Workaround enourmous load times for long bandcamp playlists

Additionally, get cover art from json instead of html

extractor/src/main/java/org/schabi/newpipe/extractor/services/bandcamp/extractors/BandcampPlaylistExtractor.java

@@ -18,11 +18,19 @@ import org.schabi.newpipe.extractor.stream.StreamInfoItemsCollector;
 import javax.annotation.Nonnull;
 import java.io.IOException;
 
+import static org.schabi.newpipe.extractor.services.bandcamp.extractors.BandcampChannelExtractor.getImageUrl;
 import static org.schabi.newpipe.extractor.services.bandcamp.extractors.BandcampExtractorHelper.getJSONFromJavaScriptVariables;
 import static org.schabi.newpipe.extractor.services.bandcamp.extractors.BandcampStreamExtractor.getAlbumInfoJson;
 
 public class BandcampPlaylistExtractor extends PlaylistExtractor {
 
+    /**
+     * An arbitrarily chosen number above which cover arts won't be fetched individually for each track;
+     * instead, it will be assumed that every track has the same cover art as the album, which is not
+     * always the case.
+     */
+    private static final int MAXIMUM_INDIVIDUAL_COVER_ARTS = 10;
+
     private Document document;
     private JSONObject albumJson;
     private JSONArray trackInfo;
@@ -57,11 +65,8 @@ public class BandcampPlaylistExtractor extends PlaylistExtractor {
 
     @Override
     public String getThumbnailUrl() throws ParsingException {
-        try {
-            return document.getElementsByAttributeValue("property", "og:image").get(0).attr("content");
-        } catch (NullPointerException e) {
-            return "";
-        }
+        if (albumJson.isNull("art_id")) return "";
+        else return getImageUrl(albumJson.getLong("art_id"), true);
     }
 
     @Override
@@ -104,13 +109,26 @@ public class BandcampPlaylistExtractor extends PlaylistExtractor {
         for (int i = 0; i < trackInfo.length(); i++) {
             JSONObject track = trackInfo.getJSONObject(i);
 
-            collector.commit(new BandcampStreamInfoItemExtractor(
-                    track.getString("title"),
-                    getUploaderUrl() + track.getString("title_link"),
-                    "",
-                    track.getLong("duration"),
-                    getService()
-            ));
+            if (trackInfo.length() < MAXIMUM_INDIVIDUAL_COVER_ARTS) {
+                // Load cover art of every track individually
+                collector.commit(new BandcampStreamInfoItemExtractor(
+                        track.getString("title"),
+                        getUploaderUrl() + track.getString("title_link"),
+                        "",
+                        track.getLong("duration"),
+                        getService()
+                ));
+            } else {
+                // Pretend every track has the same cover art as the album
+                collector.commit(new BandcampStreamInfoItemExtractor(
+                        track.getString("title"),
+                        getUploaderUrl() + track.getString("title_link"),
+                        getThumbnailUrl(),
+                        "",
+                        track.getLong("duration")
+                ));
+            }
+
         }
 
         return new InfoItemsPage<>(collector, null);

extractor/src/main/java/org/schabi/newpipe/extractor/services/bandcamp/extractors/BandcampStreamExtractor.java

@@ -21,6 +21,8 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 
+import static org.schabi.newpipe.extractor.services.bandcamp.extractors.BandcampChannelExtractor.getImageUrl;
+
 public class BandcampStreamExtractor extends StreamExtractor {
 
     private JSONObject albumJson;
@@ -103,11 +105,8 @@ public class BandcampStreamExtractor extends StreamExtractor {
     @Nonnull
     @Override
     public String getThumbnailUrl() throws ParsingException {
-        try {
-            return document.getElementsByAttributeValue("property", "og:image").get(0).attr("content");
-        } catch (NullPointerException e) {
-            return "";
-        }
+        if (albumJson.isNull("art_id")) return "";
+        else return getImageUrl(albumJson.getLong("art_id"), true);
     }
 
     @Nonnull

extractor/src/test/java/org/schabi/newpipe/extractor/services/bandcamp/BandcampPlaylistExtractorTest.java

@@ -52,6 +52,22 @@ public class BandcampPlaylistExtractorTest {
         assertNotEquals(extractor.getThumbnailUrl(), l.get(5).getThumbnailUrl());
     }
 
+    /**
+     * Tests that no attempt to load every track's cover individually is made
+     */
+    @Test(timeout = 10000L)
+    public void testDifferentTrackCoversDuration() throws ExtractionException, IOException {
+        PlaylistExtractor extractor = bandcamp.getPlaylistExtractor("https://infiniteammo.bandcamp.com/album/night-in-the-woods-vol-1-at-the-end-of-everything");
+        extractor.fetchPage();
+
+        /* All tracks in this album have the same cover art, but I don't know any albums with more than 10 tracks
+         * that has at least one track with a cover art different from the rest.
+         */
+        List<StreamInfoItem> l = extractor.getInitialPage().getItems();
+        assertEquals(extractor.getThumbnailUrl(), l.get(0).getThumbnailUrl());
+        assertEquals(extractor.getThumbnailUrl(), l.get(5).getThumbnailUrl());
+    }
+
     /**
      * Test playlists with locked content
      */

extractor/src/test/java/org/schabi/newpipe/extractor/services/bandcamp/BandcampRadioExtractorTest.java

@@ -34,7 +34,6 @@ public class BandcampRadioExtractorTest {
     @Test
     public void testRadioCount() throws ExtractionException, IOException {
         List<InfoItem> list = bandcamp.getKioskList().getExtractorById("Radio", null).getInitialPage().getItems();
-        System.out.println(list.size());
         assertTrue(list.size() > 300);
     }
 }