Hash Collision check for BlockPos MC1.12 vs Pos CodingLib

gistfile1.txt

package com.builtbroken.jlib;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.Multimap;
import icbm.classic.lib.transform.vector.Pos;
import net.minecraft.util.math.BlockPos;
import net.minecraft.util.math.ChunkPos;

import java.util.Collection;
import java.util.HashSet;
import java.util.Map;

/**
 * Test case created to check for collisions inside a chunk when using the BlockPos hash Function
 * <p>
 * Original code provided by Paul Fulham on MMD discord. Modified to compare block pos with pos
 */
public class Main
{
    public static void main(String[] args)
    {
        for (int i = 0; i < 100; i++)
        {
            int x = (int) (Math.random() * Short.MAX_VALUE);
            int z = (int) (Math.random() * Short.MAX_VALUE);
            int c = checkCollisions(x, z);
            int c2 = checkCollisionsPos(x, z);
        }

        for (int i = 0; i < 100; i++)
        {
            int x = -(int) (Math.random() * Short.MAX_VALUE);
            int z = -(int) (Math.random() * Short.MAX_VALUE);
            int c = checkCollisions(x, z);
            int c2 = checkCollisionsPos(x, z);
        }
    }

    public static int checkCollisions(int chunk_x, int chunk_z)
    {
        System.out.println("Checking: " + chunk_x + ", " + chunk_z);
        ChunkPos chunk = new ChunkPos(chunk_x, chunk_z);
        Multimap<Integer, BlockPos> map = HashMultimap.create();
        HashSet<Integer> hashSet = new HashSet();

        //Generate positions
        for (BlockPos p : BlockPos.getAllInBox(chunk.getBlock(0, 0, 0), chunk.getBlock(15, 255, 15)))
        {
            hashSet.add(p.hashCode());
            map.put(p.hashCode(), p);
        }

        //Find collisions
        int groups = 0, total = 0;
        for (Map.Entry<Integer, Collection<BlockPos>> entry : map.asMap().entrySet())
        {
            if (entry.getValue().size() > 1)
            {
                groups++;
                total += entry.getValue().size() - 1; //-1 as a single value is not a collision until more values are added
            }
        }

        //Output data
        System.out.println("\tGroups: " + groups);
        System.out.println("\tCollisions: " + total);
        System.out.println("\tHashSet: " + hashSet.size());

        return total;
    }

    public static int checkCollisionsPos(int chunk_x, int chunk_z)
    {
        System.out.println("Checking: " + chunk_x + ", " + chunk_z);
        ChunkPos chunk = new ChunkPos(chunk_x, chunk_z);
        Multimap<Integer, Pos> map = HashMultimap.create();
        HashSet<Integer> hashSet = new HashSet();

        //Generate positions
        for (BlockPos blockPos : BlockPos.getAllInBox(chunk.getBlock(0, 0, 0), chunk.getBlock(15, 255, 15)))
        {
            Pos p = new Pos(blockPos);
            hashSet.add(p.hashCode());
            map.put(p.hashCode(), p);
        }

        //Find collisions
        int groups = 0, total = 0;
        for (Map.Entry<Integer, Collection<Pos>> entry : map.asMap().entrySet())
        {
            if (entry.getValue().size() > 1)
            {
                groups++;
                total += entry.getValue().size() - 1; //-1 as a single value is not a collision until more values are added
            }
        }

        //Output data
        System.out.println("\tGroups: " + groups);
        System.out.println("\tCollisions: " + total);
        System.out.println("\tHashSet: " + hashSet.size());

        return total;
    }
}