Move SmoothStreaming manifest refresh to source level.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=128461778

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

@@ -16,7 +16,6 @@
 package com.google.android.exoplayer2.source.smoothstreaming;
 
 import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.ParserException;
 import com.google.android.exoplayer2.extractor.mp4.TrackEncryptionBox;
 import com.google.android.exoplayer2.source.AdaptiveMediaSourceEventListener;
@@ -33,7 +32,6 @@ import com.google.android.exoplayer2.source.TrackGroupArray;
 import com.google.android.exoplayer2.source.chunk.ChunkSampleStream;
 import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsManifest;
 import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsManifest.ProtectionElement;
-import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsManifest.StreamElement;
 import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsManifestParser;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 import com.google.android.exoplayer2.upstream.Allocator;
@@ -54,8 +52,7 @@ import java.util.List;
 /**
  * A SmoothStreaming {@link MediaSource}.
  */
-public final class SsMediaSource implements MediaPeriod, MediaSource,
+public final class SsMediaSource implements MediaSource,
-    SequenceableLoader.Callback<ChunkSampleStream<SsChunkSource>>,
     Loader.Callback<ParsingLoadable<SsManifest>> {
 
   /**
@@ -76,19 +73,12 @@ public final class SsMediaSource implements MediaPeriod, MediaSource,
   private MediaSource.InvalidationListener invalidationListener;
   private DataSource manifestDataSource;
   private Loader manifestLoader;
-  private ChunkSampleStream<SsChunkSource>[] sampleStreams;
-  private CompositeSequenceableLoader sequenceableLoader;
 
   private long manifestLoadStartTimestamp;
   private SsManifest manifest;
 
-  private Callback callback;
-  private Allocator allocator;
   private Handler manifestRefreshHandler;
-  private boolean prepared;
+  private SsMediaPeriod period;
-  private long durationUs;
-  private TrackEncryptionBox[] trackEncryptionBoxes;
-  private TrackGroupArray trackGroups;
 
   public SsMediaSource(Uri manifestUri, DataSource.Factory manifestDataSourceFactory,
       SsChunkSource.Factory chunkSourceFactory, Handler eventHandler,
@@ -114,6 +104,10 @@ public final class SsMediaSource implements MediaPeriod, MediaSource,
   @Override
   public void prepareSource(InvalidationListener listener) {
     this.invalidationListener = listener;
+    manifestDataSource = dataSourceFactory.createDataSource();
+    manifestLoader = new Loader("Loader:Manifest");
+    manifestRefreshHandler = new Handler();
+    startLoadingManifest();
   }
 
   @Override
@@ -124,142 +118,231 @@ public final class SsMediaSource implements MediaPeriod, MediaSource,
   @Override
   public MediaPeriod createPeriod(int index) {
     Assertions.checkArgument(index == 0);
-    return this;
+    return period;
   }
 
