Add PreloadMediaSource.clear to discard the preloading period

PiperOrigin-RevId: 633167081

RELEASENOTES.md

@@ -26,6 +26,7 @@
         source or take other actions.
     *   Fix bug where silence skipping at the end of items can trigger a
         playback exception.
+    *   Add `clear` to `PreloadMediaSource` to discard the preloading period.
 *   Transformer:
     *   Work around a decoder bug where the number of audio channels was capped
         at stereo when handling PCM input.

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/source/preload/PreloadMediaSource.java

@@ -259,6 +259,21 @@ public final class PreloadMediaSource extends WrappingMediaSource {
         });
   }
 
+  /**
+   * Clears the preloading {@link PreloadMediaPeriod} in {@link PreloadMediaSource}.
+   *
+   * <p>Can be called from any thread.
+   */
+  public void clear() {
+    preloadHandler.post(
+        () -> {
+          if (preloadingMediaPeriodAndKey != null) {
+            mediaSource.releasePeriod(preloadingMediaPeriodAndKey.first.mediaPeriod);
+            preloadingMediaPeriodAndKey = null;
+          }
+        });
+  }
+
   @Override
   protected void prepareSourceInternal() {
     if (isUsedByPlayer() && !onUsedByPlayerNotified) {
@@ -337,8 +352,7 @@ public final class PreloadMediaSource extends WrappingMediaSource {
         && preloadMediaPeriod == checkNotNull(playingPreloadedMediaPeriodAndId).first) {
       playingPreloadedMediaPeriodAndId = null;
     }
-    MediaPeriod periodToRelease = preloadMediaPeriod.mediaPeriod;
-    mediaSource.releasePeriod(periodToRelease);
+    mediaSource.releasePeriod(preloadMediaPeriod.mediaPeriod);
   }
 
   @Override

libraries/exoplayer/src/test/java/androidx/media3/exoplayer/source/preload/PreloadMediaSourceTest.java

@@ -29,6 +29,7 @@ import static org.robolectric.Shadows.shadowOf;
 import android.net.Uri;
 import android.os.Looper;
 import android.util.Pair;
+import androidx.annotation.Nullable;
 import androidx.media3.common.C;
 import androidx.media3.common.MediaItem;
 import androidx.media3.common.Timeline;
@@ -36,16 +37,21 @@ import androidx.media3.common.Tracks;
 import androidx.media3.common.util.SystemClock;
 import androidx.media3.common.util.Util;
 import androidx.media3.datasource.DefaultDataSource;
+import androidx.media3.datasource.TransferListener;
 import androidx.media3.exoplayer.Renderer;
 import androidx.media3.exoplayer.RendererCapabilities;
 import androidx.media3.exoplayer.RendererConfiguration;
 import androidx.media3.exoplayer.RenderersFactory;
 import androidx.media3.exoplayer.analytics.PlayerId;
 import androidx.media3.exoplayer.audio.AudioRendererEventListener;
+import androidx.media3.exoplayer.drm.DrmSessionEventListener;
+import androidx.media3.exoplayer.drm.DrmSessionManager;
 import androidx.media3.exoplayer.metadata.MetadataOutput;
 import androidx.media3.exoplayer.source.MediaPeriod;
 import androidx.media3.exoplayer.source.MediaSource;
+import androidx.media3.exoplayer.source.MediaSourceEventListener;
 import androidx.media3.exoplayer.source.ProgressiveMediaSource;
+import androidx.media3.exoplayer.source.TrackGroupArray;
 import androidx.media3.exoplayer.text.TextOutput;
 import androidx.media3.exoplayer.trackselection.DefaultTrackSelector;
 import androidx.media3.exoplayer.trackselection.ExoTrackSelection;
@@ -57,6 +63,7 @@ import androidx.media3.exoplayer.upstream.DefaultAllocator;
 import androidx.media3.exoplayer.upstream.DefaultBandwidthMeter;
 import androidx.media3.exoplayer.video.VideoRendererEventListener;
 import androidx.media3.test.utils.FakeAudioRenderer;
+import androidx.media3.test.utils.FakeMediaPeriod;
 import androidx.media3.test.utils.FakeMediaSource;
 import androidx.media3.test.utils.FakeMediaSourceFactory;
 import androidx.media3.test.utils.FakeTimeline;
@@ -795,6 +802,83 @@ public final class PreloadMediaSourceTest {
     verify(internalSourceReference.get(), times(2)).createPeriod(any(), any(), anyLong());
   }
 
