A more optimized island deletion and some bug fixes/optimizations.

src/main/java/com/songoda/skyblock/island/IslandLevel.java

@@ -29,23 +29,24 @@ public class IslandLevel {
         this.skyblock = skyblock;
         this.ownerUUID = ownerUUID;
 
-        Config config = skyblock.getFileManager().getConfig(new File(new File(skyblock.getDataFolder().toString() + "/level-data"), ownerUUID.toString() + ".yml"));
+        final Config config = skyblock.getFileManager().getConfig(new File(new File(skyblock.getDataFolder().toString() + "/level-data"), ownerUUID.toString() + ".yml"));
-        FileConfiguration configLoad = config.getFileConfiguration();
+        final FileConfiguration configLoad = config.getFileConfiguration();
 
-        Map<String, Long> materials;
+        final ConfigurationSection section = configLoad.getConfigurationSection("Levelling.Materials");
+        final Map<String, Long> materials;
 
-        ConfigurationSection materialSection = configLoad.getConfigurationSection("Leveling.Materials");
+        if (section != null) {
+            final Set<String> keys = section.getKeys(false);
+            materials = new HashMap<>(keys.size());
 
-        if (materialSection != null) {
+            for (String material : keys) {
-            Set<String> keys = materialSection.getKeys(false);
-            materials = new HashMap<>(keys.size() * 2);
 
-            for (String material : materialSection.getKeys(false)) {
+                ConfigurationSection current = section.getConfigurationSection(material);
-
-                final ConfigurationSection current = materialSection.getConfigurationSection(material);
 
                 if (current.isSet("Amount")) materials.put(material, current.getLong("Amount"));
+
             }
+
         } else {
             materials = new HashMap<>();
         }
@@ -71,10 +72,11 @@ public class IslandLevel {
             ConfigurationSection current = materialSection.getConfigurationSection(entry.getKey());
 
             if (current == null) continue;
-            
+
             long pointsRequired = current.getLong("Points", 0);
 
             if (pointsRequired != 0) pointsEarned = pointsEarned + (entry.getValue() * pointsRequired);
+
         }
 
         return pointsEarned;

src/main/java/com/songoda/skyblock/island/IslandManager.java

@@ -1,8 +1,38 @@
 package com.songoda.skyblock.island;
 
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.UUID;
+import java.util.stream.Collectors;
+
+import org.bukkit.Bukkit;
+import org.bukkit.ChatColor;
+import org.bukkit.Chunk;
+import org.bukkit.ChunkSnapshot;
+import org.bukkit.GameMode;
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.block.Biome;
+import org.bukkit.block.Block;
+import org.bukkit.configuration.ConfigurationSection;
+import org.bukkit.configuration.file.FileConfiguration;
+import org.bukkit.configuration.file.YamlConfiguration;
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.IllegalPluginAccessException;
+
 import com.google.common.base.Preconditions;
 import com.songoda.skyblock.SkyBlock;
-import com.songoda.skyblock.api.event.island.*;
+import com.songoda.skyblock.api.event.island.IslandCreateEvent;
+import com.songoda.skyblock.api.event.island.IslandDeleteEvent;
+import com.songoda.skyblock.api.event.island.IslandLoadEvent;
+import com.songoda.skyblock.api.event.island.IslandOwnershipTransferEvent;
+import com.songoda.skyblock.api.event.island.IslandUnloadEvent;
 import com.songoda.skyblock.ban.BanManager;
 import com.songoda.skyblock.config.FileManager;
 import com.songoda.skyblock.config.FileManager.Config;
@@ -10,6 +40,7 @@ import com.songoda.skyblock.cooldown.CooldownManager;
 import com.songoda.skyblock.cooldown.CooldownType;
 import com.songoda.skyblock.invite.Invite;
 import com.songoda.skyblock.invite.InviteManager;
+import com.songoda.skyblock.island.removal.ChunkDeleteSplitter;
 import com.songoda.skyblock.message.MessageManager;
 import com.songoda.skyblock.playerdata.PlayerData;
 import com.songoda.skyblock.playerdata.PlayerDataManager;
@@ -32,18 +63,6 @@ import com.songoda.skyblock.utils.world.WorldBorder;
 import com.songoda.skyblock.utils.world.block.BlockDegreesType;
 import com.songoda.skyblock.visit.VisitManager;
 import com.songoda.skyblock.world.WorldManager;
-import org.bukkit.*;
-import org.bukkit.block.Biome;
-import org.bukkit.block.Block;
-import org.bukkit.configuration.ConfigurationSection;
-import org.bukkit.configuration.file.FileConfiguration;
-import org.bukkit.configuration.file.YamlConfiguration;
-import org.bukkit.entity.Player;
-import org.bukkit.plugin.IllegalPluginAccessException;
-
-import java.io.File;
-import java.io.IOException;
-import java.util.*;
 
