Improved loading-speed for loading offlinePlayers (#63), fixed ban-list-filtering taking a long time (#61), started implementing MyLogger for more advanced debugging (#62)

src/main/java/com/gmail/artemis/the/gr8/playerstats/Main.java

@@ -68,8 +68,4 @@ public class Main extends JavaPlugin {
         }
         this.getLogger().info("Disabled PlayerStats!");
     }
-
-    public void logTimeTaken(String className, String methodName, long previousTime) {
-        getLogger().info(className + ", " + methodName + ": " + (System.currentTimeMillis() - previousTime) + "ms");
-    }
 }

src/main/java/com/gmail/artemis/the/gr8/playerstats/ThreadManager.java

@@ -5,13 +5,16 @@ import com.gmail.artemis.the.gr8.playerstats.reload.ReloadThread;
 import com.gmail.artemis.the.gr8.playerstats.statistic.StatRequest;
 import com.gmail.artemis.the.gr8.playerstats.statistic.StatThread;
 import com.gmail.artemis.the.gr8.playerstats.msg.MessageFactory;
+import com.gmail.artemis.the.gr8.playerstats.utils.MyLogger;
 import net.kyori.adventure.platform.bukkit.BukkitAudiences;
 import org.bukkit.command.CommandSender;
 
 
 public class ThreadManager {
 
-    private static final int threshold = 10;
+    private final int threshold = 10;
+    private int statThreadID;
+    private int reloadThreadID;
 
     private final Main plugin;
     private final BukkitAudiences adventure;
@@ -28,16 +31,27 @@ public class ThreadManager {
         messageFactory = m;
         plugin = p;
 
-        startReloadThread(null, true);
+        statThreadID = 0;
+        reloadThreadID = 0;
+        startReloadThread(null);
     }
 
-    public void startReloadThread(CommandSender sender, boolean firstTimeLoading) {
-        reloadThread = new ReloadThread(adventure, config, messageFactory, plugin, threshold, firstTimeLoading, statThread, sender);
+    public void startReloadThread(CommandSender sender) {
+        if (reloadThread == null || !reloadThread.isAlive()) {
+            reloadThreadID += 1;
+
+            reloadThread = new ReloadThread(adventure, config, messageFactory, plugin, threshold, reloadThreadID, statThread, sender);
             reloadThread.start();
         }
+        else {
+            MyLogger.threadAlreadyRunning(reloadThread.getName());
+        }
+    }
 
     public void startStatThread(StatRequest request) {
-        statThread = new StatThread(adventure, config, messageFactory, plugin, threshold, request, reloadThread);
+        statThreadID += 1;
+
+        statThread = new StatThread(adventure, config, messageFactory, plugin, statThreadID, threshold, request, reloadThread);
         statThread.start();
     }
 

src/main/java/com/gmail/artemis/the/gr8/playerstats/commands/ReloadCommand.java

@@ -17,7 +17,7 @@ public class ReloadCommand implements CommandExecutor {
 
     @Override
     public boolean onCommand(@NotNull CommandSender sender, @NotNull Command command, @NotNull String label, String[] args) {
-        threadManager.startReloadThread(sender, false);
+        threadManager.startReloadThread(sender);
         return true;
     }
 }

src/main/java/com/gmail/artemis/the/gr8/playerstats/commands/StatCommand.java

@@ -169,7 +169,7 @@ public class StatCommand implements CommandExecutor {
                     request.setPlayerName(sender.getName());
                     request.setSelection(Query.PLAYER);
                 }
-                else if (OfflinePlayerHandler.isOfflinePlayerName(arg) && request.getPlayerName() == null) {
+                else if (OfflinePlayerHandler.isRelevantPlayer(arg) && request.getPlayerName() == null) {
                     request.setPlayerName(arg);
                     request.setSelection(Query.PLAYER);
                 }

src/main/java/com/gmail/artemis/the/gr8/playerstats/config/ConfigHandler.java

@@ -2,6 +2,7 @@ package com.gmail.artemis.the.gr8.playerstats.config;
 
