Load/unload shops on chunk load/unload

This breaks shop limits, only loaded shops are counted at the moment

src/main/java/de/epiceric/shopchest/ShopChest.java

@@ -43,6 +43,8 @@ import me.wiefferink.areashop.AreaShop;
 import net.milkbowl.vault.economy.Economy;
 import org.bstats.bukkit.Metrics;
 import org.bukkit.Bukkit;
+import org.bukkit.Chunk;
+import org.bukkit.World;
 import org.bukkit.entity.Player;
 import org.bukkit.plugin.Plugin;
 import org.bukkit.plugin.RegisteredServiceProvider;
@@ -65,6 +67,7 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
+import java.util.stream.Stream;
 
 public class ShopChest extends JavaPlugin {
 
@@ -437,13 +440,26 @@ public class ShopChest extends JavaPlugin {
      * Initializes the shops
      */
     private void initializeShops() {
-        debug("Initializing Shops...");
+        getShopDatabase().connect(new Callback<Integer>(this) {
-        shopUtils.reloadShops(false, true, new Callback<Integer>(this) {
             @Override
             public void onResult(Integer result) {
-                Bukkit.getServer().getPluginManager().callEvent(new ShopInitializedEvent(result));
+                Chunk[] loadedChunks = getServer().getWorlds().stream().map(World::getLoadedChunks)
-                getLogger().info("Initialized " + result + " Shops");
+                        .flatMap(Stream::of).toArray(Chunk[]::new);
-                debug("Initialized " + result + " Shops");
+
+                shopUtils.loadShops(loadedChunks, new Callback<Integer>(ShopChest.this) {
+                    @Override
+                    public void onResult(Integer result) {
+                        getServer().getPluginManager().callEvent(new ShopInitializedEvent(result));
+                        getLogger().info("Loaded " + result + " shops in already loaded chunks");
+                        debug("Loaded " + result + " shops in already loaded chunks");
+                    }
+
+                    @Override
+                    public void onError(Throwable throwable) {
+                        getLogger().severe("Failed to load shops in already loaded chunks");
+                        if (throwable != null) getLogger().severe(throwable.getMessage());
+                    }
+                });
             }
 
             @Override

src/main/java/de/epiceric/shopchest/command/ShopCommandExecutor.java

@@ -26,8 +26,10 @@ import de.epiceric.shopchest.utils.ClickType.CreateClickType;
 import de.epiceric.shopchest.utils.ClickType.SelectClickType;
 
 import org.bukkit.Bukkit;
+import org.bukkit.Chunk;
 import org.bukkit.GameMode;
 import org.bukkit.OfflinePlayer;
+import org.bukkit.World;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandExecutor;
 import org.bukkit.command.CommandSender;
@@ -36,7 +38,9 @@ import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
+import java.util.stream.Stream;
 
 class ShopCommandExecutor implements CommandExecutor {
 
@@ -191,12 +195,40 @@ class ShopCommandExecutor implements CommandExecutor {
             return;
         }
 
-        shopUtils.reloadShops(true, true, new Callback<Integer>(plugin) {
+        // Reload configurations
+        plugin.getShopChestConfig().reload(false, true, true);
+        plugin.getHologramFormat().reload();
+        plugin.getUpdater().restart();
+
+        // Remove all shops
+        Iterator<Shop> iter = shopUtils.getShops().iterator();
+        while (iter.hasNext()) {
+            shopUtils.removeShop(iter.next(), false);
+        }
+
+        Chunk[] loadedChunks = Bukkit.getWorlds().stream().map(World::getLoadedChunks)
+                .flatMap(Stream::of).toArray(Chunk[]::new);
+
+        // Reconnect to the database and re-load shops in loaded chunks
+        plugin.getShopDatabase().connect(new Callback<Integer>(plugin) {
             @Override
             public void onResult(Integer result) {
-                sender.sendMessage(LanguageUtils.getMessage(Message.RELOADED_SHOPS,
+                shopUtils.loadShops(loadedChunks, new Callback<Integer>(plugin) {
-                        new Replacement(Placeholder.AMOUNT, String.valueOf(result))));
+                    @Override
-                plugin.debug(sender.getName() + " has reloaded " + result + " shops");
+                    public void onResult(Integer result) {
+                        sender.sendMessage(LanguageUtils.getMessage(Message.RELOADED_SHOPS,
+                                new Replacement(Placeholder.AMOUNT, String.valueOf(result))));
+                        plugin.debug(sender.getName() + " has reloaded " + result + " shops");
+                    }
+        
+                    @Override
+                    public void onError(Throwable throwable) {
+                        sender.sendMessage(LanguageUtils.getMessage(Message.ERROR_OCCURRED, 
+                                new Replacement(Placeholder.ERROR, "Failed to load shops from database")));
+                        plugin.getLogger().severe("Failed to load shops");
+                        if (throwable != null) plugin.getLogger().severe(throwable.getMessage());
+                    }
+                });
             }
 
