/* -*-	Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */

/*

 * Copyright (c) 2006 INRIA

 * Copyright (c) 2005 Mathieu Lacage

 * 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>

 *

 * This code started as a c++ translation of a java-based code written in 2005

 * to implement a heap sort. Which explains the Copyright Mathieu Lacage at the

 * top of this file.

 *

 * What is smart about this code ?

 *  - it does not use the index 0 in the array to avoid having to convert

 *    C-style array indexes (which start at zero) and heap-style indexes

 *    (which start at 1). This is why _all_ indexes start at 1, and that

 *    the index of the root is 1.

 *  - It uses a slightly non-standard while loop for top-down heapify

 *    to move one if statement out of the loop.

 */

#include "scheduler-heap.h"

#include "event-impl.h"

#include <cassert>

#define noTRACE_HEAP 1

#ifdef TRACE_HEAP

#include <iostream>

# define TRACE(x) \

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

#else /* TRACE_HEAP */

# define TRACE(format,...)

#endif /* TRACE_HEAP */

namespace ns3 {

SchedulerHeap::SchedulerHeap ()

{

	// we purposedly waste an item at the start of

	// the array to make sure the indexes in the

	// array start at one.

}

SchedulerHeap::~SchedulerHeap ()

{}

void

{

}

uint32_t

{

}

uint32_t 

SchedulerHeap::parent (uint32_t id) const

{

	return id / 2;

}

uint32_t 

SchedulerHeap::sibling (uint32_t id) const

{

	return id + 1;

}

uint32_t 

{

	return id * 2;

}

uint32_t 

{

	return id * 2 + 1;

}

uint32_t

SchedulerHeap::root (void) const

{

	return 1;

}

bool

{

	return (id == root ())?true:false;

}

uint32_t

SchedulerHeap::last (void) const

{

	return m_heap.size () - 1;

}

bool

{

	return (id >= m_heap.size ())?true:false;

}

void

SchedulerHeap::exch (uint32_t a, uint32_t b) 

{

	assert (b < m_heap.size () && a < m_heap.size ());

	TRACE ("exch " << a << ", " << b);

	std::pair<EventImpl*, Scheduler::EventKey> tmp (m_heap[a]);

	m_heap[a] = m_heap[b];

	m_heap[b] = tmp;

}

bool

{

	Scheduler::EventKeyCompare compare;

	return compare (m_heap[a].second, m_heap[b].second);

}

uint32_t 

SchedulerHeap::smallest (uint32_t a, uint32_t b)

{

}

bool

{

	return (m_heap.size () == 1)?true:false;

}

void

SchedulerHeap::bottom_up (void)

{

	uint32_t index = last ();

		exch(index, parent (index)); 

		index = parent (index); 

	}

}

void

{

	uint32_t index = root ();

		uint32_t tmp = smallest (left, right);

			return;

		}

		exch (index, tmp);

		index = tmp;

	}

		return;

	}

		return;

	}

		return;

	}

	exch (index, left);

}

EventId

{

	m_heap.push_back (std::make_pair (event, key));

	bottom_up ();

	return EventId (event, key.m_ns, key.m_uid);

}

EventImpl *

{

	return m_heap[root ()].first;

}

Scheduler::EventKey

{

	return m_heap[root ()].second;

}

void     

{

	exch (root (), last ());

	m_heap.pop_back ();

}

EventImpl *

{

	*key = m_heap[i].second;

	exch (i, last ());

	m_heap.pop_back ();

	return ev;

}

bool 

{

	Scheduler::EventKey key = m_heap[i].second;

}

}; // namespace ns3