Cache hostname lookups.

src/main/java/com/cnaude/purpleirc/GameListeners/GamePlayerJoinListener.java

@@ -38,13 +38,14 @@ public void onPlayerJoinEvent(final PlayerJoinEvent event) {
         plugin.getServer().getScheduler().runTaskLaterAsynchronously(plugin, new Runnable() {
             @Override
             public void run() {
+                plugin.clearHostCache(event.getPlayer());
                 for (PurpleBot ircBot : plugin.ircBots.values()) {
                     ircBot.gameJoin(event.getPlayer(), event.getJoinMessage());
                     if (plugin.netPackets != null) {
                         plugin.netPackets.updateTabList(event.getPlayer());
                     }
                 }
-                plugin.updateDisplayNameCache(event.getPlayer());
+                plugin.updateDisplayNameCache(event.getPlayer());                
             }
         }, 20);
     }

src/main/java/com/cnaude/purpleirc/PurpleIRC.java

@@ -48,6 +48,8 @@
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.lang.management.ManagementFactory;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
 import java.text.Collator;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -86,6 +88,7 @@ public class PurpleIRC extends JavaPlugin {
     private final CaseInsensitiveMap<CaseInsensitiveMap<String>> ircTownyChannelMessages;
     private final CaseInsensitiveMap<CaseInsensitiveMap<String>> heroChannelMessages;
     private final CaseInsensitiveMap<CaseInsensitiveMap<String>> heroActionChannelMessages;
+    private Map<String, String> hostCache;
     public String defaultPlayerSuffix,
             defaultPlayerPrefix,
             defaultPlayerGroup,
@@ -161,6 +164,7 @@ public PurpleIRC() {
         this.heroChannelMessages = new CaseInsensitiveMap<>();
         this.heroActionChannelMessages = new CaseInsensitiveMap<>();
         this.displayNameCache = new CaseInsensitiveMap<>();
+        this.hostCache = new HashMap<>();
         this.cacheFile = new File("plugins/PurpleIRC/displayName.cache");
     }
 
@@ -1176,4 +1180,30 @@ public void loadDisplayNameCache() {
             logError(e.getMessage());
         }
     }
+
+    public String getPlayerHost(Player player) {
+        String playerIP = player.getAddress().getAddress().getHostAddress();
+        if (hostCache.containsKey(playerIP)) {
+            return hostCache.get(playerIP);
+        }
+        InetAddress addr = null;
+        try {
+            addr = InetAddress.getByName(playerIP);
+        } catch (UnknownHostException ex) {
+            logError(ex.getMessage());
+        }
+        String host = "UnknownHost";
+        if ( addr != null ) {
+            host = addr.getHostName();
+            hostCache.put(playerIP, host);
+        }
+        return host;
+    }
+
+    public void clearHostCache(Player player) {
+        String playerIP = player.getAddress().getAddress().getHostAddress();
+        if (hostCache.containsKey(playerIP)) {
+            hostCache.remove(playerIP);
+        }
+    }
 }

src/main/java/com/cnaude/purpleirc/Utilities/ChatTokenizer.java

@@ -506,16 +506,7 @@ public String playerTokenizer(Player player, String message) {
         String group = plugin.getPlayerGroup(player);
         String displayName = player.getDisplayName();
         String playerIP = player.getAddress().getAddress().getHostAddress();
-        InetAddress addr = null;
-        try {
-            addr = InetAddress.getByName(playerIP);
-        } catch (UnknownHostException ex) {
-            plugin.logError(ex.getMessage());
-        }
-        String host = "";
-        if ( addr != null ) {
-            host = addr.getHostName();
-        }
+        String host = plugin.getPlayerHost(player);
         String worldName = "";
         String worldAlias = "";
         String worldColor = "";