddBig (fragment.m_head, 0xffff,
-                                              &item, &extraItem);
-          fragment.UpdateHead (written);
-          current = item.prev;
-          while (current != 0xffff)
-            {
-              ReadItems (current, &item, &extraItem);
-              written = fragment.AddBig (fragment.m_head, 0xffff,
-                                         &item, &extraItem);
-              fragment.UpdateHead (written);
-              if (current == m_head)
-                {
-                  break;
-                }
-              current = item.prev;
-            }
-          *this = fragment;
-        }
-      NS_ASSERT (item.size >= extraItem.fragmentEnd - extraItem.fragmentStart &&
-                 extraItem.fragmentStart <= extraItem.fragmentEnd);
-      if (current == m_head)
-        {
-          break;
-        }
-      current = item.prev;
-    }
-  NS_ASSERT (leftToRemove == 0);
-}
-
-void 
-PacketHistory::PrintDefault (std::ostream &os, Buffer buffer) const
-{
-  Print (os, buffer, PacketPrinter::GetDefault ());
-}
-
-uint32_t
-PacketHistory::DoPrint (struct PacketHistory::SmallItem *item, uint32_t current,
-                        Buffer data, uint32_t offset, const PacketPrinter &printer,
-                        std::ostream &os) const
-{
-  PacketHistory::ExtraItem extraItem;
-  ReadItems (current, item, &extraItem);
-  uint32_t uid = item->typeUid & 0xfffffffe;
-  if (uid == 0)
-    {
-      // payload.
-      printer.PrintPayload (os, extraItem.packetUid, item->size, 
-                            extraItem.fragmentStart, 
-                            extraItem.fragmentEnd);
-    }
-  else if (extraItem.fragmentStart != 0 ||
-           extraItem.fragmentEnd != item->size)
-    {
-      printer.PrintChunkFragment (uid, os, extraItem.packetUid, item->size, 
-                                  extraItem.fragmentStart, extraItem.fragmentEnd);
-    }
-  else if (PacketPrinter::IsHeader (uid))
-    {
-      ns3::Buffer::Iterator j = data.Begin ();
-      j.Next (offset);
-      printer.PrintChunk (uid, j, os, extraItem.packetUid, item->size);
-    }
-  else if (PacketPrinter::IsTrailer (uid))
-    {
-      ns3::Buffer::Iterator j = data.End ();
-      j.Prev (data.GetSize () - (offset + item->size));
-      printer.PrintChunk (uid, j, os, extraItem.packetUid, item->size);
-    }
-  else 
-    {
-      NS_ASSERT (false);
-    }
-  return extraItem.fragmentEnd - extraItem.fragmentStart;
-}
-
-uint32_t
-PacketHistory::GetTotalSize (void) const
-{
-  uint32_t totalSize = 0;
-  uint16_t current = m_head;
-  uint16_t tail = m_tail;
-  while (current != 0xffff)
-    {
-      struct PacketHistory::SmallItem item;
-      PacketHistory::ExtraItem extraItem;
-      ReadItems (current, &item, &extraItem);
-      totalSize += extraItem.fragmentEnd - extraItem.fragmentStart;
-      if (current == tail)
-        {
-          break;
-        }
-      current = item.next;
-    }
-  return totalSize;
-}
-
-void
-PacketHistory::Print (std::ostream &os, Buffer data, const PacketPrinter &printer) const
-{
-  if (!m_enable) 
-    {
-      return;
-    }
-  NS_ASSERT (m_data != 0);
-  NS_ASSERT (GetTotalSize () == data.GetSize ());
-  if (printer.m_forward)
-    {
-      uint32_t tail = m_tail;
-      uint32_t head = m_head;
-      uint32_t current = head;
-      uint32_t offset = 0;
-      while (current != 0xffff)
-        {
-          struct PacketHistory::SmallItem item;
-          uint32_t realSize = DoPrint (&item, current, data, offset, printer, os);
-          offset += realSize;
-          if (current == tail)
-            {
-              break;
-            }
-          current = item.next;
-        }
-    }
-  else
-    {
-      uint32_t head = m_head;
-      uint32_t tail = m_tail;
-      uint32_t current = head;
-      uint32_t offset = 0;
-      while (current != 0xffff)
-        {
-          struct PacketHistory::SmallItem item;
-          uint32_t realSize = DoPrint (&item, current, data, offset, printer, os);
-          offset -= realSize;
-          if (current == tail)
-            {
-              break;
-            }
-          current = item.prev;
-        }
-    }
-}
-
-
-
-}; // namespace ns3
-
-#include <stdarg.h>
-#include <iostream>
-#include <sstream>
-#include "ns3/test.h"
-#include "header.h"
-#include "trailer.h"
-#include "packet.h"
-
-namespace ns3 {
-
-template <int N>
-class HistoryHeader : public Header
-{
-public:
-  HistoryHeader ();
-  bool IsOk (void) const;
-private:
-  virtual std::string DoGetName (void) const;
-  virtual void PrintTo (std::ostream &os) const;
-  virtual uint32_t GetSerializedSize (void) const;
-  virtual void SerializeTo (Buffer::Iterator start) const;
-  virtual uint32_t DeserializeFrom (Buffer::Iterator start);
-  bool m_ok;
-};
-
-template <int N>
-HistoryHeader<N>::HistoryHeader ()
-  : m_ok (false)
-{}
-
-template <int N>
-bool 
-HistoryHeader<N>::IsOk (void) const
-{
-  return m_ok;
-}
-
-template <int N>
-std::string 
-HistoryHeader<N>::DoGetName (void) const
-{
-  std::ostringstream oss;
-  oss << N;
-  return oss.str ();
-}
-
-template <int N>
-void 
-HistoryHeader<N>::PrintTo (std::ostream &os) const
-{
-  NS_ASSERT (false);
-}
-template <int N>
-uint32_t 
-HistoryHeader<N>::GetSerializedSize (void) const
-{
-  return N;
-}
-template <int N>
-void 
-HistoryHeader<N>::SerializeTo (Buffer::Iterator start) const
-{
-  start.WriteU8 (N, N);
-}
-template <int N>
-uint32_t
-HistoryHeader<N>::DeserializeFrom (Buffer::Iterator start)
-{
-  m_ok = true;
-  for (int i = 0; i < N; i++)
-    {
-      if (start.ReadU8 () != N)
-        {
-          m_ok = false;
-        }
-    }
-  return N;
-}
-
-template <int N>
-class HistoryTrailer : public Trailer
-{
-public:
-  HistoryTrailer ();
-  bool IsOk (void) const;
-private:
-  virtual std::string DoGetName (void) const;
-  virtual void PrintTo (std::ostream &os) const;
-  virtual uint32_t GetSerializedSize (void) const;
-  virtual void SerializeTo (Buffer::Iterator start) const;
-  virtual uint32_t DeserializeFrom (Buffer::Iterator start);
-  bool m_ok;
-};
-
-template <int N>
-HistoryTrailer<N>::HistoryTrailer ()
-  : m_ok (false)
-{}
-
-template <int N>
-bool
-HistoryTrailer<N>::IsOk (void) const
-{
-  return m_ok;
-}
-
-template <int N>
-std::string 
-HistoryTrailer<N>::DoGetName (void) const
-{
-  std::ostringstream oss;
-  oss << N;
-  return oss.str ();
-}
-template <int N>
-void 
-HistoryTrailer<N>::PrintTo (std::ostream &os) const
-{
-  NS_ASSERT (false);
-}
-template <int N>
-uint32_t 
-HistoryTrailer<N>::GetSerializedSize (void) const
-{
-  return N;
-}
-template <int N>
-void 
-HistoryTrailer<N>::SerializeTo (Buffer::Iterator start) const
-{
-  start.Prev (N);
-  start.WriteU8 (N, N);
-}
-template <int N>
-uint32_t
-HistoryTrailer<N>::DeserializeFrom (Buffer::Iterator start)
-{
-  m_ok = true;
-  start.Prev (N);
-  for (int i = 0; i < N; i++)
-    {
-      if (start.ReadU8 () != N)
-        {
-          m_ok = false;
-        }
-    }
-  return N;
-}
-
-
-
-class PacketHistoryTest : public Test {
-public:
-  PacketHistoryTest ();
-  virtual ~PacketHistoryTest ();
-  bool CheckHistory (Packet p, char *file, int line, uint32_t n, ...);
-  virtual bool RunTests (void);
-private:
-  template <int N>
-  void PrintHeader (std::ostream &os, uint32_t packetUid, uint32_t size, const HistoryHeader<N> *header);
-  template <int N>
-  void PrintTrailer (std::ostream &os, uint32_t packetUid, uint32_t size, const HistoryTrailer<N> *trailer);
-  void PrintFragment (std::ostream &os,uint32_t packetUid,
-                      uint32_t size,std::string & name, 
-                      struct PacketPrinter::FragmentInformation info);
-  void PrintDefault (std::ostream& os,uint32_t packetUid,
-                     uint32_t size,std::string& name,
-                     struct PacketPrinter::FragmentInformation info);
-  void PrintPayload (std::ostream &os,uint32_t packetUid,
-                     uint32_t size,
-                     struct PacketPrinter::FragmentInformation info);
-  template <int N>
-  void RegisterHeader (void);
-  template <int N>
-  void RegisterTrailer (void);
-  void CleanupPrints (void);
-
-
-  bool m_headerError;
-  bool m_trailerError;
-  std::list<int> m_prints;
-  PacketPrinter m_printer;
-};
-
-PacketHistoryTest::PacketHistoryTest ()
-  : Test ("PacketHistory")
-{
-  m_printer.AddPayloadPrinter (MakeCallback (&PacketHistoryTest::PrintPayload, this));
-  m_printer.AddDefaultPrinter (MakeCallback (&PacketHistoryTest::PrintDefault, this));
-}
-
-PacketHistoryTest::~PacketHistoryTest ()
-{}
-
-template <int N>
-void 
-PacketHistoryTest::RegisterHeader (void)
-{
-  static bool registered = false;
-  if (!registered)
-    {
-      m_printer.AddHeaderPrinter (MakeCallback (&PacketHistoryTest::PrintHeader<N>, this),
-                                  MakeCallback (&PacketHistoryTest::PrintFragment, this));
-      registered = true;
-    }
-}
-
-template <int N>
-void 
-PacketHistoryTest::RegisterTrailer (void)
-{
-  static bool registered = false;
-  if (!registered)
-    {
-      m_printer.AddTrailerPrinter (MakeCallback (&PacketHistoryTest::PrintTrailer<N>, this),
-                                   MakeCallback (&PacketHistoryTest::PrintFragment, this));
-      registered = true;
-    }
-}
-
-
-template <int N>
-void 
-PacketHistoryTest::PrintHeader (std::ostream &os, uint32_t packetUid, uint32_t size, 
-                                const HistoryHeader<N> *header)
-{
-  if (!header->IsOk ())
-    {
-      m_headerError = true;
-    }
-  m_prints.push_back (N);
-}
-
-template <int N>
-void 
-PacketHistoryTest::PrintTrailer (std::ostream &os, uint32_t packetUid, uint32_t size, 
-                                 const HistoryTrailer<N> *trailer)
-{
-  if (!trailer->IsOk ())
-    {
-      m_trailerError = true;
-    }
-  m_prints.push_back (N);
-}
-void 
-PacketHistoryTest::PrintFragment (std::ostream &os,uint32_t packetUid,
-                                  uint32_t size,std::string & name, 
-                                  struct PacketPrinter::FragmentInformation info)
-{
-  m_prints.push_back (info.end - info.start);
-}
-void 
-PacketHistoryTest::PrintDefault (std::ostream& os,uint32_t packetUid,
-                     uint32_t size,std::string& name,
-                     struct PacketPrinter::FragmentInformation info)
-{
-  NS_ASSERT (false);
-}
-void 
-PacketHistoryTest::PrintPayload (std::ostream &os,uint32_t packetUid,
-                                 uint32_t size,
-                                 struct PacketPrinter::FragmentInformation info)
-{
-  m_prints.push_back (info.end - info.start);
-}
-
-
-void 
-PacketHistoryTest::CleanupPrints (void)
-{
-  m_prints.clear ();
-}
-
-bool 
-PacketHistoryTest::CheckHistory (Packet p, char *file, int line, uint32_t n, ...)
