SQLDatabaseManager optimizations, async profile loading -t00thpick1, zreed

This commit changes our shared connection into a connection pool utility to prevent
thread locks from multiple actions attempting to access the database at the same time.
In additon,  profile loading has been moved off the main thread at login time, to
allieviate the performance issues caused by it.

Fixes #2138, Fixes #2119, Fixes #1982, Fixes #1953

src/main/java/com/gmail/nossr50/runnables/player/PlayerProfileLoadingTask.java

@@ -0,0 +1,108 @@
+package com.gmail.nossr50.runnables.player;
+
+import java.util.concurrent.locks.ReentrantLock;
+
+import org.bukkit.Server;
+import org.bukkit.entity.Player;
+import org.bukkit.scheduler.BukkitRunnable;
+
+import com.gmail.nossr50.mcMMO;
+import com.gmail.nossr50.config.Config;
+import com.gmail.nossr50.datatypes.player.McMMOPlayer;
+import com.gmail.nossr50.datatypes.player.PlayerProfile;
+import com.gmail.nossr50.locale.LocaleLoader;
+import com.gmail.nossr50.runnables.commands.McScoreboardKeepTask;
+import com.gmail.nossr50.util.Misc;
+import com.gmail.nossr50.util.player.UserManager;
+import com.gmail.nossr50.util.scoreboards.ScoreboardManager;
+
+public class PlayerProfileLoadingTask extends BukkitRunnable {
+    private static final int MAX_TRIES = 5;
+    private final Player player;
+    private int attempt = 0;
+    private ReentrantLock lock = new ReentrantLock();
+    private boolean cancelled = false;
+
+    public PlayerProfileLoadingTask(Player player) {
+        this.player = player;
+    }
+
+    // WARNING: ASYNC TASK
+    // DO NOT MODIFY THE McMMOPLAYER FROM THIS CODE
+    @Override
+    public void run() {
+        lock.lock();
+
+        if (this.cancelled) {
+            return;
+        }
+
+        // Quit if they logged out
+        if (!player.isOnline()) {
+            mcMMO.p.getLogger().info("Aborting profile loading recovery for " + player.getName() + " - player logged out");
+            this.cancel();
+            cancelled = true;
+            lock.unlock();
+            return;
+        }
+
+        // Increment attempt counter and try
+        attempt++;
+
+        PlayerProfile profile = mcMMO.getDatabaseManager().loadPlayerProfile(player.getName(), player.getUniqueId(), true);
+        // If successful, schedule the apply
+        if (profile.isLoaded()) {
+            new ApplySuccessfulProfile(profile).runTask(mcMMO.p);
+            this.cancel();
+            cancelled = true;
+            lock.unlock();
+            return;
+        }
+
+        // If we've failed five times, give up
+        if (attempt >= MAX_TRIES) {
+            mcMMO.p.getLogger().severe("Giving up on attempting to load the PlayerProfile for " + player.getName());
+            mcMMO.p.getServer().broadcast(LocaleLoader.getString("Profile.Loading.AdminFailureNotice", player.getName()), Server.BROADCAST_CHANNEL_ADMINISTRATIVE);
+            player.sendMessage(LocaleLoader.getString("Profile.Loading.Failure").split("\n"));
+            this.cancel();
+            cancelled = true;
+            lock.unlock();
+            return;
+        }
+        lock.unlock();
+    }
+
+    private class ApplySuccessfulProfile extends BukkitRunnable {
+        private final PlayerProfile profile;
+
+        private ApplySuccessfulProfile(PlayerProfile profile) {
+            this.profile = profile;
+        }
+
+        // Synchronized task
+        // No database access permitted
+        @Override
+        public void run() {
+            if (!player.isOnline()) {
+                mcMMO.p.getLogger().info("Aborting profile loading recovery for " + player.getName() + " - player logged out");
+                return;
+            }
+
+            McMMOPlayer mcMMOPlayer = new McMMOPlayer(player, profile);
+            UserManager.track(mcMMOPlayer);
+            mcMMOPlayer.actualizeRespawnATS();
+            ScoreboardManager.setupPlayer(player);
+
+            if (Config.getInstance().getShowProfileLoadedMessage()) {
+                player.sendMessage(LocaleLoader.getString("Profile.Loading.Success"));
+            }
+
+            if (Config.getInstance().getShowStatsAfterLogin()) {
+                ScoreboardManager.enablePlayerStatsScoreboard(player);
+                new McScoreboardKeepTask(player).runTaskLater(mcMMO.p, 1 * Misc.TICK_CONVERSION_FACTOR);
+            }
+        }
+    }
+}
+
+