Merge pull request #6153 from ByteHamster/fast-document-file

Speed up local folder refresh

7 files changed, 175 insertions, 250 deletions

diff --git a/core/src/main/java/de/danoeh/antennapod/core/feed/LocalFeedUpdater.java b/core/src/main/java/de/danoeh/antennapod/core/feed/LocalFeedUpdater.java
index d37bc230d..8ee924243 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/feed/LocalFeedUpdater.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/feed/LocalFeedUpdater.java
@@ -8,8 +8,8 @@ import android.util.Log;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import androidx.documentfile.provider.DocumentFile;
 
+import java.io.BufferedInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.text.ParseException;
@@ -24,7 +24,10 @@ import java.util.Locale;
 import java.util.Set;
 import java.util.UUID;
 
+import androidx.annotation.VisibleForTesting;
+import androidx.documentfile.provider.DocumentFile;
 import de.danoeh.antennapod.core.R;
+import de.danoeh.antennapod.core.util.FastDocumentFile;
 import de.danoeh.antennapod.model.download.DownloadStatus;
 import de.danoeh.antennapod.core.storage.DBReader;
 import de.danoeh.antennapod.core.storage.DBTasks;
@@ -46,12 +49,22 @@ import org.apache.commons.io.input.CountingInputStream;
 public class LocalFeedUpdater {
     private static final String TAG = "LocalFeedUpdater";
 
-    static final String[] PREFERRED_FEED_IMAGE_FILENAMES = { "folder.jpg", "Folder.jpg", "folder.png", "Folder.png" };
+    static final String[] PREFERRED_FEED_IMAGE_FILENAMES = {"folder.jpg", "Folder.jpg", "folder.png", "Folder.png"};
 
     public static void updateFeed(Feed feed, Context context,
                                   @Nullable UpdaterProgressListener updaterProgressListener) {
         try {
-            tryUpdateFeed(feed, context, updaterProgressListener);
+            String uriString = feed.getDownload_url().replace(Feed.PREFIX_LOCAL_FOLDER, "");
+            DocumentFile documentFolder = DocumentFile.fromTreeUri(context, Uri.parse(uriString));
+            if (documentFolder == null) {
+                throw new IOException("Unable to retrieve document tree. "
+                        + "Try re-connecting the folder on the podcast info page.");
+            }
+            if (!documentFolder.exists() || !documentFolder.canRead()) {
+                throw new IOException("Cannot read local directory. "
+                        + "Try re-connecting the folder on the podcast info page.");
+            }
+            tryUpdateFeed(feed, context, documentFolder.getUri(), updaterProgressListener);
 
             if (mustReportDownloadSuccessful(feed)) {
                 reportSuccess(feed);
@@ -62,19 +75,9 @@ public class LocalFeedUpdater {
         }
     }
 
-    private static void tryUpdateFeed(Feed feed, Context context, UpdaterProgressListener updaterProgressListener)
-            throws IOException {
-        String uriString = feed.getDownload_url().replace(Feed.PREFIX_LOCAL_FOLDER, "");
-        DocumentFile documentFolder = DocumentFile.fromTreeUri(context, Uri.parse(uriString));
-        if (documentFolder == null) {
-            throw new IOException("Unable to retrieve document tree. "
-                    + "Try re-connecting the folder on the podcast info page.");
-        }
-        if (!documentFolder.exists() || !documentFolder.canRead()) {
-            throw new IOException("Cannot read local directory. "
-                    + "Try re-connecting the folder on the podcast info page.");
-        }
-
+    @VisibleForTesting
+    static void tryUpdateFeed(Feed feed, Context context, Uri folderUri,
+                              UpdaterProgressListener updaterProgressListener) {
         if (feed.getItems() == null) {
             feed.setItems(new ArrayList<>());
         }
@@ -82,9 +85,10 @@ public class LocalFeedUpdater {
         feed = DBTasks.updateFeed(context, feed, false);
 