             @Override

src/main/java/de/epiceric/shopchest/event/ShopInitializedEvent.java

@@ -3,6 +3,11 @@ package de.epiceric.shopchest.event;
 import org.bukkit.event.Event;
 import org.bukkit.event.HandlerList;
 
+/**
+ * @deprecated Use {@link ShopsLoadedEvent} instead since shops are loaded
+ *             dynamically based on chunk loading
+ */
+@Deprecated
 public class ShopInitializedEvent extends Event {
 
     private static final HandlerList handlers = new HandlerList();

src/main/java/de/epiceric/shopchest/event/ShopsLoadedEvent.java

@@ -0,0 +1,33 @@
+package de.epiceric.shopchest.event;
+
+import java.util.Collection;
+
+import org.bukkit.event.Event;
+import org.bukkit.event.HandlerList;
+
+import de.epiceric.shopchest.shop.Shop;
+
+/**
+ * Called when shops have been loaded and added to the server
+ */
+public class ShopsLoadedEvent extends Event {
+    private static final HandlerList handlers = new HandlerList();
+    private Collection<Shop> shops;
+
+    public ShopsLoadedEvent(Collection<Shop> shops) {
+        this.shops = shops;
+    }
+
+    public Collection<Shop> getShops() {
+        return shops;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+}

src/main/java/de/epiceric/shopchest/event/ShopsUnloadedEvent.java

@@ -0,0 +1,33 @@
+package de.epiceric.shopchest.event;
+
+import java.util.Collection;
+
+import org.bukkit.event.Event;
+import org.bukkit.event.HandlerList;
+
+import de.epiceric.shopchest.shop.Shop;
+
+/**
+ * Called when shops have been unloaded and removed from the server
+ */
+public class ShopsUnloadedEvent extends Event {
+    private static final HandlerList handlers = new HandlerList();
+    private Collection<Shop> shops;
+
+    public ShopsUnloadedEvent(Collection<Shop> shops) {
+        this.shops = shops;
+    }
+
+    public Collection<Shop> getShops() {
+        return shops;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+}

src/main/java/de/epiceric/shopchest/listeners/ShopUpdateListener.java

@@ -4,6 +4,10 @@ import de.epiceric.shopchest.ShopChest;
 import de.epiceric.shopchest.shop.Shop;
 import de.epiceric.shopchest.utils.Callback;
 
+import java.util.HashSet;
+import java.util.Set;
+
+import org.bukkit.Chunk;
 import org.bukkit.Location;
 import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
@@ -12,12 +16,14 @@ import org.bukkit.event.Listener;
 import org.bukkit.event.player.PlayerMoveEvent;
 import org.bukkit.event.player.PlayerQuitEvent;
 import org.bukkit.event.player.PlayerTeleportEvent;
-import org.bukkit.event.world.WorldLoadEvent;
+import org.bukkit.event.world.ChunkLoadEvent;
+import org.bukkit.event.world.ChunkUnloadEvent;
 import org.bukkit.scheduler.BukkitRunnable;
 
 public class ShopUpdateListener implements Listener {
 
-    private ShopChest plugin;
+    private final ShopChest plugin;
+    private final Set<Chunk> newLoadedChunks = new HashSet<>();
 
     public ShopUpdateListener(ShopChest plugin) {
         this.plugin = plugin;
@@ -83,23 +89,55 @@ public class ShopUpdateListener implements Listener {
     }
 
