Remove some more core classes from nullness blacklist

PiperOrigin-RevId: 283366568

library/core/src/main/java/com/google/android/exoplayer2/NoSampleRenderer.java

@@ -20,6 +20,7 @@ import com.google.android.exoplayer2.source.SampleStream;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.MediaClock;
 import java.io.IOException;
+import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
 /**
  * A {@link Renderer} implementation whose track type is {@link C#TRACK_TYPE_NONE} and does not
@@ -27,10 +28,10 @@ import java.io.IOException;
  */
 public abstract class NoSampleRenderer implements Renderer, RendererCapabilities {
 
-  private RendererConfiguration configuration;
+  @MonotonicNonNull private RendererConfiguration configuration;
   private int index;
   private int state;
-  private SampleStream stream;
+  @Nullable private SampleStream stream;
   private boolean streamIsFinal;
 
   @Override
@@ -285,8 +286,10 @@ public abstract class NoSampleRenderer implements Renderer, RendererCapabilities
   // Methods to be called by subclasses.
 
   /**
-   * Returns the configuration set when the renderer was most recently enabled.
+   * Returns the configuration set when the renderer was most recently enabled, or {@code null} if
+   * the renderer has never been enabled.
    */
+  @Nullable
   protected final RendererConfiguration getConfiguration() {
     return configuration;
   }

library/core/src/main/java/com/google/android/exoplayer2/audio/AudioRendererEventListener.java

@@ -15,6 +15,8 @@
  */
 package com.google.android.exoplayer2.audio;
 
+import static com.google.android.exoplayer2.util.Util.castNonNull;
+
 import android.os.Handler;
 import android.os.SystemClock;
 import androidx.annotation.Nullable;
@@ -105,8 +107,8 @@ public interface AudioRendererEventListener {
      * Invokes {@link AudioRendererEventListener#onAudioEnabled(DecoderCounters)}.
      */
     public void enabled(final DecoderCounters decoderCounters) {
-      if (listener != null) {
+      if (handler != null) {
-        handler.post(() -> listener.onAudioEnabled(decoderCounters));
+        handler.post(() -> castNonNull(listener).onAudioEnabled(decoderCounters));
       }
     }
 
@@ -115,10 +117,11 @@ public interface AudioRendererEventListener {
      */
     public void decoderInitialized(final String decoderName,
         final long initializedTimestampMs, final long initializationDurationMs) {
-      if (listener != null) {
+      if (handler != null) {
         handler.post(
             () ->
-                listener.onAudioDecoderInitialized(
+                castNonNull(listener)
+                    .onAudioDecoderInitialized(
                         decoderName, initializedTimestampMs, initializationDurationMs));
       }
     }
@@ -127,8 +130,8 @@ public interface AudioRendererEventListener {
      * Invokes {@link AudioRendererEventListener#onAudioInputFormatChanged(Format)}.
      */
     public void inputFormatChanged(final Format format) {
-      if (listener != null) {
+      if (handler != null) {
-        handler.post(() -> listener.onAudioInputFormatChanged(format));
+        handler.post(() -> castNonNull(listener).onAudioInputFormatChanged(format));
       }
     }
 
@@ -137,9 +140,11 @@ public interface AudioRendererEventListener {
      */
     public void audioTrackUnderrun(final int bufferSize, final long bufferSizeMs,
         final long elapsedSinceLastFeedMs) {
-      if (listener != null) {
+      if (handler != null) {
         handler.post(
-            () -> listener.onAudioSinkUnderrun(bufferSize, bufferSizeMs, elapsedSinceLastFeedMs));
+            () ->
+                castNonNull(listener)
+                    .onAudioSinkUnderrun(bufferSize, bufferSizeMs, elapsedSinceLastFeedMs));
       }
     }
 