   @Override
   public void releaseSource() {
-    // do nothing
+    period = null;
-  }
+    manifest = null;
-
-  // MediaPeriod implementation.
-
-  @Override
-  public void preparePeriod(Callback callback, Allocator allocator, long positionUs) {
-    this.callback = callback;
-    this.allocator = allocator;
-    sampleStreams = newSampleStreamArray(0);
-    sequenceableLoader = new CompositeSequenceableLoader(sampleStreams);
-    manifestDataSource = dataSourceFactory.createDataSource();
-    manifestLoader = new Loader("Loader:Manifest");
-    manifestRefreshHandler = new Handler();
-    startLoadingManifest();
-  }
-
-  @Override
-  public void maybeThrowPrepareError() throws IOException {
-    manifestLoader.maybeThrowError();
-  }
-
-  @Override
-  public long getDurationUs() {
-    return durationUs;
-  }
-
-  @Override
-  public TrackGroupArray getTrackGroups() {
-    return trackGroups;
-  }
-
-  @Override
-  public SampleStream[] selectTracks(List<SampleStream> oldStreams,
-      List<TrackSelection> newSelections, long positionUs) {
-    int newEnabledSourceCount = sampleStreams.length + newSelections.size() - oldStreams.size();
-    ChunkSampleStream<SsChunkSource>[] newSampleStreams =
-        newSampleStreamArray(newEnabledSourceCount);
-    int newEnabledSourceIndex = 0;
-
-    // Iterate over currently enabled streams, either releasing them or adding them to the new list.
-    for (ChunkSampleStream<SsChunkSource> sampleStream : sampleStreams) {
-      if (oldStreams.contains(sampleStream)) {
-        sampleStream.release();
-      } else {
-        newSampleStreams[newEnabledSourceIndex++] = sampleStream;
-      }
-    }
-
-    // Instantiate and return new streams.
-    SampleStream[] streamsToReturn = new SampleStream[newSelections.size()];
-    for (int i = 0; i < newSelections.size(); i++) {
-      newSampleStreams[newEnabledSourceIndex] = buildSampleStream(newSelections.get(i), positionUs);
-      streamsToReturn[i] = newSampleStreams[newEnabledSourceIndex];
-      newEnabledSourceIndex++;
-    }
-
-    sampleStreams = newSampleStreams;
-    sequenceableLoader = new CompositeSequenceableLoader(sampleStreams);
-    return streamsToReturn;
-  }
-
-  @Override
-  public boolean continueLoading(long positionUs) {
-    return sequenceableLoader.continueLoading(positionUs);
-  }
-
-  @Override
-  public long getNextLoadPositionUs() {
-    return sequenceableLoader.getNextLoadPositionUs();
-  }
-
-  @Override
-  public long readDiscontinuity() {
-    return C.UNSET_TIME_US;
-  }
-
-  @Override
-  public long getBufferedPositionUs() {
-    long bufferedPositionUs = Long.MAX_VALUE;
-    for (ChunkSampleStream<SsChunkSource> sampleStream : sampleStreams) {
-      long rendererBufferedPositionUs = sampleStream.getBufferedPositionUs();
-      if (rendererBufferedPositionUs != C.END_OF_SOURCE_US) {
-        bufferedPositionUs = Math.min(bufferedPositionUs, rendererBufferedPositionUs);
-      }
-    }
-    return bufferedPositionUs == Long.MAX_VALUE ? C.END_OF_SOURCE_US : bufferedPositionUs;
-  }
-
-  @Override
-  public long seekToUs(long positionUs) {
-    for (ChunkSampleStream<SsChunkSource> sampleStream : sampleStreams) {
-      sampleStream.seekToUs(positionUs);
-    }
-    return positionUs;
-  }
-
-  @Override
-  public void releasePeriod() {
     manifestDataSource = null;
+    manifestLoadStartTimestamp = 0;
     if (manifestLoader != null) {
       manifestLoader.release();
       manifestLoader = null;
     }
-    if (sampleStreams != null) {
-      for (ChunkSampleStream<SsChunkSource> sampleStream : sampleStreams) {
-        sampleStream.release();
-      }
-      sampleStreams = null;
-    }
-    sequenceableLoader = null;
-    manifestLoadStartTimestamp = 0;
-    manifest = null;
-    callback = null;
-    allocator = null;
     if (manifestRefreshHandler != null) {
       manifestRefreshHandler.removeCallbacksAndMessages(null);
       manifestRefreshHandler = null;
     }
-    prepared = false;
-    durationUs = 0;
-    trackEncryptionBoxes = null;
-    trackGroups = null;
   }
 
