Move stream's cache key generation in PlaybackResolver and improve PlaybackResolver's code

app/src/main/java/org/schabi/newpipe/player/helper/PlayerHelper.java

@@ -3,8 +3,6 @@ package org.schabi.newpipe.player.helper;
 import static com.google.android.exoplayer2.Player.REPEAT_MODE_ALL;
 import static com.google.android.exoplayer2.Player.REPEAT_MODE_OFF;
 import static com.google.android.exoplayer2.Player.REPEAT_MODE_ONE;
-import static org.schabi.newpipe.extractor.stream.AudioStream.UNKNOWN_BITRATE;
-import static org.schabi.newpipe.extractor.stream.VideoStream.RESOLUTION_UNKNOWN;
 import static org.schabi.newpipe.player.Player.IDLE_WINDOW_FLAGS;
 import static org.schabi.newpipe.player.Player.PLAYER_TYPE;
 import static org.schabi.newpipe.player.helper.PlayerHelper.AutoplayType.AUTOPLAY_TYPE_ALWAYS;
@@ -47,11 +45,9 @@ import com.google.android.exoplayer2.util.MimeTypes;
 import org.schabi.newpipe.R;
 import org.schabi.newpipe.extractor.InfoItem;
 import org.schabi.newpipe.extractor.MediaFormat;
-import org.schabi.newpipe.extractor.stream.AudioStream;
 import org.schabi.newpipe.extractor.stream.StreamInfo;
 import org.schabi.newpipe.extractor.stream.StreamInfoItem;
 import org.schabi.newpipe.extractor.stream.SubtitlesStream;
-import org.schabi.newpipe.extractor.stream.VideoStream;
 import org.schabi.newpipe.extractor.utils.Utils;
 import org.schabi.newpipe.player.MainPlayer;
 import org.schabi.newpipe.player.Player;
@@ -197,52 +193,6 @@ public final class PlayerHelper {
         }
     }
 
-    @NonNull
-    public static String cacheKeyOf(@NonNull final StreamInfo info,
-                                    @NonNull final VideoStream videoStream) {
-        String cacheKey = info.getUrl() + " " + videoStream.getId();
-
-        final String resolution = videoStream.getResolution();
-        final MediaFormat mediaFormat = videoStream.getFormat();
-        if (resolution.equals(RESOLUTION_UNKNOWN) && mediaFormat == null) {
-            // The hash code is only used in the cache key in the case when the resolution and the
-            // media format are unknown
-            cacheKey += " " + videoStream.hashCode();
-        } else {
-            if (mediaFormat != null) {
-                cacheKey += " " + videoStream.getFormat().getName();
-            }
-            if (!resolution.equals(RESOLUTION_UNKNOWN)) {
-                cacheKey += " " + resolution;
-            }
-        }
-
-        return cacheKey;
-    }
-
-    @NonNull
-    public static String cacheKeyOf(@NonNull final StreamInfo info,
-                                    @NonNull final AudioStream audioStream) {
-        String cacheKey = info.getUrl() + " " + audioStream.getId();
-
-        final int averageBitrate = audioStream.getAverageBitrate();
-        final MediaFormat mediaFormat = audioStream.getFormat();
-        if (averageBitrate == UNKNOWN_BITRATE && mediaFormat == null) {
-            // The hash code is only used in the cache key in the case when the resolution and the
-            // media format are unknown
-            cacheKey += " " + audioStream.hashCode();
-        } else {
-            if (mediaFormat != null) {
-                cacheKey += " " + audioStream.getFormat().getName();
-            }
-            if (averageBitrate != UNKNOWN_BITRATE) {
-                cacheKey += " " + averageBitrate;
-            }
-        }
-
-        return cacheKey;
-    }
-
     /**
      * Given a {@link StreamInfo} and the existing queue items,
      * provide the {@link SinglePlayQueue} consisting of the next video for auto queueing.

app/src/main/java/org/schabi/newpipe/player/resolver/AudioPlaybackResolver.java

@@ -13,7 +13,6 @@ import com.google.android.exoplayer2.source.MediaSource;
 import org.schabi.newpipe.extractor.stream.AudioStream;
 import org.schabi.newpipe.extractor.stream.StreamInfo;
 import org.schabi.newpipe.player.helper.PlayerDataSource;
-import org.schabi.newpipe.player.helper.PlayerHelper;
 import org.schabi.newpipe.player.mediaitem.MediaItemTag;
 import org.schabi.newpipe.player.mediaitem.StreamInfoTag;
 import org.schabi.newpipe.util.ListHelper;
@@ -57,7 +56,7 @@ public class AudioPlaybackResolver implements PlaybackResolver {
 
         try {
             return PlaybackResolver.buildMediaSource(
-                    dataSource, audio, info, PlayerHelper.cacheKeyOf(info, audio), tag);
+                    dataSource, audio, info, PlaybackResolver.cacheKeyOf(info, audio), tag);
         } catch (final IOException e) {
             Log.e(TAG, "Unable to create audio source:", e);
             return null;

app/src/main/java/org/schabi/newpipe/player/resolver/PlaybackResolver.java

@@ -1,5 +1,7 @@
 package org.schabi.newpipe.player.resolver;
 
