Fix HLS module API nullability issues and add package-level non-null-by-default

PiperOrigin-RevId: 262124441

library/hls/build.gradle

@@ -41,6 +41,7 @@ android {
 dependencies {
     implementation 'androidx.annotation:annotation:1.1.0'
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
+    compileOnly 'org.checkerframework:checker-compat-qual:' + checkerframeworkVersion
     implementation project(modulePrefix + 'library-core')
     testImplementation project(modulePrefix + 'testutils-robolectric')
 }

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/Aes128DataSource.java

@@ -105,7 +105,8 @@ import javax.crypto.spec.SecretKeySpec;
   }
 
   @Override
-  public final @Nullable Uri getUri() {
+  @Nullable
+  public final Uri getUri() {
     return upstream.getUri();
   }
 

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

@@ -84,11 +84,11 @@ public final class DefaultHlsExtractorFactory implements HlsExtractorFactory {
 
   @Override
   public Result createExtractor(
-      Extractor previousExtractor,
+      @Nullable Extractor previousExtractor,
       Uri uri,
       Format format,
-      List<Format> muxedCaptionFormats,
+      @Nullable List<Format> muxedCaptionFormats,
-      DrmInitData drmInitData,
+      @Nullable DrmInitData drmInitData,
       TimestampAdjuster timestampAdjuster,
       Map<String, List<String>> responseHeaders,
       ExtractorInput extractorInput)

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

@@ -59,10 +59,8 @@ import java.util.Map;
       clear();
     }
 
-    /**
+    /** The chunk to be loaded next. */
-     * The chunk to be loaded next.
+    @Nullable public Chunk chunk;
-     */
-    public Chunk chunk;
 
     /**
      * Indicates that the end of the stream has been reached.
@@ -70,7 +68,7 @@ import java.util.Map;
     public boolean endOfStream;
 
     /** Indicates that the chunk source is waiting for the referred playlist to be refreshed. */
-    public Uri playlistUrl;
+    @Nullable public Uri playlistUrl;
 
     /**
      * Clears the holder.
@@ -138,7 +136,7 @@ import java.util.Map;
       HlsDataSourceFactory dataSourceFactory,
       @Nullable TransferListener mediaTransferListener,
       TimestampAdjusterProvider timestampAdjusterProvider,
-      List<Format> muxedCaptionFormats) {
+      @Nullable List<Format> muxedCaptionFormats) {
     this.extractorFactory = extractorFactory;
     this.playlistTracker = playlistTracker;
     this.playlistUrls = playlistUrls;

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

@@ -16,6 +16,7 @@
 package com.google.android.exoplayer2.source.hls;
 
 import android.net.Uri;
+import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.drm.DrmInitData;
 import com.google.android.exoplayer2.extractor.Extractor;
@@ -82,11 +83,11 @@ public interface HlsExtractorFactory {
    * @throws IOException If an I/O error is encountered while sniffing.
    */
   Result createExtractor(
-      Extractor previousExtractor,
+      @Nullable Extractor previousExtractor,
       Uri uri,
       Format format,
-      List<Format> muxedCaptionFormats,
+      @Nullable List<Format> muxedCaptionFormats,
-      DrmInitData drmInitData,
+      @Nullable DrmInitData drmInitData,
       TimestampAdjuster timestampAdjuster,
       Map<String, List<String>> responseHeaders,
       ExtractorInput sniffingExtractorInput)

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

@@ -54,6 +54,7 @@ import java.util.HashSet;
 import java.util.IdentityHashMap;
 import java.util.List;
 import java.util.Map;
+import org.checkerframework.checker.nullness.compatqual.NullableType;
 
 /**
  * A {@link MediaPeriod} that loads an HLS stream.
@@ -249,8 +250,12 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
   }
 
   @Override
-  public long selectTracks(TrackSelection[] selections, boolean[] mayRetainStreamFlags,
+  public long selectTracks(
-      SampleStream[] streams, boolean[] streamResetFlags, long positionUs) {
+      @NullableType TrackSelection[] selections,
+      boolean[] mayRetainStreamFlags,
+      @NullableType SampleStream[] streams,
+      boolean[] streamResetFlags,
+      long positionUs) {
     // Map each selection and stream onto a child period index.
     int[] streamChildIndices = new int[selections.length];
     int[] selectionChildIndices = new int[selections.length];

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

@@ -110,7 +110,7 @@ public final class HlsMediaSource extends BaseMediaSource
      * @return This factory, for convenience.
      * @throws IllegalStateException If one of the {@code create} methods has already been called.
      */
-    public Factory setTag(Object tag) {
+    public Factory setTag(@Nullable Object tag) {
       Assertions.checkState(!isCreateCalled);
       this.tag = tag;
       return this;