     @EventHandler
-    public void onWorldLoad(WorldLoadEvent e) {
+    public void onChunkLoad(ChunkLoadEvent e) {
-        final String worldName = e.getWorld().getName();
+        if (!plugin.getShopDatabase().isInitialized()) {
+            return;
+        }
 
-        plugin.getShopUtils().reloadShops(false, false, new Callback<Integer>(plugin) {
+        // Wait 10 ticks after first event is triggered, so that multiple
-            @Override
+        // chunk loads can be handled at the same time without having to
-            public void onResult(Integer result) {
+        // send a database request for each chunk.
-                plugin.getLogger().info(String.format("Reloaded %d shops because a new world '%s' was loaded", result, worldName));
+        if (newLoadedChunks.isEmpty()) {
-                plugin.debug(String.format("Reloaded %d shops because a new world '%s' was loaded", result, worldName));
+            new BukkitRunnable(){
-            }
+                @Override
+                public void run() {
+                    int chunkCount = newLoadedChunks.size();
+                    plugin.getShopUtils().loadShops(newLoadedChunks.toArray(new Chunk[chunkCount]), new Callback<Integer>(plugin) {
+                        @Override
+                        public void onResult(Integer result) {
+                            if (result == 0) {
+                                return;
+                            }
+                            plugin.debug("Loaded " + result + " shops in " + chunkCount + " chunks");
+                        }
+            
+                        @Override
+                        public void onError(Throwable throwable) {
+                            // Database connection probably failed => disable plugin to prevent more errors
+                            plugin.getLogger().severe("Failed to load shops in newly loaded chunks");
+                            plugin.debug("Failed to load shops in newly loaded chunks");
+                            if (throwable != null) plugin.debug(throwable);
+                        }
+                    });
+                    newLoadedChunks.clear();
+                }
+            }.runTaskLater(plugin, 10L);
+        }
 
-            @Override
+        newLoadedChunks.add(e.getChunk());
-            public void onError(Throwable throwable) {
+    }
-                // Database connection probably failed => disable plugin to prevent more errors
+
-                plugin.getLogger().severe("No database access. Disabling ShopChest");
+    @EventHandler
-                if (throwable != null) plugin.getLogger().severe(throwable.getMessage());
+    public void onChunkUnload(ChunkUnloadEvent e) {
-                plugin.getServer().getPluginManager().disablePlugin(plugin);
+        if (!plugin.getShopDatabase().isInitialized()) {
-            }
+            return;
-        });
+        }
+
+        int num = plugin.getShopUtils().unloadShops(e.getChunk());
+
+        if (num > 0) {
+            String chunkStr = "[" + e.getChunk().getX() + "; " + e.getChunk().getZ() + "]";
+            plugin.debug("Unloaded " + num + " shops in chunk " + chunkStr);
+        }
     }
 }

src/main/java/de/epiceric/shopchest/sql/Database.java

@@ -4,13 +4,13 @@ import de.epiceric.shopchest.ShopChest;
 import de.epiceric.shopchest.config.Config;
 import de.epiceric.shopchest.event.ShopBuySellEvent;
 import de.epiceric.shopchest.event.ShopBuySellEvent.Type;
-import de.epiceric.shopchest.exceptions.WorldNotFoundException;
 import de.epiceric.shopchest.shop.Shop;
 import de.epiceric.shopchest.shop.ShopProduct;
 import de.epiceric.shopchest.shop.Shop.ShopType;
 import de.epiceric.shopchest.utils.Callback;
 import de.epiceric.shopchest.utils.Utils;
 import org.bukkit.Bukkit;
+import org.bukkit.Chunk;
 import org.bukkit.Location;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.World;
@@ -28,16 +28,20 @@ import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+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 com.zaxxer.hikari.HikariDataSource;
 
 public abstract class Database {
-    private final Set<String> notFoundWorlds = new HashSet<>();
     private final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
 
+    private boolean initialized;
+
     String tableShops;
     String tableLogs;
     String tableLogouts;
@@ -305,6 +309,7 @@ public abstract class Database {
                         ResultSet rs = s.executeQuery("SELECT COUNT(id) FROM " + tableShops);
                         if (rs.next()) {
                             int count = rs.getInt(1);
+                            initialized = true;
                             
