Clean up requesting non-media segments in downloader implementations

- Enable GZIP for media playlist + encryption key chunk requests in
  HLS, as we do during playback
- Pass around DataSpecs rather than Uris. This will be needed for if
  we add manifest cacheKey support (which seems like a good idea for
  completeness, if nothing else)

PiperOrigin-RevId: 224057139

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

@@ -62,7 +62,7 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M>> impleme
 
   private static final int BUFFER_SIZE_BYTES = 128 * 1024;
 
-  private final Uri manifestUri;
+  private final DataSpec manifestDataSpec;
   private final Cache cache;
   private final CacheDataSource dataSource;
   private final CacheDataSource offlineDataSource;
@@ -84,7 +84,7 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M>> impleme
    */
   public SegmentDownloader(
       Uri manifestUri, List<StreamKey> streamKeys, DownloaderConstructorHelper constructorHelper) {
-    this.manifestUri = manifestUri;
+    this.manifestDataSpec = getCompressibleDataSpec(manifestUri);
     this.streamKeys = new ArrayList<>(streamKeys);
     this.cache = constructorHelper.getCache();
     this.dataSource = constructorHelper.createCacheDataSource();
@@ -171,7 +171,7 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M>> impleme
   @Override
   public final void remove() throws InterruptedException {
     try {
-      M manifest = getManifest(offlineDataSource, manifestUri);
+      M manifest = getManifest(offlineDataSource, manifestDataSpec);
       List<Segment> segments = getSegments(offlineDataSource, manifest, true);
       for (int i = 0; i < segments.size(); i++) {
         removeDataSpec(segments.get(i).dataSpec);
@@ -180,7 +180,7 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M>> impleme
       // Ignore exceptions when removing.
     } finally {
       // Always attempt to remove the manifest.
-      removeDataSpec(new DataSpec(manifestUri));
+      removeDataSpec(manifestDataSpec);
     }
   }
 
@@ -190,11 +190,11 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M>> impleme
    * Loads and parses the manifest.
    *
    * @param dataSource The {@link DataSource} through which to load.
-   * @param uri The manifest uri.
+   * @param dataSpec The manifest {@link DataSpec}.
    * @return The manifest.
    * @throws IOException If an error occurs reading data.
    */
-  protected abstract M getManifest(DataSource dataSource, Uri uri) throws IOException;
+  protected abstract M getManifest(DataSource dataSource, DataSpec dataSpec) throws IOException;
 
   /**
    * Returns a list of all downloadable {@link Segment}s for a given manifest.
@@ -217,7 +217,7 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M>> impleme
   // Writes to downloadedSegments and downloadedBytes are safe. See the comment on download().
   @SuppressWarnings("NonAtomicVolatileUpdate")
   private List<Segment> initDownload() throws IOException, InterruptedException {
-    M manifest = getManifest(dataSource, manifestUri);
+    M manifest = getManifest(dataSource, manifestDataSpec);
     if (!streamKeys.isEmpty()) {
       manifest = manifest.copy(streamKeys);
     }
@@ -252,4 +252,12 @@ public abstract class SegmentDownloader<M extends FilterableManifest<M>> impleme
     CacheUtil.remove(dataSpec, cache, cacheKeyFactory);
   }
 
+  protected static DataSpec getCompressibleDataSpec(Uri uri) {
+    return new DataSpec(
+        uri,
+        /* absoluteStreamPosition= */ 0,
+        /* length= */ C.LENGTH_UNSET,
+        /* key= */ null,
+        /* flags= */ DataSpec.FLAG_ALLOW_GZIP);
+  }
 }

library/core/src/main/java/com/google/android/exoplayer2/upstream/ParsingLoadable.java

@@ -69,6 +69,24 @@ public final class ParsingLoadable<T> implements Loadable {
     return Assertions.checkNotNull(loadable.getResult());
   }
 
+  /**
+   * Loads a single parsable object.
+   *
+   * @param dataSource The {@link DataSource} through which the object should be read.
+   * @param parser The {@link Parser} to parse the object from the response.
+   * @param dataSpec The {@link DataSpec} of the object to read.
+   * @param type The type of the data. One of the {@link C}{@code DATA_TYPE_*} constants.
+   * @return The parsed object
+   * @throws IOException Thrown if there is an error while loading or parsing.
+   */
+  public static <T> T load(
+      DataSource dataSource, Parser<? extends T> parser, DataSpec dataSpec, int type)
+      throws IOException {
+    ParsingLoadable<T> loadable = new ParsingLoadable<>(dataSource, dataSpec, type, parser);
+    loadable.load();
+    return Assertions.checkNotNull(loadable.getResult());
+  }
+
   /**
    * The {@link DataSpec} that defines the data to be loaded.
    */

