-Added better player exception handling to player.

-Added expired media source cleaning to media source manager.

app/src/main/java/org/schabi/newpipe/fragments/local/bookmark/BookmarkFragment.java

@@ -56,7 +56,8 @@ public final class BookmarkFragment
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        final AppDatabase database = NewPipeDatabase.getInstance(getContext());
+        if (activity == null) return;
+        final AppDatabase database = NewPipeDatabase.getInstance(activity);
         localPlaylistManager = new LocalPlaylistManager(database);
         remotePlaylistManager = new RemotePlaylistManager(database);
         disposables = new CompositeDisposable();

app/src/main/java/org/schabi/newpipe/player/BasePlayer.java

@@ -64,6 +64,7 @@ import org.schabi.newpipe.player.helper.LoadController;
 import org.schabi.newpipe.player.helper.MediaSessionManager;
 import org.schabi.newpipe.player.helper.PlayerDataSource;
 import org.schabi.newpipe.player.helper.PlayerHelper;
+import org.schabi.newpipe.player.mediasource.FailedMediaSource;
 import org.schabi.newpipe.player.playback.BasePlayerMediaSession;
 import org.schabi.newpipe.player.playback.CustomTrackSelector;
 import org.schabi.newpipe.player.playback.MediaSourceManager;
@@ -700,26 +701,6 @@ public abstract class BasePlayer implements
         }
     }
 
-    /**
-     * Processes {@link ExoPlaybackException} tagged with {@link ExoPlaybackException#TYPE_SOURCE}.
-     * <br><br>
-     * If the current {@link com.google.android.exoplayer2.Timeline.Window window} is valid,
-     * then we know the error is produced by transitioning into a bad window, therefore we report
-     * an error to the play queue based on if the current error can be skipped.
-     * <br><br>
-     * This is done because ExoPlayer reports the source exceptions before window is
-     * transitioned on seamless playback. Because player error causes ExoPlayer to go
-     * back to {@link Player#STATE_IDLE STATE_IDLE}, we reset and prepare the media source
-     * again to resume playback.
-     * <br><br>
-     * In the event that this error is produced during a valid stream playback, we save the
-     * current position so the playback may be recovered and resumed manually by the user. This
-     * happens only if the playback is {@link #RECOVERY_SKIP_THRESHOLD} milliseconds until complete.
-     * <br><br>
-     * In the event of livestreaming being lagged behind for any reason, most notably pausing for
-     * too long, a {@link BehindLiveWindowException} will be produced. This will trigger a reload
-     * instead of skipping or removal.
-     * */
     private void processSourceError(final IOException error) {
         if (simpleExoPlayer == null || playQueue == null) return;
 
@@ -733,8 +714,14 @@ public abstract class BasePlayer implements
             reload();
         } else if (cause instanceof UnknownHostException) {
             playQueue.error(/*isNetworkProblem=*/true);
+        } else if (isCurrentWindowValid()) {
+            playQueue.error(/*isTransitioningToBadStream=*/true);
+        } else if (error instanceof FailedMediaSource.MediaSourceResolutionException) {
+            playQueue.error(/*recoverableWithNoAvailableStream=*/false);
+        } else if (error instanceof FailedMediaSource.StreamInfoLoadException) {
+            playQueue.error(/*recoverableIfLoadFailsWhenNetworkIsFine=*/false);
         } else {
-            playQueue.error(isCurrentWindowValid());
+            playQueue.error(/*noIdeaWhatHappenedAndLetUserChooseWhatToDo=*/true);
         }
     }
 

app/src/main/java/org/schabi/newpipe/player/mediasource/FailedMediaSource.java

@@ -14,13 +14,35 @@ import java.io.IOException;
 public class FailedMediaSource implements ManagedMediaSource {
     private final String TAG = "FailedMediaSource@" + Integer.toHexString(hashCode());
 