 public class IslandManager {
 
@@ -383,6 +402,8 @@ public class IslandManager {
         }
     }
 
+    int j = 0;
+    
     public void deleteIsland(Island island) {
         ScoreboardManager scoreboardManager = skyblock.getScoreboardManager();
         PlayerDataManager playerDataManager = skyblock.getPlayerDataManager();
@@ -396,17 +417,13 @@ public class IslandManager {
             Bukkit.getScheduler().runTaskLater(skyblock, () -> {
                 org.bukkit.World world = worldManager.getWorld(worldList);
                 Location location = island.getLocation(worldList, IslandEnvironment.Island);
+
                 if (location == null) return;
-                int size = island.getSize();
+
-                int xx = location.getBlockX() - size / 2;
+                List<ChunkSnapshot> snapshots = com.songoda.skyblock.levelling.Chunk.getChunksToScan(island, worldList).stream().map(ch -> world.getChunkAt(ch.getX(), ch.getZ()))
-                int zz = location.getBlockZ() - size / 2;
+                        .map(chunk -> chunk.getChunkSnapshot()).collect(Collectors.toList());
-                for (int x = xx; x < xx + size; x++) {
+
-                    for (int z = zz; z < zz + size; z++) {
+                ChunkDeleteSplitter.startDeleting(world, snapshots);
-                        for (int y = 0; y < world.getMaxHeight(); y++) {
-                            new Location(world, x, y, z).getBlock().setType(Material.AIR);
-                        }
-                    }
-                }
             }, i);
             i += 20L;
         }

src/main/java/com/songoda/skyblock/island/IslandWorld.java

@@ -12,7 +12,7 @@ public enum IslandWorld {
     Normal, Nether, End;
 
     public static List<IslandWorld> getIslandWorlds() {
-        List<IslandWorld> islandWorlds = new ArrayList<>();
+        List<IslandWorld> islandWorlds = new ArrayList<>(3);
 
         WorldManager worldManager = SkyBlock.getInstance().getWorldManager();
         if (worldManager.getWorld(Normal) != null)

src/main/java/com/songoda/skyblock/island/removal/ChunkDeleteSplitter.java

@@ -0,0 +1,95 @@
+package com.songoda.skyblock.island.removal;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+
+import org.bukkit.Bukkit;
+import org.bukkit.ChunkSnapshot;
+import org.bukkit.Material;
+import org.bukkit.World;
+import org.bukkit.scheduler.BukkitRunnable;
+
+import com.google.common.collect.Lists;
+import com.songoda.skyblock.SkyBlock;
+
+public final class ChunkDeleteSplitter extends BukkitRunnable {
+
+    private int completedNum;
+
+    private final World world;
+    private final int threadCount;
+    private final Queue<XYZPair> toRemove;
+
+    private ChunkDeleteSplitter(World world, List<ChunkSnapshot> snapshots) {
+        this.toRemove = new ConcurrentLinkedQueue<>();
+        this.world = world;
+
+        final List<List<ChunkSnapshot>> parts = Lists.partition(snapshots, 32);
+
+        this.threadCount = parts.size();
+
+        for (List<ChunkSnapshot> sub : parts) {
+            queueWork(sub);
+        }
+    }
+
+    private void queueWork(List<ChunkSnapshot> subList) {
+        Bukkit.getServer().getScheduler().runTaskAsynchronously(SkyBlock.getInstance(), () -> {
+            for (ChunkSnapshot shot : subList) {
+                for (int x = 0; x < 16; x++) {
+                    for (int z = 0; z < 16; z++) {
+                        for (int y = 0; y < 256; y++) {
+                            final Material type = shot.getBlockType(x, y, z);
+
+                            if (type == Material.AIR) continue;
+
+                            toRemove.add(new XYZPair(x, y, z));
+                        }
+                    }
+                }
+            }
+            increment();
+        });
+    }
+
+    private synchronized void increment() {
+        completedNum++;
+    }
+
+    private synchronized int get() {
+        return completedNum;
+    }
+
+    @Override
+    public void run() {
+        if (get() != threadCount) return;
+
+        int deleteAmount = 0;
+
+        for (Iterator<XYZPair> it = toRemove.iterator(); it.hasNext();) {
+
+            if (deleteAmount == 10000) break;
+
+            final XYZPair pair = it.next();
+
+            world.getBlockAt(pair.getX(), pair.getY(), pair.getZ()).setType(Material.AIR);
+
+            deleteAmount++;
+            it.remove();
+        }
+
+        if (toRemove.isEmpty()) {
+            cancel();
+        }
+    }
+
+    public static void startDeleting(World world, List<ChunkSnapshot> snapshots) {
+
+        final ChunkDeleteSplitter splitter = new ChunkDeleteSplitter(world, snapshots);
+
+        splitter.runTaskTimer(SkyBlock.getInstance(), 5, 5);
+    }
+
+}