                             plugin.debug("Initialized database with " + count + " entries");
 
@@ -362,74 +367,108 @@ public abstract class Database {
     }
 
     /**
-     * Get all shops from the database
+     * Get all shops from the database that are located in the given chunks
      * 
-     * @param showConsoleMessages Whether console messages (errors or warnings)
+     * @param chunks Shops in these chunks are retrieved
-     *                            should be shown
+     * @param callback Callback that returns an immutable collection of shops if succeeded
-     * @param callback            Callback that - if succeeded - returns a read-only
-     *                            collection of all shops (as
-     *                            {@code Collection<Shop>})
      */
-    public void getShops(final boolean showConsoleMessages, final Callback<Collection<Shop>> callback) {
+    public void getShopsInChunks(final Chunk[] chunks, final Callback<Collection<Shop>> callback) {
-        new BukkitRunnable() {
+        // Split chunks into packages containing each {splitSize} chunks at max
+        int splitSize = 80;
+        int parts = (int) Math.ceil(chunks.length / (double) splitSize);
+        Chunk[][] splitChunks = new Chunk[parts][];
+        for (int i = 0; i < parts; i++) {
+            int size = i < parts - 1 ? splitSize : chunks.length % splitSize;
+            Chunk[] tmp = new Chunk[size];
+            System.arraycopy(chunks, i * splitSize, tmp, 0, size);
+            splitChunks[i] = tmp;
+        }
+
+        new BukkitRunnable(){
             @Override
             public void run() {
-                ArrayList<Shop> shops = new ArrayList<>();
+                List<Shop> shops = new ArrayList<>();
 
-                try (Connection con = dataSource.getConnection();
+                // Send a request for each chunk package
-                        PreparedStatement ps = con.prepareStatement("SELECT * FROM " + tableShops + "")) {
+                for (Chunk[] newChunks : splitChunks) {
-                    ResultSet rs = ps.executeQuery();
 
