From be7b04004bf0e9b284f22b38328ce96ef35d6708 Mon Sep 17 00:00:00 2001
From: Johannes Donath <johannesd@torchmind.com>
Date: Sat, 4 Jul 2015 06:31:33 +0200
Subject: [PATCH] Add basic support for configurable tab-complete throttling


diff --git a/api/src/main/java/net/md_5/bungee/api/ProxyConfig.java b/api/src/main/java/net/md_5/bungee/api/ProxyConfig.java
index 293ec4e3..66d0b8a1 100644
--- a/api/src/main/java/net/md_5/bungee/api/ProxyConfig.java
+++ b/api/src/main/java/net/md_5/bungee/api/ProxyConfig.java
@@ -88,4 +88,13 @@ public interface ProxyConfig
      * If metrics is enabled
      */
     boolean isMetrics();
+
+    // Throttling options
+
+    /**
+     * How often tab-complete packets can be sent.
+     * <p/>
+     * Values in milliseconds.
+     */
+    int getTabThrottle();
 }
diff --git a/proxy/src/main/java/io/github/waterfallmc/waterfall/conf/WaterfallConfiguration.java b/proxy/src/main/java/io/github/waterfallmc/waterfall/conf/WaterfallConfiguration.java
index 056b8040..e56d3591 100644
--- a/proxy/src/main/java/io/github/waterfallmc/waterfall/conf/WaterfallConfiguration.java
+++ b/proxy/src/main/java/io/github/waterfallmc/waterfall/conf/WaterfallConfiguration.java
@@ -16,16 +16,36 @@ public class WaterfallConfiguration extends Configuration {
      */
     private boolean metrics = true;
 
+    /*
+     * Throttling options
+     * Helps prevent players from overloading the servers behind us
+     */
+
+    /**
+     * How often players are allowed to send tab throttle.
+     * Value in milliseconds.
+     * <p/>
+     * Default is one packet per second.
+     */
+    private int tabThrottle = 1000;
+
     @Override
     public void load() {
         super.load();
         YamlConfig config = new YamlConfig(new File("waterfall.yml"));
         config.load(false); // Load, but no permissions
         metrics = config.getBoolean("metrics", metrics);
+        // Throttling options
+        tabThrottle = config.getInt("throttling.tab_complete", tabThrottle);
     }
 
     @Override
     public boolean isMetrics() {
         return metrics;
     }
+
+    @Override
+    public int getTabThrottle() {
+        return tabThrottle;
+    }
 }
diff --git a/proxy/src/main/java/net/md_5/bungee/connection/UpstreamBridge.java b/proxy/src/main/java/net/md_5/bungee/connection/UpstreamBridge.java
index bb43810b..5f5f00ca 100644
--- a/proxy/src/main/java/net/md_5/bungee/connection/UpstreamBridge.java
+++ b/proxy/src/main/java/net/md_5/bungee/connection/UpstreamBridge.java
@@ -32,6 +32,8 @@ public class UpstreamBridge extends PacketHandler
     private final ProxyServer bungee;
     private final UserConnection con;
 
+    private long lastTabCompletion = -1;
+
     public UpstreamBridge(ProxyServer bungee, UserConnection con)
     {
         this.bungee = bungee;
@@ -148,6 +150,16 @@ public class UpstreamBridge extends PacketHandler
     @Override
     public void handle(TabCompleteRequest tabComplete) throws Exception
     {
+        if ( bungee.getConfig().getTabThrottle() > 0 )
+        {
+            long now = System.currentTimeMillis();
+            if ( lastTabCompletion > 0 && (now - lastTabCompletion) <= bungee.getConfig().getTabThrottle() )
+            {
+                throw CancelSendSignal.INSTANCE;
+            }
+            lastTabCompletion = now;
+        }
+
         List<String> suggestions = new ArrayList<>();
 
         if ( tabComplete.getCursor().startsWith( "/" ) )
-- 
2.14.1