parse X-Alt

core/src/main/groovy/com/muwire/core/download/DownloadSession.groovy

@@ -3,7 +3,9 @@ package com.muwire.core.download;
 import net.i2p.data.Base64
 
 import com.muwire.core.Constants
+import com.muwire.core.EventBus
 import com.muwire.core.InfoHash
+import com.muwire.core.Persona
 import com.muwire.core.connection.Endpoint
 import com.muwire.core.util.DataUtil
 
@@ -25,6 +27,7 @@ class DownloadSession {
     
     private static int SAMPLES = 10
     
+    private final EventBus eventBus
     private final String meB64
     private final Pieces pieces
     private final InfoHash infoHash
@@ -40,8 +43,9 @@ class DownloadSession {
     
     private ByteBuffer mapped
     
-    DownloadSession(String meB64, Pieces pieces, InfoHash infoHash, Endpoint endpoint, File file, 
+    DownloadSession(EventBus eventBus, String meB64, Pieces pieces, InfoHash infoHash, Endpoint endpoint, File file, 
         int pieceSize, long fileLength, Set<Integer> available) {
+        this.eventBus = eventBus
         this.meB64 = meB64
         this.pieces = pieces
         this.endpoint = endpoint
@@ -120,6 +124,15 @@ class DownloadSession {
                 String value = header.substring(colon + 1) 
                 headers[key] = value.trim()
             }
+            
+            // prase X-Alt if present
+            if (headers.containsKey("X-Alt")) {
+                headers["X-Alt"].split(",").each { 
+                    byte [] raw = Base64.decode(it)
+                    Persona source = new Persona(new ByteArrayInputStream(raw))
+                    eventBus.publish(new SourceDiscoveredEvent(infoHash : infoHash, source : source))
+                }
+            }
 
             // parse X-Have if present
             if (headers.containsKey("X-Have")) { 

core/src/main/groovy/com/muwire/core/download/Downloader.groovy

@@ -247,7 +247,7 @@ public class Downloader {
                 currentState = WorkerState.DOWNLOADING
                 boolean requestPerformed
                 while(!pieces.isComplete()) {
-                    currentSession = new DownloadSession(me.toBase64(), pieces, getInfoHash(), endpoint, incompleteFile, pieceSize, length)
+                    currentSession = new DownloadSession(eventBus, me.toBase64(), pieces, getInfoHash(), endpoint, incompleteFile, pieceSize, length)
                     requestPerformed = currentSession.request()
                     if (!requestPerformed)
                         break

core/src/main/groovy/com/muwire/core/download/SourceDiscoveredEvent.groovy

@@ -0,0 +1,10 @@
+package com.muwire.core.download
+
+import com.muwire.core.Event
+import com.muwire.core.InfoHash
+import com.muwire.core.Persona
+
+class SourceDiscoveredEvent extends Event {
+    InfoHash infoHash
+    Persona source
+}

core/src/test/groovy/com/muwire/core/download/DownloadSessionTest.groovy

@@ -3,9 +3,13 @@ package com.muwire.core.download
 import static org.junit.Assert.fail
 
 import org.junit.After
+import org.junit.Before
 import org.junit.Test
 
+import com.muwire.core.EventBus
 import com.muwire.core.InfoHash
+import com.muwire.core.Persona
+import com.muwire.core.Personas
 import com.muwire.core.connection.Endpoint
 import com.muwire.core.files.FileHasher
 import static com.muwire.core.util.DataUtil.readTillRN
@@ -16,6 +20,7 @@ import net.i2p.util.ConcurrentHashSet
 
 class DownloadSessionTest {
     
+    private EventBus eventBus
     private File source, target
     private InfoHash infoHash
     private Endpoint endpoint
@@ -32,6 +37,12 @@ class DownloadSessionTest {
     private Set<Integer> available = new ConcurrentHashSet<>()
     private volatile IOException thrown
     
+    
+    @Before
+    public void setUp() {
+        eventBus = new EventBus()
+    }
+    
     private void initSession(int size, def claimedPieces = []) {
         Random r = new Random()
         byte [] content = new byte[size]
@@ -64,7 +75,7 @@ class DownloadSessionTest {
         toUploader = new PipedOutputStream(fromDownloader)
         endpoint = new Endpoint(null, fromUploader, toUploader, null)
         
-        session = new DownloadSession("",pieces, infoHash, endpoint, target, pieceSize, size, available)
+        session = new DownloadSession(eventBus, "",pieces, infoHash, endpoint, target, pieceSize, size, available)
         downloadThread = new Thread( { perform() } as Runnable)
         downloadThread.setDaemon(true)
         downloadThread.start()
@@ -289,6 +300,29 @@ class DownloadSessionTest {
         assert start == 0
     }
     
+    @Test
+    public void testXAlt() throws Exception {
+        Personas personas = new Personas()
+        def sources = []
+        def listener = new Object() {
+            public void onSourceDiscoveredEvent(SourceDiscoveredEvent e) {
+                sources << e.source
+            }
+        }
+        eventBus.register(SourceDiscoveredEvent.class, listener)
+        
+        initSession(20)
+        readAllHeaders(fromDownloader)
+        toDownloader.write("416 don't have it\r\n".bytes)
+        toDownloader.write("X-Alt: ${personas.persona1.toBase64()},${personas.persona2.toBase64()}\r\n\r\n".bytes)
+        toDownloader.flush()
+        
+        Thread.sleep(150)
+        assert sources.contains(personas.persona1)
+        assert sources.contains(personas.persona2)
+        assert 2 == sources.size()
+    }
+    
     private static Set<String> readAllHeaders(InputStream is) {
         Set<String> rv = new HashSet<>()
         String header