Added "heartbeat" for update throttling.

guacamole/client/src/net/sourceforge/guacamole/Client.java

@@ -26,6 +26,7 @@ import net.sourceforge.guacamole.event.PointerEvent;
 
 public abstract class Client {
 
+    public abstract void ready() throws GuacamoleException;
     public abstract void send(KeyEvent event) throws GuacamoleException;
     public abstract void send(PointerEvent event) throws GuacamoleException;
     public abstract void setClipboard(String clipboard) throws GuacamoleException;

guacamole/client/src/net/sourceforge/guacamole/GuacamoleClient.java

@@ -57,6 +57,17 @@ public class GuacamoleClient extends Client {
 
     }
 
+    public void ready() throws GuacamoleException {
+
+        try {
+            output.write("ready;");
+            output.flush();
+        }
+        catch (IOException e) {
+            throw new GuacamoleException(e);
+        }
+
+    }
 
     private static final int EVENT_DEADLINE = 500;
 

guacamole/client/src/net/sourceforge/guacamole/net/GuacamoleSession.java

@@ -71,6 +71,10 @@ public class GuacamoleSession {
             client.setClipboard(clipboard);
         }
 
+        public void ready() throws GuacamoleException {
+            client.ready();
+        }
+
         public void disconnect() throws GuacamoleException {
             client.disconnect();
         }

guacamole/client/src/net/sourceforge/guacamole/net/input/Ready.java

@@ -0,0 +1,43 @@
+
+package net.sourceforge.guacamole.net.input;
+
+/*
+ *  Guacamole - Clientless Remote Desktop
+ *  Copyright (C) 2010  Michael Jumper
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import javax.servlet.ServletRequest;
+import net.sourceforge.guacamole.GuacamoleException;
+import org.w3c.dom.Element;
+
+import net.sourceforge.guacamole.net.GuacamoleSession;
+import net.sourceforge.guacamole.net.XMLGuacamoleServlet;
+
+public class Ready extends XMLGuacamoleServlet {
+
+    @Override
+    protected void handleRequest(GuacamoleSession session, ServletRequest request, Element root) throws GuacamoleException {
+
+        try {
+            session.getClient().ready();
+        }
+        catch (GuacamoleException e) {
+            throw new GuacamoleException("Error updating ready status: " + e.getMessage(), e);
+        }
+
+    }
+}
+

guacamole/client/web/WEB-INF/web.xml

@@ -61,6 +61,15 @@
         <servlet-name>Clipboard</servlet-name>
         <url-pattern>/clipboard</url-pattern>
     </servlet-mapping>
+    <servlet>
+        <description>Client "ready-to-receive" heartbeat</description>
+        <servlet-name>Ready</servlet-name>
+        <servlet-class>net.sourceforge.guacamole.net.input.Ready</servlet-class>
+    </servlet>
+    <servlet-mapping>
+        <servlet-name>Ready</servlet-name>
+        <url-pattern>/ready</url-pattern>
+    </servlet-mapping>
     <servlet>
         <description>Key input servlet.</description>
         <servlet-name>Key</servlet-name>

guacamole/client/web/javascript/guacamole.js

@@ -542,6 +542,26 @@ function VNCClient(display) {
     }
 
 
+    function sendReady() {
+
+        // Start heartbeat signal
+        var heartbeat = new XMLHttpRequest();
+        heartbeat.open("GET", "ready");
+
+        heartbeat.onreadystatechange = function() {
+
+            if (heartbeat != null && heartbeat.readyState >= 2) {
+                heartbeat = null;
+                setTimeout(sendReady, 50);
+            }
+
+        };
+
+        heartbeat.send();
+
+    }
+
+
     this.connect = function() {
 
         // Attempt connection
@@ -555,6 +575,7 @@ function VNCClient(display) {
         var message = new GuacamoleMessage(connect_xmlhttprequest.responseXML);
         if (!message.hasErrors()) {
             setState(STATE_WAITING);
+            sendReady();
             handleResponse(makeRequest()); // Start stream if connection successful
         }
         else

guacamole/proxy/client.c

@@ -85,12 +85,6 @@ void guac_start_client(guac_client* client) {
     /* VNC Client Loop */
     for (;;) {
 
-        /* Handle server messages */
-        if (client->handle_messages) {
-            client->handle_messages(client);
-            guac_flush(client->io);
-        }
-
         wait_result = guac_instructions_waiting(io);
         if (wait_result > 0) {
 
@@ -131,6 +125,12 @@ void guac_start_client(guac_client* client) {
 
             /* Otherwise, retval == 0 implies unfinished instruction */
 
+            /* Handle server messages */
+            if (client->handle_messages) {
+                client->handle_messages(client);
+                guac_flush(client->io);
+            }
+
         }
         else if (wait_result < 0)
             return;