-  // SequenceableLoader.Callback implementation
+  // MediaPeriod implementation.
+
+  // TODO: Move into separate file.
+  private static class SsMediaPeriod implements MediaPeriod,
+      SequenceableLoader.Callback<ChunkSampleStream<SsChunkSource>> {
+
+    private final SsChunkSource.Factory chunkSourceFactory;
+    private final Loader manifestLoader;
+    private final int minLoadableRetryCount;
+    private final EventDispatcher eventDispatcher;
+    private final long durationUs;
+    private final TrackGroupArray trackGroups;
+    private final TrackEncryptionBox[] trackEncryptionBoxes;
+
+    private SsManifest manifest;
+    private ChunkSampleStream<SsChunkSource>[] sampleStreams;
+    private CompositeSequenceableLoader sequenceableLoader;
+    private Callback callback;
+    private Allocator allocator;
+
+    public SsMediaPeriod(SsManifest manifest, SsChunkSource.Factory chunkSourceFactory,
+        int minLoadableRetryCount, EventDispatcher eventDispatcher, Loader manifestLoader) {
+      this.manifest = manifest;
+      this.chunkSourceFactory = chunkSourceFactory;
+      this.manifestLoader = manifestLoader;
+      this.minLoadableRetryCount = minLoadableRetryCount;
+      this.eventDispatcher = eventDispatcher;
+      durationUs = manifest.durationUs;
+      trackGroups = buildTrackGroups(manifest);
+      ProtectionElement protectionElement = manifest.protectionElement;
+      if (protectionElement != null) {
+        byte[] keyId = getProtectionElementKeyId(protectionElement.data);
+        trackEncryptionBoxes = new TrackEncryptionBox[] {
+            new TrackEncryptionBox(true, INITIALIZATION_VECTOR_SIZE, keyId)};
+      } else {
+        trackEncryptionBoxes = null;
+      }
+    }
+
+    public void updateManifest(SsManifest manifest) {
+      this.manifest = manifest;
+      if (sampleStreams != null) {
+        for (ChunkSampleStream<SsChunkSource> sampleStream : sampleStreams) {
+          sampleStream.getChunkSource().updateManifest(manifest);
+        }
+        callback.onContinueLoadingRequested(this);
+      }
+    }
+
+    @Override
+    public void preparePeriod(Callback callback, Allocator allocator, long positionUs) {
+      this.callback = callback;
+      this.allocator = allocator;
+      sampleStreams = newSampleStreamArray(0);
+      sequenceableLoader = new CompositeSequenceableLoader(sampleStreams);
+      callback.onPeriodPrepared(this);
+    }
+
+    @Override
+    public void maybeThrowPrepareError() throws IOException {
+      manifestLoader.maybeThrowError();
+    }
+
+    @Override
+    public long getDurationUs() {
+      return durationUs;
+    }
+
+    @Override
+    public TrackGroupArray getTrackGroups() {
+      return trackGroups;
+    }
+
+    @Override
+    public SampleStream[] selectTracks(List<SampleStream> oldStreams,
+        List<TrackSelection> newSelections, long positionUs) {
+      int newEnabledSourceCount = sampleStreams.length + newSelections.size() - oldStreams.size();
+      ChunkSampleStream<SsChunkSource>[] newSampleStreams =
+          newSampleStreamArray(newEnabledSourceCount);
+      int newEnabledSourceIndex = 0;
+
+      // Iterate over currently enabled streams, either releasing them or adding them to the new
+      // list.
+      for (ChunkSampleStream<SsChunkSource> sampleStream : sampleStreams) {
+        if (oldStreams.contains(sampleStream)) {
+          sampleStream.release();
+        } else {
+          newSampleStreams[newEnabledSourceIndex++] = sampleStream;
+        }
+      }
+
+      // Instantiate and return new streams.
+      SampleStream[] streamsToReturn = new SampleStream[newSelections.size()];
+      for (int i = 0; i < newSelections.size(); i++) {
+        newSampleStreams[newEnabledSourceIndex] =
+            buildSampleStream(newSelections.get(i), positionUs);
+        streamsToReturn[i] = newSampleStreams[newEnabledSourceIndex];
