Add complete offline-mode support

README.md

@@ -6,6 +6,7 @@ A (fairly bad) permissions implementation for Bukkit/BungeeCord.
 * **Temporary permissions** - users/groups can be given permissions that expire after a given time
 * **Temporary groups** - users/groups can be added to/inherit other groups temporarily
 * **Multi-server support** - data is synced across all servers/platforms
+* **Full offline-mode/mixed-mode support** - player permissions are synced properly over offline-mode or mixed online/offline-mode networks.
 * **Per-server permissions/groups** - define user/group permissions that only apply on certain servers
 * **Server-specific groups** - define groups that only apply on certain servers
 * **Tracks / paths** - users can be promoted/demoted along multiple group tracks

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

@@ -15,6 +15,7 @@ import me.lucko.luckperms.tracks.TrackManager;
 import me.lucko.luckperms.users.BukkitUserManager;
 import me.lucko.luckperms.users.UserManager;
 import me.lucko.luckperms.utils.LPConfiguration;
+import me.lucko.luckperms.utils.UuidCache;
 import me.lucko.luckperms.vaulthooks.VaultHook;
 import org.bukkit.Bukkit;
 import org.bukkit.command.PluginCommand;
@@ -38,6 +39,7 @@ public class LPBukkitPlugin extends JavaPlugin implements LuckPermsPlugin {
     private GroupManager groupManager;
     private TrackManager trackManager;
     private Datastore datastore;
+    private UuidCache uuidCache;
 
     @Override
     public void onEnable() {
@@ -81,6 +83,7 @@ public class LPBukkitPlugin extends JavaPlugin implements LuckPermsPlugin {
         datastore.init();
 
         getLogger().info("Loading internal permission managers...");
+        uuidCache = new UuidCache(getConfiguration().getOnlineMode());
         userManager = new BukkitUserManager(this);
         groupManager = new GroupManager(this);
         trackManager = new TrackManager();

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

@@ -1,11 +1,12 @@
 package me.lucko.luckperms.listeners;
 
-import lombok.AllArgsConstructor;
+import lombok.RequiredArgsConstructor;
 import me.lucko.luckperms.LPBukkitPlugin;
 import me.lucko.luckperms.commands.Util;
 import me.lucko.luckperms.constants.Message;
 import me.lucko.luckperms.users.BukkitUser;
 import me.lucko.luckperms.users.User;
+import me.lucko.luckperms.utils.UuidCache;
 import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
@@ -14,11 +15,33 @@ import org.bukkit.event.player.PlayerJoinEvent;
 import org.bukkit.event.player.PlayerLoginEvent;
 import org.bukkit.event.player.PlayerQuitEvent;
 
-@AllArgsConstructor
+import java.util.UUID;
+
+@RequiredArgsConstructor
 public class PlayerListener implements Listener {
     private static final String KICK_MESSAGE = Util.color(Message.PREFIX + "User data could not be loaded. Please contact an administrator.");
     private final LPBukkitPlugin plugin;
 
+    /*
+    cache: username --> uuid
+        returns mojang if not in offline mode
+
+
+    if server in offline mode:
+        go to datastore, look for uuid, add to cache.
+
+    *** player prelogin, load or create, using CACHE uuid
+
+
+
+    *** player login, we get their username and check if it's there
+
+    *** player join, save uuid data and refresh
+
+    *** player quit, unload
+
+     */
+
     @EventHandler
     public void onPlayerPreLogin(AsyncPlayerPreLoginEvent e) {
         if (!plugin.getDatastore().isAcceptingLogins()) {
@@ -26,13 +49,27 @@ public class PlayerListener implements Listener {
             e.disallow(AsyncPlayerPreLoginEvent.Result.KICK_OTHER, KICK_MESSAGE);
             return;
         }
-        plugin.getDatastore().loadOrCreateUser(e.getUniqueId(), e.getName());
+        
+        final UuidCache cache = plugin.getUuidCache();
+        if (!cache.isOnlineMode()) {
+            UUID uuid = plugin.getDatastore().getUUID(e.getName());
+            if (uuid != null) {
+                cache.addToCache(e.getName(), uuid);
+            } else {
+                cache.addToCache(e.getName(), e.getUniqueId());
+                plugin.getDatastore().saveUUIDData(e.getName(), e.getUniqueId(), b -> {});
+            }
+        } else {
+            plugin.getDatastore().saveUUIDData(e.getName(), e.getUniqueId(), b -> {});
+        }
+
+        plugin.getDatastore().loadOrCreateUser(cache.getUUID(e.getName(), e.getUniqueId()), e.getName());
     }
 
