Added stream compression support. SMACK-112

git-svn-id: http://svn.igniterealtime.org/svn/repos/smack/trunk@3306 b35dd754-fafc-0310-a699-88a17e54d16e

source/org/jivesoftware/smack/PacketReader.java

@@ -320,10 +320,17 @@ class PacketReader {
                         resetParser();
                     }
                     else if (parser.getName().equals("failure")) {
-                        if ("urn:ietf:params:xml:ns:xmpp-tls".equals(parser.getNamespace(null))) {
+                        String namespace = parser.getNamespace(null);
+                        if ("urn:ietf:params:xml:ns:xmpp-tls".equals(namespace)) {
                             // TLS negotiation has failed. The server will close the connection
                             throw new Exception("TLS negotiation has failed");
                         }
+                        else if ("http://jabber.org/protocol/compress".equals(namespace)) {
+                            // Stream compression has been denied. This is a recoverable
+                            // situation. It is still possible to authenticate and
+                            // use the connection but using an uncompressed connection
+                            connection.streamCompressionDenied();
+                        }
                         else {
                             // SASL authentication has failed. The server may close the connection
                             // depending on the number of retries
@@ -347,6 +354,14 @@ class PacketReader {
                         // will be to bind the resource
                         connection.getSASLAuthentication().authenticated();
                     }
+                    else if (parser.getName().equals("compressed")) {
+                        // Server confirmed that it's possible to use stream compression. Start
+                        // stream compression
+                        connection.startStreamCompression();
+                        // Reset the state of the parser since a new stream element is going
+                        // to be sent by the server
+                        resetParser();
+                    }
                 }
                 else if (eventType == XmlPullParser.END_TAG) {
                     if (parser.getName().equals("stream")) {
@@ -464,6 +479,10 @@ class PacketReader {
                     // The server supports sessions
                     connection.getSASLAuthentication().sessionsSupported();
                 }
+                else if (parser.getName().equals("compression")) {
+                    // The server supports stream compression
+                    connection.setAvailableCompressionMethods(parseCompressionMethods(parser));
+                }
             }
             else if (eventType == XmlPullParser.END_TAG) {
                 if (parser.getName().equals("features")) {
@@ -504,6 +523,28 @@ class PacketReader {
         return mechanisms;
     }
 
+    private Collection parseCompressionMethods(XmlPullParser parser)
+            throws IOException, XmlPullParserException {
+        List methods = new ArrayList();
+        boolean done = false;
+        while (!done) {
+            int eventType = parser.next();
+
+            if (eventType == XmlPullParser.START_TAG) {
+                String elementName = parser.getName();
+                if (elementName.equals("method")) {
+                    methods.add(parser.nextText());
+                }
+            }
+            else if (eventType == XmlPullParser.END_TAG) {
+                if (parser.getName().equals("compression")) {
+                    done = true;
+                }
+            }
+        }
+        return methods;
+    }
+
     /**
      * Parses an IQ packet.
      *

source/org/jivesoftware/smack/XMPPConnection.java

@@ -36,6 +36,7 @@ import javax.net.ssl.SSLSocket;
 import java.io.*;
 import java.lang.ref.WeakReference;
 import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
 import java.net.Socket;
 import java.net.UnknownHostException;
 import java.util.*;
@@ -129,6 +130,15 @@ public class XMPPConnection {
      */
     Map chats = Collections.synchronizedMap(new HashMap());
 
+    /**
+     * Collection of available stream compression methods offered by the server.
+     */
+    private Collection compressionMethods;
+    /**
+     * Flag that indicates if stream compression is actually in use.
+     */
+    private boolean usingCompression;
+
     /**
      * Creates a new connection to the specified XMPP server. A DNS SRV lookup will be
      * performed to try to determine the IP address and port corresponding to the
@@ -909,9 +919,38 @@ public class XMPPConnection {
 