         // list files in feed folder
-        List<DocumentFile> mediaFiles = new ArrayList<>();
+        List<FastDocumentFile> allFiles = FastDocumentFile.list(context, folderUri);
+        List<FastDocumentFile> mediaFiles = new ArrayList<>();
         Set<String> mediaFileNames = new HashSet<>();
-        for (DocumentFile file : documentFolder.listFiles()) {
+        for (FastDocumentFile file : allFiles) {
             String mimeType = MimeTypeUtils.getMimeType(file.getType(), file.getUri().toString());
             MediaType mediaType = MediaType.fromMimeType(mimeType);
             if (mediaType == MediaType.AUDIO || mediaType == MediaType.VIDEO) {
@@ -117,7 +121,7 @@ public class LocalFeedUpdater {
             }
         }
 
-        feed.setImageUrl(getImageUrl(documentFolder));
+        feed.setImageUrl(getImageUrl(allFiles, folderUri));
 
         feed.getPreferences().setAutoDownload(false);
         feed.getPreferences().setAutoDeleteAction(FeedPreferences.AutoDeleteAction.NO);
@@ -135,17 +139,18 @@ public class LocalFeedUpdater {
      * Returns the image URL for the local feed.
      */
     @NonNull
-    static String getImageUrl(@NonNull DocumentFile documentFolder) {
+    static String getImageUrl(List<FastDocumentFile> files, Uri folderUri) {
         // look for special file names
         for (String iconLocation : PREFERRED_FEED_IMAGE_FILENAMES) {
-            DocumentFile image = documentFolder.findFile(iconLocation);
-            if (image != null) {
-                return image.getUri().toString();
+            for (FastDocumentFile file : files) {
+                if (iconLocation.equals(file.getName())) {
+                    return file.getUri().toString();
+                }
             }
         }
 
         // use the first image in the folder if existing
-        for (DocumentFile file : documentFolder.listFiles()) {
+        for (FastDocumentFile file : files) {
             String mime = file.getType();
             if (mime != null && (mime.startsWith("image/jpeg") || mime.startsWith("image/png"))) {
                 return file.getUri().toString();
@@ -153,7 +158,7 @@ public class LocalFeedUpdater {
         }
 
         // use default icon as fallback
-        return Feed.PREFIX_GENERATIVE_COVER + documentFolder.getUri();
+        return Feed.PREFIX_GENERATIVE_COVER + folderUri;
     }
 
     private static FeedItem feedContainsFile(Feed feed, String filename) {
@@ -166,26 +171,36 @@ public class LocalFeedUpdater {
         return null;
     }
 
-    private static FeedItem createFeedItem(Feed feed, DocumentFile file, Context context) {
+    private static FeedItem createFeedItem(Feed feed, FastDocumentFile file, Context context) {
         FeedItem item = new FeedItem(0, file.getName(), UUID.randomUUID().toString(),
-                file.getName(), new Date(file.lastModified()), FeedItem.UNPLAYED, feed);
+                file.getName(), new Date(file.getLastModified()), FeedItem.UNPLAYED, feed);
         item.disableAutoDownload();
 
-        long size = file.length();
+        long size = file.getLength();
         FeedMedia media = new FeedMedia(0, item, 0, 0, size, file.getType(),
                 file.getUri().toString(), file.getUri().toString(), false, null, 0, 0);
         item.setMedia(media);
 
+        for (FeedItem existingItem : feed.getItems()) {
+            if (existingItem.getMedia() != null
+                    && existingItem.getMedia().getDownload_url().equals(file.getUri().toString())
+                    && file.getLength() == existingItem.getMedia().getSize()) {
+                // We found an old file that we already scanned. Re-use metadata.
+                item.updateFromOther(existingItem);
+                return item;
+            }
+        }
+
+        // Did not find existing item. Scan metadata.
         try {
             loadMetadata(item, file, context);
         } catch (Exception e) {
             item.setDescriptionIfLonger(e.getMessage());
         }
-
         return item;
     }
 