@@ -148,11 +153,11 @@ public interface AudioRendererEventListener {
      */
     public void disabled(final DecoderCounters counters) {
       counters.ensureUpdated();
-      if (listener != null) {
+      if (handler != null) {
         handler.post(
             () -> {
               counters.ensureUpdated();
-              listener.onAudioDisabled(counters);
+              castNonNull(listener).onAudioDisabled(counters);
             });
       }
     }
@@ -161,11 +166,9 @@ public interface AudioRendererEventListener {
      * Invokes {@link AudioRendererEventListener#onAudioSessionId(int)}.
      */
     public void audioSessionId(final int audioSessionId) {
-      if (listener != null) {
+      if (handler != null) {
-        handler.post(() -> listener.onAudioSessionId(audioSessionId));
+        handler.post(() -> castNonNull(listener).onAudioSessionId(audioSessionId));
       }
     }
-
   }
-
 }

library/core/src/main/java/com/google/android/exoplayer2/extractor/MpegAudioHeader.java

@@ -17,6 +17,7 @@ package com.google.android.exoplayer2.extractor;
 
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.util.MimeTypes;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
  * An MPEG audio frame header.
@@ -195,7 +196,7 @@ public final class MpegAudioHeader {
   /** MPEG audio header version. */
   public int version;
   /** The mime type. */
-  public String mimeType;
+  @Nullable public String mimeType;
   /** Size of the frame associated with this header, in bytes. */
   public int frameSize;
   /** Sample rate in samples per second. */
@@ -223,5 +224,4 @@ public final class MpegAudioHeader {
     this.bitrate = bitrate;
     this.samplesPerFrame = samplesPerFrame;
   }
-
 }

library/core/src/main/java/com/google/android/exoplayer2/extractor/wav/WavHeaderReader.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer2.extractor.wav;
 
+import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ParserException;
 import com.google.android.exoplayer2.audio.WavUtil;
@@ -39,6 +40,7 @@ import java.io.IOException;
    * @return A new {@code WavHeader} peeked from {@code input}, or null if the input is not a
    *     supported WAV format.
    */
+  @Nullable
   public static WavHeader peek(ExtractorInput input) throws IOException, InterruptedException {
     Assertions.checkNotNull(input);
 

library/core/src/main/java/com/google/android/exoplayer2/metadata/MetadataDecoderFactory.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer2.metadata;
 
+import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.metadata.emsg.EventMessageDecoder;
 import com.google.android.exoplayer2.metadata.icy.IcyDecoder;
@@ -62,7 +63,7 @@ public interface MetadataDecoderFactory {
 
         @Override
         public boolean supportsFormat(Format format) {
-          String mimeType = format.sampleMimeType;
+          @Nullable String mimeType = format.sampleMimeType;
           return MimeTypes.APPLICATION_ID3.equals(mimeType)
               || MimeTypes.APPLICATION_EMSG.equals(mimeType)
               || MimeTypes.APPLICATION_SCTE35.equals(mimeType)
@@ -71,7 +72,9 @@ public interface MetadataDecoderFactory {
 
         @Override
         public MetadataDecoder createDecoder(Format format) {
-          switch (format.sampleMimeType) {
+          @Nullable String mimeType = format.sampleMimeType;
+          if (mimeType != null) {
+            switch (mimeType) {
               case MimeTypes.APPLICATION_ID3:
                 return new Id3Decoder();
               case MimeTypes.APPLICATION_EMSG:
@@ -81,9 +84,11 @@ public interface MetadataDecoderFactory {
               case MimeTypes.APPLICATION_ICY:
                 return new IcyDecoder();
               default:
-              throw new IllegalArgumentException(
+                break;
-                  "Attempted to create decoder for unsupported format");
             }
           }
+          throw new IllegalArgumentException(
+              "Attempted to create decoder for unsupported MIME type: " + mimeType);
+        }
       };
 }

library/core/src/main/java/com/google/android/exoplayer2/text/SubtitleDecoderFactory.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer2.text;
 
+import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.text.cea.Cea608Decoder;
 import com.google.android.exoplayer2.text.cea.Cea708Decoder;
@@ -74,7 +75,7 @@ public interface SubtitleDecoderFactory {
 
         @Override
         public boolean supportsFormat(Format format) {
-          String mimeType = format.sampleMimeType;
+          @Nullable String mimeType = format.sampleMimeType;
           return MimeTypes.TEXT_VTT.equals(mimeType)
               || MimeTypes.TEXT_SSA.equals(mimeType)
               || MimeTypes.APPLICATION_TTML.equals(mimeType)
@@ -90,7 +91,9 @@ public interface SubtitleDecoderFactory {
 