 import com.gmail.artemis.the.gr8.playerstats.Main;
 import com.gmail.artemis.the.gr8.playerstats.enums.Query;
+import com.gmail.artemis.the.gr8.playerstats.utils.MyLogger;
 import org.bukkit.configuration.ConfigurationSection;
 import org.bukkit.configuration.file.FileConfiguration;
 import org.bukkit.configuration.file.YamlConfiguration;
@@ -24,15 +25,27 @@ public class ConfigHandler {
         configVersion = 3.1;
 
         checkConfigVersion();
+        MyLogger.setDebugLevel(debugLevel());
     }
 
-    /** Reloads the config from file, or creates a new file with default values if there is none. */
+    /** Returns the desired debugging level.
+     <p>1 = low (only show unexpected errors)</p>
+     <p>2 = medium (show all encountered exceptions, log main tasks and show time taken)</p>
+     <p>3 = high (log all tasks and time taken)</p>
+     <p>Default: 1</p>*/
+    public int debugLevel() {
+        return config.getInt("debug-level", 1);
+    }
+
+    /** Reloads the config from file, or creates a new file with default values if there is none.
+     Also reads the value for debug-level and passes it on to MyLogger. */
     public boolean reloadConfig() {
         try {
             if (!configFile.exists()) {
                 saveDefaultConfig();
             }
             config = YamlConfiguration.loadConfiguration(configFile);
+            MyLogger.setDebugLevel(debugLevel());
             return true;
         }
         catch (Exception e) {

src/main/java/com/gmail/artemis/the/gr8/playerstats/enums/DebugLevel.java

@@ -0,0 +1,5 @@
+package com.gmail.artemis.the.gr8.playerstats.enums;
+
+public enum DebugLevel {
+    LOW, MEDIUM, HIGH
+}

src/main/java/com/gmail/artemis/the/gr8/playerstats/listeners/JoinListener.java

@@ -16,7 +16,7 @@ public class JoinListener implements Listener {
     @EventHandler
     public void onPlayerJoin(PlayerJoinEvent joinEvent) {
         if (!joinEvent.getPlayer().hasPlayedBefore()) {
-            threadManager.startReloadThread(null, false);
+            threadManager.startReloadThread(null);
         }
     }
 }

src/main/java/com/gmail/artemis/the/gr8/playerstats/reload/ReloadAction.java

@@ -1,5 +1,6 @@
 package com.gmail.artemis.the.gr8.playerstats.reload;
 
+import com.gmail.artemis.the.gr8.playerstats.utils.MyLogger;
 import com.gmail.artemis.the.gr8.playerstats.utils.UnixTimeHandler;
 import org.bukkit.OfflinePlayer;
 
@@ -15,40 +16,33 @@ public class ReloadAction extends RecursiveAction {
     private final int start;
     private final int end;
 
-    private final boolean whitelistOnly;
-    private final boolean excludeBanned;
     private final int lastPlayedLimit;
     private final ConcurrentHashMap<String, UUID> offlinePlayerUUIDs;
 
     /** Fills a ConcurrentHashMap with PlayerNames and UUIDs for all OfflinePlayers that should be included in statistic calculations.
      * @param threshold the maximum length of OfflinePlayers to process in one task
      * @param players array of all OfflinePlayers (straight from Bukkit)
-     * @param whitelistOnly whether to limit players based on the whitelist
-     * @param excludeBanned whether to exclude banned players
      * @param lastPlayedLimit whether to set a limit based on last-played-date
      * @param offlinePlayerUUIDs the ConcurrentHashMap to put resulting playerNames and UUIDs on
      */
     public ReloadAction(int threshold, OfflinePlayer[] players,
-                        boolean whitelistOnly, boolean excludeBanned, int lastPlayedLimit,
-                        ConcurrentHashMap<String, UUID> offlinePlayerUUIDs) {
+                        int lastPlayedLimit, ConcurrentHashMap<String, UUID> offlinePlayerUUIDs) {
 
