From e849afbb23ada657b8bee3fd368ae844af418507 Mon Sep 17 00:00:00 2001
From: md_5 <git@md-5.net>
Date: Fri, 20 Jun 2014 20:04:22 +1000
Subject: [PATCH] Add simple address cache for those with slow or otherwise
 unresponsive DNS servers.

I wonder when @netty was supposed to add async dns lookups.
---
 .../java/net/md_5/bungee/http/HttpClient.java | 25 ++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/proxy/src/main/java/net/md_5/bungee/http/HttpClient.java b/proxy/src/main/java/net/md_5/bungee/http/HttpClient.java
index 740e6716..e1f2c1b6 100644
--- a/proxy/src/main/java/net/md_5/bungee/http/HttpClient.java
+++ b/proxy/src/main/java/net/md_5/bungee/http/HttpClient.java
@@ -1,19 +1,23 @@
 package net.md_5.bungee.http;
 
 import com.google.common.base.Preconditions;
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheBuilder;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.EventLoop;
-import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.nio.NioSocketChannel;
 import io.netty.handler.codec.http.DefaultHttpRequest;
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.HttpMethod;
 import io.netty.handler.codec.http.HttpRequest;
 import io.netty.handler.codec.http.HttpVersion;
+import java.net.InetAddress;
 import java.net.URI;
+import java.net.UnknownHostException;
+import java.util.concurrent.TimeUnit;
 import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
 import net.md_5.bungee.api.Callback;
@@ -22,7 +26,8 @@ import net.md_5.bungee.api.Callback;
 public class HttpClient
 {
 
-    public static int TIMEOUT = 5000;
+    public static final int TIMEOUT = 5000;
+    private static final Cache<String, InetAddress> addressCache = CacheBuilder.newBuilder().expireAfterWrite( 5, TimeUnit.MINUTES ).build();
 
     public static void get(String url, EventLoop eventLoop, final Callback<String> callback)
     {
@@ -51,6 +56,20 @@ public class HttpClient
             }
         }
 
+        InetAddress inetHost = addressCache.getIfPresent( uri.getHost() );
+        if ( inetHost == null )
+        {
+            try
+            {
+                inetHost = InetAddress.getByName( uri.getHost() );
+            } catch ( UnknownHostException ex )
+            {
+                callback.done( null, ex );
+                return;
+            }
+        }
+        addressCache.put( uri.getHost(), inetHost );
+
         ChannelFutureListener future = new ChannelFutureListener()
         {
             @Override
@@ -72,6 +91,6 @@ public class HttpClient
         };
 
         new Bootstrap().channel( NioSocketChannel.class ).group( eventLoop ).handler( new HttpInitializer( callback, ssl ) ).
-                option( ChannelOption.CONNECT_TIMEOUT_MILLIS, TIMEOUT ).remoteAddress( uri.getHost(), port ).connect().addListener( future );
+                option( ChannelOption.CONNECT_TIMEOUT_MILLIS, TIMEOUT ).remoteAddress( inetHost, port ).connect().addListener( future );
     }
 }