+import static org.schabi.newpipe.extractor.stream.AudioStream.UNKNOWN_BITRATE;
+import static org.schabi.newpipe.extractor.stream.VideoStream.RESOLUTION_UNKNOWN;
 import static org.schabi.newpipe.extractor.utils.Utils.isNullOrEmpty;
 import static org.schabi.newpipe.player.helper.PlayerDataSource.LIVE_STREAM_EDGE_GAP_MILLIS;
 
@@ -20,6 +22,7 @@ import com.google.android.exoplayer2.source.smoothstreaming.SsMediaSource;
 import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsManifest;
 import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsManifestParser;
 
+import org.schabi.newpipe.extractor.MediaFormat;
 import org.schabi.newpipe.extractor.ServiceList;
 import org.schabi.newpipe.extractor.services.youtube.ItagItem;
 import org.schabi.newpipe.extractor.services.youtube.dashmanifestcreators.CreationException;
@@ -49,6 +52,79 @@ import java.util.Objects;
 public interface PlaybackResolver extends Resolver<StreamInfo, MediaSource> {
     String TAG = PlaybackResolver.class.getSimpleName();
 
+    @NonNull
+    private static StringBuilder commonCacheKeyOf(@NonNull final StreamInfo info,
+                                                  @NonNull final Stream stream,
+                                                  final boolean resolutionOrBitrateUnknown) {
+        // stream info service id
+        final StringBuilder cacheKey = new StringBuilder(info.getServiceId());
+
+        // stream info id
+        cacheKey.append(" ");
+        cacheKey.append(info.getId());
+
+        // stream id (even if unknown)
+        cacheKey.append(" ");
+        cacheKey.append(stream.getId());
+
+        // mediaFormat (if not null)
+        final MediaFormat mediaFormat = stream.getFormat();
+        if (mediaFormat != null) {
+            cacheKey.append(" ");
+            cacheKey.append(mediaFormat.getName());
+        }
+
+        // content (only if other information is missing)
+        // If the media format and the resolution/bitrate are both missing, then we don't have
+        // enough information to distinguish this stream from other streams.
+        // So, only in that case, we use the content (i.e. url or manifest) to differentiate
+        // between streams.
+        // Note that if the content were used even when other information is present, then two
+        // streams with the same stats but with different contents (e.g. because the url was
+        // refreshed) will be considered different (i.e. with a different cacheKey), making the
+        // cache useless.
+        if (resolutionOrBitrateUnknown && mediaFormat == null) {
+            cacheKey.append(" ");
+            Objects.hash(stream.getContent(), stream.getManifestUrl());
+        }
+
+        return cacheKey;
+    }
+
+    @NonNull
+    static String cacheKeyOf(@NonNull final StreamInfo info,
+                             @NonNull final VideoStream videoStream) {
+        final boolean resolutionUnknown = videoStream.getResolution().equals(RESOLUTION_UNKNOWN);
+        final StringBuilder cacheKey = commonCacheKeyOf(info, videoStream, resolutionUnknown);
+
+        // resolution (if known)
+        if (!resolutionUnknown) {
+            cacheKey.append(" ");
+            cacheKey.append(videoStream.getResolution());
+        }
+
+        // isVideoOnly
+        cacheKey.append(" ");
+        cacheKey.append(videoStream.isVideoOnly());
+
+        return cacheKey.toString();
+    }
+
+    @NonNull
+    static String cacheKeyOf(@NonNull final StreamInfo info,
+                             @NonNull final AudioStream audioStream) {
+        final boolean averageBitrateUnknown = audioStream.getAverageBitrate() == UNKNOWN_BITRATE;
+        final StringBuilder cacheKey = commonCacheKeyOf(info, audioStream, averageBitrateUnknown);
+
+        // averageBitrate (if known)
+        if (!averageBitrateUnknown) {
+            cacheKey.append(" ");
+            cacheKey.append(audioStream.getAverageBitrate());
+        }
+
+        return cacheKey.toString();
+    }
+
     @Nullable
     static MediaSource maybeBuildLiveMediaSource(@NonNull final PlayerDataSource dataSource,
                                                  @NonNull final StreamInfo info) {

app/src/main/java/org/schabi/newpipe/player/resolver/VideoPlaybackResolver.java

@@ -95,7 +95,7 @@ public class VideoPlaybackResolver implements PlaybackResolver {
         if (video != null) {
             try {
                 final MediaSource streamSource = PlaybackResolver.buildMediaSource(
-                        dataSource, video, info, PlayerHelper.cacheKeyOf(info, video), tag);
+                        dataSource, video, info, PlaybackResolver.cacheKeyOf(info, video), tag);
                 mediaSources.add(streamSource);
             } catch (final IOException e) {
                 Log.e(TAG, "Unable to create video source:", e);
@@ -114,7 +114,7 @@ public class VideoPlaybackResolver implements PlaybackResolver {
         if (audio != null && (video == null || video.isVideoOnly())) {
             try {
                 final MediaSource audioSource = PlaybackResolver.buildMediaSource(
-                        dataSource, audio, info, PlayerHelper.cacheKeyOf(info, audio), tag);
+                        dataSource, audio, info, PlaybackResolver.cacheKeyOf(info, audio), tag);
                 mediaSources.add(audioSource);
                 streamSourceType = SourceType.VIDEO_WITH_SEPARATED_AUDIO;
             } catch (final IOException e) {