-{
-  m_headerError = false;
-  m_trailerError = false;
-  va_list ap;
-  p.Print (std::cerr, m_printer);
-  va_start (ap, n);
-  if (m_headerError)
-    {
-      std::cout << "PacketHistory header error. file=" << file 
-                << ", line=" << line << std::endl;
-      return false;
-    }
-  if (m_trailerError)
-    {
-      std::cout << "PacketHistory trailer error. file=" << file 
-                << ", line=" << line << std::endl;
-      return false;
-    }
-  if (n != m_prints.size ())
-    {
-      goto error;
-    }
-  for (std::list<int>::iterator i = m_prints.begin (); 
-       i != m_prints.end (); i++)
-    {
-      int v = va_arg (ap, int);
-      if (v != *i)
-        {
-          va_end (ap);
-          goto error;
-        }
-    }
-  va_end (ap);
-  return true;
- error:
-  std::cout << "PacketHistory error. file="<< file 
-            << ", line=" << line << ", got:\"";
-  for (std::list<int>::iterator i = m_prints.begin (); 
-       i != m_prints.end (); i++)
-    {
-      std::cout << *i << ", ";
-    }
-  std::cout << "\", expected: \"";
-  va_start (ap, n);
-  for (uint32_t j = 0; j < n; j++)
-    {
-      int v = va_arg (ap, int);
-      std::cout << v << ", ";
-    }
-  va_end (ap);
-  std::cout << "\"" << std::endl;
-  return false;
-}
-
-#define ADD_HEADER(p, n)                        \
-  {                                             \
-    HistoryHeader<n> header;                    \
-    RegisterHeader<n> ();                       \
-    p.AddHeader (header);                       \
-  }
-#define ADD_TRAILER(p, n)                       \
-  {                                             \
-    HistoryTrailer<n> trailer;                  \
-    RegisterTrailer<n> ();                      \
-    p.AddTrailer (trailer);                     \
-  }
-#define REM_HEADER(p, n)                        \
-  {                                             \
-    HistoryHeader<n> header;                    \
-    RegisterHeader<n> ();                       \
-    p.RemoveHeader (header);                    \
-  }
-#define REM_TRAILER(p, n)                       \
-  {                                             \
-    HistoryTrailer<n> trailer;                  \
-    RegisterTrailer<n> ();                      \
-    p.RemoveTrailer (trailer);                  \
-  }
-#define CHECK_HISTORY(p, ...)                   \
-  {                                             \
-    if (!CheckHistory (p, __FILE__,             \
-                      __LINE__, __VA_ARGS__))   \
-      {                                         \
-        ok = false;                             \
-      }                                         \
-    CleanupPrints ();                           \
-  }
-
-bool
-PacketHistoryTest::RunTests (void)
-{
-  bool ok = true;
-
-  PacketHistory::Enable ();
-
-  Packet p = Packet (0);
-  Packet p1 = Packet (0);
-
-  p = Packet (10);
-  ADD_TRAILER (p, 100);
-  CHECK_HISTORY (p, 2, 10, 100);
-
-  p = Packet (10);
-  ADD_HEADER (p, 1);
-  ADD_HEADER (p, 2);
-  ADD_HEADER (p, 3);
-  CHECK_HISTORY (p, 4, 
-                 3, 2, 1, 10);
-  ADD_HEADER (p, 5);
-  CHECK_HISTORY (p, 5, 
-                 5, 3, 2, 1, 10);
-  ADD_HEADER (p, 6);
-  CHECK_HISTORY (p, 6, 
-                 6, 5, 3, 2, 1, 10);
-
-  p = Packet (10);
-  ADD_HEADER (p, 1);
-  ADD_HEADER (p, 2);
-  ADD_HEADER (p, 3);
-  REM_HEADER (p, 3);
-  CHECK_HISTORY (p, 3, 
-                 2, 1, 10);
-
-  p = Packet (10);
-  ADD_HEADER (p, 1);
-  ADD_HEADER (p, 2);
-  ADD_HEADER (p, 3);
-  REM_HEADER (p, 3);
-  REM_HEADER (p, 2);
-  CHECK_HISTORY (p, 2, 
-                 1, 10);
-
-  p = Packet (10);
-  ADD_HEADER (p, 1);
-  ADD_HEADER (p, 2);
-  ADD_HEADER (p, 3);
-  REM_HEADER (p, 3);
-  REM_HEADER (p, 2);
-  REM_HEADER (p, 1);
-  CHECK_HISTORY (p, 1, 10);
-
-  p = Packet (10);
-  ADD_HEADER (p, 1);
-  ADD_HEADER (p, 2);
-  ADD_HEADER (p, 3);
-  p1 = p;
-  REM_HEADER (p1, 3);
-  REM_HEADER (p1, 2);
-  REM_HEADER (p1, 1);
-  CHECK_HISTORY (p1, 1, 10);
-  CHECK_HISTORY (p, 4, 
-                 3, 2, 1, 10);
-  ADD_HEADER (p1, 1);
-  ADD_HEADER (p1, 2);
-  CHECK_HISTORY (p1, 3, 
-                 2, 1, 10);
-  CHECK_HISTORY (p, 4, 
-                 3, 2, 1, 10);
-  ADD_HEADER (p, 3);
-  CHECK_HISTORY (p, 5, 
-                 3, 3, 2, 1, 10);
-  ADD_TRAILER (p, 4);
-  CHECK_HISTORY (p, 6, 
-                 3, 3, 2, 1, 10, 4);
-  ADD_TRAILER (p, 5);
-  CHECK_HISTORY (p, 7, 
-                 3, 3, 2, 1, 10, 4, 5);
-  REM_HEADER (p, 3);
-  CHECK_HISTORY (p, 6, 
-                 3, 2, 1, 10, 4, 5);
-  REM_TRAILER (p, 5);
-  CHECK_HISTORY (p, 5, 
-                 3, 2, 1, 10, 4);
-  p1 = p;
-  REM_TRAILER (p, 4);
-  CHECK_HISTORY (p, 4, 
-                 3, 2, 1, 10);
-  CHECK_HISTORY (p1, 5, 
-                 3, 2, 1, 10, 4);
-  p1.RemoveAtStart (3);
-  CHECK_HISTORY (p1, 4, 
-                 2, 1, 10, 4);
-  p1.RemoveAtStart (1);
-  CHECK_HISTORY (p1, 4, 
-                 1, 1, 10, 4);
-  p1.RemoveAtStart (1);
-  CHECK_HISTORY (p1, 3, 
-                 1, 10, 4);
-  p1.RemoveAtEnd (4);
-  CHECK_HISTORY (p1, 2, 
-                 1, 10);
-  p1.RemoveAtStart (1);
-  CHECK_HISTORY (p1, 1, 10);
-
-  p = Packet (10);
-  ADD_HEADER (p, 8);
-  ADD_TRAILER (p, 8);
-  ADD_TRAILER (p, 8);
-  p.RemoveAtStart (8+10+8);
-  CHECK_HISTORY (p, 1, 8);
-
-  p = Packet (10);
-  ADD_HEADER (p, 10);
-  ADD_HEADER (p, 8);
-  ADD_TRAILER (p, 6);
-  ADD_TRAILER (p, 7);
-  ADD_TRAILER (p, 9);
-  p.RemoveAtStart (5);
-  p.RemoveAtEnd (12);
-  CHECK_HISTORY (p, 5, 3, 10, 10, 6, 4);
-
-  p = Packet (10);
-  ADD_HEADER (p, 10);
-  ADD_TRAILER (p, 6);
-  p.RemoveAtEnd (18);
-  ADD_TRAILER (p, 5);
-  ADD_HEADER (p, 3);
-  CHECK_HISTORY (p, 3, 3, 8, 5);
-  p.RemoveAtStart (12);
-  CHECK_HISTORY (p, 1, 4);
-  p.RemoveAtEnd (2);
-  CHECK_HISTORY (p, 1, 2);
-  ADD_HEADER (p, 10);
-  CHECK_HISTORY (p, 2, 10, 2);
-  p.RemoveAtEnd (5);
-  CHECK_HISTORY (p, 1, 7);
-
-  Packet p2 = Packet (0);
-  Packet p3 = Packet (0);
-
-  p = Packet (40);
-  ADD_HEADER (p, 5);
-  ADD_HEADER (p, 8);
-  CHECK_HISTORY (p, 3, 8, 5, 40);
-  p1 = p.CreateFragment (0, 5);
-  p2 = p.CreateFragment (5, 5);
-  p3 = p.CreateFragment (10, 43);
-  CHECK_HISTORY (p1, 1, 5);
-  CHECK_HISTORY (p2, 2, 3, 2);
-  CHECK_HISTORY (p3, 2, 3, 40);
-  p1.AddAtEnd (p2);
-  CHECK_HISTORY (p1, 2, 8, 2);
-  CHECK_HISTORY (p2, 2, 3, 2);
-  p1.AddAtEnd (p3);
-  CHECK_HISTORY (p1, 3, 8, 5, 40);
-  CHECK_HISTORY (p2, 2, 3, 2);
-  CHECK_HISTORY (p3, 2, 3, 40);
-  p1 = p.CreateFragment (0, 5);
-  CHECK_HISTORY (p1, 1, 5);
-
-  p3 = Packet (50);
-  ADD_HEADER (p3, 8);
-  CHECK_HISTORY (p3, 2, 8, 50);
-  CHECK_HISTORY (p1, 1, 5);
-  p1.AddAtEnd (p3);
-  CHECK_HISTORY (p1, 3, 5, 8, 50);
-  ADD_HEADER (p1, 5);
-  CHECK_HISTORY (p1, 4, 5, 5, 8, 50);
-  ADD_TRAILER (p1, 2);
-  CHECK_HISTORY (p1, 5, 5, 5, 8, 50, 2);
-  REM_HEADER (p1, 5);
-  CHECK_HISTORY (p1, 4, 5, 8, 50, 2);
-  p1.RemoveAtEnd (60);
-  CHECK_HISTORY (p1, 1, 5);
-  p1.AddAtEnd (p2);
-  CHECK_HISTORY (p1, 2, 8, 2);
-  CHECK_HISTORY (p2, 2, 3, 2);
-
-  p3 = Packet (40);
-  ADD_HEADER (p3, 5);
-  ADD_HEADER (p3, 5);
-  CHECK_HISTORY (p3, 3, 5, 5, 40);
-  p1 = p3.CreateFragment (0, 5);
-  p2 = p3.CreateFragment (5, 5);
-  CHECK_HISTORY (p1, 1, 5);
-  CHECK_HISTORY (p2, 1, 5);
-  p1.AddAtEnd (p2);
-  CHECK_HISTORY (p1, 2, 5, 5);
-
-  p = Packet (0);
-  CHECK_HISTORY (p, 0);
-
-  p3 = Packet (0);
-  ADD_HEADER (p3, 5);
-  ADD_HEADER (p3, 5);
-  CHECK_HISTORY (p3, 2, 5, 5);
-  p1 = p3.CreateFragment (0, 4);
-  p2 = p3.CreateFragment (9, 1);
-  CHECK_HISTORY (p1, 1, 4);
-  CHECK_HISTORY (p2, 1, 1);
-  p1.AddAtEnd (p2);
-  CHECK_HISTORY (p1, 2, 4, 1);
-  
-  
-
-
-  return ok;
-}
-
-static PacketHistoryTest g_packetHistoryTest;
-
-}//namespace ns3
diff -r 62901fdaeb68 -r 777fcfabc1c8 src/common/packet-history.h
--- a/src/common/packet-history.h	Thu Jun 07 12:44:44 2007 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,235 +0,0 @@
-/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/*
- * Copyright (c) 2006,2007 INRIA
- * All rights reserved.
