Implemented Async World-Data Loading

Uses Mutex to assure no concurrent loading and saving
Merges Loaded data in Main Thread

src/com/dre/brewery/BCauldron.java

@@ -36,7 +36,6 @@ public class BCauldron {
 
 	public BCauldron(Block block) {
 		this.block = block;
-		bcauldrons.put(block, this);
 	}
 
 	// loading from file
@@ -44,7 +43,6 @@ public class BCauldron {
 		this.block = block;
 		this.state = state;
 		this.ingredients = ingredients;
-		bcauldrons.put(block, this);
 	}
 
 	public void onUpdate() {
@@ -74,6 +72,20 @@ public class BCauldron {
 		}
 	}
 
+	/**
+	 * Get the Block that this BCauldron represents
+	 */
+	public Block getBlock() {
+		return block;
+	}
+
+	/**
+	 * Get the State (Time in Minutes) that this Cauldron currently has
+	 */
+	public int getState() {
+		return state;
+	}
+
 	// get cauldron by Block
 	@Nullable
 	public static BCauldron get(Block block) {
@@ -99,6 +111,7 @@ public class BCauldron {
 			BCauldron bcauldron = get(block);
 			if (bcauldron == null) {
 				bcauldron = new BCauldron(block);
+				BCauldron.bcauldrons.put(block, bcauldron);
 			}
 
 			IngedientAddEvent event = new IngedientAddEvent(player, block, bcauldron, ingredient.clone(), rItem);

src/com/dre/brewery/Barrel.java

@@ -59,6 +59,15 @@ public class Barrel implements InventoryHolder {
 	 * load from file
 	 */
 	public Barrel(Block spigot, byte sign, BoundingBox bounds, Map<String, Object> items, float time) {
+		this(spigot, sign, bounds, items, time, false);
+	}
+
+	/**
+	 * Load from File
+	 * <p>If async: true, The Barrel Bounds will not be recreated when missing/corrupt, getBody().getBounds() will be null if it needs recreating
+	 *
+	 */
+	public Barrel(Block spigot, byte sign, BoundingBox bounds, Map<String, Object> items, float time, boolean async) {
 		this.spigot = spigot;
 		if (isLarge()) {
 			this.inventory = P.p.getServer().createInventory(this, 27, P.p.languageReader.get("Etc_Barrel"));
@@ -74,7 +83,7 @@ public class Barrel implements InventoryHolder {
 		}
 		this.time = time;
 
-		body = new BarrelBody(this, sign, bounds);
+		body = new BarrelBody(this, sign, bounds, async);
 	}
 
 	public static void onUpdate() {

src/com/dre/brewery/BarrelBody.java

@@ -30,17 +30,17 @@ public class BarrelBody {
 	/**
 	 * Loading from file
 	 */
-	public BarrelBody(Barrel barrel, byte signoffset, BoundingBox bounds) {
+	public BarrelBody(Barrel barrel, byte signoffset, BoundingBox bounds, boolean async) {
 		this(barrel, signoffset);
 
-		if (bounds == null || bounds.area() > 64 ) {
+		if (boundsSeemBad(bounds)) {
+			if (async) {
+				this.bounds = null;
+				return;
+			}
 			// If loading from old data, or block locations are missing, or other error, regenerate BoundingBox
 			// This will only be done in those extreme cases.
-			P.p.log("Regenerating Barrel BoundingBox: " + (bounds == null ? "was null" : "area=" + bounds.area()));
+			regenerateBounds();
-			Block broken = getBrokenBlock(true);
-			if (broken != null) {
-				barrel.remove(broken, null, true);
-			}
 		} else {
 			this.bounds = bounds;
 		}
@@ -79,6 +79,15 @@ public class BarrelBody {
 		signoffset = 0;
 	}
 
+	/**
+	 * Quick check if the bounds are valid or seem corrupt
+	 */
+	public static boolean boundsSeemBad(BoundingBox bounds) {
+		if (bounds == null) return true;
+		long area = bounds.area();
+		return area > 64 || area < 4;
+	}
+
 	/**
 	 * direction of the barrel from the spigot
 	 */
@@ -218,6 +227,21 @@ public class BarrelBody {
 		return block;
 	}
 
