heap.java

this a program for for database implement in this we are implementing several join algorithms

import java.io.*;
import java.util.*;
import java.lang.*;


public class Heap{

		String RelationName;
		TableScan R;
		//key for sorting
		int Key=-1;
			
		TupleNode[] tupleArray=new TupleNode[100];
		int HeapPointer=0;
	
	public Heap()
	{
		this(null,null,-1);
	}
	public Heap(String Relation,String File,int KeyIndex)
	{
		RelationName=Relation;
		R=new TableScan(RelationName,File);
		Key=KeyIndex;
	}
	
	void swap(int i,int j)
	{
		TupleNode tempNode=new TupleNode();
		tempNode=tupleArray[i];
		tupleArray[i]=tupleArray[j];
		tupleArray[j]=tempNode;
		tempNode=null;
	}

	int parent(int i)
	{
		int k=(i-1)/2;
		return k;
	}

	int leftchild(int i)
	{
		int k=2*i+1;
		return k;
	}

	int rightchild(int i)
	{
		int k=2*i+2;
		return k;
	}

	TupleNode root()
	{
		TupleNode tempNode=tupleArray[0];
		return tempNode;
	}

//-------------------
	void checkup(int i)
	{
	if(i!=0)
	{
		TupleNode a=tupleArray[i];
		TupleNode b=tupleArray[parent(i)];
		if(new Integer(a.Value[Key]).intValue()<=new Integer(b.Value[Key]).intValue())
		{
			int k=parent(i);
			swap(i,k);
			checkup(k);
		}
	}
	}

	void insert(TupleNode a)
	{
		tupleArray[HeapPointer]=a;
		checkup(HeapPointer);
		HeapPointer++;
	}

//-------------------
	int min(int i,int j)
	{
		if(tupleArray[i]==null)
		{
			return j;
		}
		else if (tupleArray[j]==null)
		{
			return i;
		}
		else if(new Integer(tupleArray[j].Value[Key]).intValue()<new Integer(tupleArray[i].Value[Key]).intValue())
		{
			return j;
		}
		else if(new Integer(tupleArray[j].Value[Key]).intValue()>new Integer(tupleArray[i].Value[Key]).intValue())
		{
			return i;
		}
		else 
		{
			return j;
		}
	}
	void checkdown(int i)
	{
		int k=leftchild(i);
		int l=rightchild(i);
		if(k<HeapPointer)
		{
			int min=min(k,l);
			if(tupleArray[min]!=null)
			{
				if(new Integer(tupleArray[min].Value[Key]).intValue()<new Integer(tupleArray[i].Value[Key]).intValue())
				{
					swap(i,min);
				}
			checkdown(min);
			}
		}
	}
	
	void deletemin()
	{
	tupleArray[0]=null;
	tupleArray[0]=tupleArray[HeapPointer-1];
	tupleArray[HeapPointer-1]=null;
	HeapPointer--;
	checkdown(0);
	}
//-------------------

	TupleNode[] getarray()
	{
		return tupleArray;
	}
	
	TupleNode Minimum()
	{
		return tupleArray[0];
	}

	//Iterator functions
	void Open()
	{
		R.Open();
		String[] s=R.GetNext();
		while(s!=null)
		{
			TupleNode t=new TupleNode(s);
			insert(t);
			s=R.GetNext();
		}
		R.Close();
	}
	
	TupleNode GetNext()
	{
		if(HeapPointer<=0)
		{
			return null;
		}
		
		TupleNode t=tupleArray[0];
		deletemin();
		return t;
	}
	
	void Close()
	{
		HeapPointer=0;
	}
	//main function
	/*
		public static void main(String args[])
		{
			Heap H=new Heap("R","R.txt",0);
			H.R.PrintRelation();
			System.out.println("\n");
			H.Open();
			
			TupleNode tuple=H.GetNext();
					
			while(tuple!=null)
			{
				H.R.PrintTuple(tuple.Value);
				tuple=H.GetNext();
			}
			H.Close();
		}
	*/
}