- *
- * 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>
- */
-#ifndef PACKET_HISTORY_H
-#define PACKET_HISTORY_H
-
-#include <stdint.h>
-#include <vector>
-#include "ns3/callback.h"
-#include "ns3/assert.h"
-#include "packet-printer.h"
-
-namespace ns3 {
-
-class Chunk;
-class Buffer;
-
-class PacketHistory {
-public:
-  static void Enable (void);
-  static void SetOptOne (bool optOne);
-
-  inline PacketHistory (uint32_t uid, uint32_t size);
-  inline PacketHistory (PacketHistory const &o);
-  inline PacketHistory &operator = (PacketHistory const& o);
-  inline ~PacketHistory ();
-
-  template <typename T>
-  void AddHeader (T const &header, uint32_t size);
-  template <typename T>
-  void RemoveHeader (T const &header, uint32_t size);
-
-  template <typename T>
-  void AddTrailer (T const &trailer, uint32_t size);
-  template <typename T>
-  void RemoveTrailer (T const &trailer, uint32_t size);
-
-  PacketHistory CreateFragment (uint32_t start, uint32_t end) const;
-  void AddAtEnd (PacketHistory const&o);
-  void AddPaddingAtEnd (uint32_t end);
-  void RemoveAtStart (uint32_t start);
-  void RemoveAtEnd (uint32_t end);
-
-  void PrintDefault (std::ostream &os, Buffer buffer) const;
-  void Print (std::ostream &os, Buffer buffer, PacketPrinter const &printer) const;
-
-  static void PrintStats (void);
-
-private:
-  /**
-     head -(next)-> tail
-       ^             |
-        \---(prev)---|
-   */
-  struct Data {
-    uint16_t m_count;
-    uint16_t m_size;
-    uint16_t m_dirtyEnd;
-    uint8_t m_data[10];
-  };
-  struct SmallItem {
-    uint16_t next;
-    uint16_t prev;
-    uint32_t typeUid;
-    uint32_t size;
-    uint16_t chunkUid;
-  };
-  struct ExtraItem {
-    uint32_t fragmentStart;
-    uint32_t fragmentEnd;
-    uint32_t packetUid;
-  };
-
-  typedef std::vector<struct Data *> DataFreeList;
-  
-  PacketHistory ();
-  void DoAddHeader (uint32_t uid, uint32_t size);
-  void DoRemoveHeader (uint32_t uid, uint32_t size);
-  void DoAddTrailer (uint32_t uid, uint32_t size);
-  void DoRemoveTrailer (uint32_t uid, uint32_t size);
-
-  inline uint16_t AddSmall (const PacketHistory::SmallItem *item);
-  uint16_t AddBig (uint32_t head, uint32_t tail,
-                   const PacketHistory::SmallItem *item, 
-                   const PacketHistory::ExtraItem *extraItem);
-  void ReplaceTail (PacketHistory::SmallItem *item, 
-                    PacketHistory::ExtraItem *extraItem,
-                    uint32_t available);
-  inline void UpdateHead (uint16_t written);
-  inline void UpdateTail (uint16_t written);
-  uint32_t GetUleb128Size (uint32_t value) const;
-  uint32_t ReadUleb128 (const uint8_t **pBuffer) const;
-  inline void Append16 (uint16_t value, uint8_t *buffer);
-  inline bool TryToAppend (uint32_t value, uint8_t **pBuffer, uint8_t *end);
-  inline bool TryToAppendFast (uint32_t value, uint8_t **pBuffer, uint8_t *end);
-  inline bool TryToAppend32 (uint32_t value, uint8_t **pBuffer, uint8_t *end);
-  inline bool TryToAppend16 (uint16_t value, uint8_t **pBuffer, uint8_t *end);
-  void AppendValue (uint32_t value, uint8_t *buffer);
-  void AppendValueExtra (uint32_t value, uint8_t *buffer);
-  inline void Reserve (uint32_t n);
-  void ReserveCopy (uint32_t n);
-  uint32_t DoPrint (struct PacketHistory::SmallItem *item, uint32_t current,
-                    Buffer data, uint32_t offset, const PacketPrinter &printer,
-                    std::ostream &os) const;
-  uint32_t GetTotalSize (void) const;
-  uint32_t ReadItems (uint16_t current, 
-                      struct PacketHistory::SmallItem *item,
-                      struct PacketHistory::ExtraItem *extraItem) const;
-
-
-  static struct PacketHistory::Data *Create (uint32_t size);
-  static void Recycle (struct PacketHistory::Data *data);
-  static struct PacketHistory::Data *Allocate (uint32_t n);
-  static void Deallocate (struct PacketHistory::Data *data);
-  
-  static DataFreeList m_freeList;
-  static bool m_enable;
-  static uint32_t m_maxSize;
-  static uint16_t m_chunkUid;
-  
-  struct Data *m_data;
-  uint16_t m_head;
-  uint16_t m_tail;
-  uint16_t m_used;
-  uint32_t m_packetUid;
-};
-
-}; // namespace ns3
-
-namespace ns3 {
-
-template <typename T>
-void 
-PacketHistory::AddHeader (T const &header, uint32_t size)
-{
-  DoAddHeader (PacketPrinter::GetHeaderUid<T> (), size);
-}
-
-template <typename T>
-void 
-PacketHistory::RemoveHeader (T const &header, uint32_t size)
-{
-  DoRemoveHeader (PacketPrinter::GetHeaderUid<T> (), size);
-}
-template <typename T>
-void 
-PacketHistory::AddTrailer (T const &trailer, uint32_t size)
-{
-  DoAddTrailer (PacketPrinter::GetTrailerUid<T> (), size);
-}
-template <typename T>
-void 
-PacketHistory::RemoveTrailer (T const &trailer, uint32_t size)
-{
-  DoRemoveTrailer (PacketPrinter::GetTrailerUid<T> (), size);
-}
-
-
-PacketHistory::PacketHistory (uint32_t uid, uint32_t size)
-  : m_data (m_data = PacketHistory::Create (10)),
-    m_head (0xffff),
-    m_tail (0xffff),
-    m_used (0),
-    m_packetUid (uid)
-{
-  memset (m_data->m_data, 0xff, 4);
-  if (size > 0)
-    {
-      DoAddHeader (0, size);
-    }
-}
-PacketHistory::PacketHistory (PacketHistory const &o)
-  : m_data (o.m_data),
-    m_head (o.m_head),
-    m_tail (o.m_tail),
-    m_used (o.m_used),
-    m_packetUid (o.m_packetUid)
-{
-  NS_ASSERT (m_data != 0);
-  m_data->m_count++;
-}
-PacketHistory &
-PacketHistory::operator = (PacketHistory const& o)
-{
-  if (m_data == o.m_data) 
-    {
-      // self assignment
-      return *this;
-    }
-  NS_ASSERT (m_data != 0);
-  m_data->m_count--;
-  if (m_data->m_count == 0) 
-    {
-      PacketHistory::Recycle (m_data);
-    }
-  m_data = o.m_data;
-  m_head = o.m_head;
-  m_tail = o.m_tail;
-  m_used = o.m_used;
-  m_packetUid = o.m_packetUid;
-  NS_ASSERT (m_data != 0);
-  m_data->m_count++;
-  return *this;
-}
-PacketHistory::~PacketHistory ()
-{
-  NS_ASSERT (m_data != 0);
-  m_data->m_count--;
-  if (m_data->m_count == 0) 
-    {
-      PacketHistory::Recycle (m_data);
-    }
-}
-
-}; // namespace ns3
-
-
-#endif /* PACKET_HISTORY_H */
diff -r 62901fdaeb68 -r 777fcfabc1c8 src/common/packet-metadata.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/common/packet-metadata.cc	Thu Jun 07 12:48:52 2007 +0200
@@ -0,0 +1,1631 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2006,2007 INRIA
+ * All rights reserved.
+ *
+ * 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 <utility>
+#include <list>
+#include "ns3/assert.h"
+#include "ns3/fatal-error.h"
+#include "ns3/debug.h"
+#include "packet-metadata.h"
+#include "chunk.h"
+#include "buffer.h"
+
+NS_DEBUG_COMPONENT_DEFINE ("PacketHistory");
+
+namespace ns3 {
+
+bool PacketHistory::m_enable = false;
+uint32_t PacketHistory::m_maxSize = 0;
+uint16_t PacketHistory::m_chunkUid = 0;
+PacketHistory::DataFreeList PacketHistory::m_freeList;
+bool g_optOne = false;
+
+void 
+PacketHistory::Enable (void)
+{
+  m_enable = true;
+}
+
+void 
+PacketHistory::SetOptOne (bool optOne)
+{
+  g_optOne = optOne;
+}
+
+void
+PacketHistory::ReserveCopy (uint32_t size)
+{
+  struct PacketHistory::Data *newData = PacketHistory::Create (m_used + size);
+  memcpy (newData->m_data, m_data->m_data, m_used);
+  newData->m_dirtyEnd = m_used;
+  m_data->m_count--;
+  if (m_data->m_count == 0) 
+    {
+      PacketHistory::Recycle (m_data);
+    }
+  m_data = newData;
+  if (m_head != 0xffff)
+    {
+      uint8_t *start;
+      NS_ASSERT (m_tail != 0xffff);
+      // clear the next field of the tail
+      start = &m_data->m_data[m_tail];
+      Append16 (0xffff, start);
+      // clear the prev field of the head
+      start = &m_data->m_data[m_head] + 2;
+      Append16 (0xffff, start);
+    }
+}
+void
+PacketHistory::Reserve (uint32_t size)
+{
+  NS_ASSERT (m_data != 0);
+  if (m_data->m_size >= m_used + size &&
+      (m_head == 0xffff ||
+       m_data->m_count == 1 ||
+       m_data->m_dirtyEnd == m_used))
+    {
+      /* enough room, not dirty. */
+    }
+  else 
+    {
+      /* (enough room and dirty) or (not enough room) */
+      ReserveCopy (size);
+    }
+}
+
+uint32_t 
+PacketHistory::GetUleb128Size (uint32_t value) const
+{
+  if (value < 0x80)
+    {
+      return 1;
+    }
+  if (value < 0x4000)
+    {
+      return 2;
+    }
+  if (value < 0x200000)
+    {
+      return 3;
+    }
+  if (value < 0x10000000)
+    {
+      return 4;
+    }
+  return 5;
+}
+uint32_t
+PacketHistory::ReadUleb128 (const uint8_t **pBuffer) const
+{
+  const uint8_t *buffer = *pBuffer;
+  uint32_t result = 0;
+  uint8_t byte;
+  result = 0;
+  byte = buffer[0];
+  result = (byte & (~0x80));
+  if (!(byte & 0x80))
+    {
+      *pBuffer = buffer + 1;
+      return result;
+    }
+  byte = buffer[1];
+  result = (byte & (~0x80)) << 7;
+  if (!(byte & 0x80))
+    {
+      *pBuffer = buffer + 2;
+      return result;
+    }
+  byte = buffer[2];
+  result = (byte & (~0x80)) << 14;
+  if (!(byte & 0x80))
+    {
+      *pBuffer = buffer + 3;
+      return result;
+    }
+  byte = buffer[3];
+  result = (byte & (~0x80)) << 21;
+  if (!(byte & 0x80))
+    {
+      *pBuffer = buffer + 4;
+      return result;
+    }
+  byte = buffer[4];
+  result = (byte & (~0x80)) << 28;
+  if (!(byte & 0x80))
+    {
+      *pBuffer = buffer + 5;
+      return result;
+    }
+  /* This means that the LEB128 number was not valid.