-       this(threshold, players, 0, players.length,
-               whitelistOnly, excludeBanned, lastPlayedLimit, offlinePlayerUUIDs);
+       this(threshold, players, 0, players.length, lastPlayedLimit, offlinePlayerUUIDs);
     }
 
     protected ReloadAction(int threshold, OfflinePlayer[] players, int start, int end,
-                           boolean whitelistOnly, boolean excludeBanned, int lastPlayedLimit,
-                           ConcurrentHashMap<String, UUID> offlinePlayerUUIDs) {
+                           int lastPlayedLimit, ConcurrentHashMap<String, UUID> offlinePlayerUUIDs) {
 
         this.threshold = threshold;
         this.players = players;
         this.start = start;
         this.end = end;
 
-        this.whitelistOnly = whitelistOnly;
-        this.excludeBanned = excludeBanned;
         this.lastPlayedLimit = lastPlayedLimit;
         this.offlinePlayerUUIDs = offlinePlayerUUIDs;
+
+        MyLogger.subActionCreated(Thread.currentThread().getName());
     }
 
     @Override
@@ -60,9 +54,9 @@ public class ReloadAction extends RecursiveAction {
         else {
             final int split = length / 2;
             final ReloadAction subTask1 = new ReloadAction(threshold, players, start, (start + split),
-                    whitelistOnly, excludeBanned, lastPlayedLimit, offlinePlayerUUIDs);
+                    lastPlayedLimit, offlinePlayerUUIDs);
             final ReloadAction subTask2 = new ReloadAction(threshold, players, (start + split), end,
-                    whitelistOnly, excludeBanned, lastPlayedLimit, offlinePlayerUUIDs);
+                    lastPlayedLimit, offlinePlayerUUIDs);
 
             //queue and compute all subtasks in the right order
             invokeAll(subTask1, subTask2);
@@ -72,11 +66,11 @@ public class ReloadAction extends RecursiveAction {
     private void process() {
         for (int i = start; i < end; i++) {
             OfflinePlayer player = players[i];
-            if (player.getName() != null &&
-                    (!whitelistOnly || player.isWhitelisted()) &&
-                    (!excludeBanned || !player.isBanned()) &&
+            String playerName = player.getName();
+            MyLogger.actionRunning(Thread.currentThread().getName(), playerName, 1);
+            if (playerName != null &&
                     (lastPlayedLimit == 0 || UnixTimeHandler.hasPlayedSince(lastPlayedLimit, player.getLastPlayed()))) {
-                offlinePlayerUUIDs.put(player.getName(), player.getUniqueId());
+                offlinePlayerUUIDs.put(playerName, player.getUniqueId());
             }
         }
     }

src/main/java/com/gmail/artemis/the/gr8/playerstats/reload/ReloadThread.java

@@ -5,6 +5,7 @@ import com.gmail.artemis.the.gr8.playerstats.ThreadManager;
 import com.gmail.artemis.the.gr8.playerstats.config.ConfigHandler;
 import com.gmail.artemis.the.gr8.playerstats.statistic.StatThread;
 import com.gmail.artemis.the.gr8.playerstats.msg.MessageFactory;
+import com.gmail.artemis.the.gr8.playerstats.utils.MyLogger;
 import com.gmail.artemis.the.gr8.playerstats.utils.OfflinePlayerHandler;
 import net.kyori.adventure.platform.bukkit.BukkitAudiences;
 import org.bukkit.Bukkit;
@@ -13,7 +14,9 @@ import org.bukkit.command.CommandSender;
 import org.bukkit.command.ConsoleCommandSender;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.Arrays;
 import java.util.ConcurrentModificationException;
+import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ForkJoinPool;
@@ -21,6 +24,7 @@ import java.util.concurrent.ForkJoinPool;
 public class ReloadThread extends Thread {
 
     private final int threshold;
+    private final int reloadThreadID;
 
     private final BukkitAudiences adventure;
     private static ConfigHandler config;
@@ -29,10 +33,11 @@ public class ReloadThread extends Thread {
 
     private final StatThread statThread;
     private final CommandSender sender;
-    private final boolean firstTimeLoading;
 