     @EventHandler
     public void onPlayerLogin(PlayerLoginEvent e) {
         final Player player = e.getPlayer();
-        final User user = plugin.getUserManager().getUser(player.getUniqueId());
+        final User user = plugin.getUserManager().getUser(plugin.getUuidCache().getUUID(e.getPlayer().getName(), e.getPlayer().getUniqueId()));
 
         if (user == null) {
             e.disallow(PlayerLoginEvent.Result.KICK_OTHER, KICK_MESSAGE);
@@ -49,23 +86,22 @@ public class PlayerListener implements Listener {
 
     @EventHandler
     public void onPlayerJoin(PlayerJoinEvent e) {
-        // Save UUID data for the player
-        plugin.getDatastore().saveUUIDData(e.getPlayer().getName(), e.getPlayer().getUniqueId(), success -> {});
-
-        final User user = plugin.getUserManager().getUser(e.getPlayer().getUniqueId());
-        if (user != null) {
         // Refresh permissions again
+        final User user = plugin.getUserManager().getUser(plugin.getUuidCache().getUUID(e.getPlayer().getName(), e.getPlayer().getUniqueId()));
+        if (user != null) {
             user.refreshPermissions();
         }
-
     }
 
     @EventHandler
     public void onPlayerQuit(PlayerQuitEvent e) {
         final Player player = e.getPlayer();
+        final UuidCache cache = plugin.getUuidCache();
 
-        // Unload the user from memory when they disconnect
+        // Unload the user from memory when they disconnect;
-        final User user = plugin.getUserManager().getUser(player.getUniqueId());
+        cache.clearCache(player.getName());
+
+        final User user = plugin.getUserManager().getUser(cache.getUUID(player.getName(), player.getUniqueId()));
         plugin.getUserManager().unloadUser(user);
     }
 

bukkit/src/main/java/me/lucko/luckperms/users/BukkitUserManager.java

@@ -57,7 +57,9 @@ public class BukkitUserManager extends UserManager {
     public void updateAllUsers() {
         // Sometimes called async, so we need to get the players on the Bukkit thread.
         plugin.doSync(() -> {
-            Set<UUID> players = plugin.getServer().getOnlinePlayers().stream().map(Player::getUniqueId).collect(Collectors.toSet());
+            Set<UUID> players = plugin.getServer().getOnlinePlayers().stream()
+                    .map(p -> plugin.getUuidCache().getUUID(p.getName(), p.getUniqueId()))
+                    .collect(Collectors.toSet());
             plugin.doAsync(() -> players.forEach(u -> plugin.getDatastore().loadUser(u)));
         });
     }

bukkit/src/main/resources/config.yml

@@ -9,6 +9,19 @@ default-group: default
 # If users on this server should have their global permissions/groups applied.
 include-global: true
 
+# If this server is in offline or online mode.
+# This setting allows a player to have the same UUID across a network of offline mode/mixed servers.
+
+# You should generally reflect the setting in server.properties here. Except when...
+
+# 1. You have Spigot servers connected to a BungeeCord proxy, with online-mode set to false, but 'bungeecord' set to true in the spigot.yml
+#    AND 'ip-forward' set to true in the BungeeCord config.yml
+#    In this case, set online-mode in LuckPerms to true, dispite the server being in offline mode.
+
+# 2. You are only running one server instance using LuckPerms, (not a network)
+#    In this case, set online-mode to true no matter what is set in server.properties. (we can just fallback to the servers uuid cache)
+online-mode: true
+
 # Which storage method the plugin should use.
 # Currently supported: mysql, sqlite, flatfile
 # Fill out connection info below if you're using MySQL

bungee/src/main/java/me/lucko/luckperms/LPBungeePlugin.java

@@ -14,6 +14,7 @@ import me.lucko.luckperms.tracks.TrackManager;
 import me.lucko.luckperms.users.BungeeUserManager;
 import me.lucko.luckperms.users.UserManager;
 import me.lucko.luckperms.utils.LPConfiguration;
+import me.lucko.luckperms.utils.UuidCache;
 import net.md_5.bungee.api.connection.ProxiedPlayer;
 import net.md_5.bungee.api.plugin.Plugin;
 
@@ -31,6 +32,7 @@ public class LPBungeePlugin extends Plugin implements LuckPermsPlugin {
     private GroupManager groupManager;
     private TrackManager trackManager;
     private Datastore datastore;
+    private UuidCache uuidCache;
 