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

@@ -28,11 +28,13 @@ import com.google.android.exoplayer2.source.dash.DashUtil;
 import com.google.android.exoplayer2.source.dash.DashWrappingSegmentIndex;
 import com.google.android.exoplayer2.source.dash.manifest.AdaptationSet;
 import com.google.android.exoplayer2.source.dash.manifest.DashManifest;
+import com.google.android.exoplayer2.source.dash.manifest.DashManifestParser;
 import com.google.android.exoplayer2.source.dash.manifest.Period;
 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 java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
@@ -73,8 +75,9 @@ public final class DashDownloader extends SegmentDownloader<DashManifest> {
   }
 
   @Override
-  protected DashManifest getManifest(DataSource dataSource, Uri uri) throws IOException {
-    return DashUtil.loadManifest(dataSource, uri);
+  protected DashManifest getManifest(DataSource dataSource, DataSpec dataSpec) throws IOException {
+    return ParsingLoadable.load(
+        dataSource, new DashManifestParser(), dataSpec, C.DATA_TYPE_MANIFEST);
   }
 
   @Override
@@ -121,8 +124,7 @@ public final class DashDownloader extends SegmentDownloader<DashManifest> {
         if (!allowIncompleteList) {
           throw e;
         }
-        // Loading failed, but generating an incomplete segment list is allowed. Advance to the next
-        // representation.
+        // Generating an incomplete segment list is allowed. Advance to the next representation.
         continue;
       }
 

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

@@ -71,35 +71,37 @@ public final class HlsDownloader extends SegmentDownloader<HlsPlaylist> {
   }
 
   @Override
-  protected HlsPlaylist getManifest(DataSource dataSource, Uri uri) throws IOException {
-    return loadManifest(dataSource, uri);
+  protected HlsPlaylist getManifest(DataSource dataSource, DataSpec dataSpec) throws IOException {
+    return loadManifest(dataSource, dataSpec);
   }
 
   @Override
   protected List<Segment> getSegments(
       DataSource dataSource, HlsPlaylist playlist, boolean allowIncompleteList) throws IOException {
-    ArrayList<Uri> mediaPlaylistUris = new ArrayList<>();
+    String baseUri = playlist.baseUri;
+
+    ArrayList<DataSpec> mediaPlaylistDataSpecs = new ArrayList<>();
     if (playlist instanceof HlsMasterPlaylist) {
       HlsMasterPlaylist masterPlaylist = (HlsMasterPlaylist) playlist;
-      addResolvedUris(masterPlaylist.baseUri, masterPlaylist.variants, mediaPlaylistUris);
-      addResolvedUris(masterPlaylist.baseUri, masterPlaylist.audios, mediaPlaylistUris);
-      addResolvedUris(masterPlaylist.baseUri, masterPlaylist.subtitles, mediaPlaylistUris);
+      addMediaPlaylistDataSpecs(baseUri, masterPlaylist.variants, mediaPlaylistDataSpecs);
+      addMediaPlaylistDataSpecs(baseUri, masterPlaylist.audios, mediaPlaylistDataSpecs);
+      addMediaPlaylistDataSpecs(baseUri, masterPlaylist.subtitles, mediaPlaylistDataSpecs);
     } else {
-      mediaPlaylistUris.add(Uri.parse(playlist.baseUri));
+      mediaPlaylistDataSpecs.add(SegmentDownloader.getCompressibleDataSpec(Uri.parse(baseUri)));
     }
-    ArrayList<Segment> segments = new ArrayList<>();
 