-    public ReloadThread(BukkitAudiences a, ConfigHandler c, MessageFactory m, Main p, int threshold, boolean firstTime, @Nullable StatThread s, @Nullable CommandSender se) {
+    public ReloadThread(BukkitAudiences a, ConfigHandler c, MessageFactory m, Main p, int threshold, int ID, @Nullable StatThread s, @Nullable CommandSender se) {
         this.threshold = threshold;
+        reloadThreadID = ID;
+
         adventure = a;
         config = c;
         messageFactory = m;
@@ -40,18 +45,21 @@ public class ReloadThread extends Thread {
 
         statThread = s;
         sender = se;
-        firstTimeLoading = firstTime;
+
+        this.setName("ReloadThread-" + reloadThreadID);
+        MyLogger.threadCreated(this.getName());
     }
 
     @Override
     public void run() {
         long time = System.currentTimeMillis();
+        MyLogger.threadStart(this.getName());
 
-        //if reload is triggered by /statreload...
-        if (!firstTimeLoading) {
+        //if reload is triggered by /statreload (aka this thread does not have ID number 1)...
+        if (reloadThreadID != 1) {
             if (statThread != null && statThread.isAlive()) {
                 try {
-                    plugin.getLogger().info("Waiting for statThread to finish up...");
+                    MyLogger.waitingForOtherThread(this.getName(), statThread.getName());
                     statThread.join();
                 } catch (InterruptedException e) {
                     plugin.getLogger().warning(e.toString());
@@ -62,7 +70,7 @@ public class ReloadThread extends Thread {
             if (config.reloadConfig()) {
 
                 try {
-                    OfflinePlayerHandler.updateOfflinePlayerList(getPlayerMap(false));
+                    OfflinePlayerHandler.updateOfflinePlayerList(getPlayerMap());
                 }
                 catch (ConcurrentModificationException e) {
                     plugin.getLogger().warning("The request could not be fully executed due to a ConcurrentModificationException");
@@ -71,7 +79,7 @@ public class ReloadThread extends Thread {
                     }
                 }
 
-                plugin.logTimeTaken("ReloadThread", ("loaded " + OfflinePlayerHandler.getOfflinePlayerCount() + " offline players"), time);
+                MyLogger.logTimeTakenDefault("ReloadThread", ("loaded " + OfflinePlayerHandler.getOfflinePlayerCount() + " offline players"), time);
                 if (sender != null) {
                     adventure.sender(sender).sendMessage(messageFactory.reloadedConfig(sender instanceof ConsoleCommandSender));
                 }
@@ -79,26 +87,36 @@ public class ReloadThread extends Thread {
         }
         //during first start-up...
         else {
-            OfflinePlayerHandler.updateOfflinePlayerList(getPlayerMap(true));
-            plugin.logTimeTaken("ReloadThread", ("loaded " + OfflinePlayerHandler.getOfflinePlayerCount() + " offline players"), time);
+            OfflinePlayerHandler.updateOfflinePlayerList(getPlayerMap());
+            MyLogger.logTimeTakenDefault("ReloadThread", ("loaded " + OfflinePlayerHandler.getOfflinePlayerCount() + " offline players"), time);
             ThreadManager.recordCalcTime(System.currentTimeMillis() - time);
         }
     }
 
