-Added state saving for streams on skip and player exception events.

-Added query for loading saved stream states.
-Modified orphan record removal to no longer consider stream table records.

app/src/main/java/org/schabi/newpipe/database/stream/dao/StreamDAO.java

@@ -92,10 +92,6 @@ public abstract class StreamDAO implements BasicDAO<StreamEntity> {
             " ON " + STREAM_ID + " = " +
             StreamHistoryEntity.STREAM_HISTORY_TABLE + "." + StreamHistoryEntity.JOIN_STREAM_ID +
 
-            " LEFT JOIN " + STREAM_STATE_TABLE +
-            " ON " + STREAM_ID + " = " +
-            StreamStateEntity.STREAM_STATE_TABLE + "." + StreamStateEntity.JOIN_STREAM_ID +
-
             " LEFT JOIN " + PLAYLIST_STREAM_JOIN_TABLE +
             " ON " + STREAM_ID + " = " +
             PlaylistStreamEntity.PLAYLIST_STREAM_JOIN_TABLE + "." + PlaylistStreamEntity.JOIN_STREAM_ID +

app/src/main/java/org/schabi/newpipe/database/stream/dao/StreamStateDAO.java

@@ -1,7 +1,10 @@
 package org.schabi.newpipe.database.stream.dao;
 
 import android.arch.persistence.room.Dao;
+import android.arch.persistence.room.Insert;
+import android.arch.persistence.room.OnConflictStrategy;
 import android.arch.persistence.room.Query;
+import android.arch.persistence.room.Transaction;
 
 import org.schabi.newpipe.database.BasicDAO;
 import org.schabi.newpipe.database.stream.model.StreamStateEntity;
@@ -28,6 +31,18 @@ public abstract class StreamStateDAO implements BasicDAO<StreamStateEntity> {
         throw new UnsupportedOperationException();
     }
 
+    @Query("SELECT * FROM " + STREAM_STATE_TABLE + " WHERE " + JOIN_STREAM_ID + " = :streamId")
+    public abstract Flowable<List<StreamStateEntity>> getState(final long streamId);
+
     @Query("DELETE FROM " + STREAM_STATE_TABLE + " WHERE " + JOIN_STREAM_ID + " = :streamId")
     public abstract int deleteState(final long streamId);
+
+    @Insert(onConflict = OnConflictStrategy.IGNORE)
+    abstract void silentInsertInternal(final StreamStateEntity streamState);
+
+    @Transaction
+    public long upsert(StreamStateEntity stream) {
+        silentInsertInternal(stream);
+        return update(stream);
+    }
 }

app/src/main/java/org/schabi/newpipe/history/HistoryFragment.java

@@ -156,7 +156,7 @@ public abstract class HistoryFragment<E> extends BaseFragment
                 .setMessage(R.string.delete_all_history_prompt)
                 .setCancelable(true)
                 .setNegativeButton(R.string.cancel, null)
-                .setPositiveButton(R.string.delete, (dialog, i) -> clearHistory())
+                .setPositiveButton(R.string.delete_all, (dialog, i) -> clearHistory())
                 .show();
     }
 

app/src/main/java/org/schabi/newpipe/history/HistoryRecordManager.java

@@ -3,23 +3,25 @@ package org.schabi.newpipe.history;
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.preference.PreferenceManager;
+import android.support.annotation.NonNull;
 
 import org.schabi.newpipe.NewPipeDatabase;
 import org.schabi.newpipe.R;
 import org.schabi.newpipe.database.AppDatabase;
 import org.schabi.newpipe.database.history.dao.SearchHistoryDAO;
-import org.schabi.newpipe.database.history.model.StreamHistoryEntry;
+import org.schabi.newpipe.database.history.dao.StreamHistoryDAO;
 import org.schabi.newpipe.database.history.model.SearchHistoryEntry;
+import org.schabi.newpipe.database.history.model.StreamHistoryEntity;
+import org.schabi.newpipe.database.history.model.StreamHistoryEntry;
 import org.schabi.newpipe.database.stream.StreamStatisticsEntry;
 import org.schabi.newpipe.database.stream.dao.StreamDAO;
-import org.schabi.newpipe.database.history.dao.StreamHistoryDAO;
+import org.schabi.newpipe.database.stream.dao.StreamStateDAO;
 import org.schabi.newpipe.database.stream.model.StreamEntity;
-import org.schabi.newpipe.database.history.model.StreamHistoryEntity;
+import org.schabi.newpipe.database.stream.model.StreamStateEntity;
 import org.schabi.newpipe.extractor.stream.StreamInfo;
 
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.Date;
 import java.util.List;
 