-    private static void loadMetadata(FeedItem item, DocumentFile file, Context context) {
+    private static void loadMetadata(FeedItem item, FastDocumentFile file, Context context) {
         MediaMetadataRetriever mediaMetadataRetriever = new MediaMetadataRetriever();
         mediaMetadataRetriever.setDataSource(context, file.getUri());
 
@@ -211,9 +226,11 @@ public class LocalFeedUpdater {
         item.getMedia().setDuration((int) Long.parseLong(durationStr));
 
         item.getMedia().setHasEmbeddedPicture(mediaMetadataRetriever.getEmbeddedPicture() != null);
+        mediaMetadataRetriever.close();
 
         try (InputStream inputStream = context.getContentResolver().openInputStream(file.getUri())) {
-            Id3MetadataReader reader = new Id3MetadataReader(new CountingInputStream(inputStream));
+            Id3MetadataReader reader = new Id3MetadataReader(
+                    new CountingInputStream(new BufferedInputStream(inputStream)));
             reader.readInputStream();
             item.setDescriptionIfLonger(reader.getComment());
         } catch (IOException | ID3ReaderException e) {
diff --git a/core/src/main/java/de/danoeh/antennapod/core/util/ChapterUtils.java b/core/src/main/java/de/danoeh/antennapod/core/util/ChapterUtils.java
index 723ea1d47..cc63bf2b0 100644
--- a/core/src/main/java/de/danoeh/antennapod/core/util/ChapterUtils.java
+++ b/core/src/main/java/de/danoeh/antennapod/core/util/ChapterUtils.java
@@ -23,6 +23,7 @@ import okhttp3.Request;
 import okhttp3.Response;
 import org.apache.commons.io.input.CountingInputStream;
 
+import java.io.BufferedInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
@@ -120,17 +121,17 @@ public class ChapterUtils {
             if (!source.exists()) {
                 throw new IOException("Local file does not exist");
             }
-            return new CountingInputStream(new FileInputStream(source));
+            return new CountingInputStream(new BufferedInputStream(new FileInputStream(source)));
         } else if (playable.getStreamUrl().startsWith(ContentResolver.SCHEME_CONTENT)) {
             Uri uri = Uri.parse(playable.getStreamUrl());
-            return new CountingInputStream(context.getContentResolver().openInputStream(uri));
+            return new CountingInputStream(new BufferedInputStream(context.getContentResolver().openInputStream(uri)));
         } else {
             Request request = new Request.Builder().url(playable.getStreamUrl()).build();
             Response response = AntennapodHttpClient.getHttpClient().newCall(request).execute();
             if (response.body() == null) {
                 throw new IOException("Body is null");
             }
-            return new CountingInputStream(response.body().byteStream());
+            return new CountingInputStream(new BufferedInputStream(response.body().byteStream()));
         }
     }
 