-    private ConcurrentHashMap<String, UUID> getPlayerMap(boolean firstTimeLoading) {
-        OfflinePlayer[] offlinePlayers = Bukkit.getOfflinePlayers();
-
-        int size;
-        if (firstTimeLoading) {
-            size = offlinePlayers.length;
+    private ConcurrentHashMap<String, UUID> getPlayerMap() {
+        long time = System.currentTimeMillis();
+        OfflinePlayer[] offlinePlayers;
+        if (config.whitelistOnly()) {
+            offlinePlayers = Bukkit.getWhitelistedPlayers().toArray(OfflinePlayer[]::new);
+            MyLogger.logTimeTaken("ReloadThread", "getting white-list-only list", time);
+        }
+        else if (config.excludeBanned()) {
+            Set<OfflinePlayer> bannedPlayers = Bukkit.getBannedPlayers();
+            offlinePlayers = Arrays.stream(Bukkit.getOfflinePlayers())
+                    .parallel()
+                    .filter(offlinePlayer -> !bannedPlayers.contains(offlinePlayer)).toArray(OfflinePlayer[]::new);
+            MyLogger.logTimeTaken("ReloadThread", "getting excluding-banned-players list", time);
         }
         else {
-            size = OfflinePlayerHandler.getOfflinePlayerCount() != 0 ? OfflinePlayerHandler.getOfflinePlayerCount() : 16;
+            offlinePlayers = Bukkit.getOfflinePlayers();
+            MyLogger.logTimeTaken("ReloadThread", "getting regular player list", time);
         }
 
+        int size = offlinePlayers != null ? offlinePlayers.length : 16;
         ConcurrentHashMap<String, UUID> playerMap = new ConcurrentHashMap<>(size);
 
-        ReloadAction task = new ReloadAction(threshold, offlinePlayers, config.whitelistOnly(), config.excludeBanned(), config.lastPlayedLimit(), playerMap);
+        ReloadAction task = new ReloadAction(threshold, offlinePlayers, config.lastPlayedLimit(), playerMap);
+        MyLogger.actionCreated((offlinePlayers != null) ? offlinePlayers.length : 0);
         ForkJoinPool commonPool = ForkJoinPool.commonPool();
 
         try {
@@ -106,6 +124,8 @@ public class ReloadThread extends Thread {
         } catch (ConcurrentModificationException e) {
             throw new ConcurrentModificationException(e.toString());
         }
+
+        MyLogger.actionFinished(1);
         return playerMap;
     }
 

src/main/java/com/gmail/artemis/the/gr8/playerstats/statistic/StatThread.java

@@ -5,6 +5,7 @@ import com.gmail.artemis.the.gr8.playerstats.enums.Query;
 import com.gmail.artemis.the.gr8.playerstats.reload.ReloadThread;
 import com.gmail.artemis.the.gr8.playerstats.ThreadManager;
 import com.gmail.artemis.the.gr8.playerstats.config.ConfigHandler;
+import com.gmail.artemis.the.gr8.playerstats.utils.MyLogger;
 import com.gmail.artemis.the.gr8.playerstats.utils.OfflinePlayerHandler;
 import com.gmail.artemis.the.gr8.playerstats.msg.MessageFactory;
 import com.google.common.collect.ImmutableList;
@@ -23,6 +24,7 @@ import java.util.stream.Collectors;
 public class StatThread extends Thread {
 
     private final int threshold;
+
     private final StatRequest request;
     private final ReloadThread reloadThread;
 
@@ -32,8 +34,9 @@ public class StatThread extends Thread {
     private final Main plugin;
 
     //constructor (called on thread creation)
-    public StatThread(BukkitAudiences a, ConfigHandler c, MessageFactory m, Main p, int threshold, StatRequest s, @Nullable ReloadThread r) {
+    public StatThread(BukkitAudiences a, ConfigHandler c, MessageFactory m, Main p, int ID, int threshold, StatRequest s, @Nullable ReloadThread r) {
         this.threshold = threshold;
+
         request = s;
         reloadThread = r;
 
@@ -41,11 +44,16 @@ public class StatThread extends Thread {
         config = c;
         messageFactory = m;
         plugin = p;
+
+        this.setName("StatThread-" + ID);
+        MyLogger.threadCreated(this.getName());
     }
 