+	/**
+	 * Regenerate the Barrel Bounds.
+	 *
+	 * @return true if successful, false if Barrel was broken and should be removed.
+	 */
+	public boolean regenerateBounds() {
+		P.p.log("Regenerating Barrel BoundingBox: " + (bounds == null ? "was null" : "area=" + bounds.area()));
+		Block broken = getBrokenBlock(true);
+		if (broken != null) {
+			barrel.remove(broken, null, true);
+			return false;
+		}
+		return true;
+	}
+
 	/**
 	 * returns null if Barrel is correctly placed; the block that is missing when not.
 	 * <p>the barrel needs to be formed correctly

src/com/dre/brewery/Wakeup.java

@@ -266,4 +266,8 @@ public class Wakeup {
 		}
 	}
 
+	public static void onUnload(String worldName) {
+		wakeups.removeIf(wakeup -> wakeup.loc.getWorld().getName().equals(worldName));
+	}
+
 }

src/com/dre/brewery/filedata/BData.java

@@ -23,9 +23,12 @@ import java.io.DataInputStream;
 import java.io.File;
 import java.io.IOException;
 import java.util.*;
+import java.util.concurrent.atomic.AtomicInteger;
 
 public class BData {
 
+	public static AtomicInteger dataMutex = new AtomicInteger(0); // -1 = Saving, 0 = Free, >= 1 = Loading
+
 
 	// load all Data
 	public static void readData() {
@@ -136,7 +139,7 @@ public class BData {
 				P.p.bad = 0;
 				P.p.terr = 0;
 				if (!Brew.noLegacy()) {
-					for (Brew brew : Brew.legacyPotions.values()) {
+					for (int i = Brew.legacyPotions.size(); i > 0; i--) {
 						P.p.metricsForCreate(false);
 					}
 				}
@@ -186,13 +189,27 @@ public class BData {
 				}
 			}
 
-			for (World world : P.p.getServer().getWorlds()) {
+
+			final FileConfiguration finalData = data;
+			final List<World> worlds = P.p.getServer().getWorlds();
+			P.p.getServer().getScheduler().runTaskAsynchronously(P.p, () -> {
+				if (!acquireDataLoadMutex()) return; // Tries for 60 sec
+
+				try {
+					for (World world : worlds) {
+						P.p.log("World Init: " + world.getName());
 						if (world.getName().startsWith("DXL_")) {
-					loadWorldData(BUtil.getDxlName(world.getName()), world, data);
+							loadWorldData(BUtil.getDxlName(world.getName()), world, finalData);
 						} else {
-					loadWorldData(world.getUID().toString(), world, data);
+							loadWorldData(world.getUID().toString(), world, finalData);
 						}
 					}
+				} catch (Exception e) {
+					e.printStackTrace();
+				} finally {
+					releaseDataLoadMutex();
+				}
+			});
 
 		} else {
 			P.p.log("No data.yml found, will create new one!");
@@ -266,6 +283,7 @@ public class BData {
 	}
 
 	// load Block locations of given world
+	// can be run async
 	public static void loadWorldData(String uuid, World world, FileConfiguration data) {
 
 		if (data == null) {
@@ -278,6 +296,7 @@ public class BData {
 		}
 
 		// loading BCauldron
+		final Map<Block, BCauldron> initCauldrons = new HashMap<>();
 		if (data.contains("BCauldron." + uuid)) {
 			ConfigurationSection section = data.getConfigurationSection("BCauldron." + uuid);
 			for (String cauldron : section.getKeys(false)) {
@@ -291,7 +310,7 @@ public class BData {
 						BIngredients ingredients = loadCauldronIng(section, cauldron + ".ingredients");
 						int state = section.getInt(cauldron + ".state", 0);
 
-						new BCauldron(worldBlock, ingredients, state);
+						initCauldrons.put(worldBlock, new BCauldron(worldBlock, ingredients, state));
 					} else {
 						P.p.errorLog("Incomplete Block-Data in data.yml: " + section.getCurrentPath() + "." + cauldron);
 					}
@@ -302,6 +321,8 @@ public class BData {
 		}
 