-                    while (rs.next()) {
+                    // Map chunks by world
-                        int id = rs.getInt("id");
+                    Map<String, Set<Chunk>> chunksByWorld = new HashMap<>();
-
+                    for (Chunk chunk : newChunks) {
-                        plugin.debug("Getting Shop... (#" + id + ")");
+                        String world = chunk.getWorld().getName();
-
+                        Set<Chunk> chunksForWorld = chunksByWorld.getOrDefault(world, new HashSet<>());
-                        String worldName = rs.getString("world");
+                        chunksForWorld.add(chunk);
-                        World world = Bukkit.getWorld(worldName);
+                        chunksByWorld.put(world, chunksForWorld);
-
+                    }
-                        if (world == null) {
+    
-                            WorldNotFoundException ex = new WorldNotFoundException(worldName);
+                    // Create query dynamically
-                            if (showConsoleMessages && !notFoundWorlds.contains(worldName)) {
+                    String query = "SELECT * FROM " + tableShops + " WHERE ";
-                                plugin.getLogger().warning(ex.getMessage());
+                    for (String world : chunksByWorld.keySet()) {
-                                notFoundWorlds.add(worldName);
+                        query += "(world = ? AND (";
-                            }
+                        int chunkNum = chunksByWorld.get(world).size();
-                            plugin.debug("Failed to get shop (#" + id + ")");
+                        for (int i = 0; i < chunkNum; i++) {
-                            plugin.debug(ex);
+                            query += "((x BETWEEN ? AND ?) AND (z BETWEEN ? AND ?)) OR ";
-                            continue;
                         }
-
+                        query += "1=0)) OR ";
-                        int x = rs.getInt("x");
-                        int y = rs.getInt("y");
-                        int z = rs.getInt("z");
-                        Location location = new Location(world, x, y, z);
-                        OfflinePlayer vendor = Bukkit.getOfflinePlayer(UUID.fromString(rs.getString("vendor")));
-                        ItemStack itemStack = Utils.decode(rs.getString("product"));
-                        int amount = rs.getInt("amount");
-                        ShopProduct product = new ShopProduct(itemStack, amount);
-                        double buyPrice = rs.getDouble("buyprice");
-                        double sellPrice = rs.getDouble("sellprice");
-                        ShopType shopType = ShopType.valueOf(rs.getString("shoptype"));
-
-                        plugin.debug("Initializing new shop... (#" + id + ")");
-
-                        shops.add(new Shop(id, plugin, vendor, product, location, buyPrice, sellPrice, shopType));
                     }
+                    query += "1=0";
+    
+                    try (Connection con = dataSource.getConnection();
+                            PreparedStatement ps = con.prepareStatement(query)) {
+                        int index = 0;
+                        for (String world : chunksByWorld.keySet()) {
+                            ps.setString(++index, world);
+                            for (Chunk chunk : chunksByWorld.get(world)) {
+                                int minX = chunk.getX() * 16;
+                                int minZ = chunk.getZ() * 16;
+                                ps.setInt(++index, minX);
+                                ps.setInt(++index, minX + 15);
+                                ps.setInt(++index, minZ);
+                                ps.setInt(++index, minZ + 15);
+                            }
+                        }
+    
+                        ResultSet rs = ps.executeQuery();
+                        while (rs.next()) {
+                            int id = rs.getInt("id");
+    
+                            plugin.debug("Getting Shop... (#" + id + ")");
+    
+                            int x = rs.getInt("x");
+                            int y = rs.getInt("y");
+                            int z = rs.getInt("z");
+    
+                            World world = plugin.getServer().getWorld(rs.getString("world"));
+                            Location location = new Location(world, x, y, z);
+                            OfflinePlayer vendor = Bukkit.getOfflinePlayer(UUID.fromString(rs.getString("vendor")));
+                            ItemStack itemStack = Utils.decode(rs.getString("product"));
+                            int amount = rs.getInt("amount");
+                            ShopProduct product = new ShopProduct(itemStack, amount);
+                            double buyPrice = rs.getDouble("buyprice");
+                            double sellPrice = rs.getDouble("sellprice");
+                            ShopType shopType = ShopType.valueOf(rs.getString("shoptype"));
+    
+                            plugin.debug("Initializing new shop... (#" + id + ")");
+    
+                            shops.add(new Shop(id, plugin, vendor, product, location, buyPrice, sellPrice, shopType));
+                        }
+                    } catch (SQLException ex) {
+                        if (callback != null) {
+                            callback.callSyncError(ex);
+                        }
+    
+                        plugin.getLogger().severe("Failed to get shops from database");
+                        plugin.debug("Failed to get shops");
+                        plugin.debug(ex);
 
-                    if (callback != null) {
+                        return;
-                        callback.callSyncResult(Collections.unmodifiableCollection(shops));
                     }
-                } catch (SQLException ex) {
-                    if (callback != null) {
-                        callback.callSyncError(ex);
-                    }
-
-                    plugin.getLogger().severe("Failed to get shops from database");
-                    plugin.debug("Failed to get shops");
-                    plugin.debug(ex);
                 }
-
+    
-            }
+                if (callback != null) {
+                    callback.callSyncResult(Collections.unmodifiableCollection(shops));
+                }
+            };
         }.runTaskAsynchronously(plugin);
     }
 
@@ -730,6 +769,13 @@ public abstract class Database {
         }
     }
 
+    /**
+     * Returns whether a connection to the database has been established
+     */
+    public boolean isInitialized() {
+        return initialized;
+    }
+
     public enum DatabaseType {
         SQLite, MySQL
     }

src/main/java/de/epiceric/shopchest/utils/ShopUtils.java

@@ -2,8 +2,12 @@ package de.epiceric.shopchest.utils;
 
 import de.epiceric.shopchest.ShopChest;
 import de.epiceric.shopchest.config.Config;
+import de.epiceric.shopchest.event.ShopsLoadedEvent;
+import de.epiceric.shopchest.event.ShopsUnloadedEvent;
 import de.epiceric.shopchest.shop.Shop;
 