     @Override
     public void onEnable() {
@@ -69,6 +71,7 @@ public class LPBungeePlugin extends Plugin implements LuckPermsPlugin {
         datastore.init();
 
         getLogger().info("Loading internal permission managers...");
+        uuidCache = new UuidCache(getConfiguration().getOnlineMode());
         userManager = new BungeeUserManager(this);
         groupManager = new GroupManager(this);
         trackManager = new TrackManager();

bungee/src/main/java/me/lucko/luckperms/listeners/PlayerListener.java

@@ -5,14 +5,18 @@ import me.lucko.luckperms.LPBungeePlugin;
 import me.lucko.luckperms.commands.Util;
 import me.lucko.luckperms.constants.Message;
 import me.lucko.luckperms.users.User;
+import me.lucko.luckperms.utils.UuidCache;
 import net.md_5.bungee.api.chat.TextComponent;
+import net.md_5.bungee.api.connection.PendingConnection;
 import net.md_5.bungee.api.connection.ProxiedPlayer;
+import net.md_5.bungee.api.event.LoginEvent;
 import net.md_5.bungee.api.event.PlayerDisconnectEvent;
 import net.md_5.bungee.api.event.PostLoginEvent;
 import net.md_5.bungee.api.plugin.Listener;
 import net.md_5.bungee.event.EventHandler;
 
 import java.lang.ref.WeakReference;
+import java.util.UUID;
 import java.util.concurrent.TimeUnit;
 
 @AllArgsConstructor
@@ -22,39 +26,62 @@ public class PlayerListener implements Listener {
     );
     private final LPBungeePlugin plugin;
 
+    @EventHandler
+    public void onPlayerLogin(LoginEvent e) {
+        /* Delay the login here, as we want to cache UUID data before the player is connected to a backend bukkit server.
+           This means that a player will have the same UUID across the network, even if parts of the network are running in
+           Offline mode. */
+        e.registerIntent(plugin);
+        plugin.doAsync(() -> {
+            final UuidCache cache = plugin.getUuidCache();
+            final PendingConnection c = e.getConnection();
+
+            if (!cache.isOnlineMode()) {
+                UUID uuid = plugin.getDatastore().getUUID(c.getName());
+                if (uuid != null) {
+                    cache.addToCache(c.getName(), uuid);
+                } else {
+                    cache.addToCache(c.getName(), c.getUniqueId());
+                    plugin.getDatastore().saveUUIDData(c.getName(), c.getUniqueId());
+                }
+            } else {
+                plugin.getDatastore().saveUUIDData(c.getName(), c.getUniqueId());
+            }
+
+            // We have to make a new user on this thread whilst the connection is being held, or we get concurrency issues as the Bukkit server
+            // and the BungeeCord server try to make a new user at the same time.
+            plugin.getDatastore().loadOrCreateUser(cache.getUUID(c.getName(), c.getUniqueId()), c.getName());
+            e.completeIntent(plugin);
+        });
+    }
+
     @EventHandler
     public void onPlayerPostLogin(PostLoginEvent e) {
         final ProxiedPlayer player = e.getPlayer();
         final WeakReference<ProxiedPlayer> p = new WeakReference<>(player);
 
-        // Create user async and at post login. We're not concerned if data couldn't be loaded, the player won't be kicked.
+        final User user = plugin.getUserManager().getUser(plugin.getUuidCache().getUUID(e.getPlayer().getName(), e.getPlayer().getUniqueId()));
-        plugin.getDatastore().loadOrCreateUser(player.getUniqueId(), player.getName(), success -> {
+        if (user == null) {
-            if (!success) {
             plugin.getProxy().getScheduler().schedule(plugin, () -> {
                 final ProxiedPlayer pl = p.get();
                 if (pl != null) {
                     pl.sendMessage(WARN_MESSAGE);
                 }
             }, 3, TimeUnit.SECONDS);
-
         } else {
-                final ProxiedPlayer pl = p.get();
-                if (pl != null) {
-                    final User user = plugin.getUserManager().getUser(pl.getUniqueId());
             user.refreshPermissions();
         }
     }
-        });
-
-        plugin.getDatastore().saveUUIDData(player.getName(), player.getUniqueId(), success -> {});
-    }
 
     @EventHandler
     public void onPlayerQuit(PlayerDisconnectEvent e) {
         final ProxiedPlayer player = e.getPlayer();
+        final UuidCache cache = plugin.getUuidCache();
 
-        // Unload the user from memory when they disconnect
+        // Unload the user from memory when they disconnect;
-        final User user = plugin.getUserManager().getUser(player.getUniqueId());
+        cache.clearCache(player.getName());
+
+        final User user = plugin.getUserManager().getUser(cache.getUUID(player.getName(), player.getUniqueId()));
         plugin.getUserManager().unloadUser(user);
     }
 }

bungee/src/main/java/me/lucko/luckperms/users/BungeeUserManager.java

@@ -1,7 +1,6 @@
 package me.lucko.luckperms.users;
 
 import me.lucko.luckperms.LPBungeePlugin;
-import net.md_5.bungee.api.connection.ProxiedPlayer;
 
 import java.util.UUID;
 