src/main/java/com/songoda/skyblock/island/removal/XYZPair.java

@@ -0,0 +1,27 @@
+package com.songoda.skyblock.island.removal;
+
+public class XYZPair {
+
+    private final int x;
+    private final int y;
+    private final int z;
+
+    public XYZPair(final int x, final int y, final int z) {
+        this.x = x;
+        this.y = y;
+        this.z = z;
+    }
+
+    public int getX() {
+        return x;
+    }
+
+    public int getY() {
+        return y;
+    }
+
+    public int getZ() {
+        return z;
+    }
+
+}

src/main/java/com/songoda/skyblock/leaderboard/LeaderboardManager.java

@@ -42,9 +42,11 @@ public class LeaderboardManager {
 
         visitManager.loadIslands();
 
-        List<LeaderboardPlayer> islandLevels = new ArrayList<>();
+        int arraySize = visitManager.getIslands().size();
-        List<LeaderboardPlayer> islandBanks = new ArrayList<>();
+        
-        List<LeaderboardPlayer> islandVotes = new ArrayList<>();
+        List<LeaderboardPlayer> islandLevels = new ArrayList<>(arraySize);
+        List<LeaderboardPlayer> islandBanks = new ArrayList<>(arraySize);
+        List<LeaderboardPlayer> islandVotes = new ArrayList<>(arraySize);
 
         boolean enableExemptions = skyblock.getFileManager().getConfig(new File(skyblock.getDataFolder(), "config.yml"))
                 .getFileConfiguration().getBoolean("Island.Leaderboard.Exemptions.Enable");
@@ -87,7 +89,7 @@ public class LeaderboardManager {
         VisitManager visitManager = skyblock.getVisitManager();
         visitManager.loadIslands();
 
-        List<LeaderboardPlayer> leaderboardPlayers = new ArrayList<>();
+        List<LeaderboardPlayer> leaderboardPlayers = new ArrayList<>(visitManager.getIslands().size());
 
         switch (type) {
             case Level:
@@ -145,9 +147,11 @@ public class LeaderboardManager {
     }
 
     public Leaderboard getLeaderboardFromPosition(Leaderboard.Type type, int position) {
-        for (Leaderboard leaderboardPlayerList : leaderboardStorage)
+        for (Leaderboard leaderboardPlayerList : leaderboardStorage) {
-            if (leaderboardPlayerList.getType() == type && leaderboardPlayerList.getPosition() == position)
+            if (leaderboardPlayerList.getType() == type && leaderboardPlayerList.getPosition() == position) {
                 return leaderboardPlayerList;
+            }
+        }
         return null;
     }
 

src/main/java/com/songoda/skyblock/levelling/Chunk.java

@@ -12,8 +12,11 @@ import org.bukkit.configuration.file.FileConfiguration;
 import org.bukkit.entity.Player;
 
 import java.io.File;
+import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Set;
 
 public class Chunk {
@@ -43,7 +46,7 @@ public class Chunk {
 
             for (IslandWorld islandWorld : IslandWorld.getIslandWorlds()) {
                 if (islandWorld == IslandWorld.Normal || (islandWorld == IslandWorld.Nether && hasNether) || (islandWorld == IslandWorld.End && hasEnd)) {
-                    this.getChunksToScan(islandWorld);
+                    chunkPositions.addAll(getChunksToScan(island, islandWorld));
                 }
             }
 
@@ -130,12 +133,15 @@ public class Chunk {
         }
     }
 
-    private void getChunksToScan(IslandWorld islandWorld) {
+    public static List<ChunkPosition> getChunksToScan(Island island, IslandWorld islandWorld) {
-        Location islandLocation = this.island.getLocation(islandWorld, IslandEnvironment.Island);
+        Location islandLocation = island.getLocation(islandWorld, IslandEnvironment.Island);
+        
+        if (islandLocation == null) return new ArrayList<>(0);
+        
         World world = islandLocation.getWorld();
 