@@ -34,6 +36,7 @@ public class HistoryRecordManager {
     private final StreamDAO streamTable;
     private final StreamHistoryDAO streamHistoryTable;
     private final SearchHistoryDAO searchHistoryTable;
+    private final StreamStateDAO streamStateTable;
     private final SharedPreferences sharedPreferences;
     private final String searchHistoryKey;
     private final String streamHistoryKey;
@@ -43,15 +46,12 @@ public class HistoryRecordManager {
         streamTable = database.streamDAO();
         streamHistoryTable = database.streamHistoryDAO();
         searchHistoryTable = database.searchHistoryDAO();
+        streamStateTable = database.streamStateDAO();
         sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
         searchHistoryKey = context.getString(R.string.enable_search_history_key);
         streamHistoryKey = context.getString(R.string.enable_watch_history_key);
     }
 
-    public Single<Integer> removeOrphanedRecords() {
-        return Single.fromCallable(streamTable::deleteOrphans).subscribeOn(Schedulers.io());
-    }
-
     ///////////////////////////////////////////////////////
     // Watch History
     ///////////////////////////////////////////////////////
@@ -161,4 +161,31 @@ public class HistoryRecordManager {
     private boolean isSearchHistoryEnabled() {
         return sharedPreferences.getBoolean(searchHistoryKey, false);
     }
+
+    ///////////////////////////////////////////////////////
+    // Stream State History
+    ///////////////////////////////////////////////////////
+
+    @SuppressWarnings("unused")
+    public Maybe<StreamStateEntity> loadStreamState(final StreamInfo info) {
+        return Maybe.fromCallable(() -> streamTable.upsert(new StreamEntity(info)))
+                .flatMap(streamId -> streamStateTable.getState(streamId).firstElement())
+                .flatMap(states -> states.isEmpty() ? Maybe.empty() : Maybe.just(states.get(0)))
+                .subscribeOn(Schedulers.io());
+    }
+
+    public Maybe<Long> saveStreamState(@NonNull final StreamInfo info, final long progressTime) {
+        return Maybe.fromCallable(() -> database.runInTransaction(() -> {
+            final long streamId = streamTable.upsert(new StreamEntity(info));
+            return streamStateTable.upsert(new StreamStateEntity(streamId, progressTime));
+        })).subscribeOn(Schedulers.io());
+    }
+
+    ///////////////////////////////////////////////////////
+    // Utility
+    ///////////////////////////////////////////////////////
+
+    public Single<Integer> removeOrphanedRecords() {
+        return Single.fromCallable(streamTable::deleteOrphans).subscribeOn(Schedulers.io());
+    }
 }

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

@@ -581,6 +581,8 @@ public abstract class BasePlayer implements Player.EventListener, PlaybackListen
             errorToast = null;
         }
 
+        savePlaybackState();
+
         switch (error.type) {
             case ExoPlaybackException.TYPE_SOURCE:
                 if (simpleExoPlayer.getCurrentPosition() <
@@ -758,6 +760,8 @@ public abstract class BasePlayer implements Player.EventListener, PlaybackListen
         if (simpleExoPlayer == null || playQueue == null) return;
         if (DEBUG) Log.d(TAG, "onPlayPrevious() called");
 
+        savePlaybackState();
+
         /* If current playback has run for PLAY_PREV_ACTIVATION_LIMIT milliseconds, restart current track.
         * Also restart the track if the current track is the first in a queue.*/
         if (simpleExoPlayer.getCurrentPosition() > PLAY_PREV_ACTIVATION_LIMIT || playQueue.getIndex() == 0) {
@@ -772,6 +776,8 @@ public abstract class BasePlayer implements Player.EventListener, PlaybackListen
         if (playQueue == null) return;
         if (DEBUG) Log.d(TAG, "onPlayNext() called");
 
+        savePlaybackState();
+
         playQueue.offsetIndex(+1);
     }
 
@@ -833,6 +839,24 @@ public abstract class BasePlayer implements Player.EventListener, PlaybackListen
         );
     }
 
+    protected void savePlaybackState(final StreamInfo info, final long progress) {
+        if (context == null || info == null || databaseUpdateReactor == null) return;
+        final Disposable stateSaver = recordManager.saveStreamState(info, progress)
+                .observeOn(AndroidSchedulers.mainThread())
+                .onErrorComplete()
+                .subscribe();
+        databaseUpdateReactor.add(stateSaver);
+    }
+
+    private void savePlaybackState() {
+        if (simpleExoPlayer == null || currentInfo == null) return;
+
+        if (simpleExoPlayer.getCurrentPosition() > RECOVERY_SKIP_THRESHOLD &&
+                simpleExoPlayer.getCurrentPosition() <
+                        simpleExoPlayer.getDuration() - RECOVERY_SKIP_THRESHOLD) {
+            savePlaybackState(currentInfo, simpleExoPlayer.getCurrentPosition());
+        }
+    }
     /*//////////////////////////////////////////////////////////////////////////
     // Getters and Setters
     //////////////////////////////////////////////////////////////////////////*/