@@ -41,6 +40,8 @@ public class BungeeUserManager extends UserManager {
 
     @Override
     public void updateAllUsers() {
-        plugin.getProxy().getPlayers().stream().map(ProxiedPlayer::getUniqueId).forEach(u -> plugin.getDatastore().loadUser(u));
+        plugin.getProxy().getPlayers().stream()
+                .map(p -> plugin.getUuidCache().getUUID(p.getName(), p.getUniqueId()))
+                .forEach(u -> plugin.getDatastore().loadUser(u));
     }
 }

bungee/src/main/resources/config.yml

@@ -9,6 +9,19 @@ default-group: default
 # If users on this server should have their global permissions/groups applied.
 include-global: false
 
+# If this server is in offline or online mode.
+# This setting allows a player to have the same UUID across a network of offline mode/mixed servers.
+
+# You should generally reflect the setting in server.properties here. Except when...
+
+# 1. You have Spigot servers connected to a BungeeCord proxy, with online-mode set to false, but 'bungeecord' set to true in the spigot.yml
+#    AND 'ip-forward' set to true in the BungeeCord config.yml
+#    In this case, set online-mode in LuckPerms to true, dispite the server being in offline mode.
+
+# 2. You are only running one server instance using LuckPerms, (not a network)
+#    In this case, set online-mode to true no matter what is set in server.properties. (we can just fallback to the servers uuid cache)
+online-mode: true
+
 # Which storage method the plugin should use.
 # Currently supported: mysql & flatfile
 # Fill out connection info below if you're using MySQL

common/src/main/java/me/lucko/luckperms/LuckPermsPlugin.java

@@ -5,6 +5,7 @@ import me.lucko.luckperms.groups.GroupManager;
 import me.lucko.luckperms.tracks.TrackManager;
 import me.lucko.luckperms.users.UserManager;
 import me.lucko.luckperms.utils.LPConfiguration;
+import me.lucko.luckperms.utils.UuidCache;
 
 import java.util.List;
 import java.util.UUID;
@@ -48,6 +49,12 @@ public interface LuckPermsPlugin {
      */
     Logger getLogger();
 
+    /**
+     * Retrieves the {@link UuidCache} for the plugin
+     * @return the plugin's {@link UuidCache}
+     */
+    UuidCache getUuidCache();
+
     /**
      * @return the version of the plugin
      */

common/src/main/java/me/lucko/luckperms/commands/misc/InfoCommand.java

@@ -20,7 +20,7 @@ public class InfoCommand extends MainCommand {
     protected void execute(LuckPermsPlugin plugin, Sender sender, List<String> args, String label) {
         final LPConfiguration c = plugin.getConfiguration();
         Message.INFO.send(sender, plugin.getVersion(), plugin.getDatastore().getName(), c.getServer(),
-                c.getDefaultGroupName(), c.getSyncTime(), c.getIncludeGlobalPerms());
+                c.getDefaultGroupName(), c.getSyncTime(), c.getIncludeGlobalPerms(), c.getOnlineMode());
     }
 
     @Override

common/src/main/java/me/lucko/luckperms/constants/Message.java

@@ -99,7 +99,8 @@ public enum Message {
             PREFIX + "&eServer Name: &6%s" + "\n" +
             PREFIX + "&eDefault Group: &6%s" + "\n" +
             PREFIX + "&eSync Interval: &6%s minutes" + "\n" +
-            PREFIX + "&eInclude Global Perms: &6%s",
+            PREFIX + "&eInclude Global Perms: &6%s" + "\n" +
+            PREFIX + "&eOnline Mode: &6%s",
             false
     ),
     DEBUG(

common/src/main/java/me/lucko/luckperms/utils/LPConfiguration.java

@@ -61,6 +61,10 @@ public abstract class LPConfiguration<T extends LuckPermsPlugin> {
         return getBoolean("include-global", defaultIncludeGlobal);
     }
 
+    public boolean getOnlineMode() {
+        return getBoolean("online-mode", true);
+    }
+
     public String getDatabaseValue(String value) {
         return getString("sql." + value, null);
     }

common/src/main/java/me/lucko/luckperms/utils/UuidCache.java

@@ -0,0 +1,38 @@
+package me.lucko.luckperms.utils;
+
+import lombok.Getter;
+
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+
+public class UuidCache {
+
+    private Map<String, UUID> cache;
+
+    @Getter
+    private final boolean onlineMode;
+
+    public UuidCache(boolean onlineMode) {
+        this.onlineMode = onlineMode;
+
+        if (!onlineMode) {
+            cache = new ConcurrentHashMap<>();
+        }
+    }
+
+    public UUID getUUID(String name, UUID fallback) {
+        return onlineMode ? fallback : (cache.containsKey(name) ? cache.get(name) : fallback);
+    }
+
+    public void addToCache(String name, UUID uuid) {
+        if (onlineMode) return;
+        cache.put(name, uuid);
+    }
+
+    public void clearCache(String name) {
+        if (onlineMode) return;
+        cache.remove(name);
+    }
+
+}