+   * ie: the last (5th) byte did not have the high-order bit zeroed.
+   */
+  NS_ASSERT (false);
+  return 0;
+}
+
+void
+PacketHistory::Append16 (uint16_t value, uint8_t *buffer)
+{
+  buffer[0] = value & 0xff;
+  value >>= 8;
+  buffer[1] = value;
+}
+bool
+PacketHistory::TryToAppendFast (uint32_t value, uint8_t **pBuffer, uint8_t *end)
+{
+  uint8_t *start = *pBuffer;
+  if (value < 0x80 && start < end)
+    {
+      start[0] = value;
+      *pBuffer = start + 1;
+      return true;
+    }
+  if (value < 0x4000 && start + 1 < end)
+    {
+      uint8_t byte = value & (~0x80);
+      start[0] = 0x80 | byte;
+      value >>= 7;
+      start[1] = value;
+      *pBuffer = start + 2;
+      return true;
+    }
+  return false;
+}
+bool
+PacketHistory::TryToAppend16 (uint16_t value,  uint8_t **pBuffer, uint8_t *end)
+{
+  uint8_t *start = *pBuffer;
+  if (start + 1 < end)
+    {
+      start[0] = value & 0xff;
+      start[1] = value >> 8;
+      *pBuffer = start + 2;
+      return true;
+    }
+  return false;
+}
+bool
+PacketHistory::TryToAppend32 (uint32_t value,  uint8_t **pBuffer, uint8_t *end)
+{
+  uint8_t *start = *pBuffer;
+  if (start + 3 < end)
+    {
+      start[0] = value & 0xff;
+      start[1] = (value >> 8) & 0xff;
+      start[2] = (value >> 16) & 0xff;
+      start[3] = (value >> 24) & 0xff;
+      *pBuffer = start + 4;
+      return true;
+    }
+  return false;
+}
+bool
+PacketHistory::TryToAppend (uint32_t value, uint8_t **pBuffer, uint8_t *end)
+{
+  uint8_t *start = *pBuffer;
+  if (value < 0x80 && start < end)
+    {
+      start[0] = value;
+      *pBuffer = start + 1;
+      return true;
+    }
+  if (value < 0x4000 && start + 1 < end)
+    {
+      uint8_t byte = value & (~0x80);
+      start[0] = 0x80 | byte;
+      value >>= 7;
+      start[1] = value;
+      *pBuffer = start + 2;
+      return true;
+    }
+  if (value < 0x200000 && start + 2 < end)
+    {
+      uint8_t byte = value & (~0x80);
+      start[0] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      start[1] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      start[2] = value;
+      *pBuffer = start + 3;
+      return true;
+    }
+  if (value < 0x10000000 && start + 3 < end)
+    {
+      uint8_t byte = value & (~0x80);
+      start[0] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      start[1] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      start[2] = 0x80 | byte;
+      value >>= 7;
+      start[3] = value;
+      *pBuffer = start + 4;
+      return true;
+    }
+  if (start + 4 < end)
+    {
+      uint8_t byte = value & (~0x80);
+      start[0] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      start[1] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      start[2] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      start[3] = 0x80 | byte;
+      value >>= 7;
+      start[4] = value;
+      *pBuffer = start + 5;
+      return true;
+    }
+  return false;
+}
+
+void
+PacketHistory::AppendValueExtra (uint32_t value, uint8_t *buffer)
+{
+  if (value < 0x200000)
+    {
+      uint8_t byte = value & (~0x80);
+      buffer[0] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      buffer[1] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      buffer[2] = value;
+      return;
+    }
+  if (value < 0x10000000)
+    {
+      uint8_t byte = value & (~0x80);
+      buffer[0] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      buffer[1] = 0x80 | byte;
+      value >>= 7;
+      byte = value & (~0x80);
+      buffer[2] = 0x80 | byte;
+      value >>= 7;
+      buffer[3] = value;
+      return;
+    }
+  {
+    uint8_t byte = value & (~0x80);
+    buffer[0] = 0x80 | byte;
+    value >>= 7;
+    byte = value & (~0x80);
+    buffer[1] = 0x80 | byte;
+    value >>= 7;
+    byte = value & (~0x80);
+    buffer[2] = 0x80 | byte;
+    value >>= 7;
+    byte = value & (~0x80);
+    buffer[3] = 0x80 | byte;
+    value >>= 7;
+    buffer[4] = value;
+  }
+}
+
+void
+PacketHistory::AppendValue (uint32_t value, uint8_t *buffer)
+{
+  if (value < 0x80)
+    {
+      buffer[0] = value;
+      return;
+    }
+  if (value < 0x4000)
+    {
+      uint8_t byte = value & (~0x80);
+      buffer[0] = 0x80 | byte;
+      value >>= 7;
+      buffer[1] = value;
+      return;
+    }
+  AppendValueExtra (value, buffer);
+}
+
+void
+PacketHistory::UpdateTail (uint16_t written)
+{
+  if (m_head == 0xffff)
+    {
+      NS_ASSERT (m_tail == 0xffff);
+      m_head = m_used;
+      m_tail = m_used;
+    } 
+  else
+    {
+      NS_ASSERT (m_tail != 0xffff);
+      // overwrite the next field of the previous tail of the list.
+      uint8_t *previousTail = &m_data->m_data[m_tail];
+      Append16 (m_used, previousTail);
+      // update the tail of the list to the new node.
+      m_tail = m_used;
+    }
+  NS_ASSERT (m_tail != 0xffff);
+  NS_ASSERT (m_head != 0xffff);
+  m_used += written;
+  m_data->m_dirtyEnd = m_used;
+}
+
+
+void
+PacketHistory::UpdateHead (uint16_t written)
+{
+  if (m_head == 0xffff)
+    {
+      NS_ASSERT (m_tail == 0xffff);
+      m_head = m_used;
+      m_tail = m_used;
+    } 
+  else
+    {
+      NS_ASSERT (m_head != 0xffff);
+      // overwrite the prev field of the previous head of the list.
+      uint8_t *previousHead = &m_data->m_data[m_head + 2];
+      Append16 (m_used, previousHead);
+      // update the head of list to the new node.
+      m_head = m_used;
+    }
+  NS_ASSERT (m_tail != 0xffff);
+  NS_ASSERT (m_head != 0xffff);
+  m_used += written;
+  m_data->m_dirtyEnd = m_used;
+}
+
+uint16_t
+PacketHistory::AddSmall (const struct PacketHistory::SmallItem *item)
+{
+  NS_ASSERT (m_data != 0);
+  if (g_optOne)
+    {
+      uint32_t typeUidSize = GetUleb128Size (item->typeUid);
+      uint32_t sizeSize = GetUleb128Size (item->size);
+      uint32_t n = typeUidSize + sizeSize + 2 + 2 + 2;
+    restart:
+      if (m_used + n <= m_data->m_size &&
+      (m_head == 0xffff ||
+       m_data->m_count == 1 ||
+       m_used == m_data->m_dirtyEnd))
+        {
+          uint8_t *buffer = &m_data->m_data[m_used];
+          Append16 (item->next, buffer);
+          buffer += 2;
+          Append16 (item->prev, buffer);
+          buffer += 2;
+          AppendValue (item->typeUid, buffer);
+          buffer += typeUidSize;
+          AppendValue (item->size, buffer);
+          buffer += sizeSize;
+          Append16 (item->chunkUid, buffer);
+        }
+      else
+        {
+          ReserveCopy (n);
+          goto restart;
+        }
+      return n;
+    }
+ append:
+  uint8_t *start = &m_data->m_data[m_used];
+  uint8_t *end = &m_data->m_data[m_data->m_size];
+  if (end - start >= 8 &&
+      (m_head == 0xffff ||
+       m_data->m_count == 1 ||
+       m_used == m_data->m_dirtyEnd))
+    {
+      uint8_t *buffer = start;
+
+      Append16 (item->next, buffer);
+      buffer += 2;
+      Append16 (item->prev, buffer);
+      buffer += 2;
+      if (TryToAppendFast (item->typeUid, &buffer, end) &&
+          TryToAppendFast (item->size, &buffer, end) &&
+          TryToAppend16 (item->chunkUid, &buffer, end))
+        {
+          uintptr_t written = buffer - start;
+          NS_ASSERT (written <= 0xffff);
+          return written;
+        }
+    }
+  uint32_t n = GetUleb128Size (item->typeUid);
+  n += GetUleb128Size (item->size);
+  n += 2;
+  n += 2 + 2;
+  Reserve (n);
+  goto append;
+}
+
+uint16_t
+PacketHistory::AddBig (uint32_t next, uint32_t prev, 
+                       const PacketHistory::SmallItem *item, 
+                       const PacketHistory::ExtraItem *extraItem)
+{
+  NS_ASSERT (m_data != 0);
+  uint32_t typeUid = ((item->typeUid & 0x1) == 0x1)?item->typeUid:item->typeUid+1;
+ append:
+  uint8_t *start = &m_data->m_data[m_used];
+  uint8_t *end = &m_data->m_data[m_data->m_size];
+  if (end - start >= 14 &&
+      (m_head == 0xffff ||
+       m_data->m_count == 1 ||
+       m_used == m_data->m_dirtyEnd))
+    {
+      uint8_t *buffer = start;
+
+      Append16 (next, buffer);
+      buffer += 2;
+      Append16 (prev, buffer);
+      buffer += 2;
+      if (TryToAppend (typeUid, &buffer, end) &&
+          TryToAppend (item->size, &buffer, end) &&
+          TryToAppend16 (item->chunkUid, &buffer, end) &&
+          TryToAppend (extraItem->fragmentStart, &buffer, end) &&
+          TryToAppend (extraItem->fragmentEnd, &buffer, end) &&
+          TryToAppend32 (extraItem->packetUid, &buffer, end))
+        {
+          uintptr_t written = buffer - start;
+          NS_ASSERT (written <= 0xffff);
+          return written;
+        }
+    }
+
+  uint32_t n = GetUleb128Size (typeUid);
+  n += GetUleb128Size (item->size);
+  n += 2;
+  n += GetUleb128Size (extraItem->fragmentStart);
+  n += GetUleb128Size (extraItem->fragmentEnd);
+  n += 4;
+  n += 2 + 2;
+  ReserveCopy (n);
+  goto append;
+}
+
+void
+PacketHistory::ReplaceTail (PacketHistory::SmallItem *item, 
+                            PacketHistory::ExtraItem *extraItem,
+                            uint32_t available)
+{
+  NS_ASSERT (m_data != 0);  
+  if (available >= 14 &&
+      m_data->m_count == 1)
+    {
+      uint8_t *buffer = &m_data->m_data[m_tail];
+      uint8_t *end = buffer + available;
+
+      Append16 (item->next, buffer);
+      buffer += 2;
+      Append16 (item->prev, buffer);
+      buffer += 2;
+      if (TryToAppend (item->typeUid, &buffer, end) &&
+          TryToAppend (item->size, &buffer, end) &&
+          TryToAppend16 (item->chunkUid, &buffer, end) &&
+          TryToAppend (extraItem->fragmentStart, &buffer, end) &&
+          TryToAppend (extraItem->fragmentEnd, &buffer, end) &&
+          TryToAppend32 (extraItem->packetUid, &buffer, end))
+        {
+          m_used = buffer - &m_data->m_data[0];
+          m_data->m_dirtyEnd = m_used;
+          return;
+        }
+    }
+  
+  // create a copy of the packet.