         @Override
         public SubtitleDecoder createDecoder(Format format) {
-          switch (format.sampleMimeType) {
+          @Nullable String mimeType = format.sampleMimeType;
+          if (mimeType != null) {
+            switch (mimeType) {
               case MimeTypes.TEXT_VTT:
                 return new WebvttDecoder();
               case MimeTypes.TEXT_SSA:
@@ -105,7 +108,7 @@ public interface SubtitleDecoderFactory {
                 return new Tx3gDecoder(format.initializationData);
               case MimeTypes.APPLICATION_CEA608:
               case MimeTypes.APPLICATION_MP4CEA608:
-              return new Cea608Decoder(format.sampleMimeType, format.accessibilityChannel);
+                return new Cea608Decoder(mimeType, format.accessibilityChannel);
               case MimeTypes.APPLICATION_CEA708:
                 return new Cea708Decoder(format.accessibilityChannel, format.initializationData);
               case MimeTypes.APPLICATION_DVBSUBS:
@@ -113,9 +116,11 @@ public interface SubtitleDecoderFactory {
               case MimeTypes.APPLICATION_PGS:
                 return new PgsDecoder();
               default:
-              throw new IllegalArgumentException(
+                break;
-                  "Attempted to create decoder for unsupported format");
             }
           }
+          throw new IllegalArgumentException(
+              "Attempted to create decoder for unsupported MIME type: " + mimeType);
+        }
       };
 }

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

@@ -190,8 +190,8 @@ public final class Loader implements LoaderErrorThrower {
 
   private final ExecutorService downloadExecutorService;
 
-  private LoadTask<? extends Loadable> currentTask;
+  @Nullable private LoadTask<? extends Loadable> currentTask;
-  private IOException fatalError;
+  @Nullable private IOException fatalError;
 
   /**
    * @param threadName A name for the loader's thread.
@@ -242,39 +242,34 @@ public final class Loader implements LoaderErrorThrower {
    */
   public <T extends Loadable> long startLoading(
       T loadable, Callback<T> callback, int defaultMinRetryCount) {
-    Looper looper = Looper.myLooper();
+    Looper looper = Assertions.checkStateNotNull(Looper.myLooper());
-    Assertions.checkState(looper != null);
     fatalError = null;
     long startTimeMs = SystemClock.elapsedRealtime();
     new LoadTask<>(looper, loadable, callback, defaultMinRetryCount, startTimeMs).start(0);
     return startTimeMs;
   }
 
-  /**
+  /** Returns whether the loader is currently loading. */
-   * Returns whether the {@link Loader} is currently loading a {@link Loadable}.
-   */
   public boolean isLoading() {
     return currentTask != null;
   }
 
   /**
-   * Cancels the current load. This method should only be called when a load is in progress.
+   * Cancels the current load.
+   *
+   * @throws IllegalStateException If the loader is not currently loading.
    */
   public void cancelLoading() {
-    currentTask.cancel(false);
+    Assertions.checkStateNotNull(currentTask).cancel(false);
   }
 
-  /**
+  /** Releases the loader. This method should be called when the loader is no longer required. */
-   * Releases the {@link Loader}. This method should be called when the {@link Loader} is no longer
-   * required.
-   */
   public void release() {
     release(null);
   }
 
   /**
-   * Releases the {@link Loader}. This method should be called when the {@link Loader} is no longer
+   * Releases the loader. This method should be called when the loader is no longer required.
-   * required.
    *
    * @param callback An optional callback to be called on the loading thread once the loader has
    *     been released.
@@ -325,10 +320,10 @@ public final class Loader implements LoaderErrorThrower {
     private final long startTimeMs;
 
     @Nullable private Loader.Callback<T> callback;
-    private IOException currentError;
+    @Nullable private IOException currentError;
     private int errorCount;
 
-    private volatile Thread executorThread;
+    @Nullable private volatile Thread executorThread;
     private volatile boolean canceled;
     private volatile boolean released;
 