 		// loading Barrel
+		final List<Barrel> initBarrels = new ArrayList<>();
+		final List<Barrel> initBadBarrels = new ArrayList<>();
 		if (data.contains("Barrel." + uuid)) {
 			ConfigurationSection section = data.getConfigurationSection("Barrel." + uuid);
 			for (String barrel : section.getKeys(false)) {
@@ -346,16 +367,17 @@ public class BData {
 
 						Barrel b;
 						if (invSection != null) {
-							b = new Barrel(block, sign, box, invSection.getValues(true), time);
+							b = new Barrel(block, sign, box, invSection.getValues(true), time, true);
 						} else {
 							// Barrel has no inventory
-							b = new Barrel(block, sign, box, null, time);
+							b = new Barrel(block, sign, box, null, time, true);
 						}
 
-						// In case Barrel Block locations were missing and could not be recreated: do not add the barrel
-
 						if (b.getBody().getBounds() != null) {
-							Barrel.barrels.add(b);
+							initBarrels.add(b);
+						} else {
+							// The Barrel Bounds need recreating, as they were missing or corrupt
+							initBadBarrels.add(b);
 						}
 
 					} else {
@@ -368,6 +390,7 @@ public class BData {
 		}
 
 		// loading Wakeup
+		final List<Wakeup> initWakeups = new ArrayList<>();
 		if (data.contains("Wakeup." + uuid)) {
 			ConfigurationSection section = data.getConfigurationSection("Wakeup." + uuid);
 			for (String wakeup : section.getKeys(false)) {
@@ -384,7 +407,7 @@ public class BData {
 						float yaw = NumberUtils.toFloat(splitted[4]);
 						Location location = new Location(world, x, y, z, yaw, pitch);
 
-						Wakeup.wakeups.add(new Wakeup(location));
+						initWakeups.add(new Wakeup(location));
 
 					} else {
 						P.p.errorLog("Incomplete Location-Data in data.yml: " + section.getCurrentPath() + "." + wakeup);
@@ -393,5 +416,51 @@ public class BData {
 			}
 		}
 
+		// Merge Loaded Data in Main Thred
+		P.p.getServer().getScheduler().runTask(P.p, () -> {
+			if (P.p.getServer().getWorld(world.getUID()) == null) {
+				return;
+			}
+			if (!initCauldrons.isEmpty()) {
+				BCauldron.bcauldrons.putAll(initCauldrons);
+			}
+			if (!initBarrels.isEmpty()) {
+				Barrel.barrels.addAll(initBarrels);
+			}
+			if (!initBadBarrels.isEmpty()) {
+				for (Barrel badBarrel : initBadBarrels) {
+					if (badBarrel.getBody().regenerateBounds()) {
+						Barrel.barrels.add(badBarrel);
+					}
+					// In case Barrel Block locations were missing and could not be recreated: do not add the barrel
+				}
+
+			}
+			if (!initWakeups.isEmpty()) {
+				Wakeup.wakeups.addAll(initWakeups);
+			}
+		});
+	}
+
+	public static boolean acquireDataLoadMutex() {
+		int wait = 0;
+		// Increment the Data Mutex if it is not -1
+		while (BData.dataMutex.updateAndGet(i -> i >= 0 ? i + 1 : i) <= 0) {
+			wait++;
+			if (wait > 60) {
+				P.p.errorLog("Could not load World Data, Mutex: " + BData.dataMutex.get());
+				return false;
+			}
+			try {
+				Thread.sleep(1000);
+			} catch (InterruptedException e) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	public static void releaseDataLoadMutex() {
+		dataMutex.decrementAndGet();
 	}
 }