+  @Test
+  public void clear_preloadingPeriodReleased() throws Exception {
+    AtomicBoolean onPreparedCalled = new AtomicBoolean();
+    PreloadMediaSource.PreloadControl preloadControl =
+        new PreloadMediaSource.PreloadControl() {
+          @Override
+          public boolean onTimelineRefreshed(PreloadMediaSource mediaSource) {
+            return true;
+          }
+
+          @Override
+          public boolean onPrepared(PreloadMediaSource mediaSource) {
+            onPreparedCalled.set(true);
+            return false;
+          }
+
+          @Override
+          public boolean onContinueLoadingRequested(
+              PreloadMediaSource mediaSource, long bufferedPositionUs) {
+            return false;
+          }
+
+          @Override
+          public void onUsedByPlayer(PreloadMediaSource mediaSource) {}
+        };
+    MediaSource.Factory mockMediaSourceFactory = mock(MediaSource.Factory.class);
+    AtomicBoolean preloadingMediaPeriodReleased = new AtomicBoolean();
+    when(mockMediaSourceFactory.createMediaSource(any()))
+        .thenReturn(
+            new FakeMediaSource() {
+              @Override
+              protected MediaPeriod createMediaPeriod(
+                  MediaPeriodId id,
+                  TrackGroupArray trackGroupArray,
+                  Allocator allocator,
+                  MediaSourceEventListener.EventDispatcher mediaSourceEventDispatcher,
+                  DrmSessionManager drmSessionManager,
+                  DrmSessionEventListener.EventDispatcher drmEventDispatcher,
+                  @Nullable TransferListener transferListener) {
+                return new FakeMediaPeriod(
+                    trackGroupArray,
+                    allocator,
+                    FakeTimeline.TimelineWindowDefinition.DEFAULT_WINDOW_OFFSET_IN_FIRST_PERIOD_US,
+                    mediaSourceEventDispatcher) {
+                  @Override
+                  public void release() {
+                    preloadingMediaPeriodReleased.set(true);
+                  }
+                };
+              }
+            });
+    TrackSelector trackSelector =
+        new DefaultTrackSelector(ApplicationProvider.getApplicationContext());
+    trackSelector.init(() -> {}, bandwidthMeter);
+    PreloadMediaSource.Factory preloadMediaSourceFactory =
+        new PreloadMediaSource.Factory(
+            mockMediaSourceFactory,
+            preloadControl,
+            trackSelector,
+            bandwidthMeter,
+            getRendererCapabilities(renderersFactory),
+            allocator,
+            Util.getCurrentOrMainLooper());
+    PreloadMediaSource preloadMediaSource =
+        preloadMediaSourceFactory.createMediaSource(
+            new MediaItem.Builder()
+                .setUri(Uri.parse("asset://android_asset/media/mp4/sample.mp4"))
+                .build());
+    preloadMediaSource.preload(/* startPositionUs= */ 0L);
+    runMainLooperUntil(onPreparedCalled::get);
+
+    preloadMediaSource.clear();
+    shadowOf(Looper.getMainLooper()).idle();
+
+    assertThat(preloadingMediaPeriodReleased.get()).isTrue();
+  }
+
   @Test
   public void releaseSourceByAllExternalCallers_preloadNotCalledBefore_releaseInternalSource() {
     PreloadMediaSource.PreloadControl preloadControl =