     //what the thread will do once started
     @Override
     public void run() throws IllegalStateException, NullPointerException {
+        MyLogger.threadStart(this.getName());
+
         if (messageFactory == null || plugin == null) {
             throw new IllegalStateException("Not all classes off the plugin are running!");
         }
@@ -54,8 +62,10 @@ public class StatThread extends Thread {
         }
         if (reloadThread != null && reloadThread.isAlive()) {
             try {
-                plugin.getLogger().info("Waiting for reloadThread to finish up...");
-                adventure.sender(request.getCommandSender()).sendMessage(messageFactory.stillReloading(request.getCommandSender() instanceof ConsoleCommandSender));
+                MyLogger.waitingForOtherThread(this.getName(), reloadThread.getName());
+                adventure.sender(request.getCommandSender())
+                        .sendMessage(messageFactory
+                                .stillReloading(request.getCommandSender() instanceof ConsoleCommandSender));
                 reloadThread.join();
             } catch (InterruptedException e) {
                 plugin.getLogger().warning(e.toString());
@@ -128,10 +138,11 @@ public class StatThread extends Thread {
         int size = OfflinePlayerHandler.getOfflinePlayerCount() != 0 ? (int) (OfflinePlayerHandler.getOfflinePlayerCount() * 1.05) : 16;
         ConcurrentHashMap<String, Integer> playerStats = new ConcurrentHashMap<>(size);
         ImmutableList<String> playerNames = ImmutableList.copyOf(OfflinePlayerHandler.getOfflinePlayerNames());
-        TopStatAction task = new TopStatAction(threshold, playerNames,
-                request, playerStats);
 
+        TopStatAction task = new TopStatAction(threshold, playerNames, request, playerStats);
+        MyLogger.actionCreated(playerNames.size());
         ForkJoinPool commonPool = ForkJoinPool.commonPool();
+
         try {
             commonPool.invoke(task);
         } catch (ConcurrentModificationException e) {
@@ -140,8 +151,9 @@ public class StatThread extends Thread {
             throw new ConcurrentModificationException(e.toString());
         }
 
+        MyLogger.actionFinished(2);
         ThreadManager.recordCalcTime(System.currentTimeMillis() - time);
-        plugin.logTimeTaken("StatThread", "calculated all stats", time);
+        MyLogger.logTimeTakenDefault("StatThread", "calculated all stats", time);
 
         return playerStats;
     }

src/main/java/com/gmail/artemis/the/gr8/playerstats/statistic/TopStatAction.java

@@ -1,5 +1,6 @@
 package com.gmail.artemis.the.gr8.playerstats.statistic;
 
+import com.gmail.artemis.the.gr8.playerstats.utils.MyLogger;
 import com.gmail.artemis.the.gr8.playerstats.utils.OfflinePlayerHandler;
 import com.google.common.collect.ImmutableList;
 import org.bukkit.OfflinePlayer;
@@ -31,6 +32,8 @@ public class TopStatAction extends RecursiveAction {
 
         this.request = statRequest;
         this.playerStats = playerStats;
+
+        MyLogger.subActionCreated(Thread.currentThread().getName());
     }
 
     @Override
@@ -53,6 +56,7 @@ public class TopStatAction extends RecursiveAction {
             if (iterator.hasNext()) {
                 do {
                     String playerName = iterator.next();
+                    MyLogger.actionRunning(Thread.currentThread().getName(), playerName, 2);
                     OfflinePlayer player = OfflinePlayerHandler.getOfflinePlayer(playerName);
                     if (player != null) {
                         int statistic = 0;