+        newEnabledSourceIndex++;
+      }
+
+      sampleStreams = newSampleStreams;
+      sequenceableLoader = new CompositeSequenceableLoader(sampleStreams);
+      return streamsToReturn;
+    }
+
+    @Override
+    public boolean continueLoading(long positionUs) {
+      return sequenceableLoader.continueLoading(positionUs);
+    }
+
+    @Override
+    public long getNextLoadPositionUs() {
+      return sequenceableLoader.getNextLoadPositionUs();
+    }
+
+    @Override
+    public long readDiscontinuity() {
+      return C.UNSET_TIME_US;
+    }
+
+    @Override
+    public long getBufferedPositionUs() {
+      long bufferedPositionUs = Long.MAX_VALUE;
+      for (ChunkSampleStream<SsChunkSource> sampleStream : sampleStreams) {
+        long rendererBufferedPositionUs = sampleStream.getBufferedPositionUs();
+        if (rendererBufferedPositionUs != C.END_OF_SOURCE_US) {
+          bufferedPositionUs = Math.min(bufferedPositionUs, rendererBufferedPositionUs);
+        }
+      }
+      return bufferedPositionUs == Long.MAX_VALUE ? C.END_OF_SOURCE_US : bufferedPositionUs;
+    }
+
+    @Override
+    public long seekToUs(long positionUs) {
+      for (ChunkSampleStream<SsChunkSource> sampleStream : sampleStreams) {
+        sampleStream.seekToUs(positionUs);
+      }
+      return positionUs;
+    }
+
+    @Override
+    public void releasePeriod() {
+      if (sampleStreams != null) {
+        for (ChunkSampleStream<SsChunkSource> sampleStream : sampleStreams) {
+          sampleStream.release();
+        }
+        sampleStreams = null;
+      }
+      sequenceableLoader = null;
+      callback = null;
+      allocator = null;
+    }
+
+    // SequenceableLoader.Callback implementation
+
+    @Override
+    public void onContinueLoadingRequested(ChunkSampleStream<SsChunkSource> sampleStream) {
+      callback.onContinueLoadingRequested(this);
+    }
+
+    // Private methods.
+
+    private ChunkSampleStream<SsChunkSource> buildSampleStream(TrackSelection selection,
+        long positionUs) {
+      int streamElementIndex = trackGroups.indexOf(selection.group);
+      SsChunkSource chunkSource = chunkSourceFactory.createChunkSource(manifestLoader, manifest,
+          streamElementIndex, selection, trackEncryptionBoxes);
+      return new ChunkSampleStream<>(manifest.streamElements[streamElementIndex].type, chunkSource,
+          this, allocator, positionUs, minLoadableRetryCount, eventDispatcher);
+    }
+
+    private static TrackGroupArray buildTrackGroups(SsManifest manifest) {
+      TrackGroup[] trackGroupArray = new TrackGroup[manifest.streamElements.length];
+      for (int i = 0; i < manifest.streamElements.length; i++) {
+        trackGroupArray[i++] = new TrackGroup(manifest.streamElements[i].formats);
+      }
+      return new TrackGroupArray(trackGroupArray);
+    }
+
+    @SuppressWarnings("unchecked")
+    private static ChunkSampleStream<SsChunkSource>[] newSampleStreamArray(int length) {
+      return new ChunkSampleStream[length];
+    }
+
+    private static byte[] getProtectionElementKeyId(byte[] initData) {
+      StringBuilder initDataStringBuilder = new StringBuilder();
+      for (int i = 0; i < initData.length; i += 2) {
+        initDataStringBuilder.append((char) initData[i]);
+      }
+      String initDataString = initDataStringBuilder.toString();
+      String keyIdString = initDataString.substring(
+          initDataString.indexOf("<KID>") + 5, initDataString.indexOf("</KID>"));
+      byte[] keyId = Base64.decode(keyIdString, Base64.DEFAULT);
+      swap(keyId, 0, 3);
+      swap(keyId, 1, 2);
+      swap(keyId, 4, 5);
+      swap(keyId, 6, 7);
+      return keyId;
+    }
+
+    private static void swap(byte[] data, int firstPosition, int secondPosition) {
+      byte temp = data[firstPosition];
+      data[firstPosition] = data[secondPosition];
+      data[secondPosition] = temp;
+    }
 