-        Location minLocation = new Location(world, islandLocation.getBlockX() - this.island.getRadius(), 0, islandLocation.getBlockZ() - this.island.getRadius());
+        Location minLocation = new Location(world, islandLocation.getBlockX() - island.getRadius(), 0, islandLocation.getBlockZ() - island.getRadius());
-        Location maxLocation = new Location(world, islandLocation.getBlockX() + this.island.getRadius(), world.getMaxHeight(), islandLocation.getBlockZ() + this.island.getRadius());
+        Location maxLocation = new Location(world, islandLocation.getBlockX() + island.getRadius(), world.getMaxHeight(), islandLocation.getBlockZ() + island.getRadius());
 
         int minX = Math.min(maxLocation.getBlockX(), minLocation.getBlockX());
         int minZ = Math.min(maxLocation.getBlockZ(), minLocation.getBlockZ());
@@ -143,10 +149,14 @@ public class Chunk {
         int maxX = Math.max(maxLocation.getBlockX(), minLocation.getBlockX());
         int maxZ = Math.max(maxLocation.getBlockZ(), minLocation.getBlockZ());
 
+        List<ChunkPosition> positions = new LinkedList<>();
+        
         for (int x = minX; x < maxX + 16; x += 16) {
             for (int z = minZ; z < maxZ + 16; z += 16) {
-                this.chunkPositions.add(new ChunkPosition(world, x >> 4, z >> 4));
+                positions.add(new ChunkPosition(world, x >> 4, z >> 4));
             }
         }
+        
+        return positions;
     }
 }

src/main/java/com/songoda/skyblock/listeners/Portal.java

@@ -174,7 +174,7 @@ public class Portal implements Listener {
 
     }
 
-    public class Tick {
+    public static class Tick {
         private int tick = 1;
         private long last = System.currentTimeMillis() - 1001;
 

src/main/java/com/songoda/skyblock/listeners/Respawn.java

@@ -38,10 +38,11 @@ public class Respawn implements Listener {
             FileConfiguration configLoad = config.getFileConfiguration();
 
             if (configLoad.getBoolean("Island.Death.Respawn.Island")) {
-                Island island = islandManager.getIslandAtLocation(player.getLocation());
+                Location playerLocation = player.getLocation();
+                Island island = islandManager.getIslandAtLocation(playerLocation);
 
                 if (island != null) {
-                    Location playerLocation = player.getLocation().clone(), islandLocation;
+                    Location islandLocation;
                     IslandWorld world = worldManager.getIslandWorld(player.getWorld());
 
                     if (island.hasRole(IslandRole.Member, player.getUniqueId())
@@ -67,10 +68,8 @@ public class Respawn implements Listener {
             if (config.getFileConfiguration().getString("Location.Spawn") == null) {
                 Bukkit.getServer().getLogger().log(Level.WARNING, "SkyBlock | Error: A spawn point hasn't been set.");
             } else {
-                Location playerLocation = player.getLocation().clone(),
+                Location playerLocation = player.getLocation(), spawnLocation = fileManager.getLocation(config, "Location.Spawn", true);
-                        spawnLocation = fileManager.getLocation(config, "Location.Spawn", true);
+                Bukkit.getServer().getPluginManager().callEvent(new PlayerTeleportEvent(player, playerLocation, spawnLocation));
-                Bukkit.getServer().getPluginManager()
-                        .callEvent(new PlayerTeleportEvent(player, playerLocation, spawnLocation));
                 event.setRespawnLocation(spawnLocation);
             }
         }

src/main/java/com/songoda/skyblock/menus/admin/Generator.java

@@ -118,7 +118,7 @@ public class Generator implements Listener {
             com.songoda.skyblock.generator.Generator generator = generatorManager
                     .getGenerator(((Generator.Viewer) playerData.getViewer()).getName());
 
-            List<String> permissionLore = new ArrayList<>();
+            final List<String> permissionLore;
 
             if (generator.isPermission()) {
                 permissionLore = configLoad

src/main/java/com/songoda/skyblock/message/MessageManager.java

@@ -36,7 +36,7 @@ public class MessageManager {
                     messages.add(ChatColor.translateAlternateColorCodes('&', messageList));
                 }
 
-                sender.sendMessage(messages.toArray(new String[0]));
+                sender.sendMessage(messages.toArray(new String[messages.size()]));
             } else {
                 sender.sendMessage(ChatColor.translateAlternateColorCodes('&', message));
             }
@@ -50,7 +50,7 @@ public class MessageManager {
                     messages.add(ChatColor.stripColor(ChatColor.translateAlternateColorCodes('&', messageList)));
                 }
 
