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

/*

 * Copyright (c) 2007 University of Washington

 *

 * 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

 */

#include "ns3/log.h"

#include "ns3/trace-source-accessor.h"

#include "queue.h"

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("Queue");

NS_OBJECT_ENSURE_REGISTERED (Queue);

TypeId 

Queue::GetTypeId (void)

{

  static TypeId tid = TypeId ("ns3::Queue")

    .SetParent<Object> ()

    .AddTraceSource ("Enqueue", "Enqueue a packet in the queue.",

    .AddTraceSource ("Dequeue", "Dequeue a packet from the queue.",

    .AddTraceSource ("Drop", "Drop a packet stored in the queue.",

  ;

  return tid;

}

Queue::Queue() : 

  m_nBytes (0),

  m_nTotalReceivedBytes (0),

  m_nPackets (0),

  m_nTotalReceivedPackets (0),

  m_nTotalDroppedBytes (0),

  m_nTotalDroppedPackets (0)

{

  NS_LOG_FUNCTION (this);

}

Queue::~Queue()

{

  NS_LOG_FUNCTION (this);

}

bool 

Queue::Enqueue (Ptr<Packet> p)

{

  NS_LOG_FUNCTION (this << p);

  //

  // If DoEnqueue fails, Queue::Drop is called by the subclass

  //

  bool retval = DoEnqueue (p);

  if (retval)

    {

      NS_LOG_LOGIC ("m_traceEnqueue (p)");

      m_traceEnqueue (p);

      uint32_t size = p->GetSize ();

      m_nBytes += size;

      m_nTotalReceivedBytes += size;

      m_nPackets++;

      m_nTotalReceivedPackets++;

    }

  return retval;

}

Ptr<Packet>

Queue::Dequeue (void)

{

  NS_LOG_FUNCTION (this);

  Ptr<Packet> packet = DoDequeue ();

  if (packet != 0)

    {

      NS_ASSERT (m_nBytes >= packet->GetSize ());

      NS_ASSERT (m_nPackets > 0);

      m_nBytes -= packet->GetSize ();

      m_nPackets--;

      NS_LOG_LOGIC ("m_traceDequeue (packet)");

      m_traceDequeue (packet);

    }

  return packet;

}

void

Queue::DequeueAll (void)

{

  NS_LOG_FUNCTION (this);

  while (!IsEmpty ())

    {

      Dequeue ();

    }

}

Ptr<const Packet>

Queue::Peek (void) const

{

  NS_LOG_FUNCTION (this);

  return DoPeek ();

}

uint32_t 

Queue::GetNPackets (void) const

{

  NS_LOG_FUNCTION (this);

  NS_LOG_LOGIC ("returns " << m_nPackets);

  return m_nPackets;

}

uint32_t

Queue::GetNBytes (void) const

{

  NS_LOG_FUNCTION (this);

  NS_LOG_LOGIC (" returns " << m_nBytes);

  return m_nBytes;

}

bool

Queue::IsEmpty (void) const

{

  NS_LOG_FUNCTION (this);

  NS_LOG_LOGIC ("returns " << (m_nPackets == 0));

  return m_nPackets == 0;

}

uint32_t

Queue::GetTotalReceivedBytes (void) const

{

  NS_LOG_FUNCTION (this);

  NS_LOG_LOGIC ("returns " << m_nTotalReceivedBytes);

  return m_nTotalReceivedBytes;

}

uint32_t

Queue::GetTotalReceivedPackets (void) const

{

  NS_LOG_FUNCTION (this);

  NS_LOG_LOGIC ("returns " << m_nTotalReceivedPackets);

  return m_nTotalReceivedPackets;

}

uint32_t

Queue:: GetTotalDroppedBytes (void) const

{

  NS_LOG_FUNCTION (this);

  NS_LOG_LOGIC ("returns " << m_nTotalDroppedBytes);

  return m_nTotalDroppedBytes;

}

uint32_t

Queue::GetTotalDroppedPackets (void) const

{

  NS_LOG_FUNCTION (this);

  NS_LOG_LOGIC ("returns " << m_nTotalDroppedPackets);

  return m_nTotalDroppedPackets;

}

void 

Queue::ResetStatistics (void)

{

  NS_LOG_FUNCTION (this);

  m_nTotalReceivedBytes = 0;

  m_nTotalReceivedPackets = 0;

  m_nTotalDroppedBytes = 0;

  m_nTotalDroppedPackets = 0;

}

void

Queue::Drop (Ptr<Packet> p)

{

  NS_LOG_FUNCTION (this << p);

  m_nTotalDroppedPackets++;

  m_nTotalDroppedBytes += p->GetSize ();

  NS_LOG_LOGIC ("m_traceDrop (p)");

  m_traceDrop (p);

}

} // namespace ns3