+import org.bukkit.Bukkit;
+import org.bukkit.Chunk;
 import org.bukkit.Location;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.block.Chest;
@@ -246,6 +250,7 @@ public class ShopUtils {
      * @return The amount of a shops a player has (if {@link Config#excludeAdminShops} is true, admin shops won't be counted)
      */
     public int getShopAmount(OfflinePlayer p) {
+        // FIXME: currently only showing loaded shops
         float shopCount = 0;
 
         for (Shop shop : getShops()) {
@@ -265,54 +270,65 @@ public class ShopUtils {
     }
 
     /**
-     * Reload the shops
+     * Gets all shops in the given chunk from the database and adds them to the server
-     * @param reloadConfig Whether the configuration should also be reloaded
+     * @param chunk The chunk to load shops from
-     * @param showConsoleMessages Whether messages about the language file should be shown in the console
+     * @param callback Callback that returns the amount of shops added if succeeded
-     * @param callback Callback that - if succeeded - returns the amount of shops that were reloaded (as {@code int})
+     * @see ShopUtils#loadShops(Chunk[], Callback)
      */
-    public void reloadShops(boolean reloadConfig, final boolean showConsoleMessages, final Callback<Integer> callback) {
+    public void loadShops(final Chunk chunk, final Callback<Integer> callback) {
-        plugin.debug("Reloading shops...");
+        loadShops(new Chunk[] {chunk}, callback);
+    }
 
-        if (reloadConfig) {
+    /**
-            plugin.getShopChestConfig().reload(false, true, showConsoleMessages);
+     * Gets all shops in the given chunks from the database and adds them to the server
-            plugin.getHologramFormat().reload();
+     * @param chunk The chunks to load shops from
-            plugin.getUpdater().restart();
+     * @param callback Callback that returns the amount of shops added if succeeded
-        }
+     * @see ShopUtils#loadShops(Chunk Callback)
-
+     */
-        plugin.getShopDatabase().connect(new Callback<Integer>(plugin) {
+    public void loadShops(final Chunk[] chunks, final Callback<Integer> callback) {
+        plugin.getShopDatabase().getShopsInChunks(chunks, new Callback<Collection<Shop>>(plugin) {
             @Override
-            public void onResult(Integer result) {
+            public void onResult(Collection<Shop> result) {
-                for (Shop shop : getShopsCopy()) {
+                for (Shop shop : result) {
-                    removeShop(shop, false);
+                    if (shop.create(true)) {
-                    plugin.debug("Removed shop (#" + shop.getID() + ")");
+                        addShop(shop, false);
+                    }
                 }
 
-                plugin.getShopDatabase().getShops(showConsoleMessages, new Callback<Collection<Shop>>(plugin) {
+                if (callback != null) callback.onResult(result.size());
-                    @Override
-                    public void onResult(Collection<Shop> result) {
-                        for (Shop shop : result) {
-                            if (shop.create(showConsoleMessages)) {
-                                addShop(shop, false);
-                            }
-                        }
 
-                        if (callback != null) callback.callSyncResult(result.size());
+                Bukkit.getPluginManager().callEvent(new ShopsLoadedEvent(result));
-                    }
-
-                    @Override
-                    public void onError(Throwable throwable) {
-                        if (callback != null) callback.callSyncError(throwable);
-                    }
-                });
             }
 
             @Override
             public void onError(Throwable throwable) {
-                if (callback != null) callback.callSyncError(throwable);
+                if (callback != null) callback.onError(throwable);
             }
         });
     }
 
+    /**
+     * Removes all shops from the given chunk from the server
+     * @param chunk The chunk containing the shops to unload
+     * @return The amount of shops that were unloaded
+     */
+    public int unloadShops(final Chunk chunk) {
+        Set<Shop> unloadedShops = new HashSet<>();
+
+        Iterator<Shop> iter = getShops().iterator();
+        while(iter.hasNext()) {
+            Shop shop = iter.next();
+            if (shop.getLocation().getChunk().equals(chunk)) {
+                removeShop(shop, false);
+                unloadedShops.add(shop);
+                plugin.debug("Unloaded shop (#" + shop.getID() + ")");
+            }
+        }
+        
+        Bukkit.getPluginManager().callEvent(new ShopsUnloadedEvent(Collections.unmodifiableCollection(unloadedShops)));
+        return unloadedShops.size();
+    }
+
     /**
      * Update hologram and item of all shops for a player
      * @param player Player to show the updates