@@ -368,6 +363,7 @@ public final class Loader implements LoaderErrorThrower {
       } else {
         canceled = true;
         loadable.cancelLoad();
+        Thread executorThread = this.executorThread;
         if (executorThread != null) {
           executorThread.interrupt();
         }
@@ -375,7 +371,8 @@ public final class Loader implements LoaderErrorThrower {
       if (released) {
         finish();
         long nowMs = SystemClock.elapsedRealtime();
-        callback.onLoadCanceled(loadable, nowMs, nowMs - startTimeMs, true);
+        Assertions.checkNotNull(callback)
+            .onLoadCanceled(loadable, nowMs, nowMs - startTimeMs, true);
         // If loading, this task will be referenced from a GC root (the loading thread) until
         // cancellation completes. The time taken for cancellation to complete depends on the
         // implementation of the Loadable that the task is loading. We null the callback reference
@@ -450,6 +447,7 @@ public final class Loader implements LoaderErrorThrower {
       finish();
       long nowMs = SystemClock.elapsedRealtime();
       long durationMs = nowMs - startTimeMs;
+      Loader.Callback<T> callback = Assertions.checkNotNull(this.callback);
       if (canceled) {
         callback.onLoadCanceled(loadable, nowMs, durationMs, false);
         return;
@@ -492,7 +490,7 @@ public final class Loader implements LoaderErrorThrower {
 
     private void execute() {
       currentError = null;
-      downloadExecutorService.execute(currentTask);
+      downloadExecutorService.execute(Assertions.checkNotNull(currentTask));
     }
 
     private void finish() {

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

@@ -172,7 +172,7 @@ public final class CacheUtil {
       @Nullable CacheKeyFactory cacheKeyFactory,
       CacheDataSource dataSource,
       byte[] buffer,
-      PriorityTaskManager priorityTaskManager,
+      @Nullable PriorityTaskManager priorityTaskManager,
       int priority,
       @Nullable ProgressListener progressListener,
       @Nullable AtomicBoolean isCanceled,
@@ -268,11 +268,11 @@ public final class CacheUtil {
       long length,
       DataSource dataSource,
       byte[] buffer,
-      PriorityTaskManager priorityTaskManager,
+      @Nullable PriorityTaskManager priorityTaskManager,
       int priority,
       @Nullable ProgressNotifier progressNotifier,
       boolean isLastBlock,
-      AtomicBoolean isCanceled)
+      @Nullable AtomicBoolean isCanceled)
       throws IOException, InterruptedException {
     long positionOffset = absoluteStreamPosition - dataSpec.absoluteStreamPosition;
     long initialPositionOffset = positionOffset;
@@ -392,7 +392,7 @@ public final class CacheUtil {
         .buildCacheKey(dataSpec);
   }
 
-  private static void throwExceptionIfInterruptedOrCancelled(AtomicBoolean isCanceled)
+  private static void throwExceptionIfInterruptedOrCancelled(@Nullable AtomicBoolean isCanceled)
       throws InterruptedException {
     if (Thread.interrupted() || (isCanceled != null && isCanceled.get())) {
       throw new InterruptedException();

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

@@ -17,13 +17,10 @@ package com.google.android.exoplayer2.upstream.cache;
 
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.upstream.cache.Cache.CacheException;
-import java.util.Comparator;
 import java.util.TreeSet;
 
-/**
+/** Evicts least recently used cache files first. */
- * Evicts least recently used cache files first.
+public final class LeastRecentlyUsedCacheEvictor implements CacheEvictor {
- */
-public final class LeastRecentlyUsedCacheEvictor implements CacheEvictor, Comparator<CacheSpan> {
 
   private final long maxBytes;
   private final TreeSet<CacheSpan> leastRecentlyUsed;
@@ -32,7 +29,7 @@ public final class LeastRecentlyUsedCacheEvictor implements CacheEvictor, Compar
 
   public LeastRecentlyUsedCacheEvictor(long maxBytes) {
     this.maxBytes = maxBytes;
-    this.leastRecentlyUsed = new TreeSet<>(this);
+    this.leastRecentlyUsed = new TreeSet<>(LeastRecentlyUsedCacheEvictor::compare);
   }
 
   @Override
@@ -71,16 +68,6 @@ public final class LeastRecentlyUsedCacheEvictor implements CacheEvictor, Compar
     onSpanAdded(cache, newSpan);
   }
 