+    public static class FailedMediaSourceException extends IOException {
+        FailedMediaSourceException(String message) {
+            super(message);
+        }
+
+        FailedMediaSourceException(Throwable cause) {
+            super(cause);
+        }
+    }
+
+    public static final class MediaSourceResolutionException extends FailedMediaSourceException {
+        public MediaSourceResolutionException(String message) {
+            super(message);
+        }
+    }
+
+    public static final class StreamInfoLoadException extends FailedMediaSourceException {
+        public StreamInfoLoadException(Throwable cause) {
+            super(cause);
+        }
+    }
+
     private final PlayQueueItem playQueueItem;
-    private final Throwable error;
+    private final FailedMediaSourceException error;
 
     private final long retryTimestamp;
 
     public FailedMediaSource(@NonNull final PlayQueueItem playQueueItem,
-                             @NonNull final Throwable error,
+                             @NonNull final FailedMediaSourceException error,
                              final long retryTimestamp) {
         this.playQueueItem = playQueueItem;
         this.error = error;
@@ -32,7 +54,7 @@ public class FailedMediaSource implements ManagedMediaSource {
      * The error will always be propagated to ExoPlayer.
      * */
     public FailedMediaSource(@NonNull final PlayQueueItem playQueueItem,
-                             @NonNull final Throwable error) {
+                             @NonNull final FailedMediaSourceException error) {
         this.playQueueItem = playQueueItem;
         this.error = error;
         this.retryTimestamp = Long.MAX_VALUE;
@@ -42,7 +64,7 @@ public class FailedMediaSource implements ManagedMediaSource {
         return playQueueItem;
     }
 
-    public Throwable getError() {
+    public FailedMediaSourceException getError() {
         return error;
     }
 
@@ -57,7 +79,7 @@ public class FailedMediaSource implements ManagedMediaSource {
 
     @Override
     public void maybeThrowSourceInfoRefreshError() throws IOException {
-        throw new IOException(error);
+        throw error;
     }
 
     @Override

app/src/main/java/org/schabi/newpipe/player/mediasource/ManagedMediaSourcePlaylist.java

@@ -129,15 +129,16 @@ public class ManagedMediaSourcePlaylist {
         if (index < 0 || index >= internalSource.getSize()) return;
 
         // Add and remove are sequential on the same thread, therefore here, the exoplayer
-        // message queue must receive and process add before remove.
+        // message queue must receive and process add before remove, effectively treating them
+        // as atomic.
 
-        // However, finalizing action occurs strictly after the timeline has completed
+        // Since the finalizing action occurs strictly after the timeline has completed
-        // all its changes on the playback thread, so it is possible, in the meantime, other calls
+        // all its changes on the playback thread, thus, it is possible, in the meantime,
-        // that modifies the playlist media source may occur in between. Therefore,
+        // other calls that modifies the playlist media source occur in between. This makes
-        // it is not safe to call remove as the finalizing action of add.
+        // it unsafe to call remove as the finalizing action of add.
         internalSource.addMediaSource(index + 1, source);
 
-        // Also, because of the above, it is thus only safe to synchronize the player
+        // Because of the above race condition, it is thus only safe to synchronize the player
         // in the finalizing action AFTER the removal is complete and the timeline has changed.
         internalSource.removeMediaSource(index, finalizingAction);
     }

app/src/main/java/org/schabi/newpipe/player/playback/MediaSourceManager.java

@@ -2,6 +2,7 @@ package org.schabi.newpipe.player.playback;
 
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import android.support.v4.util.ArraySet;
 import android.util.Log;
 
 import com.google.android.exoplayer2.source.DynamicConcatenatingMediaSource;
@@ -24,7 +25,6 @@ import org.schabi.newpipe.playlist.events.ReorderEvent;
 import org.schabi.newpipe.util.ServiceHelper;
 
 import java.util.Collections;
-import java.util.HashSet;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -39,6 +39,7 @@ import io.reactivex.functions.Consumer;
 import io.reactivex.internal.subscriptions.EmptySubscription;
 import io.reactivex.subjects.PublishSubject;
 
