Add complete offline-mode support

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());
+        // Refresh permissions again
+        final User user = plugin.getUserManager().getUser(plugin.getUuidCache().getUUID(e.getPlayer().getName(), e.getPlayer().getUniqueId()));
         if (user != null) {
-            // Refresh permissions again
             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
-        final User user = plugin.getUserManager().getUser(player.getUniqueId());
+        // Unload the user from memory when they disconnect;
+        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)));
         });
     }