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

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer2.source.hls;
 
+import androidx.annotation.Nullable;
 import android.text.TextUtils;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
@@ -49,7 +50,7 @@ public final class WebvttExtractor implements Extractor {
   private static final int HEADER_MIN_LENGTH = 6 /* "WEBVTT" */;
   private static final int HEADER_MAX_LENGTH = 3 /* optional Byte Order Mark */ + HEADER_MIN_LENGTH;
 
-  private final String language;
+  @Nullable private final String language;
   private final TimestampAdjuster timestampAdjuster;
   private final ParsableByteArray sampleDataWrapper;
 
@@ -58,7 +59,7 @@ public final class WebvttExtractor implements Extractor {
   private byte[] sampleData;
   private int sampleSize;
 
-  public WebvttExtractor(String language, TimestampAdjuster timestampAdjuster) {
+  public WebvttExtractor(@Nullable String language, TimestampAdjuster timestampAdjuster) {
     this.language = language;
     this.timestampAdjuster = timestampAdjuster;
     this.sampleDataWrapper = new ParsableByteArray();

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/offline/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@NonNullApi
+package com.google.android.exoplayer2.source.hls.offline;
+
+import com.google.android.exoplayer2.util.NonNullApi;

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@NonNullApi
+package com.google.android.exoplayer2.source.hls;
+
+import com.google.android.exoplayer2.util.NonNullApi;

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

@@ -172,6 +172,7 @@ public final class DefaultHlsPlaylistTracker
   }
 
   @Override
+  @Nullable
   public HlsMediaPlaylist getPlaylistSnapshot(Uri url, boolean isForPlayback) {
     HlsMediaPlaylist snapshot = playlistBundles.get(url).getPlaylistSnapshot();
     if (snapshot != null && isForPlayback) {
@@ -448,7 +449,7 @@ public final class DefaultHlsPlaylistTracker
     private final Loader mediaPlaylistLoader;
     private final ParsingLoadable<HlsPlaylist> mediaPlaylistLoadable;
 
-    private HlsMediaPlaylist playlistSnapshot;
+    @Nullable private HlsMediaPlaylist playlistSnapshot;
     private long lastSnapshotLoadMs;
     private long lastSnapshotChangeMs;
     private long earliestNextLoadTimeMs;
@@ -467,6 +468,7 @@ public final class DefaultHlsPlaylistTracker
               mediaPlaylistParser);
     }
 
+    @Nullable
     public HlsMediaPlaylist getPlaylistSnapshot() {
       return playlistSnapshot;
     }

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

@@ -174,7 +174,7 @@ public final class HlsMasterPlaylist extends HlsPlaylist {
    * The format of the audio muxed in the variants. May be null if the playlist does not declare any
    * muxed audio.
    */
-  public final Format muxedAudioFormat;
+  @Nullable public final Format muxedAudioFormat;
   /**
    * The format of the closed captions declared by the playlist. May be empty if the playlist
    * explicitly declares no captions are available, or null if the playlist does not declare any
@@ -208,7 +208,7 @@ public final class HlsMasterPlaylist extends HlsPlaylist {
       List<Rendition> audios,
       List<Rendition> subtitles,
       List<Rendition> closedCaptions,
-      Format muxedAudioFormat,
+      @Nullable Format muxedAudioFormat,
       List<Format> muxedCaptionFormats,
       boolean hasIndependentSegments,
       Map<String, String> variableDefinitions,

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

@@ -16,7 +16,6 @@
 package com.google.android.exoplayer2.source.hls.playlist;
 
 import androidx.annotation.IntDef;
-import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.drm.DrmInitData;
@@ -95,8 +94,8 @@ public final class HlsMediaPlaylist extends HlsPlaylist {
         String uri,
         long byterangeOffset,
         long byterangeLength,
-        String fullSegmentEncryptionKeyUri,
+        @Nullable String fullSegmentEncryptionKeyUri,
-        String encryptionIV) {
+        @Nullable String encryptionIV) {
       this(
           uri,
           /* initializationSegment= */ null,
@@ -154,7 +153,7 @@ public final class HlsMediaPlaylist extends HlsPlaylist {
     }
 
     @Override
-    public int compareTo(@NonNull Long relativeStartTimeUs) {
+    public int compareTo(Long relativeStartTimeUs) {
       return this.relativeStartTimeUs > relativeStartTimeUs
           ? 1 : (this.relativeStartTimeUs < relativeStartTimeUs ? -1 : 0);
     }

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/playlist/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+@NonNullApi
+package com.google.android.exoplayer2.source.hls.playlist;
+
+import com.google.android.exoplayer2.util.NonNullApi;