remove HOPELESS downloads from the download list via an event

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

@@ -23,6 +23,7 @@ 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.DownloadHopelessEvent
 import com.muwire.core.download.DownloadManager
 import com.muwire.core.download.SourceDiscoveredEvent
 import com.muwire.core.download.SourceVerifiedEvent
@@ -391,6 +392,7 @@ public class Core {
         eventBus.register(SourceDiscoveredEvent.class, downloadManager)
         eventBus.register(UIDownloadPausedEvent.class, downloadManager)
         eventBus.register(UIDownloadResumedEvent.class, downloadManager)
+        eventBus.register(DownloadHopelessEvent.class, downloadManager)
 
         log.info("initializing upload manager")
         uploadManager = new UploadManager(eventBus, fileManager, meshManager, downloadManager, persisterFolderService, props)

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

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

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

@@ -112,6 +112,11 @@ public class DownloadManager {
         persistDownloaders()
     }
 
+    public void onDownloadHopelessEvent(DownloadHopelessEvent e) {
+        downloaders.remove(e.downloader.infoHash)
+        persistDownloaders()
+    }
+    
     public void onUIDownloadPausedEvent(UIDownloadPausedEvent e) {
         persistDownloaders()
     }

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

@@ -66,6 +66,7 @@ public class Downloader {
 
     private volatile boolean cancelled, paused
     private final AtomicBoolean eventFired = new AtomicBoolean()
+    private final AtomicBoolean hopelessEventFired = new AtomicBoolean()
     private boolean piecesFileClosed
 
     private final AtomicLong dataSinceLastRead = new AtomicLong(0)
@@ -436,6 +437,8 @@ public class Downloader {
             } catch (Exception bad) {
                 log.log(Level.WARNING,"Exception while downloading",DataUtil.findRoot(bad))
                 markFailed(destination)
+                if (!hasLiveSources() && hopelessEventFired.compareAndSet(false, true)) 
+                    eventBus.publish(new DownloadHopelessEvent(downloader : Downloader.this))
             } finally {
                 writePieces()
                 currentState = WorkerState.FINISHED