hook up download manager

core/src/main/groovy/com/muwire/core/Constants.groovy

@@ -8,4 +8,6 @@ class Constants {
     
     public static final int MAX_HEADER_SIZE = 0x1 << 14
     public static final int MAX_HEADERS = 16
+    
+    public static final float DOWNLOAD_SEQUENTIAL_RATIO = 0.8f
 }

core/src/main/groovy/com/muwire/core/Core.groovy

@@ -11,6 +11,8 @@ import com.muwire.core.connection.I2PAcceptor
 import com.muwire.core.connection.I2PConnector
 import com.muwire.core.connection.LeafConnectionManager
 import com.muwire.core.connection.UltrapeerConnectionManager
+import com.muwire.core.download.DownloadManager
+import com.muwire.core.download.UIDownloadEvent
 import com.muwire.core.files.FileDownloadedEvent
 import com.muwire.core.files.FileHashedEvent
 import com.muwire.core.files.FileHasher
@@ -179,6 +181,10 @@ class Core {
 		eventBus.register(QueryEvent.class, searchManager)
 		eventBus.register(ResultsEvent.class, searchManager)
 		
+        log.info("initializing download manager")
+        DownloadManager downloadManager = new DownloadManager(eventBus, i2pConnector)
+        eventBus.register(UIDownloadEvent.class, downloadManager)
+        
         log.info("initializing upload manager")
         UploadManager uploadManager = new UploadManager(eventBus, fileManager)
         

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

@@ -0,0 +1,33 @@
+package com.muwire.core.download
+
+import com.muwire.core.connection.I2PConnector
+import com.muwire.core.EventBus
+
+import java.util.concurrent.Executor
+import java.util.concurrent.Executors
+
+public class DownloadManager {
+    
+    private final EventBus eventBus
+    private final I2PConnector connector
+    private final Executor executor
+    
+    public DownloadManager(EventBus eventBus, I2PConnector connector) {
+        this.eventBus = eventBus
+        this.connector = connector
+        this.executor = Executors.newCachedThreadPool({ r ->
+            Thread rv = new Thread(r)
+            rv.setName("download-worker")
+            rv.setDaemon(true)
+            rv
+        })
+    }
+    
+    
+    public void onUIDownloadEvent(UIDownloadEvent e) {
+        def downloader = new Downloader(e.target, e.result.size,
+            e.result.infohash, e.result.pieceSize, connector, e.result.sender.destination)
+        executor.execute({downloader.download()} as Runnable)
+        eventBus.publish(new DownloadStartedEvent(downloader : downloader))
+    }
+}

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

@@ -138,4 +138,8 @@ class DownloadSession {
             try { channel?.close() } catch (IOException ignore) {}
         }
     }
+    
+    synchronized int positionInPiece() {
+        mapped.position()
+    }
 }

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

@@ -0,0 +1,7 @@
+package com.muwire.core.download
+
+import com.muwire.core.Event
+
+class DownloadStartedEvent extends Event {
+    Downloader downloader
+}

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

@@ -0,0 +1,66 @@
+package com.muwire.core.download
+
+import com.muwire.core.InfoHash
+import com.muwire.core.connection.Endpoint
+import com.muwire.core.Constants
+import com.muwire.core.connection.I2PConnector
+
+import net.i2p.data.Destination
+
+public class Downloader {
+    public enum DownloadState { CONNECTING, DOWNLOADING, FINISHED }
+    
+    private final File file
+    private final Pieces pieces
+    private final long length
+    private final InfoHash infoHash
+    private final int pieceSize
+    private final I2PConnector connector
+    private final Destination destination
+    
+    private Endpoint endpoint
+    private volatile DownloadSession currentSession
+    private volatile DownloadState currentState
+    
+    public Downloader(File file, long length, InfoHash infoHash, int pieceSizePow2, I2PConnector connector, Destination destination) {
+        this.file = file
+        this.infoHash = infoHash
+        this.length = length
+        this.connector = connector
+        this.destination = destination
+        this.pieceSize = 1 << pieceSizePow2
+        
+        int nPieces
+        if (length % pieceSize == 0)
+            nPieces = length / pieceSize
+        else
+            nPieces = length / pieceSize + 1
+        
+        pieces = new Pieces(nPieces, Constants.DOWNLOAD_SEQUENTIAL_RATIO)
+        currentState = DownloadState.CONNECTING
+    }
+    
+    void download() {
+        Endpoint endpoint = connector.connect(destination)
+        currentState = DownloadState.DOWNLOADING
+        while(!pieces.isComplete()) {
+            currentSession = new DownloadSession(pieces, infoHash, endpoint, file, pieceSize, length)
+            currentSession.request()
+        }
+        currentState = DownloadState.FINISHED
+    }
+    
+    public long donePieces() {
+        pieces.donePieces()
+    }
+    
+    public int positionInPiece() {
+        if (currentSession == null)
+            return 0
+        currentSession.positionInPiece()
+    }
+    
+    public DownloadState getCurrentState() {
+        currentState
+    }
+}

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

@@ -0,0 +1,10 @@
+package com.muwire.core.download
+
+import com.muwire.core.Event
+import com.muwire.core.search.UIResultEvent
+
+class UIDownloadEvent extends Event {
+    
+    UIResultEvent result
+    File target
+}