Implement command list updater for Fabric (#3060)

fabric/src/main/java/me/lucko/luckperms/fabric/LPFabricPlugin.java

@@ -44,6 +44,7 @@ import me.lucko.luckperms.fabric.context.FabricContextManager;
 import me.lucko.luckperms.fabric.context.FabricPlayerCalculator;
 import me.lucko.luckperms.fabric.listeners.FabricConnectionListener;
 import me.lucko.luckperms.fabric.listeners.PermissionCheckListener;
+import me.lucko.luckperms.fabric.listeners.FabricCommandListUpdater;
 import me.lucko.luckperms.fabric.messaging.FabricMessagingFactory;
 
 import net.fabricmc.loader.api.ModContainer;
@@ -159,6 +160,10 @@ public class LPFabricPlugin extends AbstractLuckPermsPlugin {
 
     @Override
     protected void performFinalSetup() {
+        // register fabric command list updater
+        if (getConfiguration().get(ConfigKeys.UPDATE_CLIENT_COMMAND_LIST)) {
+            getApiProvider().getEventBus().subscribe(new FabricCommandListUpdater(this));
+        }
     }
 
     public FabricSenderFactory getSenderFactory() {

fabric/src/main/java/me/lucko/luckperms/fabric/context/FabricPlayerCalculator.java

@@ -123,6 +123,7 @@ public class FabricPlayerCalculator implements ContextCalculator<ServerPlayerEnt
     private void onWorldChange(ServerWorld origin, ServerWorld destination, ServerPlayerEntity player) {
         if (this.world) {
             this.plugin.getContextManager().invalidateCache(player);
+            this.plugin.getContextManager().signalContextUpdate(player);
         }
     }
 

fabric/src/main/java/me/lucko/luckperms/fabric/listeners/FabricCommandListUpdater.java

@@ -0,0 +1,118 @@
+/*
+ * This file is part of LuckPerms, licensed under the MIT License.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  Permission is hereby granted, free of charge, to any person obtaining a copy
+ *  of this software and associated documentation files (the "Software"), to deal
+ *  in the Software without restriction, including without limitation the rights
+ *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ *  copies of the Software, and to permit persons to whom the Software is
+ *  furnished to do so, subject to the following conditions:
+ *
+ *  The above copyright notice and this permission notice shall be included in all
+ *  copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+package me.lucko.luckperms.fabric.listeners;
+
+import com.github.benmanes.caffeine.cache.LoadingCache;
+
+import me.lucko.luckperms.fabric.LPFabricPlugin;
+import me.lucko.luckperms.common.cache.BufferedRequest;
+import me.lucko.luckperms.common.event.LuckPermsEventListener;
+import me.lucko.luckperms.common.util.CaffeineFactory;
+import me.lucko.luckperms.common.api.implementation.ApiGroup;
+
+import net.luckperms.api.event.EventBus;
+import net.luckperms.api.event.context.ContextUpdateEvent;
+import net.luckperms.api.event.user.UserDataRecalculateEvent;
+import net.luckperms.api.event.group.GroupDataRecalculateEvent;
+import net.minecraft.server.network.ServerPlayerEntity;
+
+import java.util.UUID;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Calls {@link net.minecraft.server.PlayerManager#sendCommandTree()} when a players permissions change.
+ *
+ * TODO: Extract base class for this and BukkitCommandListUpdater
+ */
+public class FabricCommandListUpdater implements LuckPermsEventListener {
+
+    private final LPFabricPlugin plugin;
+    private final LoadingCache<UUID, SendBuffer> sendingBuffers = CaffeineFactory.newBuilder()
+            .expireAfterAccess(10, TimeUnit.SECONDS)
+            .build(SendBuffer::new);
+
+    public FabricCommandListUpdater(LPFabricPlugin plugin) {
+        this.plugin = plugin;
+    }
+
+    @Override
+    public void bind(EventBus bus) {
+        bus.subscribe(UserDataRecalculateEvent.class, this::onUserDataRecalculate);
+        bus.subscribe(GroupDataRecalculateEvent.class, this::onGroupDataRecalculate);
+        bus.subscribe(ContextUpdateEvent.class, this::onContextUpdate);
+    }
+
+    private void onUserDataRecalculate(UserDataRecalculateEvent e) {
+        requestUpdate(e.getUser().getUniqueId());
+    }
+
+    private void onGroupDataRecalculate(GroupDataRecalculateEvent e) {
+        plugin.getUserManager().getAll().values().stream()
+            .filter(u -> u.resolveInheritanceTree(u.getQueryOptions())
+                .contains(ApiGroup.cast(e.getGroup())))
+            .forEach(u -> requestUpdate(u.getUniqueId()));
+    }
+
+    private void onContextUpdate(ContextUpdateEvent e) {
+        e.getSubject(ServerPlayerEntity.class).ifPresent(p -> requestUpdate(p.getUuid()));
+    }
+
+    private void requestUpdate(UUID uniqueId) {
+        if (!this.plugin.getBootstrap().isPlayerOnline(uniqueId)) {
+            return;
+        }
+
+        // Buffer the request to send a commands update.
+        this.sendingBuffers.get(uniqueId).request();
+    }
+
+    // Called when the buffer times out.
+    private void sendUpdate(UUID uniqueId) {
+        this.plugin.getBootstrap().getScheduler().sync()
+                .execute(() -> this.plugin.getBootstrap().getPlayer(uniqueId)
+                    .ifPresent(player -> this.plugin.getBootstrap().getServer()
+                        .ifPresent(server -> {
+                            server.getPlayerManager().sendCommandTree(player);
+                        })
+                    )
+                );
+    }
+
+    private final class SendBuffer extends BufferedRequest<Void> {
+        private final UUID uniqueId;
+
+        SendBuffer(UUID uniqueId) {
+            super(500, TimeUnit.MILLISECONDS, FabricCommandListUpdater.this.plugin.getBootstrap().getScheduler());
+            this.uniqueId = uniqueId;
+        }
+
+        @Override
+        protected Void perform() {
+            sendUpdate(this.uniqueId);
+            return null;
+        }
+    }
+}