fix performance issues in BukkitPlayer permission (#665)

* fix performance issues in BukkitPlayer permission stuff

* Put PermissionAttachmentManager in seperate file

Co-authored-by: @weaondara

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitPermissionAttachmentManager.java

@@ -0,0 +1,58 @@
+package com.sk89q.worldedit.bukkit;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+import org.bukkit.entity.Player;
+import org.bukkit.permissions.PermissionAttachment;
+
+public class BukkitPermissionAttachmentManager {
+
+    private final WorldEditPlugin plugin;
+    private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
+    private final Map<Player, PermissionAttachment> attachments = new HashMap();
+
+    public BukkitPermissionAttachmentManager(WorldEditPlugin plugin) {
+        this.plugin = plugin;
+    }
+
+    public synchronized PermissionAttachment addAttachment(Player p) {
+        PermissionAttachment attach;
+
+        //try find attachment
+        lock.readLock().lock();
+        try {
+            attach = attachments.get(p);
+        } finally {
+            lock.readLock().unlock();
+        }
+
+        if (attach == null) {
+            lock.writeLock().lock();
+            try {
+                //check again - do not remove this
+                attach = attachments.get(p);
+                if (attach == null) {
+                    attach = p.addAttachment(plugin);
+                    attachments.put(p, attach);
+                }
+            } finally {
+                lock.writeLock().unlock();
+            }
+        }
+        return attach;
+    }
+
+    public void removeAttachment(Player p) {
+        PermissionAttachment attach;
+        lock.writeLock().lock();
+        try {
+            attach = attachments.remove(p);
+        } finally {
+            lock.writeLock().unlock();
+        }
+        if (attach != null) {
+            p.removeAttachment(attach);
+        }
+    }
+}

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitPlayer.java

@@ -67,26 +67,27 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Locale;
 import java.util.UUID;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 import javax.annotation.Nullable;
 
 public class BukkitPlayer extends AbstractPlayerActor {
 
-    private Player player;
-    private WorldEditPlugin plugin;
-    private PermissionAttachment permAttachment;
+    private final Player player;
+    private final WorldEditPlugin plugin;
+    private final PermissionAttachment permAttachment;
 
     public BukkitPlayer(Player player) {
         super(getExistingMap(WorldEditPlugin.getInstance(), player));
         this.plugin = WorldEditPlugin.getInstance();
         this.player = player;
-        this.permAttachment = player.addAttachment(plugin);
+        this.permAttachment = plugin.getPermissionAttachmentManager().addAttachment(player);
     }
 
     public BukkitPlayer(WorldEditPlugin plugin, Player player) {
         this.plugin = plugin;
         this.player = player;
-        this.permAttachment = player.addAttachment(plugin);
+        this.permAttachment = plugin.getPermissionAttachmentManager().addAttachment(player);
         if (Settings.IMP.CLIPBOARD.USE_DISK) {
             loadClipboardFromDisk();
         }
@@ -402,7 +403,7 @@ public class BukkitPlayer extends AbstractPlayerActor {
     @Override
     public void unregister() {
         player.removeMetadata("WE", WorldEditPlugin.getInstance());
+        plugin.getPermissionAttachmentManager().removeAttachment(player);
         super.unregister();
     }
-
 }

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/WorldEditPlugin.java

@@ -112,6 +112,7 @@ public class WorldEditPlugin extends JavaPlugin { //implements TabCompleter
     private BukkitImplAdapter bukkitAdapter;
     private BukkitServerInterface server;
     private BukkitConfiguration config;
+    private BukkitPermissionAttachmentManager permissionAttachmentManager;
 
     @Override
     public void onLoad() {
@@ -126,6 +127,8 @@ public class WorldEditPlugin extends JavaPlugin { //implements TabCompleter
         server = new BukkitServerInterface(this, getServer());
         worldEdit.getPlatformManager().register(server);
         
+        permissionAttachmentManager = new BukkitPermissionAttachmentManager(this);
+
         Path delChunks = Paths.get(getDataFolder().getPath(), DELCHUNKS_FILE_NAME);
         if (Files.exists(delChunks)) {
             ChunkDeleter.runFromFile(delChunks, true);
@@ -481,6 +484,15 @@ public class WorldEditPlugin extends JavaPlugin { //implements TabCompleter
         return PermissionsResolverManager.getInstance();
     }
     
+    /**
+     * Get the permissions resolver in use.
+     *
+     * @return the permissions resolver
+     */
+    public BukkitPermissionAttachmentManager getPermissionAttachmentManager() {
+        return permissionAttachmentManager;
+    }
+
     /**
      * Used to wrap a Bukkit Player as a WorldEdit Player.
      *