-                sender.sendMessage(messages.toArray(new String[0]));
+                sender.sendMessage(messages.toArray(new String[messages.size()]));
             } else {
                 sender.sendMessage(ChatColor.stripColor(ChatColor.translateAlternateColorCodes('&', message)));
             }

src/main/java/com/songoda/skyblock/placeholder/EZPlaceholder.java

@@ -13,18 +13,16 @@ import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
 import org.bukkit.configuration.file.FileConfiguration;
 import org.bukkit.entity.Player;
-import org.bukkit.event.Listener;
 
 import java.io.File;
 import java.util.List;
 
-public class EZPlaceholder extends PlaceholderExpansion implements Listener {
+public class EZPlaceholder extends PlaceholderExpansion {
 
     private final SkyBlock skyblock;
 
     public EZPlaceholder(SkyBlock skyblock) {
         this.skyblock = skyblock;
-        Bukkit.getPluginManager().registerEvents(this, skyblock);
     }
 
     public String getIdentifier() {

src/main/java/com/songoda/skyblock/placeholder/PlaceholderManager.java

@@ -400,7 +400,7 @@ public class PlaceholderManager {
     }
 
     public List<String> getPlaceholders() {
-        List<String> placeholders = new ArrayList<>();
+        List<String> placeholders = new ArrayList<>(25);
         placeholders.add("fabledskyblock_island_exists");
         placeholders.add("fabledskyblock_island_isopen");
         placeholders.add("fabledskyblock_island_size");

src/main/java/com/songoda/skyblock/stackable/StackableManager.java

@@ -84,11 +84,8 @@ public class StackableManager {
 
     public Stackable getStack(Location location, Material material) {
         Stackable stackable = stacks.get(location);
-
+        
-        if (stackable != null && stackable.getMaterial() == material)
+        return stackable != null && stackable.getMaterial() == material ? stackable : null;
-            return stacks.get(location);
-        else
-            return null;
     }
 
     public Stackable addStack(Stackable stackable) {

src/main/java/com/songoda/skyblock/upgrade/UpgradeManager.java

@@ -59,11 +59,8 @@ public class UpgradeManager {
     }
 
     public List<Upgrade> getUpgrades(Upgrade.Type type) {
-        if (upgradeStorage.containsKey(type)) {
+        return upgradeStorage.get(type);
-            return upgradeStorage.get(type);
-        }
 
-        return null;
     }
 
     public void addUpgrade(Upgrade.Type type, int value) {

src/main/java/com/songoda/skyblock/utils/world/LocationUtil.java

@@ -237,16 +237,16 @@ public final class LocationUtil {
         int rndX = rnd.nextInt(xRange);
         int rndZ = rnd.nextInt(zRange);
 
-        if (loadChunk) {
+        if (loadChunk) world.getChunkAt(new Location(world, rndX, 10, rndZ));
-            Chunk chunk = world.getChunkAt(new Location(world, rndX, 10, rndZ));
-            world.loadChunk(chunk);
-        }
 
         double rndY = -1;
 
         if (world.getEnvironment() == Environment.NETHER) {
+            
+            Location rndLoc = new Location(world, rndX, 0, rndZ);
+            
             for (int i = 120; i > 0; i--) {
-                Location rndLoc = new Location(world, rndX, i, rndZ);
+                rndLoc.setY(i);
 
                 if (rndLoc.getBlock().getType() != Material.AIR
                         && rndLoc.clone().add(0.0D, 1.0D, 0.0D).getBlock().getType() == Material.AIR
@@ -254,7 +254,6 @@ public final class LocationUtil {
                         && rndLoc.clone().add(0.0D, 3.0D, 0.0D).getBlock().getType() == Material.AIR
                         && rndLoc.clone().add(0.0D, 4.0D, 0.0D).getBlock().getType() == Material.AIR) {
                     rndY = i;
-
                     break;
                 }
             }

src/main/java/com/songoda/skyblock/visit/VisitManager.java

@@ -33,8 +33,7 @@ public class VisitManager {
     public void onDisable() {
         HashMap<UUID, Visit> visitIslands = getIslands();
 
-        for (UUID visitIslandList : visitIslands.keySet()) {
+        for (Visit visit : visitIslands.values()) {
-            Visit visit = visitIslands.get(visitIslandList);
             visit.save();
         }
     }