+  PacketHistory h (m_packetUid, 0);
+  uint16_t current = m_head;
+  while (current != 0xffff && current != m_tail)
+    {
+      struct PacketHistory::SmallItem tmpItem;
+      PacketHistory::ExtraItem tmpExtraItem;
+      ReadItems (current, &tmpItem, &tmpExtraItem);
+      uint16_t written = h.AddBig (0xffff, h.m_tail, 
+                                   &tmpItem, &tmpExtraItem);
+      h.UpdateTail (written);
+    }
+  // append new tail.
+  uint16_t written = h.AddBig (0xffff, h.m_tail, item, extraItem);
+  h.UpdateTail (written);
+
+  *this = h;
+}
+
+uint32_t
+PacketHistory::ReadItems (uint16_t current, 
+                          struct PacketHistory::SmallItem *item,
+                          struct PacketHistory::ExtraItem *extraItem) const
+{
+  const uint8_t *buffer = &m_data->m_data[current];
+  item->next = buffer[0];
+  item->next |= (buffer[1]) << 8;
+  item->prev = buffer[2];
+  item->prev |= (buffer[3]) << 8;
+  buffer += 4;
+  item->typeUid = ReadUleb128 (&buffer);
+  item->size = ReadUleb128 (&buffer);
+  item->chunkUid = buffer[0];
+  item->chunkUid |= (buffer[1]) << 8;
+  buffer += 2;
+
+  bool isExtra = (item->typeUid & 0x1) == 0x1;
+  if (isExtra)
+    {
+      extraItem->fragmentStart = ReadUleb128 (&buffer);
+      extraItem->fragmentEnd = ReadUleb128 (&buffer);
+      extraItem->packetUid = buffer[0];
+      extraItem->packetUid |= buffer[1] << 8;
+      extraItem->packetUid |= buffer[2] << 16;
+      extraItem->packetUid |= buffer[3] << 24;
+      buffer += 4;
+    }
+  else
+    {
+      extraItem->fragmentStart = 0;
+      extraItem->fragmentEnd = item->size;
+      extraItem->packetUid = m_packetUid;
+    }
+  NS_ASSERT (buffer <= &m_data->m_data[m_data->m_size]);
+  return buffer - &m_data->m_data[current];
+}
+
+struct PacketHistory::Data *
+PacketHistory::Create (uint32_t size)
+{
+  NS_DEBUG ("create size="<<size<<", max="<<m_maxSize);
+  if (size > m_maxSize)
+    {
+      m_maxSize = size;
+    }
+  while (!m_freeList.empty ()) 
+    {
+      struct PacketHistory::Data *data = m_freeList.back ();
+      m_freeList.pop_back ();
+      if (data->m_size >= size) 
+        {
+          NS_DEBUG ("create found size="<<data->m_size);
+          data->m_count = 1;
+          return data;
+        }
+      PacketHistory::Deallocate (data);
+      NS_DEBUG ("create dealloc size="<<data->m_size);
+    }
+  NS_DEBUG ("create alloc size="<<m_maxSize);
+  return PacketHistory::Allocate (m_maxSize);
+}
+
+void
+PacketHistory::Recycle (struct PacketHistory::Data *data)
+{
+  NS_DEBUG ("recycle size="<<data->m_size<<", list="<<m_freeList.size ());
+  NS_ASSERT (data->m_count == 0);
+  if (m_freeList.size () > 1000 ||
+      data->m_size < m_maxSize) 
+    {
+      PacketHistory::Deallocate (data);
+    } 
+  else 
+    {
+      m_freeList.push_back (data);
+    }
+}
+
+struct PacketHistory::Data *
+PacketHistory::Allocate (uint32_t n)
+{
+  uint32_t size = sizeof (struct Data);
+  if (n <= 10)
+    {
+      n = 10;
+    }
+  size += n - 10;
+  uint8_t *buf = new uint8_t [size];
+  struct PacketHistory::Data *data = (struct PacketHistory::Data *)buf;
+  data->m_size = n;
+  data->m_count = 1;
+  data->m_dirtyEnd = 0;
+  return data;
+}
+void 
+PacketHistory::Deallocate (struct PacketHistory::Data *data)
+{
+  uint8_t *buf = (uint8_t *)data;
+  delete [] buf;
+}
+
+
+PacketHistory 
+PacketHistory::CreateFragment (uint32_t start, uint32_t end) const
+{
+  PacketHistory fragment = *this;
+  fragment.RemoveAtStart (start);
+  fragment.RemoveAtEnd (end);
+  return fragment;
+}
+
+void 
+PacketHistory::DoAddHeader (uint32_t uid, uint32_t size)
+{
+  if (!m_enable)
+    {
+      return;
+    }
+  struct PacketHistory::SmallItem item;
+  item.next = m_head;
+  item.prev = 0xffff;
+  item.typeUid = uid;
+  item.size = size;
+  item.chunkUid = m_chunkUid;
+  m_chunkUid++;
+  uint16_t written = AddSmall (&item);
+  UpdateHead (written);
+}
+void 
+PacketHistory::DoRemoveHeader (uint32_t uid, uint32_t size)
+{
+  if (!m_enable) 
+    {
+      return;
+    }
+  struct PacketHistory::SmallItem item;
+  struct PacketHistory::ExtraItem extraItem;
+  ReadItems (m_head, &item, &extraItem);
+  if ((item.typeUid & 0xfffffffe) != uid ||
+      item.size != size)
+    {
+      NS_FATAL_ERROR ("Removing unexpected header.");
+    }
+  else if (item.typeUid != uid &&
+           (extraItem.fragmentStart != 0 ||
+            extraItem.fragmentEnd != size))
+    {
+      NS_FATAL_ERROR ("Removing incomplete header.");
+    }
+  m_head = item.next;
+  if (m_head > m_tail)
+    {
+      m_used = m_head;
+    }
+}
+void 
+PacketHistory::DoAddTrailer (uint32_t uid, uint32_t size)
+{
+  if (!m_enable)
+    {
+      return;
+    }
+  struct PacketHistory::SmallItem item;
+  item.next = 0xffff;
+  item.prev = m_tail;
+  item.typeUid = uid;
+  item.size = size;
+  item.chunkUid = m_chunkUid;
+  m_chunkUid++;
+  uint16_t written = AddSmall (&item);
+  UpdateTail (written);
+}
+void 
+PacketHistory::DoRemoveTrailer (uint32_t uid, uint32_t size)
+{
+  if (!m_enable) 
+    {
+      return;
+    }
+  struct PacketHistory::SmallItem item;
+  struct PacketHistory::ExtraItem extraItem;
+  ReadItems (m_tail, &item, &extraItem);
+  if ((item.typeUid & 0xfffffffe) != uid ||
+      item.size != size)
+    {
+      NS_FATAL_ERROR ("Removing unexpected trailer.");
+    }
+  else if (item.typeUid != uid &&
+           (extraItem.fragmentStart != 0 ||
+            extraItem.fragmentEnd != size))
+    {
+      NS_FATAL_ERROR ("Removing incomplete trailer.");
+    }
+  m_tail = item.prev;
+  if (m_tail > m_head)
+    {
+      m_used = m_tail;
+    }
+}
+void
+PacketHistory::AddAtEnd (PacketHistory const&o)
+{
+  if (!m_enable) 
+    {
+      return;
+    }
+  if (m_tail == 0xffff)
+    {
+      *this = o;
+      return;
+    }
+  NS_ASSERT (m_head != 0xffff && m_tail != 0xffff);
+
+  uint16_t lastTail;
+  lastTail = m_tail;
+  struct PacketHistory::SmallItem lastItem;
+  PacketHistory::ExtraItem lastExtraItem;
+  uint32_t lastTailSize = ReadItems (m_tail, &lastItem, &lastExtraItem);
+  if (m_tail + lastTailSize == m_used &&
+      m_used == m_data->m_dirtyEnd)
+    {
+      lastTailSize = m_data->m_size - m_tail;
+    }
+
+  uint16_t current = o.m_head;
+  while (current != 0xffff)
+    {
+      struct PacketHistory::SmallItem item;
+      PacketHistory::ExtraItem extraItem;
+      o.ReadItems (current, &item, &extraItem);
+      if (extraItem.packetUid == lastExtraItem.packetUid &&
+          item.typeUid == lastItem.typeUid &&
+          item.chunkUid == lastItem.chunkUid &&
+          item.size == lastItem.size &&
+          extraItem.fragmentStart == lastExtraItem.fragmentEnd)
+        {
+          // replace previous tail.
+          lastExtraItem.fragmentEnd = extraItem.fragmentEnd;
+          NS_ASSERT (m_tail == lastTail);
+          ReplaceTail (&lastItem, &lastExtraItem, lastTailSize);
+        }
+      else
+        {
+          // append the extra items.
+          uint16_t written = AddBig (0xffff, m_tail, &item, &extraItem);
+          UpdateTail (written);
+        }
+      if (current == o.m_tail)
+        {
+          break;
+        }
+      current = item.next;
+    }
+}
+void
+PacketHistory::AddPaddingAtEnd (uint32_t end)
+{
+  if (!m_enable)
+    {
+      return;
+    }
+}
+void 
+PacketHistory::RemoveAtStart (uint32_t start)
+{
+  if (!m_enable) 
+    {
+      return;
+    }
+  NS_ASSERT (m_data != 0);
+  uint32_t leftToRemove = start;
+  uint16_t current = m_head;
+  while (current != 0xffff && leftToRemove > 0)
+    {
+      struct PacketHistory::SmallItem item;
+      PacketHistory::ExtraItem extraItem;
+      ReadItems (current, &item, &extraItem);
+      uint32_t itemRealSize = extraItem.fragmentEnd - extraItem.fragmentStart;
+      if (itemRealSize <= leftToRemove)
+        {
+          // remove from list.
+          m_head = item.next;
+          leftToRemove -= itemRealSize;
+        }
+      else
+        {
+          // fragment the list item.
