File transfer fault tolerance

git-svn-id: http://svn.igniterealtime.org/svn/repos/smack/trunk@3406 b35dd754-fafc-0310-a699-88a17e54d16e

source/org/jivesoftware/smackx/filetransfer/FaultTolerantNegotiator.java

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+/**
+ * $RCSfile$
+ * $Revision: $
+ * $Date: $
+ *
+ * Copyright 2003-2006 Jive Software.
+ *
+ * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.filetransfer;
+
+import org.jivesoftware.smack.PacketCollector;
+import org.jivesoftware.smack.SmackConfiguration;
+import org.jivesoftware.smack.XMPPConnection;
+import org.jivesoftware.smack.XMPPException;
+import org.jivesoftware.smack.filter.OrFilter;
+import org.jivesoftware.smack.filter.PacketFilter;
+import org.jivesoftware.smack.packet.Packet;
+import org.jivesoftware.smackx.packet.StreamInitiation;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+
+/**
+ * The fault tolerant negotiator takes two stream negotiators, the primary and the secondary negotiator.
+ * If the primary negotiator fails during the stream negotiaton process, the second negotiator is used.
+ */
+public class FaultTolerantNegotiator extends StreamNegotiator {
+
+    private StreamNegotiator primaryNegotiator;
+    private StreamNegotiator secondaryNegotiator;
+    private XMPPConnection connection;
+    private PacketFilter primaryFilter;
+    private PacketFilter secondaryFilter;
+
+    public FaultTolerantNegotiator(XMPPConnection connection, StreamNegotiator primary, StreamNegotiator secondary) {
+        this.primaryNegotiator = primary;
+        this.secondaryNegotiator = secondary;
+        this.connection = connection;
+    }
+
+    public PacketFilter getInitiationPacketFilter(String from, String streamID) {
+        if (primaryFilter == null || secondaryFilter == null) {
+            primaryFilter = primaryNegotiator.getInitiationPacketFilter(from, streamID);
+            secondaryFilter = secondaryNegotiator.getInitiationPacketFilter(from, streamID);
+        }
+        return new OrFilter(primaryFilter, secondaryFilter);
+    }
+
+    InputStream negotiateIncomingStream(Packet streamInitiation) throws XMPPException {
+        throw new UnsupportedOperationException("Negotiation only handled by create incoming stream method.");
+    }
+
+    final Packet initiateIncomingStream(XMPPConnection connection, StreamInitiation initiation) throws XMPPException {
+        throw new UnsupportedOperationException("Initiation handled by createIncomingStream method");
+    }
+
+    public InputStream createIncomingStream(StreamInitiation initiation) throws XMPPException {
+        PacketFilter filter = getInitiationPacketFilter(initiation.getFrom(), initiation.getSessionID());
+        PacketCollector collector = connection.createPacketCollector(filter);
+
+        StreamInitiation response = super.createInitiationAccept(initiation, getNamespaces());
+        connection.sendPacket(response);
+
+        InputStream stream;
+        try {
+            Packet streamInitiation = collector.nextResult(SmackConfiguration.getPacketReplyTimeout());
+            if (streamInitiation == null) {
+                throw new XMPPException("No response from remote client");
+            }
+            StreamNegotiator negotiator = determineNegotiator(streamInitiation);
+            stream = negotiator.negotiateIncomingStream(streamInitiation);
+        }
+        catch (XMPPException ex) {
+            ex.printStackTrace();
+            Packet streamInitiation = collector.nextResult(SmackConfiguration.getPacketReplyTimeout());
+            collector.cancel();
+            if (streamInitiation == null) {
+                throw new XMPPException("No response from remote client");
+            }
+            StreamNegotiator negotiator = determineNegotiator(streamInitiation);
+            stream = negotiator.negotiateIncomingStream(streamInitiation);
+        } finally {
+            collector.cancel();
+        }
+
+        return stream;
+    }
+
+    private StreamNegotiator determineNegotiator(Packet streamInitiation) {
+        return primaryFilter.accept(streamInitiation) ? primaryNegotiator : secondaryNegotiator;
+    }
+
+    public OutputStream createOutgoingStream(String streamID, String initiator, String target) throws XMPPException {
+        OutputStream stream;
+        try {
+            stream = primaryNegotiator.createOutgoingStream(streamID, initiator, target);
+        }
+        catch (XMPPException ex) {
+            stream = secondaryNegotiator.createOutgoingStream(streamID, initiator, target);
+        }
+
+        return stream;
+    }
+
+    public String[] getNamespaces() {
+        String [] primary = primaryNegotiator.getNamespaces();
+        String [] secondary = secondaryNegotiator.getNamespaces();
+
+        String [] namespaces = new String[primary.length + secondary.length];
+        System.arraycopy(primary, 0, namespaces, 0, primary.length);
+        System.arraycopy(secondary, 0, namespaces, primary.length, secondary.length);
+
+        return namespaces;
+    }
+
+    public void cleanup() {
+    }
+
+}