     private void initReaderAndWriter() throws XMPPException {
         try {
+            if (!usingCompression) {
                 reader = new BufferedReader(new InputStreamReader(socket.getInputStream(), "UTF-8"));
                 writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream(), "UTF-8"));
             }
+            else {
+                try {
+                    Class zoClass = Class.forName("com.jcraft.jzlib.ZOutputStream");
+                    //ZOutputStream out = new ZOutputStream(socket.getOutputStream(), JZlib.Z_BEST_COMPRESSION);
+                    Constructor constructor =
+                            zoClass.getConstructor(new Class[]{OutputStream.class, Integer.TYPE});
+                    Object out = constructor.newInstance(new Object[] {socket.getOutputStream(), new Integer(9)});
+                    //out.setFlushMode(JZlib.Z_PARTIAL_FLUSH);
+                    Method method = zoClass.getMethod("setFlushMode", new Class[] {Integer.TYPE});
+                    method.invoke(out, new Object[] {new Integer(1)});
+                    writer = new BufferedWriter(new OutputStreamWriter((OutputStream) out, "UTF-8"));
+
+                    Class ziClass = Class.forName("com.jcraft.jzlib.ZInputStream");
+                    //ZInputStream in = new ZInputStream(socket.getInputStream());
+                    constructor = ziClass.getConstructor(new Class[]{InputStream.class});
+                    Object in = constructor.newInstance(new Object[] {socket.getInputStream()});
+                    //in.setFlushMode(JZlib.Z_PARTIAL_FLUSH);
+                    method = ziClass.getMethod("setFlushMode", new Class[] {Integer.TYPE});
+                    method.invoke(in, new Object[] {new Integer(1)});
+                    reader = new BufferedReader(new InputStreamReader((InputStream) in, "UTF-8"));
+                }
+                catch (Exception e) {
+                    e.printStackTrace();
+                    reader = new BufferedReader(new InputStreamReader(socket.getInputStream(), "UTF-8"));
+                    writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream(), "UTF-8"));
+                }
+            }
+        }
         catch (IOException ioe) {
             throw new XMPPException(
                 "XMPPError establishing connection with server.",
@@ -1061,4 +1100,128 @@ public class XMPPConnection {
         // Send a new opening stream to the server
         packetWriter.openStream();
     }
+
+    /**
+     * Sets the available stream compression methods offered by the server.
+     *
+     * @param methods compression methods offered by the server.
+     */
+    void setAvailableCompressionMethods(Collection methods) {
+        compressionMethods = methods;
+    }
+
+    /**
+     * Returns true if the specified compression method was offered by the server.
+     *
+     * @param method the method to check.
+     * @return true if the specified compression method was offered by the server.
+     */
+    private boolean hasAvailableCompressionMethod(String method) {
+        return compressionMethods != null && compressionMethods.contains(method);
+    }
+
+    /**
+     * Returns true if the server offered stream compression to the client.
+     *
+     * @return true if the server offered stream compression to the client.
+     */
+    public boolean getServerSupportsCompression() {
+        return compressionMethods != null && !compressionMethods.isEmpty();
+    }
+
+    /**
+     * Returns true if network traffic is being compressed. When using stream compression network
+     * traffic can be reduced up to 90%. Therefore, stream compression is ideal when using a slow
+     * speed network connection. However, the server will need to use more CPU time in order to
+     * un/compress network data so under high load the server performance might be affected.<p>
+     *
+     * Note: To use stream compression the smackx.jar file has to be present in the classpath.
+     *
+     * @return true if network traffic is being compressed.
+     */
+    public boolean isUsingCompression() {
+        return usingCompression;
+    }
+
+    /**
+     * Starts using stream compression that will compress network traffic. Traffic can be
+     * reduced up to 90%. Therefore, stream compression is ideal when using a slow speed network
+     * connection. However, the server and the client will need to use more CPU time in order to
+     * un/compress network data so under high load the server performance might be affected.<p>
+     *
+     * Stream compression has to have been previously offered by the server. Currently only the
+     * zlib method is supported by the client. Stream compression negotiation has to be done
+     * before authentication took place.<p>
+     *
+     * Note: To use stream compression the smackx.jar file has to be present in the classpath.
+     *
+     * @return true if stream compression negotiation was successful.
+     */
+    public boolean useCompression() {
+        // If stream compression was offered by the server and we want to use
+        // compression then send compression request to the server
+        if (authenticated) {
+            throw new IllegalStateException("Compression should be negotiated before authentication.");
+        }
+        try {
+            Class.forName("com.jcraft.jzlib.ZOutputStream");
+        }
+        catch (ClassNotFoundException e) {
+            throw new IllegalStateException("Cannot use compression. Add smackx.jar to the classpath");
+        }
+        if (hasAvailableCompressionMethod("zlib")) {
+            requestStreamCompression();
+            // Wait until compression is being used or a timeout happened
+            synchronized (this) {
+                try {
+                    this.wait(SmackConfiguration.getPacketReplyTimeout() * 5);
+                }
+                catch (InterruptedException e) {}
+            }
+            return usingCompression;
+        }
+        return false;
+    }
+
+    /**
+     * Request the server that we want to start using stream compression. When using TLS
+     * then negotiation of stream compression can only happen after TLS was negotiated. If TLS
+     * compression is being used the stream compression should not be used.
+     */
+    private void requestStreamCompression() {
+        try {
+            writer.write("<compress xmlns='http://jabber.org/protocol/compress'>");
+            writer.write("<method>zlib</method></compress>");
+            writer.flush();
+        }
+        catch (IOException e) {
+            packetReader.notifyConnectionError(e);
+        }
+    }
+
+    /**
+     * Start using stream compression since the server has acknowledged stream compression.
+     */
+    void startStreamCompression() throws Exception {
+        // Secure the plain connection
+        usingCompression = true;
+        // Initialize the reader and writer with the new secured version
+        initReaderAndWriter();
+
+        // Set the new  writer to use
+        packetWriter.setWriter(writer);
+        // Send a new opening stream to the server
+        packetWriter.openStream();
+        // Notify that compression is being used
+        synchronized (this) {
+            this.notify();
+        }
+    }
+
+    void streamCompressionDenied() {
+        // Notify that compression has been denied
+        synchronized (this) {
+            this.notify();
+        }
+    }
 }