src/main/java/com/gmail/artemis/the/gr8/playerstats/utils/MyLogger.java

@@ -0,0 +1,166 @@
+package com.gmail.artemis.the.gr8.playerstats.utils;
+
+import com.gmail.artemis.the.gr8.playerstats.enums.DebugLevel;
+import org.bukkit.Bukkit;
+import org.bukkit.plugin.Plugin;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.logging.Logger;
+
+public class MyLogger {
+
+    private static final Logger logger;
+    private static DebugLevel debugLevel;
+
+    private static final String[] processedPlayers;
+    private static final AtomicInteger playersIndex;
+    private static ConcurrentHashMap<String, Integer> threadNames;
+
+    static{
+        Plugin plugin = Bukkit.getPluginManager().getPlugin("PlayerStats");
+
+        logger = plugin != null ? plugin.getLogger() : Bukkit.getLogger();
+        debugLevel = DebugLevel.LOW;
+
+        processedPlayers = new String[10];
+        playersIndex = new AtomicInteger(0);
+        threadNames = new ConcurrentHashMap<>();
+    }
+
+    private MyLogger() {
+    }
+
+    /** Accesses the playersIndex to up it by 1 and return its previous value. */
+    private static int nextPlayersIndex() {
+        return playersIndex.getAndIncrement();
+    }
+
+    /** Returns true if the playersIndex is 10, or any subsequent increment of 10. */
+    private static boolean incrementOfTen() {
+        return (playersIndex.get() == 10 || (playersIndex.get() > 10 && playersIndex.get() % 10 == 0));
+    }
+
+    /** Sets the desired debugging level.
+     <p>1 = low (only show unexpected errors)</p>
+     <p>2 = medium (show all encountered exceptions, log main tasks and show time taken)</p>
+     <p>3 = high (log all tasks and time taken)</p>
+     <p>Default: 1</p>*/
+    public static void setDebugLevel(int level) {
+        if (level == 2) {
+            debugLevel = DebugLevel.MEDIUM;
+        }
+        else if (level == 3) {
+            debugLevel = DebugLevel.HIGH;
+        }
+        else {
+            debugLevel = DebugLevel.LOW;
+        }
+    }
+
+    /** Output to console that the given thread has been created (but not started yet).*/
+    public static void threadCreated(String threadName) {
+        if (debugLevel != DebugLevel.LOW) {
+            logger.info(threadName + " created!");
+        }
+    }
+
+    /** Output to console that the given thread has been started. */
+    public static void threadStart(String threadName) {
+        if (debugLevel == DebugLevel.MEDIUM || debugLevel == DebugLevel.HIGH) {
+            logger.info(threadName + " started!");
+        }
+    }
+
+    /** Output to console that another reloadThread is already running. */
+    public static void threadAlreadyRunning(String threadName) {
+        logger.info("Another reloadThread is already running! (" + threadName + ")");
+    }
+
+    /** Output to console that the executingThread is waiting for otherThread to finish up. */
+    public static void waitingForOtherThread(String executingThread, String otherThread) {
+        logger.info(executingThread + ": Waiting for " + otherThread + " to finish up...");
+    }
+
+    /** If DebugLevel is MEDIUM or HIGH, output to console that an action has started.
+     @param taskLength Length of the action (in terms of units-to-process)*/
+    public static void actionCreated(int taskLength) {
+        if (debugLevel != DebugLevel.LOW) {
+            threadNames = new ConcurrentHashMap<>();
+            playersIndex.set(0);
+            logger.info("Initial Action created for " + taskLength + " Players. Start Index is " + playersIndex.get() + ". Processing...");
+        }
+    }
+
+    /** Internally save the name of the executing thread for later logging of this action.
+    The list of names is reset upon the start of every new action.
+     @param threadName Name of the executing thread*/
+    public static void subActionCreated(String threadName) {
+        if (debugLevel == DebugLevel.HIGH) {
+            if (!threadNames.containsKey(threadName)) {
+                threadNames.put(threadName, threadNames.size());
+            }
+        }
+    }
+
+    /** Internally save the name of the executing thread and processed player for logging,
+     and for the ReloadThread, if DebugLevel is HIGH, output the last 10 processed players once
+     there have been 10 names saved in MyLogger. This method is synchronized.
+     @param threadName Name of the executing thread
+     @param playerName Name of the player that was processed in this action
+     @param thread 1 for ReloadThread, 2 for StatThread */
+    public static synchronized void actionRunning(String threadName, String playerName, int thread) {
+        if (debugLevel != DebugLevel.LOW) {
+            if (!threadNames.containsKey(threadName)) {
+                threadNames.put(threadName, threadNames.size());
+            }
+            if (thread == 1 && debugLevel == DebugLevel.HIGH) {
+                if (incrementOfTen()) {
+                    logger.info(Arrays.asList(processedPlayers).toString());
+                }
+                processedPlayers[nextPlayersIndex() % 10] = playerName;
+            }
+            else if (debugLevel == DebugLevel.MEDIUM) {
+                nextPlayersIndex();
+            }
+        }
+    }
+
+    /** Output to console that an action has finished.
+     <p>For the ReloadThread, if DebugLevel is HIGH, output the left-over processed players.
+     For both threads, if DebugLevel is MEDIUM or HIGH, output the names of the threads that were used.</p>
+     @param thread 1 for ReloadThread, 2 for StatThread */
+    public static void actionFinished(int thread) {
+        if (thread == 1 && debugLevel == DebugLevel.HIGH) {
+            ArrayList<String> leftOvers = new ArrayList<>(Arrays.asList(processedPlayers).subList(playersIndex.intValue() % 10, 10));
+            logger.info(leftOvers.toString());
+        }
+        if (debugLevel != DebugLevel.LOW) {
+            logger.info("Finished Recursive Action! In total " +
+                    threadNames.size() + " Threads were used to process " +
+                    playersIndex.get() + " Players: " +
+                    Collections.list(threadNames.keys()));
+        }
+    }
+
+    /** Output to console how long a certain task has taken if DebugLevel is MEDIUM or HIGH.
+     @param className Name of the class executing the task
+     @param methodName Name or description of the task
+     @param startTime Timestamp marking the beginning of the task */
+    public static void logTimeTaken(String className, String methodName, long startTime) {
+        if (debugLevel != DebugLevel.LOW) {
+            logger.info(className + " " + methodName + ": " + (System.currentTimeMillis() - startTime) + "ms");
+        }
+    }
+
+    /** Output to console how long a certain task has taken (regardless of DebugLevel).
+     @param className Name of the class executing the task
+     @param methodName Name or description of the task
+     @param startTime Timestamp marking the beginning of the task */
+    public static void logTimeTakenDefault(String className, String methodName, long startTime) {
+        logger.info(className + " " + methodName + ":" + (System.currentTimeMillis() - startTime) + "ms");
+    }
+}

