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

/*

 * Copyright (c) 2007 University of Washington

 * 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

 */

#include "ns3/debug.h"

#include "ns3/composite-trace-resolver.h"

#include "queue.h"

NS_DEBUG_COMPONENT_DEFINE ("Queue");

namespace ns3 {

Queue* Queue::defaultQueue = 0;

Queue::Queue() : 

  m_nBytes(0), 

  m_nTotalReceivedBytes(0),

  m_nPackets(0), 

  m_nTotalReceivedPackets(0),

  m_nTotalDroppedBytes(0),

  m_nTotalDroppedPackets(0)

{

  NS_DEBUG("Queue::Queue ()");

}

Queue::~Queue()

{

  NS_DEBUG("Queue::~Queue ()");

}

TraceResolver *

Queue::CreateTraceResolver (TraceContext const &context)

{

  CompositeTraceResolver *resolver = new CompositeTraceResolver (context);

  resolver->Add ("enqueue", m_traceEnqueue, Queue::ENQUEUE);

  resolver->Add ("dequeue", m_traceDequeue, Queue::DEQUEUE);

  resolver->Add ("drop", m_traceDrop, Queue::DROP);

  return resolver;

}

bool 

Queue::Enqueue (const Packet& p)

{

  NS_DEBUG("Queue::Enqueue (" << &p << ")");

  NS_DEBUG("Queue::Enqueue (): m_traceEnqueue (p)");

  m_traceEnqueue (p);

  bool retval = DoEnqueue (p);

  if (retval)

    {

      m_nBytes += p.GetSize ();

      m_nPackets++;

    }

  return retval;

}

bool

Queue::Dequeue (Packet &p)

{

  NS_DEBUG("Queue::Dequeue (" << &p << ")");

  bool retval = DoDequeue (p);

  if (retval)

    {

      m_nBytes -= p.GetSize ();

      m_nPackets--;

      NS_ASSERT (m_nBytes >= 0);

      NS_ASSERT (m_nPackets >= 0);

      NS_DEBUG("Queue::Dequeue (): m_traceDequeue (p)");

      const Packet packet = p;

      m_traceDequeue (packet);

    }

  return retval;

}

void

Queue::DequeueAll (void)

{

  NS_DEBUG("Queue::DequeueAll ()");

  NS_ASSERT (!"Don't know what to do with dequeued packets!");

}

bool

Queue::Peek (Packet &p)

{

  NS_DEBUG("Queue::Peek (" << &p << ")");

  return DoPeek (p);

}

uint32_t 

Queue::GetNPackets (void)

{

  NS_DEBUG("Queue::GetNPackets () <= " << m_nPackets);

  return m_nPackets;

}

uint32_t

Queue::GetNBytes (void)

{

  NS_DEBUG("Queue::GetNBytes () <= " << m_nBytes);

  return m_nBytes;

}

bool

Queue::IsEmpty (void)

{

  NS_DEBUG("Queue::IsEmpty () <= " << (m_nPackets == 0));

  return m_nPackets == 0;

}

uint32_t

Queue::GetTotalReceivedBytes (void)

{

  NS_DEBUG("Queue::GetTotalReceivedBytes () <= " << m_nTotalReceivedBytes);

  return m_nTotalReceivedBytes;

}

uint32_t

Queue::GetTotalReceivedPackets (void)

{

  NS_DEBUG("Queue::GetTotalReceivedPackets () <= " << m_nTotalReceivedPackets);

  return m_nTotalReceivedPackets;

}

uint32_t

Queue:: GetTotalDroppedBytes (void)

{

  NS_DEBUG(

    "Queue::GetTotalDroppedBytes () <= " << m_nTotalDroppedBytes

    );

  return m_nTotalDroppedBytes;

}

uint32_t

Queue::GetTotalDroppedPackets (void)

{

  NS_DEBUG(

           "Queue::GetTotalDroppedPackets () <= " << m_nTotalDroppedPackets);

  return m_nTotalDroppedPackets;

}

void 

Queue::ResetStatistics (void)

{

  NS_DEBUG("Queue::ResetStatistics ()");

  m_nTotalReceivedBytes = 0;

  m_nTotalReceivedPackets = 0;

  m_nTotalDroppedBytes = 0;

  m_nTotalDroppedPackets = 0;

}

void

Queue::Drop (const Packet& p)

{

  NS_DEBUG("Queue::Drop (" << &p << ")");

  m_nTotalDroppedPackets++;

  m_nTotalDroppedBytes += p.GetSize ();

  NS_DEBUG("Queue::Drop (): m_traceDrop (p)");

  m_traceDrop (p);

}

// Static methods for managing default queue

// Set new default

void Queue::Default(const Queue& q)

{

  delete defaultQueue;      // delete previous (if any)

  defaultQueue = q.Copy();  // set new default

}

// Get current default

Queue& Queue::Default()

{

  // ! Need to schedule an "at end" event to delete the default

  return *defaultQueue;

}

}; // namespace ns3