SegmentDownloader: Pull manifest loading up to base class.

This will make it a bit easier to push manifest loads to an Executor.

Issue: #5978
PiperOrigin-RevId: 308608155

library/core/src/main/java/com/google/android/exoplayer2/offline/SegmentDownloader.java

@@ -21,6 +21,8 @@ import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
+import com.google.android.exoplayer2.upstream.ParsingLoadable;
+import com.google.android.exoplayer2.upstream.ParsingLoadable.Parser;
 import com.google.android.exoplayer2.upstream.cache.Cache;
 import com.google.android.exoplayer2.upstream.cache.CacheDataSource;
 import com.google.android.exoplayer2.upstream.cache.CacheKeyFactory;
@@ -68,6 +70,7 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M>> impleme
   private static final long MAX_MERGED_SEGMENT_START_TIME_DIFF_US = 20 * C.MICROS_PER_SECOND;
 
   private final DataSpec manifestDataSpec;
+  private final Parser<M> manifestParser;
   private final ArrayList<StreamKey> streamKeys;
   private final CacheDataSource.Factory cacheDataSourceFactory;
   private final Executor executor;
@@ -75,6 +78,7 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M>> impleme
 
   /**
    * @param manifestUri The {@link Uri} of the manifest to be downloaded.
+   * @param manifestParser A parser for the manifest.
    * @param streamKeys Keys defining which streams in the manifest should be selected for download.
    *     If empty, all streams are downloaded.
    * @param cacheDataSourceFactory A {@link CacheDataSource.Factory} for the cache into which the
@@ -85,10 +89,12 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M>> impleme
    */
   public SegmentDownloader(
       Uri manifestUri,
+      Parser<M> manifestParser,
       List<StreamKey> streamKeys,
       CacheDataSource.Factory cacheDataSourceFactory,
       Executor executor) {
     this.manifestDataSpec = getCompressibleDataSpec(manifestUri);
+    this.manifestParser = manifestParser;
     this.streamKeys = new ArrayList<>(streamKeys);
     this.cacheDataSourceFactory = cacheDataSourceFactory;
     this.executor = executor;
@@ -209,14 +215,16 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M>> impleme
   // Internal methods.
 
   /**
-   * Loads and parses the manifest.
+   * Loads and parses a manifest.
    *
    * @param dataSource The {@link DataSource} through which to load.
    * @param dataSpec The manifest {@link DataSpec}.
    * @return The manifest.
    * @throws IOException If an error occurs reading data.
    */
-  protected abstract M getManifest(DataSource dataSource, DataSpec dataSpec) throws IOException;
+  protected final M getManifest(DataSource dataSource, DataSpec dataSpec) throws IOException {
+    return ParsingLoadable.load(dataSource, manifestParser, dataSpec, C.DATA_TYPE_MANIFEST);
+  }
 
   /**
    * Returns a list of all downloadable {@link Segment}s for a given manifest.

library/dash/src/main/java/com/google/android/exoplayer2/source/dash/offline/DashDownloader.java

@@ -33,7 +33,6 @@ import com.google.android.exoplayer2.source.dash.manifest.RangedUri;
 import com.google.android.exoplayer2.source.dash.manifest.Representation;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
-import com.google.android.exoplayer2.upstream.ParsingLoadable;
 import com.google.android.exoplayer2.upstream.cache.CacheDataSource;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -92,13 +91,7 @@ public final class DashDownloader extends SegmentDownloader<DashManifest> {
       List<StreamKey> streamKeys,
       CacheDataSource.Factory cacheDataSourceFactory,
       Executor executor) {
-    super(manifestUri, streamKeys, cacheDataSourceFactory, executor);
-  }
-
-  @Override
-  protected DashManifest getManifest(DataSource dataSource, DataSpec dataSpec) throws IOException {
-    return ParsingLoadable.load(
-        dataSource, new DashManifestParser(), dataSpec, C.DATA_TYPE_MANIFEST);
+    super(manifestUri, new DashManifestParser(), streamKeys, cacheDataSourceFactory, executor);
   }
 
