#2753: Add configurable remote ping caching

api/src/main/java/net/md_5/bungee/api/ProxyConfig.java

@@ -56,6 +56,14 @@ public interface ProxyConfig
      */
     boolean isLogCommands();
 
+    /**
+     * Time in milliseconds to cache server list info from a ping request from
+     * the proxy to a server.
+     *
+     * @return cache time
+     */
+    int getRemotePingCache();
+
     /**
      * Returns the player max.
      *

proxy/src/main/java/net/md_5/bungee/BungeeServerInfo.java

@@ -123,6 +123,18 @@ public class BungeeServerInfo implements ServerInfo
         }
     }
 
+    private long lastPing;
+    private ServerPing cachedPing;
+
+    public void cachePing(ServerPing serverPing)
+    {
+        if ( ProxyServer.getInstance().getConfig().getRemotePingCache() > 0 )
+        {
+            this.cachedPing = serverPing;
+            this.lastPing = System.currentTimeMillis();
+        }
+    }
+
     @Override
     public InetSocketAddress getAddress()
     {
@@ -139,6 +151,18 @@ public class BungeeServerInfo implements ServerInfo
     {
         Preconditions.checkNotNull( callback, "callback" );
 
+        int pingCache = ProxyServer.getInstance().getConfig().getRemotePingCache();
+        if ( pingCache > 0 && cachedPing != null && ( lastPing - System.currentTimeMillis() ) > pingCache )
+        {
+            cachedPing = null;
+        }
+
+        if ( cachedPing != null )
+        {
+            callback.done( cachedPing, null );
+            return;
+        }
+
         ChannelFutureListener listener = new ChannelFutureListener()
         {
             @Override

proxy/src/main/java/net/md_5/bungee/conf/Configuration.java

@@ -52,6 +52,7 @@ public class Configuration implements ProxyConfig
      */
     private boolean logCommands;
     private boolean logPings = true;
+    private int remotePingCache = -1;
     private int playerLimit = -1;
     private Collection<String> disabledCommands;
     private int throttle = 4000;
@@ -85,6 +86,7 @@ public class Configuration implements ProxyConfig
         onlineMode = adapter.getBoolean( "online_mode", onlineMode );
         logCommands = adapter.getBoolean( "log_commands", logCommands );
         logPings = adapter.getBoolean( "log_pings", logPings );
+        remotePingCache = adapter.getInt( "remote_ping_cache", remotePingCache );
         playerLimit = adapter.getInt( "player_limit", playerLimit );
         throttle = adapter.getInt( "connection_throttle", throttle );
         throttleLimit = adapter.getInt( "connection_throttle_limit", throttleLimit );

proxy/src/main/java/net/md_5/bungee/connection/PingHandler.java

@@ -4,6 +4,7 @@ import com.google.gson.Gson;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import lombok.RequiredArgsConstructor;
 import net.md_5.bungee.BungeeCord;
+import net.md_5.bungee.BungeeServerInfo;
 import net.md_5.bungee.api.Callback;
 import net.md_5.bungee.api.ProxyServer;
 import net.md_5.bungee.api.ServerPing;
@@ -65,7 +66,9 @@ public class PingHandler extends PacketHandler
     public void handle(StatusResponse statusResponse) throws Exception
     {
         Gson gson = BungeeCord.getInstance().gson;
-        callback.done( gson.fromJson( statusResponse.getResponse(), ServerPing.class ), null );
+        ServerPing serverPing = gson.fromJson( statusResponse.getResponse(), ServerPing.class );
+        ( (BungeeServerInfo) target ).cachePing( serverPing );
+        callback.done( serverPing, null );
         channel.close();
     }