@@ -171,7 +172,7 @@ public class ChapterUtils {
 
     @NonNull
     private static List<Chapter> readOggChaptersFromInputStream(InputStream input) throws VorbisCommentReaderException {
-        VorbisCommentChapterReader reader = new VorbisCommentChapterReader(input);
+        VorbisCommentChapterReader reader = new VorbisCommentChapterReader(new BufferedInputStream(input));
         reader.readInputStream();
         List<Chapter> chapters = reader.getChapters();
         if (chapters == null) {
diff --git a/core/src/main/java/de/danoeh/antennapod/core/util/FastDocumentFile.java b/core/src/main/java/de/danoeh/antennapod/core/util/FastDocumentFile.java
new file mode 100644
index 000000000..885d66687
--- /dev/null
+++ b/core/src/main/java/de/danoeh/antennapod/core/util/FastDocumentFile.java
@@ -0,0 +1,77 @@
+package de.danoeh.antennapod.core.util;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.net.Uri;
+import android.provider.DocumentsContract;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Android's DocumentFile is slow because every single method call queries the ContentResolver.
+ * This queries the ContentResolver a single time with all the information.
+ */
+public class FastDocumentFile {
+    private final String name;
+    private final String type;
+    private final Uri uri;
+    private final long length;
+    private final long lastModified;
+
+    public static List<FastDocumentFile> list(Context context, Uri folderUri) {
+        if (android.os.Build.VERSION.SDK_INT < 21) {
+            return Collections.emptyList();
+        }
+
+        Uri childrenUri = DocumentsContract.buildChildDocumentsUriUsingTree(folderUri,
+                DocumentsContract.getDocumentId(folderUri));
+        Cursor cursor = context.getContentResolver().query(childrenUri, new String[] {
+                DocumentsContract.Document.COLUMN_DOCUMENT_ID,
+                DocumentsContract.Document.COLUMN_DISPLAY_NAME,
+                DocumentsContract.Document.COLUMN_SIZE,
+                DocumentsContract.Document.COLUMN_LAST_MODIFIED,
+                DocumentsContract.Document.COLUMN_MIME_TYPE}, null, null, null);
+        ArrayList<FastDocumentFile> list = new ArrayList<>();
+        while (cursor.moveToNext()) {
+            String id = cursor.getString(0);
+            Uri uri = DocumentsContract.buildDocumentUriUsingTree(folderUri, id);
+            String name = cursor.getString(1);
+            long size = cursor.getLong(2);
+            long lastModified = cursor.getLong(3);
+            String mimeType = cursor.getString(4);
+            list.add(new FastDocumentFile(name, mimeType, uri, size, lastModified));
+        }
+        cursor.close();
+        return list;
+    }
+
+    public FastDocumentFile(String name, String type, Uri uri, long length, long lastModified) {
+        this.name = name;
+        this.type = type;
+        this.uri = uri;
+        this.length = length;
+        this.lastModified = lastModified;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getType() {
+        return type;
+    }
+
+    public Uri getUri() {
+        return uri;
+    }
+
+    public long getLength() {
+        return length;
+    }
+
+    public long getLastModified() {
+        return lastModified;
+    }
+}
diff --git a/core/src/test/java/androidx/documentfile/provider/AssetsDocumentFile.java b/core/src/test/java/androidx/documentfile/provider/AssetsDocumentFile.java
deleted file mode 100644
index 8a8205c10..000000000
--- a/core/src/test/java/androidx/documentfile/provider/AssetsDocumentFile.java
+++ /dev/null
@@ -1,138 +0,0 @@
-package androidx.documentfile.provider;
-
-import android.content.res.AssetManager;
-import android.net.Uri;
-import android.webkit.MimeTypeMap;
-
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-
-import java.io.IOException;
-
-/**
- * <p>Wraps an Android assets file or folder as a DocumentFile object.</p>
- *
- * <p>This is used to emulate access to the external storage.</p>
- */
-public class AssetsDocumentFile extends DocumentFile {
-
-    /**
-     * Absolute file path in the assets folder.
-     */
-    @NonNull
-    private final String fileName;
-
-    @NonNull
-    private final AssetManager assetManager;
-
-    public AssetsDocumentFile(@NonNull String fileName, @NonNull AssetManager assetManager) {
-        super(null);
-        this.fileName = fileName;
-        this.assetManager = assetManager;
-    }
-
-    @Nullable
-    @Override
-    public DocumentFile createFile(@NonNull String mimeType, @NonNull String displayName) {
-        return null;
-    }
-
-    @Nullable
-    @Override
-    public DocumentFile createDirectory(@NonNull String displayName) {
-        return null;
-    }
-
-    @NonNull
-    @Override
-    public Uri getUri() {
-        return Uri.parse(fileName);
-    }
-
-    @Nullable
-    @Override
-    public String getName() {
-        int pos = fileName.indexOf('/');
-        if (pos >= 0) {
-            return fileName.substring(pos + 1);
-        } else {
-            return fileName;
-        }
-    }
-
-    @Nullable
-    @Override
-    public String getType() {
-        String extension = MimeTypeMap.getFileExtensionFromUrl(fileName);
-        return MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
-    }
-
-    @Override
-    public boolean isDirectory() {
-        return false;
-    }
-
-    @Override
-    public boolean isFile() {
-        return true;
-    }
-
-    @Override
-    public boolean isVirtual() {
-        return false;
-    }
-
-    @Override
-    public long lastModified() {
-        return 0;
-    }
-
-    @Override
-    public long length() {
-        return 0;
-    }
-
-    @Override
-    public boolean canRead() {
-        return true;
-    }
-
-    @Override
-    public boolean canWrite() {
-        return false;
-    }
-
-    @Override
-    public boolean delete() {
-        return false;
-    }
-
-    @Override
-    public boolean exists() {
-        return true;
-    }
-
-    @NonNull
-    @Override
-    public DocumentFile[] listFiles() {
-        try {
-            String[] files = assetManager.list(fileName);
-            if (files == null) {
-                return new DocumentFile[0];
-            }
-            DocumentFile[] result = new DocumentFile[files.length];
-            for (int i = 0; i < files.length; i++) {
-                String subFileName = fileName + '/' + files[i];
-                result[i] = new AssetsDocumentFile(subFileName, assetManager);
-            }
-            return result;
-        } catch (IOException e) {
-            return new DocumentFile[0];
-        }
-    }
-
-    @Override
-    public boolean renameTo(@NonNull String displayName) {
-        return false;
-    }
-}
diff --git a/core/src/test/java/de/danoeh/antennapod/core/feed/LocalFeedUpdaterTest.java b/core/src/test/java/de/danoeh/antennapod/core/feed/LocalFeedUpdaterTest.java
index 05b0584ed..4cf746ba4 100644
--- a/core/src/test/java/de/danoeh/antennapod/core/feed/LocalFeedUpdaterTest.java
+++ b/core/src/test/java/de/danoeh/antennapod/core/feed/LocalFeedUpdaterTest.java
@@ -7,11 +7,10 @@ import android.net.Uri;
 import android.webkit.MimeTypeMap;
 