+import static org.schabi.newpipe.player.mediasource.FailedMediaSource.*;
 import static org.schabi.newpipe.playlist.PlayQueue.DEBUG;
 
 public class MediaSourceManager {
@@ -144,7 +145,7 @@ public class MediaSourceManager {
 
         this.playlist = new ManagedMediaSourcePlaylist();
 
-        this.loadingItems = Collections.synchronizedSet(new HashSet<>());
+        this.loadingItems = Collections.synchronizedSet(new ArraySet<>());
 
         playQueue.getBroadcastReceiver()
                 .observeOn(AndroidSchedulers.mainThread())
@@ -321,9 +322,9 @@ public class MediaSourceManager {
     }
 
     private void maybeSynchronizePlayer() {
-        cleanSweep();
         maybeUnblock();
         maybeSync();
+        cleanPlaylist();
     }
 
     /*//////////////////////////////////////////////////////////////////////////
@@ -366,7 +367,7 @@ public class MediaSourceManager {
         final int leftBound = Math.max(0, currentIndex - WINDOW_SIZE);
         final int rightLimit = currentIndex + WINDOW_SIZE + 1;
         final int rightBound = Math.min(playQueue.size(), rightLimit);
-        final Set<PlayQueueItem> items = new HashSet<>(
+        final Set<PlayQueueItem> items = new ArraySet<>(
                 playQueue.getStreams().subList(leftBound,rightBound));
 
         // Do a round robin
@@ -402,19 +403,19 @@ public class MediaSourceManager {
         return stream.getStream().map(streamInfo -> {
             final MediaSource source = playbackListener.sourceOf(stream, streamInfo);
             if (source == null) {
-                final Exception exception = new IllegalStateException(
+                final String message = "Unable to resolve source from stream info." +
-                        "Unable to resolve source from stream info." +
+                        " URL: " + stream.getUrl() +
-                                " URL: " + stream.getUrl() +
+                        ", audio count: " + streamInfo.getAudioStreams().size() +
-                                ", audio count: " + streamInfo.getAudioStreams().size() +
+                        ", video count: " + streamInfo.getVideoOnlyStreams().size() +
-                                ", video count: " + streamInfo.getVideoOnlyStreams().size() +
+                        streamInfo.getVideoStreams().size();
-                                streamInfo.getVideoStreams().size());
+                return new FailedMediaSource(stream, new MediaSourceResolutionException(message));
-                return new FailedMediaSource(stream, exception);
             }
 
             final long expiration = System.currentTimeMillis() +
                     ServiceHelper.getCacheExpirationMillis(streamInfo.getServiceId());
             return new LoadedMediaSource(source, stream, expiration);
-        }).onErrorReturn(throwable -> new FailedMediaSource(stream, throwable));
+        }).onErrorReturn(throwable -> new FailedMediaSource(stream,
+                new StreamInfoLoadException(throwable)));
     }
 
     private void onMediaSourceReceived(@NonNull final PlayQueueItem item,
@@ -478,13 +479,15 @@ public class MediaSourceManager {
     }
 
     /**
-     * Scans the entire playlist for {@link MediaSource}s that requires correction,
+     * Scans the entire playlist for {@link ManagedMediaSource}s that requires correction,
-     * and replace these sources with a {@link PlaceholderMediaSource}.
+     * and replaces these sources with a {@link PlaceholderMediaSource} if they are not part
+     * of the excluded items.
      * */
-    private void cleanSweep() {
+    private void cleanPlaylist() {
-        for (int index = 0; index < playlist.size(); index++) {
+        if (DEBUG) Log.d(TAG, "cleanPlaylist() called.");
-            if (isCorrectionNeeded(playQueue.getItem(index))) {
+        for (final PlayQueueItem item : playQueue.getStreams()) {
-                playlist.invalidate(index);
+            if (isCorrectionNeeded(item)) {
+                playlist.invalidate(playQueue.indexOf(item));
             }
         }
     }