/*=============================================================================
# Filename: Heap.cpp
# Author: syzz
# Mail: 1181955272@qq.com
# Last Modified: 2015-04-26 16:37
# Description: achieve functions in Heap.h
=============================================================================*/

#include "Heap.h"

using namespace std;

Heap::Heap()
{
	this->length = this->size = 0;
	this->heap = NULL;
}

Heap::Heap(unsigned _size)
{
	this->length = 0;
	this->size = _size;
	//this->heap = (Node**)malloc(this->size * sizeof(Node*));	//not use 4 or 8
	this->heap = new Node*[this->size];
	if(this->heap == NULL)
	{
		this->print("error in Heap: Allocation fail!");
		exit(1);
	}
	/*
	this->npmap = (Map*)malloc(this->size * sizeof(struct Map));
	if(this->npmap == NULL)
	{
		this->print("error in Heap: Allocation fail!");
		exit(1);
	}
	*/
}

Node*
Heap::getTop() const
{
	if(this->length > 0)
		return this->heap[0];
	else
		return NULL;
}

unsigned
Heap::getLen() const
{
	return this->length;
}

unsigned 
Heap::getSize() const
{
	return this->size;
}

bool 
Heap::isEmpty() const
{
	return this->length == 0;
}

bool
Heap::insert(Node* _np)
{
	if(this->length == this->size)	//when full, reallocate
	{
		this->heap = (Node**)realloc(this->heap, 2 * this->size * sizeof(Node*));
		if(this->heap == NULL)
		{
			print("error in isert: Reallocation fail!");
			return false;
		}
		/*
		this->npmap = (struct Map*)realloc(this->npmap, 2 * this->size * sizeof(struct Map));
		if(this->npmap == NULL)
		{
			print("error in insert: Reallocation fail!");
			return false;
		}
		*/
		this->size = 2 * this->size;
	}
	unsigned i = this->length, j;
	while(i != 0)
	{
		j = (i-1)/2;
		if(_np->getRank() >= this->heap[j]->getRank())
			break;
		heap[i] = heap[j];
		//this->npmap[k].pos = i;			//adjust the position
		i = j;
	}
	this->heap[i] = _np;
	this->length++;
	return true;
}

bool
Heap::remove()
{
	if(this->length == 0)
	{
		print("error in remove: remove from empty heap!");
		return false;
	}
	//Node* tp = this->heap[0];
	this->length--;
	if(this->length == 0)
		return true;
	Node* xp = this->heap[this->length];
	unsigned i = 0, j = 1;
	while(j < this->length)
	{
		if(j < this->length-1 && this->heap[j]->getRank() > this->heap[j+1]->getRank())
			j++;
		if(xp->getRank() <= this->heap[j]->getRank())
			break;
		this->heap[i] = this->heap[j];
		i = j;
		j = 2 * i + 1;
	}
	this->heap[i] = xp;
	return true;
}

bool
Heap::modify(Node* _np, bool _flag)	//control direction
{
	//search and adjust
	unsigned i, j;
	for(i = 0; i < this->length; ++i)
		if(this->heap[i] == _np)
			break;
	if(_flag == true)	//move up
	{
		while(i != 0)
		{
			j = (i-1)/2;
			if(_np->getRank() < heap[j]->getRank())
			{
				heap[i] = heap[j];
				heap[j] = _np;
				i = j;
			}
			else
				break;
		}
	}
	else				//move down
	{
		j = 2 * i + 1;
		while(j < this->length)
		{
			if(j < this->length - 1 && heap[j]->getRank() > heap[j+1]->getRank())
				j++;
			if(heap[j]->getRank() < _np->getRank())
			{
				heap[i] = heap[j];
				heap[j] = _np;
				i = j;
			}
			else
				break;
		}
	}
	return true;
}

Heap::~Heap()
{
	delete[] this->heap;
	this->heap = NULL;
	this->length = this->size = 0;
}

void
Heap::print(string s)
{
#ifdef DEBUG_KVSTORE
#endif
}