+    ArrayList<Segment> segments = new ArrayList<>();
     HashSet<Uri> seenEncryptionKeyUris = new HashSet<>();
-    for (Uri mediaPlaylistUri : mediaPlaylistUris) {
+    for (DataSpec mediaPlaylistDataSpec : mediaPlaylistDataSpecs) {
+      segments.add(new Segment(/* startTimeUs= */ 0, mediaPlaylistDataSpec));
       HlsMediaPlaylist mediaPlaylist;
       try {
-        mediaPlaylist = (HlsMediaPlaylist) loadManifest(dataSource, mediaPlaylistUri);
-        segments.add(new Segment(mediaPlaylist.startTimeUs, new DataSpec(mediaPlaylistUri)));
+        mediaPlaylist = (HlsMediaPlaylist) loadManifest(dataSource, mediaPlaylistDataSpec);
       } catch (IOException e) {
         if (!allowIncompleteList) {
           throw e;
         }
-        segments.add(new Segment(0, new DataSpec(mediaPlaylistUri)));
+        // Generating an incomplete segment list is allowed. Advance to the next media playlist.
         continue;
       }
       HlsMediaPlaylist.Segment lastInitSegment = null;
@@ -109,39 +111,43 @@ public final class HlsDownloader extends SegmentDownloader<HlsPlaylist> {
         HlsMediaPlaylist.Segment initSegment = segment.initializationSegment;
         if (initSegment != null && initSegment != lastInitSegment) {
           lastInitSegment = initSegment;
-          addSegment(segments, mediaPlaylist, initSegment, seenEncryptionKeyUris);
+          addSegment(mediaPlaylist, initSegment, seenEncryptionKeyUris, segments);
         }
-        addSegment(segments, mediaPlaylist, segment, seenEncryptionKeyUris);
+        addSegment(mediaPlaylist, segment, seenEncryptionKeyUris, segments);
       }
     }
     return segments;
   }
 
-  private static HlsPlaylist loadManifest(DataSource dataSource, Uri uri) throws IOException {
-    return ParsingLoadable.load(dataSource, new HlsPlaylistParser(), uri, C.DATA_TYPE_MANIFEST);
+  private void addMediaPlaylistDataSpecs(String baseUri, List<HlsUrl> urls, List<DataSpec> out) {
+    for (int i = 0; i < urls.size(); i++) {
+      Uri playlistUri = UriUtil.resolveToUri(baseUri, urls.get(i).url);
+      out.add(SegmentDownloader.getCompressibleDataSpec(playlistUri));
+    }
   }
 
-  private static void addSegment(
-      ArrayList<Segment> segments,
+  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 hlsSegment,
-      HashSet<Uri> seenEncryptionKeyUris) {
-    long startTimeUs = mediaPlaylist.startTimeUs + hlsSegment.relativeStartTimeUs;
-    if (hlsSegment.fullSegmentEncryptionKeyUri != null) {
-      Uri keyUri = UriUtil.resolveToUri(mediaPlaylist.baseUri,
-          hlsSegment.fullSegmentEncryptionKeyUri);
+      HlsMediaPlaylist.Segment segment,
+      HashSet<Uri> seenEncryptionKeyUris,
+      ArrayList<Segment> out) {
+    String baseUri = mediaPlaylist.baseUri;
+    long startTimeUs = mediaPlaylist.startTimeUs + segment.relativeStartTimeUs;
+    if (segment.fullSegmentEncryptionKeyUri != null) {
+      Uri keyUri = UriUtil.resolveToUri(baseUri, segment.fullSegmentEncryptionKeyUri);
       if (seenEncryptionKeyUris.add(keyUri)) {
-        segments.add(new Segment(startTimeUs, new DataSpec(keyUri)));
+        out.add(new Segment(startTimeUs, SegmentDownloader.getCompressibleDataSpec(keyUri)));
       }
     }
-    Uri resolvedUri = UriUtil.resolveToUri(mediaPlaylist.baseUri, hlsSegment.url);
-    segments.add(new Segment(startTimeUs,
-        new DataSpec(resolvedUri, hlsSegment.byterangeOffset, hlsSegment.byterangeLength, null)));
-  }
-
-  private static void addResolvedUris(String baseUri, List<HlsUrl> urls, List<Uri> out) {
-    for (int i = 0; i < urls.size(); i++) {
-      out.add(UriUtil.resolveToUri(baseUri, urls.get(i).url));
-    }
+    Uri segmentUri = UriUtil.resolveToUri(baseUri, segment.url);
+    DataSpec dataSpec =
+        new DataSpec(segmentUri, segment.byterangeOffset, segment.byterangeLength, /* key= */ null);
+    out.add(new Segment(startTimeUs, dataSpec));
   }
 }

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

@@ -68,8 +68,8 @@ public final class SsDownloader extends SegmentDownloader<SsManifest> {
   }
 
   @Override
-  protected SsManifest getManifest(DataSource dataSource, Uri uri) throws IOException {
-    return ParsingLoadable.load(dataSource, new SsManifestParser(), uri, C.DATA_TYPE_MANIFEST);
+  protected SsManifest getManifest(DataSource dataSource, DataSpec dataSpec) throws IOException {
+    return ParsingLoadable.load(dataSource, new SsManifestParser(), dataSpec, C.DATA_TYPE_MANIFEST);
   }
 
   @Override