Forward queue of media chunks to getNextChunk.

This allows to use this queue in the track selection in the future.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=202954871

library/core/src/main/java/com/google/android/exoplayer2/source/chunk/ChunkSampleStream.java

@@ -486,16 +486,16 @@ public class ChunkSampleStream<T extends ChunkSource> implements SampleStream, S
     }
 
     boolean pendingReset = isPendingReset();
-    MediaChunk previousChunk;
+    List<BaseMediaChunk> chunkQueue;
     long loadPositionUs;
     if (pendingReset) {
-      previousChunk = null;
+      chunkQueue = Collections.emptyList();
       loadPositionUs = pendingResetPositionUs;
     } else {
-      previousChunk = getLastMediaChunk();
-      loadPositionUs = previousChunk.endTimeUs;
+      chunkQueue = readOnlyMediaChunks;
+      loadPositionUs = getLastMediaChunk().endTimeUs;
     }
-    chunkSource.getNextChunk(previousChunk, positionUs, loadPositionUs, nextChunkHolder);
+    chunkSource.getNextChunk(positionUs, loadPositionUs, chunkQueue, nextChunkHolder);
     boolean endOfStream = nextChunkHolder.endOfStream;
     Chunk loadable = nextChunkHolder.chunk;
     nextChunkHolder.clear();

library/core/src/main/java/com/google/android/exoplayer2/source/chunk/ChunkSource.java

@@ -59,22 +59,25 @@ public interface ChunkSource {
 
   /**
    * Returns the next chunk to load.
-   * <p>
-   * If a chunk is available then {@link ChunkHolder#chunk} is set. If the end of the stream has
+   *
+   * <p>If a chunk is available then {@link ChunkHolder#chunk} is set. If the end of the stream has
    * been reached then {@link ChunkHolder#endOfStream} is set. If a chunk is not available but the
    * end of the stream has not been reached, the {@link ChunkHolder} is not modified.
    *
-   * @param previous The most recently loaded media chunk.
    * @param playbackPositionUs The current playback position in microseconds. If playback of the
    *     period to which this chunk source belongs has not yet started, the value will be the
    *     starting position in the period minus the duration of any media in previous periods still
    *     to be played.
-   * @param loadPositionUs The current load position in microseconds. If {@code previous} is null,
+   * @param loadPositionUs The current load position in microseconds. If {@code queue} is empty,
    *     this is the starting position from which chunks should be provided. Else it's equal to
-   *     {@code previous.endTimeUs}.
+   *     {@link MediaChunk#endTimeUs} of the last chunk in the {@code queue}.
+   * @param queue The queue of buffered {@link MediaChunk}s.
    * @param out A holder to populate.
    */
-  void getNextChunk(MediaChunk previous, long playbackPositionUs, long loadPositionUs,
+  void getNextChunk(
+      long playbackPositionUs,
+      long loadPositionUs,
+      List<? extends MediaChunk> queue,
       ChunkHolder out);
 
   /**

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

@@ -238,7 +238,10 @@ public class DefaultDashChunkSource implements DashChunkSource {
   }
 
   @Override
-  public void getNextChunk(MediaChunk previous, long playbackPositionUs, long loadPositionUs,
+  public void getNextChunk(
+      long playbackPositionUs,
+      long loadPositionUs,
+      List<? extends MediaChunk> queue,
       ChunkHolder out) {
     if (fatalError != null) {
       return;
@@ -311,11 +314,11 @@ public class DefaultDashChunkSource implements DashChunkSource {
     updateLiveEdgeTimeUs(representationHolder, lastAvailableSegmentNum);
 
     long segmentNum;
-    if (previous == null) {
+    if (queue.isEmpty()) {
       segmentNum = Util.constrainValue(representationHolder.getSegmentNum(loadPositionUs),
           firstAvailableSegmentNum, lastAvailableSegmentNum);
     } else {
-      segmentNum = previous.getNextChunkIndex();
+      segmentNum = queue.get(queue.size() - 1).getNextChunkIndex();
       if (segmentNum < firstAvailableSegmentNum) {
         // This is before the first chunk in the current manifest.
         fatalError = new BehindLiveWindowException();
@@ -332,7 +335,7 @@ public class DefaultDashChunkSource implements DashChunkSource {
 
     int maxSegmentCount =
         (int) Math.min(maxSegmentsPerLoad, lastAvailableSegmentNum - segmentNum + 1);
-    long seekTimeUs = previous == null ? loadPositionUs : C.TIME_UNSET;
+    long seekTimeUs = queue.isEmpty() ? loadPositionUs : C.TIME_UNSET;
     out.chunk =
         newMediaChunk(
             representationHolder,

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

@@ -204,18 +204,20 @@ import java.util.List;
    * but the end of the stream has not been reached, {@link HlsChunkHolder#playlist} is set to
    * contain the {@link HlsUrl} that refers to the playlist that needs refreshing.
    *
-   * @param previous The most recently loaded media chunk.
    * @param playbackPositionUs The current playback position relative to the period start in
    *     microseconds. If playback of the period to which this chunk source belongs has not yet
    *     started, the value will be the starting position in the period minus the duration of any
    *     media in previous periods still to be played.
    * @param loadPositionUs The current load position relative to the period start in microseconds.
-   *     If {@code previous} is null, this is the starting position from which chunks should be
-   *     provided. Else it's equal to {@code previous.endTimeUs}.
+   *     If {@code queue} is empty, this is the starting position from which chunks should be
+   *     provided. Else it's equal to {@link HlsMediaChunk#endTimeUs} of the last chunk in the
+   *     {@code queue}.
+   * @param queue The queue of buffered {@link HlsMediaChunk}s.
    * @param out A holder to populate.
    */
   public void getNextChunk(
-      HlsMediaChunk previous, long playbackPositionUs, long loadPositionUs, HlsChunkHolder out) {
+      long playbackPositionUs, long loadPositionUs, List<HlsMediaChunk> queue, HlsChunkHolder out) {
+    HlsMediaChunk previous = queue.isEmpty() ? null : queue.get(queue.size() - 1);
     int oldVariantIndex = previous == null ? C.INDEX_UNSET
         : trackGroup.indexOf(previous.trackFormat);
     long bufferedDurationUs = loadPositionUs - playbackPositionUs;