+          PacketHistory fragment (m_packetUid, 0);
+          extraItem.fragmentStart += leftToRemove;
+          leftToRemove = 0;
+          uint16_t written = fragment.AddBig (0xffff, fragment.m_tail,
+                                              &item, &extraItem);
+          fragment.UpdateTail (written);
+          current = item.next;
+          while (current != 0xffff)
+            {
+              ReadItems (current, &item, &extraItem);
+              written = fragment.AddBig (0xffff, fragment.m_tail,
+                                         &item, &extraItem);
+              fragment.UpdateTail (written);
+              if (current == m_tail)
+                {
+                  break;
+                }
+              current = item.next;
+            }
+          *this = fragment;
+        }
+      NS_ASSERT (item.size >= extraItem.fragmentEnd - extraItem.fragmentStart &&
+                 extraItem.fragmentStart <= extraItem.fragmentEnd);
+      if (current == m_tail)
+        {
+          break;
+        }
+      current = item.next;
+    }
+  NS_ASSERT (leftToRemove == 0);
+}
+void 
+PacketHistory::RemoveAtEnd (uint32_t end)
+{
+  if (!m_enable) 
+    {
+      return;
+    }
+  NS_ASSERT (m_data != 0);
+
+  uint32_t leftToRemove = end;
+  uint16_t current = m_tail;
+  while (current != 0xffff && leftToRemove > 0)
+    {
+      struct PacketHistory::SmallItem item;
+      PacketHistory::ExtraItem extraItem;
+      ReadItems (current, &item, &extraItem);
+      uint32_t itemRealSize = extraItem.fragmentEnd - extraItem.fragmentStart;
+      if (itemRealSize <= leftToRemove)
+        {
+          // remove from list.
+          m_tail = item.prev;
+          leftToRemove -= itemRealSize;
+        }
+      else
+        {
+          // fragment the list item.
+          PacketHistory fragment (m_packetUid, 0);
+          NS_ASSERT (extraItem.fragmentEnd > leftToRemove);
+          extraItem.fragmentEnd -= leftToRemove;
+          leftToRemove = 0;
+          uint16_t written = fragment.AddBig (fragment.m_head, 0xffff,
+                                              &item, &extraItem);
+          fragment.UpdateHead (written);
+          current = item.prev;
+          while (current != 0xffff)
+            {
+              ReadItems (current, &item, &extraItem);
+              written = fragment.AddBig (fragment.m_head, 0xffff,
+                                         &item, &extraItem);
+              fragment.UpdateHead (written);
+              if (current == m_head)
+                {
+                  break;
+                }
+              current = item.prev;
+            }
+          *this = fragment;
+        }
+      NS_ASSERT (item.size >= extraItem.fragmentEnd - extraItem.fragmentStart &&
+                 extraItem.fragmentStart <= extraItem.fragmentEnd);
+      if (current == m_head)
+        {
+          break;
+        }
+      current = item.prev;
+    }
+  NS_ASSERT (leftToRemove == 0);
+}
+
+void 
+PacketHistory::PrintDefault (std::ostream &os, Buffer buffer) const
+{
+  Print (os, buffer, PacketPrinter::GetDefault ());
+}
+
+uint32_t
+PacketHistory::DoPrint (struct PacketHistory::SmallItem *item, uint32_t current,
+                        Buffer data, uint32_t offset, const PacketPrinter &printer,
+                        std::ostream &os) const
+{
+  PacketHistory::ExtraItem extraItem;
+  ReadItems (current, item, &extraItem);
+  uint32_t uid = item->typeUid & 0xfffffffe;
+  if (uid == 0)
+    {
+      // payload.
+      printer.PrintPayload (os, extraItem.packetUid, item->size, 
+                            extraItem.fragmentStart, 
+                            extraItem.fragmentEnd);
+    }
+  else if (extraItem.fragmentStart != 0 ||
+           extraItem.fragmentEnd != item->size)
+    {
+      printer.PrintChunkFragment (uid, os, extraItem.packetUid, item->size, 
+                                  extraItem.fragmentStart, extraItem.fragmentEnd);
+    }
+  else if (PacketPrinter::IsHeader (uid))
+    {
+      ns3::Buffer::Iterator j = data.Begin ();
+      j.Next (offset);
+      printer.PrintChunk (uid, j, os, extraItem.packetUid, item->size);
+    }
+  else if (PacketPrinter::IsTrailer (uid))
+    {
+      ns3::Buffer::Iterator j = data.End ();
+      j.Prev (data.GetSize () - (offset + item->size));
+      printer.PrintChunk (uid, j, os, extraItem.packetUid, item->size);
+    }
+  else 
+    {
+      NS_ASSERT (false);
+    }
+  return extraItem.fragmentEnd - extraItem.fragmentStart;
+}
+
+uint32_t
+PacketHistory::GetTotalSize (void) const
+{
+  uint32_t totalSize = 0;
+  uint16_t current = m_head;
+  uint16_t tail = m_tail;
+  while (current != 0xffff)
+    {
+      struct PacketHistory::SmallItem item;
+      PacketHistory::ExtraItem extraItem;
+      ReadItems (current, &item, &extraItem);
+      totalSize += extraItem.fragmentEnd - extraItem.fragmentStart;
+      if (current == tail)
+        {
+          break;
+        }
+      current = item.next;
+    }
+  return totalSize;
+}
+
+void
+PacketHistory::Print (std::ostream &os, Buffer data, const PacketPrinter &printer) const
+{
+  if (!m_enable) 
+    {
+      return;
+    }
+  NS_ASSERT (m_data != 0);
+  NS_ASSERT (GetTotalSize () == data.GetSize ());
+  if (printer.m_forward)
+    {
+      uint32_t tail = m_tail;
+      uint32_t head = m_head;
+      uint32_t current = head;
+      uint32_t offset = 0;
+      while (current != 0xffff)
+        {
+          struct PacketHistory::SmallItem item;
+          uint32_t realSize = DoPrint (&item, current, data, offset, printer, os);
+          offset += realSize;
+          if (current == tail)
+            {
+              break;
+            }
+          current = item.next;
+        }
+    }
+  else
+    {
+      uint32_t head = m_head;
+      uint32_t tail = m_tail;
+      uint32_t current = head;
+      uint32_t offset = 0;
+      while (current != 0xffff)
+        {
+          struct PacketHistory::SmallItem item;
+          uint32_t realSize = DoPrint (&item, current, data, offset, printer, os);
+          offset -= realSize;
+          if (current == tail)
+            {
+              break;
+            }
+          current = item.prev;
+        }
+    }
+}
+
+
+
+}; // namespace ns3
+
+#include <stdarg.h>
+#include <iostream>
+#include <sstream>
+#include "ns3/test.h"
+#include "header.h"
+#include "trailer.h"
+#include "packet.h"
+
+namespace ns3 {
+
+template <int N>
+class HistoryHeader : public Header
+{
+public:
+  HistoryHeader ();
+  bool IsOk (void) const;
+private:
+  virtual std::string DoGetName (void) const;
+  virtual void PrintTo (std::ostream &os) const;
+  virtual uint32_t GetSerializedSize (void) const;
+  virtual void SerializeTo (Buffer::Iterator start) const;
+  virtual uint32_t DeserializeFrom (Buffer::Iterator start);
+  bool m_ok;
+};
+
+template <int N>
+HistoryHeader<N>::HistoryHeader ()
+  : m_ok (false)
+{}
+
+template <int N>
+bool 
+HistoryHeader<N>::IsOk (void) const
+{
+  return m_ok;
+}
+
+template <int N>
+std::string 
+HistoryHeader<N>::DoGetName (void) const
+{
+  std::ostringstream oss;
+  oss << N;
+  return oss.str ();
+}
+
+template <int N>
+void 
+HistoryHeader<N>::PrintTo (std::ostream &os) const
+{
+  NS_ASSERT (false);
+}
+template <int N>
+uint32_t 
+HistoryHeader<N>::GetSerializedSize (void) const
+{
+  return N;
+}
+template <int N>
+void 
+HistoryHeader<N>::SerializeTo (Buffer::Iterator start) const
+{
+  start.WriteU8 (N, N);
+}
+template <int N>
+uint32_t
+HistoryHeader<N>::DeserializeFrom (Buffer::Iterator start)
+{
+  m_ok = true;
+  for (int i = 0; i < N; i++)
+    {
+      if (start.ReadU8 () != N)
+        {
+          m_ok = false;
+        }
+    }
+  return N;
+}
+
+template <int N>
+class HistoryTrailer : public Trailer
+{
+public:
+  HistoryTrailer ();
+  bool IsOk (void) const;
+private:
+  virtual std::string DoGetName (void) const;
+  virtual void PrintTo (std::ostream &os) const;
+  virtual uint32_t GetSerializedSize (void) const;
+  virtual void SerializeTo (Buffer::Iterator start) const;
+  virtual uint32_t DeserializeFrom (Buffer::Iterator start);
+  bool m_ok;
+};
+
+template <int N>
+HistoryTrailer<N>::HistoryTrailer ()
+  : m_ok (false)
+{}
+
+template <int N>
+bool
+HistoryTrailer<N>::IsOk (void) const
+{
+  return m_ok;
+}
+
+template <int N>
+std::string 
+HistoryTrailer<N>::DoGetName (void) const
+{
+  std::ostringstream oss;
+  oss << N;
+  return oss.str ();
+}
+template <int N>
+void 
+HistoryTrailer<N>::PrintTo (std::ostream &os) const
+{
+  NS_ASSERT (false);
+}
+template <int N>
+uint32_t 
+HistoryTrailer<N>::GetSerializedSize (void) const
+{
+  return N;
+}
+template <int N>
+void 
+HistoryTrailer<N>::SerializeTo (Buffer::Iterator start) const
+{
+  start.Prev (N);
+  start.WriteU8 (N, N);
+}
+template <int N>
+uint32_t
+HistoryTrailer<N>::DeserializeFrom (Buffer::Iterator start)
+{
+  m_ok = true;
+  start.Prev (N);
+  for (int i = 0; i < N; i++)
+    {
+      if (start.ReadU8 () != N)
+        {
+          m_ok = false;
+        }
+    }
+  return N;
+}
+
+
+
+class PacketHistoryTest : public Test {
+public:
+  PacketHistoryTest ();
+  virtual ~PacketHistoryTest ();
+  bool CheckHistory (Packet p, char *file, int line, uint32_t n, ...);
+  virtual bool RunTests (void);
+private:
+  template <int N>
+  void PrintHeader (std::ostream &os, uint32_t packetUid, uint32_t size, const HistoryHeader<N> *header);
+  template <int N>
+  void PrintTrailer (std::ostream &os, uint32_t packetUid, uint32_t size, const HistoryTrailer<N> *trailer);
+  void PrintFragment (std::ostream &os,uint32_t packetUid,
+                      uint32_t size,std::string & name, 
+                      struct PacketPrinter::FragmentInformation info);
+  void PrintDefault (std::ostream& os,uint32_t packetUid,
+                     uint32_t size,std::string& name,
+                     struct PacketPrinter::FragmentInformation info);
+  void PrintPayload (std::ostream &os,uint32_t packetUid,
+                     uint32_t size,
+                     struct PacketPrinter::FragmentInformation info);
+  template <int N>
+  void RegisterHeader (void);
+  template <int N>
+  void RegisterTrailer (void);
+  void CleanupPrints (void);
+
+
+  bool m_headerError;
+  bool m_trailerError;
+  std::list<int> m_prints;
+  PacketPrinter m_printer;
+};
+
+PacketHistoryTest::PacketHistoryTest ()
+  : Test ("PacketHistory")
+{
+  m_printer.AddPayloadPrinter (MakeCallback (&PacketHistoryTest::PrintPayload, this));
+  m_printer.AddDefaultPrinter (MakeCallback (&PacketHistoryTest::PrintDefault, this));
+}
+
+PacketHistoryTest::~PacketHistoryTest ()
+{}
+
+template <int N>
+void 
+PacketHistoryTest::RegisterHeader (void)
+{
+  static bool registered = false;
+  if (!registered)
+    {
+      m_printer.AddHeaderPrinter (MakeCallback (&PacketHistoryTest::PrintHeader<N>, this),
+                                  MakeCallback (&PacketHistoryTest::PrintFragment, this));
+      registered = true;
+    }
+}
+
+template <int N>
+void 
+PacketHistoryTest::RegisterTrailer (void)
+{
+  static bool registered = false;
+  if (!registered)
+    {
+      m_printer.AddTrailerPrinter (MakeCallback (&PacketHistoryTest::PrintTrailer<N>, this),
+                                   MakeCallback (&PacketHistoryTest::PrintFragment, this));
+      registered = true;
+    }
+}
+
+
+template <int N>
+void 
+PacketHistoryTest::PrintHeader (std::ostream &os, uint32_t packetUid, uint32_t size, 
+                                const HistoryHeader<N> *header)
+{
+  if (!header->IsOk ())
+    {
+      m_headerError = true;
+    }
+  m_prints.push_back (N);
+}
+
+template <int N>
+void 
+PacketHistoryTest::PrintTrailer (std::ostream &os, uint32_t packetUid, uint32_t size, 
+                                 const HistoryTrailer<N> *trailer)
+{
+  if (!trailer->IsOk ())
+    {
+      m_trailerError = true;
+    }
+  m_prints.push_back (N);
+}
+void 
+PacketHistoryTest::PrintFragment (std::ostream &os,uint32_t packetUid,
+                                  uint32_t size,std::string & name, 
+                                  struct PacketPrinter::FragmentInformation info)
+{
+  m_prints.push_back (info.end - info.start);
+}
+void 
+PacketHistoryTest::PrintDefault (std::ostream& os,uint32_t packetUid,
+                     uint32_t size,std::string& name,
+                     struct PacketPrinter::FragmentInformation info)
+{
+  NS_ASSERT (false);
+}
+void 
+PacketHistoryTest::PrintPayload (std::ostream &os,uint32_t packetUid,
+                                 uint32_t size,
+                                 struct PacketPrinter::FragmentInformation info)
+{
+  m_prints.push_back (info.end - info.start);
+}
+
+
+void 
+PacketHistoryTest::CleanupPrints (void)
+{
+  m_prints.clear ();
+}
+
+bool 
+PacketHistoryTest::CheckHistory (Packet p, char *file, int line, uint32_t n, ...)
