bt_node.h

// 91574 Database II - C++ Programming
// Swathi Kurunji, UMass Lowell, MA, 2011
// bt_node.h - definition of class BtreeNode for this project.

#ifndef BT_NODE_H
#define BT_NODE_H

#include<iostream>
#include<cstdlib>
using namespace std;

#include "bt_errors.h"

// BtreeNode is the basic structure of B+tree nodes
// Each BtreeNode will be of one page size which is 1024

class BtreeNode
{
	protected:

		//NodeId nodeNo;  	//node number of the BtreeNode.
		int type;   		//can be index or leaf
		int keyCount; 		//number of keys in the node

		KeyId key[MAX_NUM_KEYS];	//key of the record
		BtreeNode *ptr[MAX_NUM_PTRS]; 	//In leaf node pointers will be null

		BtreeNode *parentPtr;

	public:
		BtreeNode();

		virtual ~BtreeNode();

		//void init();

		int get_keyCount();

		void set_keyCount( int );

		//set type of node
		void set_type( int );

		//get type of node. used while insertion, deletion or scan of record
		int get_type();

		KeyId getKey( int n )
		{
			return key[n];
		}

		void setKey( int n, KeyId newKey )
		{
			key[n] = newKey;
		}

		BtreeNode* getPtr( int n )
		{
			return ptr[n];
		}

		void setPtr( BtreeNode *pointer, int n )
		{
			ptr[n] = pointer;
		}

		BtreeNode* get_parentPtr();

		void set_parentPtr( BtreeNode *pointer );

		//insert function with 4 parameters - needed for BtreeIndex
		virtual Status insertKey( KeyId, int, BtreeNode*& leftChild,
				BtreeNode*& rightChild )
		{
			cout << "U r in wrong place" << endl;
			return OK;
		}

		//insert function with 2 parameters - BtreeLeaf
		virtual Status insertKey( KeyId, int )
		{
			cout << "U r in wrong place" << endl;
			return OK;
		}

		virtual Status deleteKey( KeyId, int )
		{
			cout << "U r in wrong place" << endl;
			return OK;
		}

		//search function with 3 parameters - needed for BtreeIndex, where childPtr will be set to the pointer on which we need to move downwards in tree
		virtual Status searchKey( KeyId, int, BtreeNode*& childPtr )
		{
			cout << "U r in wrong place" << endl;
			return OK;
		}

		//search function with 2 parameters - BtreeLeaf
		virtual Status searchKey( KeyId, int )
		{
			cout << "U r in wrong place" << endl;
			return OK;
		}
};

#endif