src/main/java/com/gmail/artemis/the/gr8/playerstats/utils/OfflinePlayerHandler.java

@@ -12,18 +12,23 @@ public class OfflinePlayerHandler {
     private static ConcurrentHashMap<String, UUID> offlinePlayerUUIDs;
     private static ArrayList<String> playerNames;
 
+    static{
+        offlinePlayerUUIDs = new ConcurrentHashMap<>();
+        playerNames = new ArrayList<>();
+    }
+
     private OfflinePlayerHandler() {
     }
 
     /** Checks if a given playerName is on the private HashMap of players that should be included in statistic calculations
      @param playerName String, case-sensitive */
-    public static boolean isOfflinePlayerName(String playerName) {
+    public static boolean isRelevantPlayer(String playerName) {
         return offlinePlayerUUIDs.containsKey(playerName);
     }
 
     /** Returns the number of OfflinePlayers that are included in statistic calculations */
     public static int getOfflinePlayerCount() {
-        return offlinePlayerUUIDs != null ? offlinePlayerUUIDs.size() : 0;
+        return offlinePlayerUUIDs.size();
     }
 
     /** Get an ArrayList of names from all OfflinePlayers that should be included in statistic calculations */

src/main/resources/config.yml

@@ -8,6 +8,12 @@ config-version: 3.1
 #                                #            General              #                                     #
 #                                # ------------------------------- #                                     #
 
+# How much output in console you'll get while PlayerStats is processing
+# 1 = low (only show unexpected errors)
+# 2 = medium (show all encountered exceptions, log main tasks and show time taken)
+# 3 = high (log all tasks and time taken)
+debug-level: 1
+
 # Filtering options to control which players should be included in statistic calculations
 include-whitelist-only: false
 exclude-banned-players: false