Fixed a memory leak in MySQL that would cause errors if users were

removed from the DB

Changelog.txt

@@ -1,3 +1,7 @@
+Version 2.1.66
+    Fixed a bug that could happen if a player was removed from the DB when using MySQL/MariaDB when the user was offline
+    Fixed a minor memory leak for MySQL
+
 Version 2.1.65
     Corrected a bug that would cause RetroMode to use Linear formula regardless of setting
 

pom.xml

@@ -2,7 +2,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.gmail.nossr50.mcMMO</groupId>
     <artifactId>mcMMO</artifactId>
-    <version>2.1.65</version>
+    <version>2.1.66-SNAPSHOT</version>
     <name>mcMMO</name>
     <url>https://github.com/mcMMO-Dev/mcMMO</url>
     <scm>

src/main/java/com/gmail/nossr50/commands/database/McremoveCommand.java

@@ -5,6 +5,7 @@ import com.gmail.nossr50.mcMMO;
 import com.gmail.nossr50.util.commands.CommandUtils;
 import com.gmail.nossr50.util.player.UserManager;
 import com.google.common.collect.ImmutableList;
+import org.bukkit.Bukkit;
 import org.bukkit.command.Command;
 import org.bukkit.command.CommandSender;
 import org.bukkit.command.TabExecutor;
@@ -12,6 +13,7 @@ import org.bukkit.util.StringUtil;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.UUID;
 
 public class McremoveCommand implements TabExecutor {
     @Override
@@ -24,7 +26,13 @@ public class McremoveCommand implements TabExecutor {
                     return true;
                 }
 
-                if (mcMMO.getDatabaseManager().removeUser(playerName)) {
+                UUID uuid = null;
+
+                if(Bukkit.getPlayer(playerName) != null) {
+                    uuid = Bukkit.getPlayer(playerName).getUniqueId();
+                }
+
+                if (mcMMO.getDatabaseManager().removeUser(playerName, uuid)) {
                     sender.sendMessage(LocaleLoader.getString("Commands.mcremove.Success", playerName));
                 }
                 else {

src/main/java/com/gmail/nossr50/database/DatabaseManager.java

@@ -30,9 +30,17 @@ public interface DatabaseManager {
      * Remove a user from the database.
      *
      * @param playerName The name of the user to remove
+     * @param uuid player UUID, can be null
      * @return true if the user was successfully removed, false otherwise
      */
-    public boolean removeUser(String playerName);
+    public boolean removeUser(String playerName, UUID uuid);
+
+    /**
+     * Removes any cache used for faster lookups
+     * Currently only used for SQL
+     * @param uuid target UUID to cleanup
+     */
+    public void cleanupUser(UUID uuid);
 
     /**
      * Save a user to the database.

src/main/java/com/gmail/nossr50/database/FlatfileDatabaseManager.java

@@ -185,7 +185,8 @@ public final class FlatfileDatabaseManager implements DatabaseManager {
         mcMMO.p.getLogger().info("Purged " + removedPlayers + " users from the database.");
     }
 
-    public boolean removeUser(String playerName) {
+    public boolean removeUser(String playerName, UUID uuid) {
+        //NOTE: UUID is unused for FlatFile for this interface implementation
         boolean worked = false;
 
         BufferedReader in = null;
@@ -240,6 +241,11 @@ public final class FlatfileDatabaseManager implements DatabaseManager {
         return worked;
     }
 
+    @Override
+    public void cleanupUser(UUID uuid) {
+        //Not used in FlatFile
+    }
+
     public boolean saveUser(PlayerProfile profile) {
         String playerName = profile.getPlayerName();
         UUID uuid = profile.getUniqueId();

src/main/java/com/gmail/nossr50/database/SQLDatabaseManager.java

@@ -15,6 +15,7 @@ import com.gmail.nossr50.runnables.database.UUIDUpdateAsyncTask;
 import com.gmail.nossr50.util.Misc;
 import org.apache.tomcat.jdbc.pool.DataSource;
 import org.apache.tomcat.jdbc.pool.PoolProperties;
+import org.bukkit.Bukkit;
 import org.bukkit.scheduler.BukkitRunnable;
 
 import java.sql.*;
@@ -172,7 +173,7 @@ public final class SQLDatabaseManager implements DatabaseManager {
         mcMMO.p.getLogger().info("Purged " + purged + " users from the database.");
     }
 
-    public boolean removeUser(String playerName) {
+    public boolean removeUser(String playerName, UUID uuid) {
         boolean success = false;
         Connection connection = null;
         PreparedStatement statement = null;
@@ -200,12 +201,20 @@ public final class SQLDatabaseManager implements DatabaseManager {
         }
 
         if (success) {
+            if(uuid != null)
+                cleanupUser(uuid);
+
             Misc.profileCleanup(playerName);
         }
 
         return success;
     }
 
+    public void cleanupUser(UUID uuid) {
+        if(cachedUserIDs.containsKey(uuid))
+            cachedUserIDs.remove(uuid);
+    }
+
     public boolean saveUser(PlayerProfile profile) {
         boolean success = true;
         PreparedStatement statement = null;

src/main/java/com/gmail/nossr50/datatypes/player/McMMOPlayer.java

@@ -1008,5 +1008,8 @@ public class McMMOPlayer {
         if (inParty()) {
             party.removeOnlineMember(thisPlayer);
         }
+
+        //Remove user from cache
+        mcMMO.getDatabaseManager().cleanupUser(thisPlayer.getUniqueId());
     }
 }