PoolingStack.java

package org.jbox2d.pooling;

import java.lang.reflect.Array;


public class PoolingStack<E>
{

	private final E[] pool;
	private int index;
	private final int size;
	private final PoolContainer<E> container;

	@SuppressWarnings("unchecked")
	public PoolingStack(Class<E> argClass, int argStackSize)
	{
		size= argStackSize;
		pool= (E[]) Array.newInstance(argClass, argStackSize);

		for (int i= 0; i < argStackSize; i++)
		{
			System.out.println("adgadg");
			try
			{
				pool[i]= argClass.newInstance();
			}
			catch (InstantiationException e)
			{
				System.err.println("Error creating pooled object " + argClass.getCanonicalName());
				e.printStackTrace();
			}
			catch (IllegalAccessException e)
			{
				System.err.println("Error creating pooled object " + argClass.getCanonicalName());
				e.printStackTrace();
			}
		}
		index= 0;
		container= new PoolContainer<E>();
	}

	public final E pop()
	{
		assert (index < size) : "End of stack reached, there is probably a leak somewhere";
		return pool[index++];
	}

	public final PoolContainer<E> pop(int argNum)
	{
		assert (index + argNum < size) : "End of stack reached, there is probably a leak somewhere";

		switch (argNum)
		{
			case 9:
				container.p8= pool[index++];
			case 8:
				container.p7= pool[index++];
			case 7:
				container.p6= pool[index++];
			case 6:
				container.p5= pool[index++];
			case 5:
				container.p4= pool[index++];
			case 4:
				container.p3= pool[index++];
			case 3:
				container.p2= pool[index++];
			case 2:
				container.p1= pool[index++];
			case 1:
				container.p0= pool[index++];
				break;
			default:
				assert (false);
		}
		return container;
	}

	public final void push(int argNum)
	{
		index-= argNum;
		assert (index >= 0) : "Beginning of stack reached, push/pops are unmatched";
	}

	public static class PoolContainer<E>
	{
		public static final int MAX_MEMBERS= 9;

		public E p0, p1, p2, p3, p4, p5, p6, p7, p8;

		public void populate(E[] argRay)
		{
			p0= argRay[0];
			p1= argRay[1];
			p2= argRay[2];
			p3= argRay[3];
			p4= argRay[4];
			p5= argRay[5];
			p6= argRay[6];
			p7= argRay[7];
			p8= argRay[8];
		}
	}
}