AlttdGriefPrevention/src/me/ryanhamshire/GriefPrevention/EntityCleanupTask.java

/*
    GriefPrevention Server Plugin for Minecraft
    Copyright (C) 2012 Ryan Hamshire

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package me.ryanhamshire.GriefPrevention;

import java.util.ArrayList;
import java.util.List;

import org.bukkit.Material;
import org.bukkit.World;
import org.bukkit.entity.Boat;
import org.bukkit.entity.Entity;
import org.bukkit.entity.Player;
import org.bukkit.entity.Vehicle;

//FEATURE: creative mode worlds get a regular entity cleanup

//this main thread task revisits the location of a partially chopped tree from several minutes ago
//if any part of the tree is still there and nothing else has been built in its place, remove the remaining parts
class EntityCleanupTask implements Runnable 
{
	//where to start cleaning in the list of entities
	private double percentageStart;
	
	public EntityCleanupTask(double percentageStart)
	{
		this.percentageStart = percentageStart;
	}
	
	@Override
	public void run() 
	{
		ArrayList<World> worlds = new ArrayList<World>();
		for(World world : GriefPrevention.instance.getServer().getWorlds())
	    {
		    if(GriefPrevention.instance.config_claims_worldModes.get(world) == ClaimsMode.Creative)
		    {
		        worlds.add(world);
		    }
	    }
		
		for(int i = 0; i < worlds.size(); i++)
		{
			World world = worlds.get(i);
			
			List<Entity> entities = world.getEntities();
			
			//starting and stopping point.  each execution of the task scans 10% of the server's (loaded) entities
			int j = (int)(entities.size() * this.percentageStart);
			int k = (int)(entities.size() * (this.percentageStart + .1));
			Claim cachedClaim = null;
			for(; j < entities.size() && j < k; j++)
			{
				Entity entity = entities.get(j);
				
				boolean remove = false;
				if(entity instanceof Boat) //boats must be occupied
				{
					Boat boat = (Boat)entity;
					if(boat.isEmpty()) remove = true;
				}
				
				else if(entity instanceof Vehicle)
				{
					Vehicle vehicle = (Vehicle)entity;
					
					//minecarts in motion must be occupied by a player
					if(vehicle.getVelocity().lengthSquared() != 0)
					{
						if(vehicle.isEmpty() || !(vehicle.getPassenger() instanceof Player))
						{
							remove = true;
						}
					}
					
					//stationary carts must be on rails
					else
					{
						Material material = world.getBlockAt(vehicle.getLocation()).getType();
						if(material != Material.RAILS && material != Material.POWERED_RAIL && material != Material.DETECTOR_RAIL)
						{
							remove = true;
						}
					}
				}
				
				//all non-player entities must be in claims
				else if(!(entity instanceof Player))
				{
					Claim claim = GriefPrevention.instance.dataStore.getClaimAt(entity.getLocation(), false, cachedClaim);
					if(claim != null)
					{
						cachedClaim = claim;
					}
					else
					{
						remove = true;
					}
				}
				
				if(remove)
				{
					entity.remove();
				}
			}
		}
		
		//starting and stopping point.  each execution of the task scans 5% of the server's claims
		List<Claim> claims = GriefPrevention.instance.dataStore.claims;
		int j = (int)(claims.size() * this.percentageStart);
		int k = (int)(claims.size() * (this.percentageStart + .05));
		for(; j < claims.size() && j < k; j++)
		{
			Claim claim = claims.get(j);
			
			//if it's a creative mode claim
			if(GriefPrevention.instance.creativeRulesApply(claim.getLesserBoundaryCorner()))
			{
				//check its entity count and remove any extras
				claim.allowMoreEntities(true);
			}			
		}
		
		//schedule the next run of this task, in 3 minutes (20L is approximately 1 second)
		double nextRunPercentageStart = this.percentageStart + .05;
		if(nextRunPercentageStart > .99)
		{
			nextRunPercentageStart = 0;
		}
		
		EntityCleanupTask task = new EntityCleanupTask(nextRunPercentageStart);
		GriefPrevention.instance.getServer().getScheduler().scheduleSyncDelayedTask(GriefPrevention.instance, task, 20L * 60 * 1);
	}
}