-  @Override
-  public void onContinueLoadingRequested(
-      ChunkSampleStream<SsChunkSource> sampleStream) {
-    callback.onContinueLoadingRequested(this);
   }
 
   // Loader.Callback implementation
@@ -271,25 +354,15 @@ public final class SsMediaSource implements MediaPeriod, MediaSource,
         loadDurationMs, loadable.bytesLoaded());
     manifest = loadable.getResult();
     manifestLoadStartTimestamp = elapsedRealtimeMs - loadDurationMs;
-    if (!prepared) {
+    if (period == null) {
-      durationUs = manifest.durationUs;
+      period = new SsMediaPeriod(manifest, chunkSourceFactory, minLoadableRetryCount,
-      Timeline timeline = durationUs == C.UNSET_TIME_US ? new SinglePeriodTimeline(this, manifest)
+          eventDispatcher, manifestLoader);
-          : new SinglePeriodTimeline(this, manifest, durationUs / 1000);
+      Timeline timeline = manifest.durationUs == C.UNSET_TIME_US
+          ? new SinglePeriodTimeline(this, manifest)
+          : new SinglePeriodTimeline(this, manifest, manifest.durationUs / 1000);
       invalidationListener.onTimelineChanged(timeline);
-      buildTrackGroups(manifest);
-      ProtectionElement protectionElement = manifest.protectionElement;
-      if (protectionElement != null) {
-        byte[] keyId = getProtectionElementKeyId(protectionElement.data);
-        trackEncryptionBoxes = new TrackEncryptionBox[] {
-            new TrackEncryptionBox(true, INITIALIZATION_VECTOR_SIZE, keyId)};
-      }
-      prepared = true;
-      callback.onPeriodPrepared(this);
     } else {
-      for (ChunkSampleStream<SsChunkSource> sampleStream : sampleStreams) {
+      period.updateManifest(manifest);
-        sampleStream.getChunkSource().updateManifest(manifest);
-      }
-      callback.onContinueLoadingRequested(this);
     }
     scheduleManifestRefresh();
   }
@@ -333,50 +406,4 @@ public final class SsMediaSource implements MediaPeriod, MediaSource,
     eventDispatcher.loadStarted(loadable.dataSpec, loadable.type, elapsedRealtimeMs);
   }
 
-  private void buildTrackGroups(SsManifest manifest) {
-    TrackGroup[] trackGroupArray = new TrackGroup[manifest.streamElements.length];
-    for (int i = 0; i < manifest.streamElements.length; i++) {
-      StreamElement streamElement = manifest.streamElements[i];
-      Format[] formats = streamElement.formats;
-      trackGroupArray[i] = new TrackGroup(formats);
-    }
-    trackGroups = new TrackGroupArray(trackGroupArray);
-  }
-
-  private ChunkSampleStream<SsChunkSource> buildSampleStream(TrackSelection selection,
-      long positionUs) {
-    int streamElementIndex = trackGroups.indexOf(selection.group);
-    SsChunkSource chunkSource = chunkSourceFactory.createChunkSource(manifestLoader, manifest,
-        streamElementIndex, selection, trackEncryptionBoxes);
-    return new ChunkSampleStream<>(manifest.streamElements[streamElementIndex].type, chunkSource,
-        this, allocator, positionUs, minLoadableRetryCount, eventDispatcher);
-  }
-
-  @SuppressWarnings("unchecked")
-  private static ChunkSampleStream<SsChunkSource>[] newSampleStreamArray(int length) {
-    return new ChunkSampleStream[length];
-  }
-
-  private static byte[] getProtectionElementKeyId(byte[] initData) {
-    StringBuilder initDataStringBuilder = new StringBuilder();
-    for (int i = 0; i < initData.length; i += 2) {
-      initDataStringBuilder.append((char) initData[i]);
-    }
-    String initDataString = initDataStringBuilder.toString();
-    String keyIdString = initDataString.substring(
-        initDataString.indexOf("<KID>") + 5, initDataString.indexOf("</KID>"));
-    byte[] keyId = Base64.decode(keyIdString, Base64.DEFAULT);
-    swap(keyId, 0, 3);
-    swap(keyId, 1, 2);
-    swap(keyId, 4, 5);
-    swap(keyId, 6, 7);
-    return keyId;
-  }
-
-  private static void swap(byte[] data, int firstPosition, int secondPosition) {
-    byte temp = data[firstPosition];
-    data[firstPosition] = data[secondPosition];
-    data[secondPosition] = temp;
-  }
-
 }