   @Override

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/offline/HlsDownloader.java

@@ -16,7 +16,7 @@
 package com.google.android.exoplayer2.source.hls.offline;
 
 import android.net.Uri;
-import com.google.android.exoplayer2.C;
+import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.offline.SegmentDownloader;
 import com.google.android.exoplayer2.offline.StreamKey;
 import com.google.android.exoplayer2.source.hls.playlist.HlsMasterPlaylist;
@@ -25,7 +25,6 @@ import com.google.android.exoplayer2.source.hls.playlist.HlsPlaylist;
 import com.google.android.exoplayer2.source.hls.playlist.HlsPlaylistParser;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
-import com.google.android.exoplayer2.upstream.ParsingLoadable;
 import com.google.android.exoplayer2.upstream.cache.CacheDataSource;
 import com.google.android.exoplayer2.util.UriUtil;
 import java.io.IOException;
@@ -86,12 +85,7 @@ public final class HlsDownloader extends SegmentDownloader<HlsPlaylist> {
       List<StreamKey> streamKeys,
       CacheDataSource.Factory cacheDataSourceFactory,
       Executor executor) {
-    super(playlistUri, streamKeys, cacheDataSourceFactory, executor);
-  }
-
-  @Override
-  protected HlsPlaylist getManifest(DataSource dataSource, DataSpec dataSpec) throws IOException {
-    return loadManifest(dataSource, dataSpec);
+    super(playlistUri, new HlsPlaylistParser(), streamKeys, cacheDataSourceFactory, executor);
   }
 
   @Override
@@ -112,7 +106,7 @@ public final class HlsDownloader extends SegmentDownloader<HlsPlaylist> {
       segments.add(new Segment(/* startTimeUs= */ 0, mediaPlaylistDataSpec));
       HlsMediaPlaylist mediaPlaylist;
       try {
-        mediaPlaylist = (HlsMediaPlaylist) loadManifest(dataSource, mediaPlaylistDataSpec);
+        mediaPlaylist = (HlsMediaPlaylist) getManifest(dataSource, mediaPlaylistDataSpec);
       } catch (IOException e) {
         if (!allowIncompleteList) {
           throw e;
@@ -120,7 +114,7 @@ public final class HlsDownloader extends SegmentDownloader<HlsPlaylist> {
         // Generating an incomplete segment list is allowed. Advance to the next media playlist.
         continue;
       }
-      HlsMediaPlaylist.Segment lastInitSegment = null;
+      @Nullable HlsMediaPlaylist.Segment lastInitSegment = null;
       List<HlsMediaPlaylist.Segment> hlsSegments = mediaPlaylist.segments;
       for (int i = 0; i < hlsSegments.size(); i++) {
         HlsMediaPlaylist.Segment segment = hlsSegments.get(i);
@@ -141,12 +135,6 @@ public final class HlsDownloader extends SegmentDownloader<HlsPlaylist> {
     }
   }
 
-  private static HlsPlaylist loadManifest(DataSource dataSource, DataSpec dataSpec)
-      throws IOException {
-    return ParsingLoadable.load(
-        dataSource, new HlsPlaylistParser(), dataSpec, C.DATA_TYPE_MANIFEST);
-  }
-
   private void addSegment(
       HlsMediaPlaylist mediaPlaylist,
       HlsMediaPlaylist.Segment segment,

library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/offline/SsDownloader.java

@@ -16,7 +16,6 @@
 package com.google.android.exoplayer2.source.smoothstreaming.offline;
 
 import android.net.Uri;
-import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.offline.SegmentDownloader;
 import com.google.android.exoplayer2.offline.StreamKey;
 import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsManifest;
@@ -25,9 +24,7 @@ import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsManifestP
 import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsUtil;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
-import com.google.android.exoplayer2.upstream.ParsingLoadable;
 import com.google.android.exoplayer2.upstream.cache.CacheDataSource;
-import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.Executor;
@@ -85,12 +82,12 @@ public final class SsDownloader extends SegmentDownloader<SsManifest> {
       List<StreamKey> streamKeys,
       CacheDataSource.Factory cacheDataSourceFactory,
       Executor executor) {
-    super(SsUtil.fixManifestUri(manifestUri), streamKeys, cacheDataSourceFactory, executor);
-  }
-
-  @Override
-  protected SsManifest getManifest(DataSource dataSource, DataSpec dataSpec) throws IOException {
-    return ParsingLoadable.load(dataSource, new SsManifestParser(), dataSpec, C.DATA_TYPE_MANIFEST);
+    super(
+        SsUtil.fixManifestUri(manifestUri),
+        new SsManifestParser(),
+        streamKeys,
+        cacheDataSourceFactory,
+        executor);
   }
 
   @Override