test/org/jivesoftware/smack/test/SmackTestCase.java

@@ -1,53 +1,21 @@
 /**
  * $RCSfile$
  * $Revision$
- * $Date$
+ * $Date: $
  *
- * Copyright (C) 2002-2003 Jive Software. All rights reserved.
+ * Copyright 2003-2005 Jive Software.
- * ====================================================================
- * The Jive Software License (based on Apache Software License, Version 1.1)
  *
- * Redistribution and use in source and binary forms, with or without
+ * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
- * modification, are permitted provided that the following conditions
+ * you may not use this file except in compliance with the License.
- * are met:
+ * You may obtain a copy of the License at
  *
- * 1. Redistributions of source code must retain the above copyright
+ *     http://www.apache.org/licenses/LICENSE-2.0
- *    notice, this list of conditions and the following disclaimer.
  *
- * 2. Redistributions in binary form must reproduce the above copyright
+ * Unless required by applicable law or agreed to in writing, software
- *    notice, this list of conditions and the following disclaimer in
+ * distributed under the License is distributed on an "AS IS" BASIS,
- *    the documentation and/or other materials provided with the
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *    distribution.
+ * See the License for the specific language governing permissions and
- *
+ * limitations under the License.
- * 3. The end-user documentation included with the redistribution,
- *    if any, must include the following acknowledgment:
- *       "This product includes software developed by
- *        Jive Software (http://www.jivesoftware.com)."
- *    Alternately, this acknowledgment may appear in the software itself,
- *    if and wherever such third-party acknowledgments normally appear.
- *
- * 4. The names "Smack" and "Jive Software" must not be used to
- *    endorse or promote products derived from this software without
- *    prior written permission. For written permission, please
- *    contact webmaster@jivesoftware.com.
- *
- * 5. Products derived from this software may not be called "Smack",
- *    nor may "Smack" appear in their name, without prior written
- *    permission of Jive Software.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED.  IN NO EVENT SHALL JIVE SOFTWARE OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
- * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- * ====================================================================
  */
 package org.jivesoftware.smack.test;
 
@@ -242,6 +210,9 @@ public abstract class SmackTestCase extends TestCase {
                         throw e;
                     }
                 }
+                if (Boolean.getBoolean("test.compressionEnabled")) {
+                    getConnection(i).useCompression();
+                }
                 // Login with the new test account
                 getConnection(i).login("user" + i, "user" + i);
             }