Remove the 'use-server-uuids' option and internal UuidCache system

The feature has stuck around since the early days - and solves a problem which really should never occur.

bukkit/src/main/java/me/lucko/luckperms/bukkit/LPBukkitPlugin.java

@@ -80,7 +80,6 @@ import me.lucko.luckperms.common.tasks.CacheHousekeepingTask;
 import me.lucko.luckperms.common.tasks.ExpireTemporaryTask;
 import me.lucko.luckperms.common.tasks.UpdateTask;
 import me.lucko.luckperms.common.treeview.PermissionVault;
-import me.lucko.luckperms.common.utils.UuidCache;
 import me.lucko.luckperms.common.verbose.VerboseHandler;
 
 import org.bukkit.command.PluginCommand;
@@ -120,7 +119,6 @@ public class LPBukkitPlugin extends JavaPlugin implements LuckPermsPlugin {
     private Storage storage;
     private FileWatcher fileWatcher = null;
     private InternalMessagingService messagingService = null;
-    private UuidCache uuidCache;
     private LuckPermsApiProvider apiProvider;
     private EventFactory eventFactory;
     private Logger log;
@@ -238,7 +236,6 @@ public class LPBukkitPlugin extends JavaPlugin implements LuckPermsPlugin {
 
         // load internal managers
         getLog().info("Loading internal permission managers...");
-        this.uuidCache = new UuidCache(this);
         this.userManager = new StandardUserManager(this);
         this.groupManager = new StandardGroupManager(this);
         this.trackManager = new StandardTrackManager(this);
@@ -318,7 +315,7 @@ public class LPBukkitPlugin extends JavaPlugin implements LuckPermsPlugin {
             this.scheduler.doAsync(() -> {
                 try {
                     connectionListener.loadUser(player.getUniqueId(), player.getName());
-                    User user = getUserManager().getIfLoaded(getUuidCache().getUUID(player.getUniqueId()));
+                    User user = getUserManager().getIfLoaded(player.getUniqueId());
                     if (user != null) {
                         this.scheduler.doSync(() -> {
                             try {
@@ -363,7 +360,7 @@ public class LPBukkitPlugin extends JavaPlugin implements LuckPermsPlugin {
                 player.setOp(false);
             }
 
-            final User user = getUserManager().getIfLoaded(getUuidCache().getUUID(player.getUniqueId()));
+            final User user = getUserManager().getIfLoaded(player.getUniqueId());
             if (user != null) {
                 user.getCachedData().invalidateCaches();
                 getUserManager().unload(user);
@@ -496,7 +493,7 @@ public class LPBukkitPlugin extends JavaPlugin implements LuckPermsPlugin {
 
     @Override
     public Player getPlayer(User user) {
-        return getServer().getPlayer(this.uuidCache.getExternalUUID(user.getUuid()));
+        return getServer().getPlayer(user.getUuid());
     }
 
     @Override
@@ -615,11 +612,6 @@ public class LPBukkitPlugin extends JavaPlugin implements LuckPermsPlugin {
         return this.storage;
     }
 
-    @Override
-    public UuidCache getUuidCache() {
-        return this.uuidCache;
-    }
-
     @Override
     public LuckPermsApiProvider getApiProvider() {
         return this.apiProvider;

bukkit/src/main/java/me/lucko/luckperms/bukkit/listeners/BukkitConnectionListener.java

@@ -129,7 +129,7 @@ public class BukkitConnectionListener extends AbstractLoginListener implements L
             this.plugin.getLog().info("Processing login for " + player.getUniqueId() + " - " + player.getName());
         }
 
-        final User user = this.plugin.getUserManager().getIfLoaded(this.plugin.getUuidCache().getUUID(player.getUniqueId()));
+        final User user = this.plugin.getUserManager().getIfLoaded(player.getUniqueId());
 
         /* User instance is null for whatever reason. Could be that it was unloaded between asyncpre and now. */
         if (user == null) {

bukkit/src/main/java/me/lucko/luckperms/bukkit/vault/VaultChatHook.java

@@ -246,7 +246,7 @@ public class VaultChatHook extends AbstractVaultChat {
     // utility methods for getting user and group instances
 
     private User getUser(UUID uuid) {
-        return this.plugin.getUserManager().getIfLoaded(this.plugin.getUuidCache().getUUID(uuid));
+        return this.plugin.getUserManager().getIfLoaded(uuid);
     }
 
     private Group getGroup(String name) {

bukkit/src/main/java/me/lucko/luckperms/bukkit/vault/VaultPermissionHook.java

@@ -287,7 +287,7 @@ public class VaultPermissionHook extends AbstractVaultPermission {
     // utility methods for getting user and group instances
 
     private User getUser(UUID uuid) {
-        return this.plugin.getUserManager().getIfLoaded(this.plugin.getUuidCache().getUUID(uuid));
+        return this.plugin.getUserManager().getIfLoaded(uuid);
     }
 
     private Group getGroup(String name) {

bukkit/src/main/resources/config.yml

@@ -38,34 +38,6 @@ apply-global-groups: true
 # If users on this server should have global (non-world specific) groups applied
 apply-global-world-groups: true
 
-# If UUIDs should be pulled from the server, or looked up by username based upon previous
-# connections.
-#
-# This option should be set to true in most cases. When set to false, in order to get a player's
-# UUID, LuckPerms will:
-#
-# 1. Check if a player with the given username has joined before, if they have, use the UUID they
-#    used on their previous login.
-# 2. Save and return the players "current" uuid.
-#
-# For offline mode (cracked) servers, a players UUID is generated based upon their username.
-#
-# IMPORTANT:
-# If you are using BungeeCord proxy running in online mode, it is important that "online-mode=false"
-# is set in server.properties, but "bungeecord: true" is set in the spigot.yml. You also need to set
-# "ip_forward: true" in BungeeCord's config.yml.
-#
-# If for whatever reason you are not able to do this, and do not have ip-forward enabled, then you
-# may need to set "use-server-uuids" to false.
-#
-# If your proxy is running in offline mode, you should still be setting up ip-forwarding as
-# described above, but may also find that you need to set "bungee-online-mode" to false in
-# paper.yml, if you are using Paper. (https://ci.destroystokyo.com/job/PaperSpigot/)
-#
-# This option only really exists for networks who for whatever reason cannot setup proper ip
-# forwarding.
-use-server-uuids: true
-
 # If the servers own UUID cache/lookup facility should be used when there is no record for a player
 # in the LuckPerms cache.
 use-server-uuid-cache: false