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

@@ -49,6 +49,8 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
 
 /**
  * Loads {@link HlsMediaChunk}s obtained from a {@link HlsChunkSource}, and provides
@@ -100,6 +102,7 @@ import java.util.Arrays;
   private final EventDispatcher eventDispatcher;
   private final HlsChunkSource.HlsChunkHolder nextChunkHolder;
   private final ArrayList<HlsMediaChunk> mediaChunks;
+  private final List<HlsMediaChunk> readOnlyMediaChunks;
   private final Runnable maybeFinishPrepareRunnable;
   private final Runnable onTracksEndedRunnable;
   private final Handler handler;
@@ -168,6 +171,7 @@ import java.util.Arrays;
     sampleQueueIsAudioVideoFlags = new boolean[0];
     sampleQueuesEnabledStates = new boolean[0];
     mediaChunks = new ArrayList<>();
+    readOnlyMediaChunks = Collections.unmodifiableList(mediaChunks);
     hlsSampleStreams = new ArrayList<>();
     maybeFinishPrepareRunnable =
         new Runnable() {
@@ -527,16 +531,16 @@ import java.util.Arrays;
       return false;
     }
 
-    HlsMediaChunk previousChunk;
+    List<HlsMediaChunk> chunkQueue;
     long loadPositionUs;
     if (isPendingReset()) {
-      previousChunk = null;
+      chunkQueue = Collections.emptyList();
       loadPositionUs = pendingResetPositionUs;
     } else {
-      previousChunk = getLastMediaChunk();
-      loadPositionUs = previousChunk.endTimeUs;
+      chunkQueue = readOnlyMediaChunks;
+      loadPositionUs = getLastMediaChunk().endTimeUs;
     }
-    chunkSource.getNextChunk(previousChunk, positionUs, loadPositionUs, nextChunkHolder);
+    chunkSource.getNextChunk(positionUs, loadPositionUs, chunkQueue, nextChunkHolder);
     boolean endOfStream = nextChunkHolder.endOfStream;
     Chunk loadable = nextChunkHolder.chunk;
     HlsMasterPlaylist.HlsUrl playlistToLoad = nextChunkHolder.playlist;

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

@@ -166,7 +166,10 @@ public class DefaultSsChunkSource implements SsChunkSource {
   }
 
   @Override
-  public final void getNextChunk(MediaChunk previous, long playbackPositionUs, long loadPositionUs,
+  public final void getNextChunk(
+      long playbackPositionUs,
+      long loadPositionUs,
+      List<? extends MediaChunk> queue,
       ChunkHolder out) {
     if (fatalError != null) {
       return;
@@ -180,10 +183,11 @@ public class DefaultSsChunkSource implements SsChunkSource {
     }
 
     int chunkIndex;
-    if (previous == null) {
+    if (queue.isEmpty()) {
       chunkIndex = streamElement.getChunkIndex(loadPositionUs);
     } else {
-      chunkIndex = (int) (previous.getNextChunkIndex() - currentManifestChunkOffset);
+      chunkIndex =
+          (int) (queue.get(queue.size() - 1).getNextChunkIndex() - currentManifestChunkOffset);
       if (chunkIndex < 0) {
         // This is before the first chunk in the current manifest.
         fatalError = new BehindLiveWindowException();
@@ -203,7 +207,7 @@ public class DefaultSsChunkSource implements SsChunkSource {
 
     long chunkStartTimeUs = streamElement.getStartTimeUs(chunkIndex);
     long chunkEndTimeUs = chunkStartTimeUs + streamElement.getChunkDurationUs(chunkIndex);
-    long chunkSeekTimeUs = previous == null ? loadPositionUs : C.TIME_UNSET;
+    long chunkSeekTimeUs = queue.isEmpty() ? loadPositionUs : C.TIME_UNSET;
     int currentAbsoluteChunkIndex = chunkIndex + currentManifestChunkOffset;
 
     int trackSelectionIndex = trackSelection.getSelectedIndex();

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeChunkSource.java

@@ -95,14 +95,17 @@ public final class FakeChunkSource implements ChunkSource {
   }
 
   @Override
-  public void getNextChunk(MediaChunk previous, long playbackPositionUs, long loadPositionUs,
+  public void getNextChunk(
+      long playbackPositionUs,
+      long loadPositionUs,
+      List<? extends MediaChunk> queue,
       ChunkHolder out) {
     long bufferedDurationUs = loadPositionUs - playbackPositionUs;
     trackSelection.updateSelectedTrack(playbackPositionUs, bufferedDurationUs, C.TIME_UNSET);
     int chunkIndex =
-        previous == null
+        queue.isEmpty()
             ? dataSet.getChunkIndexByPosition(playbackPositionUs)
-            : (int) previous.getNextChunkIndex();
+            : (int) queue.get(queue.size() - 1).getNextChunkIndex();
     if (chunkIndex >= dataSet.getChunkCount()) {
       out.endOfStream = true;
     } else {