 import androidx.annotation.NonNull;
-import androidx.documentfile.provider.AssetsDocumentFile;
-import androidx.documentfile.provider.DocumentFile;
 import androidx.test.platform.app.InstrumentationRegistry;
 
 import de.danoeh.antennapod.core.preferences.PlaybackPreferences;
+import de.danoeh.antennapod.core.util.FastDocumentFile;
 import de.danoeh.antennapod.model.feed.Feed;
 import de.danoeh.antennapod.model.feed.FeedItem;
 import de.danoeh.antennapod.storage.database.PodDBAdapter;
@@ -24,11 +23,12 @@ import org.mockito.Mockito;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.shadows.ShadowMediaMetadataRetriever;
 
-import java.io.IOException;
-import java.util.Calendar;
-import java.util.Date;
-import java.util.GregorianCalendar;
+import java.io.File;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 
 import de.danoeh.antennapod.core.ApplicationCallbacks;
 import de.danoeh.antennapod.core.ClientConfig;
@@ -60,8 +60,8 @@ public class LocalFeedUpdaterTest {
      */
     private static final String FEED_URL =
             "content://com.android.externalstorage.documents/tree/primary%3ADownload%2Flocal-feed";
-    private static final String LOCAL_FEED_DIR1 = "local-feed1";
-    private static final String LOCAL_FEED_DIR2 = "local-feed2";
+    private static final String LOCAL_FEED_DIR1 = "src/test/assets/local-feed1";
+    private static final String LOCAL_FEED_DIR2 = "src/test/assets/local-feed2";
 
     private Context context;
 
@@ -172,74 +172,61 @@ public class LocalFeedUpdaterTest {
 
         Feed feed = verifySingleFeedInDatabase();
         List<FeedItem> feedItems = DBReader.getFeedItemList(feed);
-        FeedItem feedItem = feedItems.get(0);
-
-        assertEquals("track1.mp3", feedItem.getTitle());
-
-        Date pubDate = feedItem.getPubDate();
-        Calendar calendar = GregorianCalendar.getInstance();
-        calendar.setTime(pubDate);
-        assertEquals(2020, calendar.get(Calendar.YEAR));
-        assertEquals(6 - 1, calendar.get(Calendar.MONTH));
-        assertEquals(1, calendar.get(Calendar.DAY_OF_MONTH));
-        assertEquals(22, calendar.get(Calendar.HOUR_OF_DAY));
-        assertEquals(23, calendar.get(Calendar.MINUTE));
-        assertEquals(24, calendar.get(Calendar.SECOND));
+        assertEquals("track1.mp3", feedItems.get(0).getTitle());
     }
 
