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

/*

 * Copyright (c) 2006 INRIA

 *

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

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

 * published by the Free Software Foundation;

 *

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

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

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

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

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

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

 *

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

 * The idea to use a std c++ map came from GTNetS

 */

#include "scheduler-map.h"

#include "scheduler-factory.h"

#include "event-impl.h"

#include "ns3/assert.h"

#include <string>

#define noTRACE_MAP 1

#ifdef TRACE_MAP

#include <iostream>

# define TRACE(x) \

std::cout << "MAP TRACE " << x << std::endl;

#else /* TRACE_MAP */

# define TRACE(format,...)

#endif /* TRACE_MAP */

namespace ns3 {

static class SchedulerMapFactory : public SchedulerFactory 

{

public:

  SchedulerMapFactory ()

  {

    SchedulerFactory::Add (this, "Map");

  }

private:

  virtual Scheduler *DoCreate (void) const

  {

    return new SchedulerMap ();

  }

} g_schedulerMapFactory;

SchedulerMap::SchedulerMap ()

{}

SchedulerMap::~SchedulerMap ()

{}

/* Note the invariants which this function must provide:

 * - irreflexibility: f (x,x) is false)

 * - antisymmetry: f(x,y) = !f(y,x)

 * - transitivity: f(x,y) and f(y,z) => f(x,z)

 */

bool

SchedulerMap::EventKeyCompare::operator () (struct EventKey const&a, struct EventKey const&b)

{

  if (a.m_ts < b.m_ts) 

    {

      return true;

    } 

  else if (a.m_ts > b.m_ts)

    {

      return false;

    } 

  else if (a.m_uid < b.m_uid)

    {

      return true;

    }

  else 

    {

      return false;

    }

}

void

SchedulerMap::Insert (const EventId &id)

{

  // acquire a single ref

  EventImpl *event = id.PeekEventImpl ();

  event->Ref ();

  Scheduler::EventKey key;

  key.m_ts = id.GetTs ();

  key.m_uid = id.GetUid ();

  std::pair<EventMapI,bool> result;

  result = m_list.insert (std::make_pair (key, event));

  NS_ASSERT (result.second);

}

bool

SchedulerMap::IsEmpty (void) const

{

  return m_list.empty ();

}

EventId

SchedulerMap::PeekNext (void) const

{

  EventMapCI i = m_list.begin ();

  NS_ASSERT (i != m_list.end ());

  return EventId (i->second, i->first.m_ts, i->first.m_uid);

}

EventId

SchedulerMap::RemoveNext (void)

{

  EventMapI i = m_list.begin ();

  std::pair<Scheduler::EventKey, EventImpl*> next = *i;

  m_list.erase (i);

  return EventId (Ptr<EventImpl> (next.second, false), next.first.m_ts, next.first.m_uid);

}

bool

SchedulerMap::Remove (const EventId &id)

{

  Scheduler::EventKey key;

  key.m_ts = id.GetTs ();

  key.m_uid = id.GetUid ();

  EventMapI i = m_list.find (key);

  NS_ASSERT (i->second == id.PeekEventImpl ());

  // release single ref.

  i->second->Unref ();

  m_list.erase (i);

  return true;

}

}; // namespace ns3