+{
+  m_headerError = false;
+  m_trailerError = false;
+  va_list ap;
+  p.Print (std::cerr, m_printer);
+  va_start (ap, n);
+  if (m_headerError)
+    {
+      std::cout << "PacketHistory header error. file=" << file 
+                << ", line=" << line << std::endl;
+      return false;
+    }
+  if (m_trailerError)
+    {
+      std::cout << "PacketHistory trailer error. file=" << file 
+                << ", line=" << line << std::endl;
+      return false;
+    }
+  if (n != m_prints.size ())
+    {
+      goto error;
+    }
+  for (std::list<int>::iterator i = m_prints.begin (); 
+       i != m_prints.end (); i++)
+    {
+      int v = va_arg (ap, int);
+      if (v != *i)
+        {
+          va_end (ap);
+          goto error;
+        }
+    }
+  va_end (ap);
+  return true;
+ error:
+  std::cout << "PacketHistory error. file="<< file 
+            << ", line=" << line << ", got:\"";
+  for (std::list<int>::iterator i = m_prints.begin (); 
+       i != m_prints.end (); i++)
+    {
+      std::cout << *i << ", ";
+    }
+  std::cout << "\", expected: \"";
+  va_start (ap, n);
+  for (uint32_t j = 0; j < n; j++)
+    {
+      int v = va_arg (ap, int);
+      std::cout << v << ", ";
+    }
+  va_end (ap);
+  std::cout << "\"" << std::endl;
+  return false;
+}
+
+#define ADD_HEADER(p, n)                        \
+  {                                             \
+    HistoryHeader<n> header;                    \
+    RegisterHeader<n> ();                       \
+    p.AddHeader (header);                       \
+  }
+#define ADD_TRAILER(p, n)                       \
+  {                                             \
+    HistoryTrailer<n> trailer;                  \
+    RegisterTrailer<n> ();                      \
+    p.AddTrailer (trailer);                     \
+  }
+#define REM_HEADER(p, n)                        \
+  {                                             \
+    HistoryHeader<n> header;                    \
+    RegisterHeader<n> ();                       \
+    p.RemoveHeader (header);                    \
+  }
+#define REM_TRAILER(p, n)                       \
+  {                                             \
+    HistoryTrailer<n> trailer;                  \
+    RegisterTrailer<n> ();                      \
+    p.RemoveTrailer (trailer);                  \
+  }
+#define CHECK_HISTORY(p, ...)                   \
+  {                                             \
+    if (!CheckHistory (p, __FILE__,             \
+                      __LINE__, __VA_ARGS__))   \
+      {                                         \
+        ok = false;                             \
+      }                                         \
+    CleanupPrints ();                           \
+  }
+
+bool
+PacketHistoryTest::RunTests (void)
+{
+  bool ok = true;
+
+  PacketHistory::Enable ();
+
+  Packet p = Packet (0);
+  Packet p1 = Packet (0);
+
+  p = Packet (10);
+  ADD_TRAILER (p, 100);
+  CHECK_HISTORY (p, 2, 10, 100);
+
+  p = Packet (10);
+  ADD_HEADER (p, 1);
+  ADD_HEADER (p, 2);
+  ADD_HEADER (p, 3);
+  CHECK_HISTORY (p, 4, 
+                 3, 2, 1, 10);
+  ADD_HEADER (p, 5);
+  CHECK_HISTORY (p, 5, 
+                 5, 3, 2, 1, 10);
+  ADD_HEADER (p, 6);
+  CHECK_HISTORY (p, 6, 
+                 6, 5, 3, 2, 1, 10);
+
+  p = Packet (10);
+  ADD_HEADER (p, 1);
+  ADD_HEADER (p, 2);
+  ADD_HEADER (p, 3);
+  REM_HEADER (p, 3);
+  CHECK_HISTORY (p, 3, 
+                 2, 1, 10);
+
+  p = Packet (10);
+  ADD_HEADER (p, 1);
+  ADD_HEADER (p, 2);
+  ADD_HEADER (p, 3);
+  REM_HEADER (p, 3);
+  REM_HEADER (p, 2);
+  CHECK_HISTORY (p, 2, 
+                 1, 10);
+
+  p = Packet (10);
+  ADD_HEADER (p, 1);
+  ADD_HEADER (p, 2);
+  ADD_HEADER (p, 3);
+  REM_HEADER (p, 3);
+  REM_HEADER (p, 2);
+  REM_HEADER (p, 1);
+  CHECK_HISTORY (p, 1, 10);
+
+  p = Packet (10);
+  ADD_HEADER (p, 1);
+  ADD_HEADER (p, 2);
+  ADD_HEADER (p, 3);
+  p1 = p;
+  REM_HEADER (p1, 3);
+  REM_HEADER (p1, 2);
+  REM_HEADER (p1, 1);
+  CHECK_HISTORY (p1, 1, 10);
+  CHECK_HISTORY (p, 4, 
+                 3, 2, 1, 10);
+  ADD_HEADER (p1, 1);
+  ADD_HEADER (p1, 2);
+  CHECK_HISTORY (p1, 3, 
+                 2, 1, 10);
+  CHECK_HISTORY (p, 4, 
+                 3, 2, 1, 10);
+  ADD_HEADER (p, 3);
+  CHECK_HISTORY (p, 5, 
+                 3, 3, 2, 1, 10);
+  ADD_TRAILER (p, 4);
+  CHECK_HISTORY (p, 6, 
+                 3, 3, 2, 1, 10, 4);
+  ADD_TRAILER (p, 5);
+  CHECK_HISTORY (p, 7, 
+                 3, 3, 2, 1, 10, 4, 5);
+  REM_HEADER (p, 3);
+  CHECK_HISTORY (p, 6, 
+                 3, 2, 1, 10, 4, 5);
+  REM_TRAILER (p, 5);
+  CHECK_HISTORY (p, 5, 
+                 3, 2, 1, 10, 4);
+  p1 = p;
+  REM_TRAILER (p, 4);
+  CHECK_HISTORY (p, 4, 
+                 3, 2, 1, 10);
+  CHECK_HISTORY (p1, 5, 
+                 3, 2, 1, 10, 4);
+  p1.RemoveAtStart (3);
+  CHECK_HISTORY (p1, 4, 
+                 2, 1, 10, 4);
+  p1.RemoveAtStart (1);
+  CHECK_HISTORY (p1, 4, 
+                 1, 1, 10, 4);
+  p1.RemoveAtStart (1);
+  CHECK_HISTORY (p1, 3, 
+                 1, 10, 4);
+  p1.RemoveAtEnd (4);
+  CHECK_HISTORY (p1, 2, 
+                 1, 10);
+  p1.RemoveAtStart (1);
+  CHECK_HISTORY (p1, 1, 10);
+
+  p = Packet (10);
+  ADD_HEADER (p, 8);
+  ADD_TRAILER (p, 8);
+  ADD_TRAILER (p, 8);
+  p.RemoveAtStart (8+10+8);
+  CHECK_HISTORY (p, 1, 8);
+
+  p = Packet (10);
+  ADD_HEADER (p, 10);
+  ADD_HEADER (p, 8);
+  ADD_TRAILER (p, 6);
+  ADD_TRAILER (p, 7);
+  ADD_TRAILER (p, 9);
+  p.RemoveAtStart (5);
+  p.RemoveAtEnd (12);
+  CHECK_HISTORY (p, 5, 3, 10, 10, 6, 4);
+
+  p = Packet (10);
+  ADD_HEADER (p, 10);
+  ADD_TRAILER (p, 6);
+  p.RemoveAtEnd (18);
+  ADD_TRAILER (p, 5);
+  ADD_HEADER (p, 3);
+  CHECK_HISTORY (p, 3, 3, 8, 5);
+  p.RemoveAtStart (12);
+  CHECK_HISTORY (p, 1, 4);
+  p.RemoveAtEnd (2);
+  CHECK_HISTORY (p, 1, 2);
+  ADD_HEADER (p, 10);
+  CHECK_HISTORY (p, 2, 10, 2);
+  p.RemoveAtEnd (5);
+  CHECK_HISTORY (p, 1, 7);
+
+  Packet p2 = Packet (0);
+  Packet p3 = Packet (0);
+
+  p = Packet (40);
+  ADD_HEADER (p, 5);
+  ADD_HEADER (p, 8);
+  CHECK_HISTORY (p, 3, 8, 5, 40);
+  p1 = p.CreateFragment (0, 5);
+  p2 = p.CreateFragment (5, 5);
+  p3 = p.CreateFragment (10, 43);
+  CHECK_HISTORY (p1, 1, 5);
+  CHECK_HISTORY (p2, 2, 3, 2);
+  CHECK_HISTORY (p3, 2, 3, 40);
+  p1.AddAtEnd (p2);
+  CHECK_HISTORY (p1, 2, 8, 2);
+  CHECK_HISTORY (p2, 2, 3, 2);
+  p1.AddAtEnd (p3);
+  CHECK_HISTORY (p1, 3, 8, 5, 40);
+  CHECK_HISTORY (p2, 2, 3, 2);
+  CHECK_HISTORY (p3, 2, 3, 40);
+  p1 = p.CreateFragment (0, 5);
+  CHECK_HISTORY (p1, 1, 5);
+
+  p3 = Packet (50);
+  ADD_HEADER (p3, 8);
+  CHECK_HISTORY (p3, 2, 8, 50);
+  CHECK_HISTORY (p1, 1, 5);
+  p1.AddAtEnd (p3);
+  CHECK_HISTORY (p1, 3, 5, 8, 50);
+  ADD_HEADER (p1, 5);
+  CHECK_HISTORY (p1, 4, 5, 5, 8, 50);
+  ADD_TRAILER (p1, 2);
+  CHECK_HISTORY (p1, 5, 5, 5, 8, 50, 2);
+  REM_HEADER (p1, 5);
+  CHECK_HISTORY (p1, 4, 5, 8, 50, 2);
+  p1.RemoveAtEnd (60);
+  CHECK_HISTORY (p1, 1, 5);
+  p1.AddAtEnd (p2);
+  CHECK_HISTORY (p1, 2, 8, 2);
+  CHECK_HISTORY (p2, 2, 3, 2);
+
+  p3 = Packet (40);
+  ADD_HEADER (p3, 5);
+  ADD_HEADER (p3, 5);
+  CHECK_HISTORY (p3, 3, 5, 5, 40);
+  p1 = p3.CreateFragment (0, 5);
+  p2 = p3.CreateFragment (5, 5);
+  CHECK_HISTORY (p1, 1, 5);
+  CHECK_HISTORY (p2, 1, 5);
+  p1.AddAtEnd (p2);
+  CHECK_HISTORY (p1, 2, 5, 5);
+
+  p = Packet (0);
+  CHECK_HISTORY (p, 0);
+
+  p3 = Packet (0);
+  ADD_HEADER (p3, 5);
+  ADD_HEADER (p3, 5);
+  CHECK_HISTORY (p3, 2, 5, 5);
+  p1 = p3.CreateFragment (0, 4);
+  p2 = p3.CreateFragment (9, 1);
+  CHECK_HISTORY (p1, 1, 4);
+  CHECK_HISTORY (p2, 1, 1);
+  p1.AddAtEnd (p2);
+  CHECK_HISTORY (p1, 2, 4, 1);
+  
+  
+
+
+  return ok;
+}
+
+static PacketHistoryTest g_packetHistoryTest;
+
+}//namespace ns3
diff -r 62901fdaeb68 -r 777fcfabc1c8 src/common/packet-metadata.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/common/packet-metadata.h	Thu Jun 07 12:48:52 2007 +0200
@@ -0,0 +1,235 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2006,2007 INRIA
+ * All rights reserved.