     @Test
     public void testGetImageUrl_EmptyFolder() {
-        DocumentFile documentFolder = mockDocumentFolder();
-        String imageUrl = LocalFeedUpdater.getImageUrl(documentFolder);
+        String imageUrl = LocalFeedUpdater.getImageUrl(Collections.emptyList(), Uri.EMPTY);
         assertThat(imageUrl, startsWith(Feed.PREFIX_GENERATIVE_COVER));
     }
 
     @Test
     public void testGetImageUrl_NoImageButAudioFiles() {
-        DocumentFile documentFolder = mockDocumentFolder(mockDocumentFile("audio.mp3", "audio/mp3"));
-        String imageUrl = LocalFeedUpdater.getImageUrl(documentFolder);
+        List<FastDocumentFile> folder = Collections.singletonList(mockDocumentFile("audio.mp3", "audio/mp3"));
+        String imageUrl = LocalFeedUpdater.getImageUrl(folder, Uri.EMPTY);
         assertThat(imageUrl, startsWith(Feed.PREFIX_GENERATIVE_COVER));
     }
 
     @Test
     public void testGetImageUrl_PreferredImagesFilenames() {
         for (String filename : LocalFeedUpdater.PREFERRED_FEED_IMAGE_FILENAMES) {
-            DocumentFile documentFolder = mockDocumentFolder(mockDocumentFile("audio.mp3", "audio/mp3"),
+            List<FastDocumentFile> folder = Arrays.asList(mockDocumentFile("audio.mp3", "audio/mp3"),
                     mockDocumentFile(filename, "image/jpeg")); // image MIME type doesn't matter
-            String imageUrl = LocalFeedUpdater.getImageUrl(documentFolder);
+            String imageUrl = LocalFeedUpdater.getImageUrl(folder, Uri.EMPTY);
             assertThat(imageUrl, endsWith(filename));
         }
     }
 
     @Test
     public void testGetImageUrl_OtherImageFilenameJpg() {
-        DocumentFile documentFolder = mockDocumentFolder(mockDocumentFile("audio.mp3", "audio/mp3"),
+        List<FastDocumentFile> folder = Arrays.asList(mockDocumentFile("audio.mp3", "audio/mp3"),
                 mockDocumentFile("my-image.jpg", "image/jpeg"));
-        String imageUrl = LocalFeedUpdater.getImageUrl(documentFolder);
+        String imageUrl = LocalFeedUpdater.getImageUrl(folder, Uri.EMPTY);
         assertThat(imageUrl, endsWith("my-image.jpg"));
     }
 
     @Test
     public void testGetImageUrl_OtherImageFilenameJpeg() {
-        DocumentFile documentFolder = mockDocumentFolder(mockDocumentFile("audio.mp3", "audio/mp3"),
+        List<FastDocumentFile> folder = Arrays.asList(mockDocumentFile("audio.mp3", "audio/mp3"),
                 mockDocumentFile("my-image.jpeg", "image/jpeg"));
-        String imageUrl = LocalFeedUpdater.getImageUrl(documentFolder);
+        String imageUrl = LocalFeedUpdater.getImageUrl(folder, Uri.EMPTY);
         assertThat(imageUrl, endsWith("my-image.jpeg"));
     }
 
     @Test
     public void testGetImageUrl_OtherImageFilenamePng() {
-        DocumentFile documentFolder = mockDocumentFolder(mockDocumentFile("audio.mp3", "audio/mp3"),
+        List<FastDocumentFile> folder = Arrays.asList(mockDocumentFile("audio.mp3", "audio/mp3"),
                 mockDocumentFile("my-image.png", "image/png"));
-        String imageUrl = LocalFeedUpdater.getImageUrl(documentFolder);
+        String imageUrl = LocalFeedUpdater.getImageUrl(folder, Uri.EMPTY);
         assertThat(imageUrl, endsWith("my-image.png"));
     }
 