src/com/dre/brewery/filedata/DataSave.java

@@ -34,14 +34,21 @@ public class DataSave extends BukkitRunnable {
 	@Override
 	public void run() {
 		long saveTime = System.nanoTime();
+		// Mutex has been acquired in ReadOldData
+		try {
 			FileConfiguration oldData;
 			if (read != null) {
 				if (!read.done) {
 					// Wait for async thread to load old data
-				if (System.currentTimeMillis() - time > 30000) {
+					if (System.currentTimeMillis() - time > 50000) {
-					P.p.errorLog("Old Data took too long to load!");
+						P.p.errorLog("Old Data took too long to load! Mutex: " + BData.dataMutex.get());
+						try {
 							cancel();
-					return;
+							read.cancel();
+						} catch (IllegalStateException ignored) {
+						}
+						running = null;
+						BData.dataMutex.set(0);
 					}
 					return;
 				}
@@ -104,6 +111,11 @@ public class DataSave extends BukkitRunnable {
 			} else {
 				new WriteData(configFile).run();
 			}
+			// Mutex will be released in WriteData
+		} catch (Exception e) {
+			e.printStackTrace();
+			BData.dataMutex.set(0);
+		}
 	}
 
 	// Finish the collection of data immediately

src/com/dre/brewery/filedata/ReadOldData.java

@@ -17,6 +17,22 @@ public class ReadOldData extends BukkitRunnable {
 	@SuppressWarnings("ResultOfMethodCallIgnored")
 	@Override
 	public void run() {
+		int wait = 0;
+		// Set the Data Mutex to -1 if it is 0=Free
+		while (!BData.dataMutex.compareAndSet(0, -1)) {
+			if (wait > 300) {
+				P.p.errorLog("Loading Process active for too long while trying to save! Mutex: " + BData.dataMutex.get());
+				return;
+			}
+			wait++;
+			try {
+				Thread.sleep(100);
+			} catch (InterruptedException e) {
+				return;
+			}
+		}
+
+
 		File datafile = new File(P.p.getDataFolder(), "data.yml");
 		if (!datafile.exists()) {
 			data = new YamlConfiguration();

src/com/dre/brewery/filedata/WriteData.java

@@ -25,11 +25,12 @@ public class WriteData implements Runnable {
 
 		try {
 			data.save(datafile);
-		} catch (IOException e) {
+		} catch (Exception e) {
 			e.printStackTrace();
 		}
 
 		DataSave.lastSave = 1;
 		DataSave.running = null;
+		BData.dataMutex.set(0);
 	}
 }

src/com/dre/brewery/listeners/WorldListener.java

@@ -2,6 +2,8 @@ package com.dre.brewery.listeners;
 
 import com.dre.brewery.BCauldron;
 import com.dre.brewery.Barrel;
+import com.dre.brewery.P;
+import com.dre.brewery.Wakeup;
 import com.dre.brewery.utility.BUtil;
 import com.dre.brewery.filedata.BData;
 import com.dre.brewery.filedata.DataSave;
@@ -16,20 +18,35 @@ public class WorldListener implements Listener {
 
 	@EventHandler
 	public void onWorldLoad(WorldLoadEvent event) {
-		World world = event.getWorld();
+		final World world = event.getWorld();
+		P.p.log("World Load: " + event.getWorld().getName());
 
+		P.p.getServer().getScheduler().runTaskAsynchronously(P.p, () -> {
+			if (!BData.acquireDataLoadMutex()) return;  // Tries for 60 sec
+
+			try {
 				if (world.getName().startsWith("DXL_")) {
 					BData.loadWorldData(BUtil.getDxlName(world.getName()), world, null);
 				} else {
 					BData.loadWorldData(world.getUID().toString(), world, null);
 				}
+			} catch (Exception e) {
+				e.printStackTrace();
+			} finally {
+				BData.releaseDataLoadMutex();
+			}
+
+		});
+
 	}
 
 	@EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
 	public void onWorldUnload(WorldUnloadEvent event) {
 		DataSave.save(true);
-		Barrel.onUnload(event.getWorld().getName());
+		String worldName = event.getWorld().getName();
-		BCauldron.onUnload(event.getWorld().getName());
+		Barrel.onUnload(worldName);
+		BCauldron.onUnload(worldName);
+		Wakeup.onUnload(worldName);
 	}
 
 }