+ *
+ * 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>
+ */
+#ifndef PACKET_HISTORY_H
+#define PACKET_HISTORY_H
+
+#include <stdint.h>
+#include <vector>
+#include "ns3/callback.h"
+#include "ns3/assert.h"
+#include "packet-printer.h"
+
+namespace ns3 {
+
+class Chunk;
+class Buffer;
+
+class PacketHistory {
+public:
+  static void Enable (void);
+  static void SetOptOne (bool optOne);
+
+  inline PacketHistory (uint32_t uid, uint32_t size);
+  inline PacketHistory (PacketHistory const &o);
+  inline PacketHistory &operator = (PacketHistory const& o);
+  inline ~PacketHistory ();
+
+  template <typename T>
+  void AddHeader (T const &header, uint32_t size);
+  template <typename T>
+  void RemoveHeader (T const &header, uint32_t size);
+
+  template <typename T>
+  void AddTrailer (T const &trailer, uint32_t size);
+  template <typename T>
+  void RemoveTrailer (T const &trailer, uint32_t size);
+
+  PacketHistory CreateFragment (uint32_t start, uint32_t end) const;
+  void AddAtEnd (PacketHistory const&o);
+  void AddPaddingAtEnd (uint32_t end);
+  void RemoveAtStart (uint32_t start);
+  void RemoveAtEnd (uint32_t end);
+
+  void PrintDefault (std::ostream &os, Buffer buffer) const;
+  void Print (std::ostream &os, Buffer buffer, PacketPrinter const &printer) const;
+
+  static void PrintStats (void);
+
+private:
+  /**
+     head -(next)-> tail
+       ^             |
+        \---(prev)---|
+   */
+  struct Data {
+    uint16_t m_count;
+    uint16_t m_size;
+    uint16_t m_dirtyEnd;
+    uint8_t m_data[10];
+  };
+  struct SmallItem {
+    uint16_t next;
+    uint16_t prev;
+    uint32_t typeUid;
+    uint32_t size;
+    uint16_t chunkUid;
+  };
+  struct ExtraItem {
+    uint32_t fragmentStart;
+    uint32_t fragmentEnd;
+    uint32_t packetUid;
+  };
+
+  typedef std::vector<struct Data *> DataFreeList;
+  
+  PacketHistory ();
+  void DoAddHeader (uint32_t uid, uint32_t size);
+  void DoRemoveHeader (uint32_t uid, uint32_t size);
+  void DoAddTrailer (uint32_t uid, uint32_t size);
+  void DoRemoveTrailer (uint32_t uid, uint32_t size);
+
+  inline uint16_t AddSmall (const PacketHistory::SmallItem *item);
+  uint16_t AddBig (uint32_t head, uint32_t tail,
+                   const PacketHistory::SmallItem *item, 
+                   const PacketHistory::ExtraItem *extraItem);
+  void ReplaceTail (PacketHistory::SmallItem *item, 
+                    PacketHistory::ExtraItem *extraItem,
+                    uint32_t available);
+  inline void UpdateHead (uint16_t written);
+  inline void UpdateTail (uint16_t written);
+  uint32_t GetUleb128Size (uint32_t value) const;
+  uint32_t ReadUleb128 (const uint8_t **pBuffer) const;
+  inline void Append16 (uint16_t value, uint8_t *buffer);
+  inline bool TryToAppend (uint32_t value, uint8_t **pBuffer, uint8_t *end);
+  inline bool TryToAppendFast (uint32_t value, uint8_t **pBuffer, uint8_t *end);
+  inline bool TryToAppend32 (uint32_t value, uint8_t **pBuffer, uint8_t *end);
+  inline bool TryToAppend16 (uint16_t value, uint8_t **pBuffer, uint8_t *end);
+  void AppendValue (uint32_t value, uint8_t *buffer);
+  void AppendValueExtra (uint32_t value, uint8_t *buffer);
+  inline void Reserve (uint32_t n);
+  void ReserveCopy (uint32_t n);
+  uint32_t DoPrint (struct PacketHistory::SmallItem *item, uint32_t current,
+                    Buffer data, uint32_t offset, const PacketPrinter &printer,
+                    std::ostream &os) const;
+  uint32_t GetTotalSize (void) const;
+  uint32_t ReadItems (uint16_t current, 
+                      struct PacketHistory::SmallItem *item,
+                      struct PacketHistory::ExtraItem *extraItem) const;
+
+
+  static struct PacketHistory::Data *Create (uint32_t size);
+  static void Recycle (struct PacketHistory::Data *data);
+  static struct PacketHistory::Data *Allocate (uint32_t n);
+  static void Deallocate (struct PacketHistory::Data *data);
+  
+  static DataFreeList m_freeList;
+  static bool m_enable;
+  static uint32_t m_maxSize;
+  static uint16_t m_chunkUid;
+  
+  struct Data *m_data;
+  uint16_t m_head;
+  uint16_t m_tail;
+  uint16_t m_used;
+  uint32_t m_packetUid;
+};
+
+}; // namespace ns3
+
+namespace ns3 {
+
+template <typename T>
+void 
+PacketHistory::AddHeader (T const &header, uint32_t size)
+{
+  DoAddHeader (PacketPrinter::GetHeaderUid<T> (), size);
+}
+
+template <typename T>
+void 
+PacketHistory::RemoveHeader (T const &header, uint32_t size)
+{
+  DoRemoveHeader (PacketPrinter::GetHeaderUid<T> (), size);
+}
+template <typename T>
+void 
+PacketHistory::AddTrailer (T const &trailer, uint32_t size)
+{
+  DoAddTrailer (PacketPrinter::GetTrailerUid<T> (), size);
+}
+template <typename T>
+void 
+PacketHistory::RemoveTrailer (T const &trailer, uint32_t size)
+{
+  DoRemoveTrailer (PacketPrinter::GetTrailerUid<T> (), size);
+}
+
+
+PacketHistory::PacketHistory (uint32_t uid, uint32_t size)
+  : m_data (m_data = PacketHistory::Create (10)),
+    m_head (0xffff),
+    m_tail (0xffff),
+    m_used (0),
+    m_packetUid (uid)
+{
+  memset (m_data->m_data, 0xff, 4);
+  if (size > 0)
+    {
+      DoAddHeader (0, size);
+    }
+}
+PacketHistory::PacketHistory (PacketHistory const &o)
+  : m_data (o.m_data),
+    m_head (o.m_head),
+    m_tail (o.m_tail),
+    m_used (o.m_used),
+    m_packetUid (o.m_packetUid)
+{
+  NS_ASSERT (m_data != 0);
+  m_data->m_count++;
+}
+PacketHistory &
+PacketHistory::operator = (PacketHistory const& o)
+{
+  if (m_data == o.m_data) 
+    {
+      // self assignment
+      return *this;
+    }
+  NS_ASSERT (m_data != 0);
+  m_data->m_count--;
+  if (m_data->m_count == 0) 
+    {
+      PacketHistory::Recycle (m_data);
+    }
+  m_data = o.m_data;
+  m_head = o.m_head;
+  m_tail = o.m_tail;
+  m_used = o.m_used;
+  m_packetUid = o.m_packetUid;
+  NS_ASSERT (m_data != 0);
+  m_data->m_count++;
+  return *this;
+}
+PacketHistory::~PacketHistory ()
+{
+  NS_ASSERT (m_data != 0);
+  m_data->m_count--;
+  if (m_data->m_count == 0) 
+    {
+      PacketHistory::Recycle (m_data);
+    }
+}
+
+}; // namespace ns3
+
+
+#endif /* PACKET_HISTORY_H */
diff -r 62901fdaeb68 -r 777fcfabc1c8 src/common/packet.h
--- a/src/common/packet.h	Thu Jun 07 12:44:44 2007 +0200
+++ b/src/common/packet.h	Thu Jun 07 12:48:52 2007 +0200
@@ -26,7 +26,7 @@
 #include "header.h"
 #include "trailer.h"
 #include "tags.h"
-#include "packet-history.h"
+#include "packet-metadata.h"
 #include "ns3/callback.h"
 #include "ns3/assert.h"
 
diff -r 62901fdaeb68 -r 777fcfabc1c8 utils/bench-packets.cc
--- a/utils/bench-packets.cc	Thu Jun 07 12:44:44 2007 +0200
+++ b/utils/bench-packets.cc	Thu Jun 07 12:48:52 2007 +0200
@@ -20,7 +20,7 @@
  */
 #include "ns3/system-wall-clock-ms.h"
 #include "ns3/packet.h"
-#include "ns3/packet-history.h"
+#include "ns3/packet-metadata.h"
 #include <iostream>
 #include <sstream>