     @Test
     public void testGetImageUrl_OtherImageFilenameUnsupportedMimeType() {
-        DocumentFile documentFolder = mockDocumentFolder(mockDocumentFile("audio.mp3", "audio/mp3"),
+        List<FastDocumentFile> folder = Arrays.asList(mockDocumentFile("audio.mp3", "audio/mp3"),
                 mockDocumentFile("my-image.svg", "image/svg+xml"));
-        String imageUrl = LocalFeedUpdater.getImageUrl(documentFolder);
+        String imageUrl = LocalFeedUpdater.getImageUrl(folder, Uri.EMPTY);
         assertThat(imageUrl, startsWith(Feed.PREFIX_GENERATIVE_COVER));
     }
 
@@ -248,9 +235,8 @@ public class LocalFeedUpdaterTest {
      *
      * @param localFeedDir assets local feed folder with media files
      */
-    private void mapDummyMetadata(@NonNull String localFeedDir) throws IOException {
-        String[] fileNames = context.getAssets().list(localFeedDir);
-        for (String fileName : fileNames) {
+    private void mapDummyMetadata(@NonNull String localFeedDir) {
+        for (String fileName : Objects.requireNonNull(new File(localFeedDir).list())) {
             String path = localFeedDir + '/' + fileName;
             ShadowMediaMetadataRetriever.addMetadata(path,
                     MediaMetadataRetriever.METADATA_KEY_DURATION, "10");
@@ -259,24 +245,21 @@ public class LocalFeedUpdaterTest {
             ShadowMediaMetadataRetriever.addMetadata(path,
                     MediaMetadataRetriever.METADATA_KEY_DATE, "20200601T222324");
         }
-
     }
 
     /**
-     * Calls the method {@link LocalFeedUpdater#updateFeed(Feed, Context)} with
-     * the given local feed folder.
+     * Calls the method LocalFeedUpdater#tryUpdateFeed with the given local feed folder.
      *
      * @param localFeedDir assets local feed folder with media files
      */
     private void callUpdateFeed(@NonNull String localFeedDir) {
-        DocumentFile documentFile = new AssetsDocumentFile(localFeedDir, context.getAssets());
-        try (MockedStatic<DocumentFile> dfMock = Mockito.mockStatic(DocumentFile.class)) {
+        try (MockedStatic<FastDocumentFile> dfMock = Mockito.mockStatic(FastDocumentFile.class)) {
             // mock external storage
-            dfMock.when(() -> DocumentFile.fromTreeUri(any(), any())).thenReturn(documentFile);
+            dfMock.when(() -> FastDocumentFile.list(any(), any())).thenReturn(mockLocalFolder(localFeedDir));
 
             // call method to test
             Feed feed = new Feed(FEED_URL, null);
-            LocalFeedUpdater.updateFeed(feed, context, null);
+            LocalFeedUpdater.tryUpdateFeed(feed, context, null, null);
         }
     }
 
@@ -306,21 +289,18 @@ public class LocalFeedUpdaterTest {
      * Create a DocumentFile mock object.
      */
     @NonNull
-    private static DocumentFile mockDocumentFile(@NonNull String fileName, @NonNull String mimeType) {
-        DocumentFile file = mock(DocumentFile.class);
-        when(file.getName()).thenReturn(fileName);
-        when(file.getUri()).thenReturn(Uri.parse("file:///path/" + fileName));
-        when(file.getType()).thenReturn(mimeType);
-        return file;
+    private static FastDocumentFile mockDocumentFile(@NonNull String fileName, @NonNull String mimeType) {
+        return new FastDocumentFile(fileName, mimeType, Uri.parse("file:///path/" + fileName), 0, 0);
     }
 
-    /**
-     *  Create a DocumentFile folder mock object with a list of files.
-     */
-    @NonNull
-    private static DocumentFile mockDocumentFolder(DocumentFile... files) {
-        DocumentFile documentFolder = mock(DocumentFile.class);
-        when(documentFolder.listFiles()).thenReturn(files);
-        return documentFolder;
+    private static List<FastDocumentFile> mockLocalFolder(String folderName) {
+        List<FastDocumentFile> files = new ArrayList<>();
+        for (File f : Objects.requireNonNull(new File(folderName).listFiles())) {
+            String extension = MimeTypeMap.getFileExtensionFromUrl(f.getPath());
+            String mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
+            files.add(new FastDocumentFile(f.getName(), mimeType,
+                    Uri.parse(f.toURI().toString()), f.length(), f.lastModified()));
+        }
+        return files;
     }
 }
diff --git a/parser/media/src/main/java/de/danoeh/antennapod/parser/media/id3/ID3Reader.java b/parser/media/src/main/java/de/danoeh/antennapod/parser/media/id3/ID3Reader.java
index baaff2752..a791baf66 100644
--- a/parser/media/src/main/java/de/danoeh/antennapod/parser/media/id3/ID3Reader.java
+++ b/parser/media/src/main/java/de/danoeh/antennapod/parser/media/id3/ID3Reader.java
@@ -46,7 +46,7 @@ public class ID3Reader {
     }
 
     protected void readFrame(@NonNull FrameHeader frameHeader) throws IOException, ID3ReaderException {
-        Log.d(TAG, "Skipping frame: " + frameHeader.toString());
+        Log.d(TAG, "Skipping frame: " + frameHeader.getId() + ", size: " + frameHeader.getSize());
         skipBytes(frameHeader.getSize());
     }
 
@@ -106,7 +106,7 @@ public class ID3Reader {
 
     @NonNull
     FrameHeader readFrameHeader() throws IOException {
-        String id = readIsoStringFixed(FRAME_ID_LENGTH);
+        String id = readPlainBytesToString(FRAME_ID_LENGTH);
         int size = readInt();
         if (tagHeader != null && tagHeader.getVersion() >= 0x0400) {
             size = unsynchsafe(size);
@@ -136,15 +136,14 @@ public class ID3Reader {
         return readEncodedString(encoding, max - 1);
     }
 
-    @SuppressWarnings("CharsetObjectCanBeUsed")
-    protected String readIsoStringFixed(int length) throws IOException {
-        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
+    protected String readPlainBytesToString(int length) throws IOException {
+        StringBuilder stringBuilder = new StringBuilder();
         int bytesRead = 0;
         while (bytesRead < length) {
-            bytes.write(readByte());
+            stringBuilder.append((char) readByte());
             bytesRead++;
         }
-        return Charset.forName("ISO-8859-1").newDecoder().decode(ByteBuffer.wrap(bytes.toByteArray())).toString();
+        return stringBuilder.toString();
     }
 
     protected String readIsoStringNullTerminated(int max) throws IOException {
diff --git a/parser/media/src/main/java/de/danoeh/antennapod/parser/media/id3/model/FrameHeader.java b/parser/media/src/main/java/de/danoeh/antennapod/parser/media/id3/model/FrameHeader.java
index 1a298a0df..3dd19008c 100644
--- a/parser/media/src/main/java/de/danoeh/antennapod/parser/media/id3/model/FrameHeader.java
+++ b/parser/media/src/main/java/de/danoeh/antennapod/parser/media/id3/model/FrameHeader.java
@@ -1,18 +1,7 @@
 package de.danoeh.antennapod.parser.media.id3.model;
 
-import androidx.annotation.NonNull;
-
 public class FrameHeader extends Header {
-    private final short flags;
-
     public FrameHeader(String id, int size, short flags) {
         super(id, size);
-        this.flags = flags;
-    }
-
-    @Override
-    @NonNull
-    public String toString() {
-        return String.format("FrameHeader [flags=%s, id=%s, size=%s]", Integer.toBinaryString(flags), id, size);
     }
 }