-  @Override
-  public int compare(CacheSpan lhs, CacheSpan rhs) {
-    long lastTouchTimestampDelta = lhs.lastTouchTimestamp - rhs.lastTouchTimestamp;
-    if (lastTouchTimestampDelta == 0) {
-      // Use the standard compareTo method as a tie-break.
-      return lhs.compareTo(rhs);
-    }
-    return lhs.lastTouchTimestamp < rhs.lastTouchTimestamp ? -1 : 1;
-  }
-
   private void evictCache(Cache cache, long requiredSpace) {
     while (currentSize + requiredSpace > maxBytes && !leastRecentlyUsed.isEmpty()) {
       try {
@@ -91,4 +78,12 @@ public final class LeastRecentlyUsedCacheEvictor implements CacheEvictor, Compar
     }
   }
 
+  private static int compare(CacheSpan lhs, CacheSpan rhs) {
+    long lastTouchTimestampDelta = lhs.lastTouchTimestamp - rhs.lastTouchTimestamp;
+    if (lastTouchTimestampDelta == 0) {
+      // Use the standard compareTo method as a tie-break.
+      return lhs.compareTo(rhs);
+    }
+    return lhs.lastTouchTimestamp < rhs.lastTouchTimestamp ? -1 : 1;
+  }
 }

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

@@ -116,10 +116,11 @@ import java.util.regex.Pattern;
       File file, long length, long lastTouchTimestamp, CachedContentIndex index) {
     String name = file.getName();
     if (!name.endsWith(SUFFIX)) {
-      file = upgradeFile(file, index);
+      @Nullable File upgradedFile = upgradeFile(file, index);
-      if (file == null) {
+      if (upgradedFile == null) {
         return null;
       }
+      file = upgradedFile;
       name = file.getName();
     }
 
@@ -174,8 +175,12 @@ import java.util.regex.Pattern;
       key = matcher.group(1); // Keys were not escaped in version 1.
     }
 
-    File newCacheFile = getCacheFile(file.getParentFile(), index.assignIdForKey(key),
+    File newCacheFile =
-        Long.parseLong(matcher.group(2)), Long.parseLong(matcher.group(3)));
+        getCacheFile(
+            Assertions.checkStateNotNull(file.getParentFile()),
+            index.assignIdForKey(key),
+            Long.parseLong(matcher.group(2)),
+            Long.parseLong(matcher.group(3)));
     if (!file.renameTo(newCacheFile)) {
       return null;
     }

library/core/src/main/java/com/google/android/exoplayer2/video/VideoRendererEventListener.java

@@ -15,6 +15,8 @@
  */
 package com.google.android.exoplayer2.video;
 
+import static com.google.android.exoplayer2.util.Util.castNonNull;
+
 import android.os.Handler;
 import android.os.SystemClock;
 import android.view.Surface;
@@ -126,33 +128,34 @@ public interface VideoRendererEventListener {
 
     /** Invokes {@link VideoRendererEventListener#onVideoEnabled(DecoderCounters)}. */
     public void enabled(DecoderCounters decoderCounters) {
-      if (listener != null) {
+      if (handler != null) {
-        handler.post(() -> listener.onVideoEnabled(decoderCounters));
+        handler.post(() -> castNonNull(listener).onVideoEnabled(decoderCounters));
       }
     }
 
     /** Invokes {@link VideoRendererEventListener#onVideoDecoderInitialized(String, long, long)}. */
     public void decoderInitialized(
         String decoderName, long initializedTimestampMs, long initializationDurationMs) {
-      if (listener != null) {
+      if (handler != null) {
         handler.post(
             () ->
-                listener.onVideoDecoderInitialized(
+                castNonNull(listener)
+                    .onVideoDecoderInitialized(
                         decoderName, initializedTimestampMs, initializationDurationMs));
       }
     }
 
     /** Invokes {@link VideoRendererEventListener#onVideoInputFormatChanged(Format)}. */
     public void inputFormatChanged(Format format) {
-      if (listener != null) {
+      if (handler != null) {
-        handler.post(() -> listener.onVideoInputFormatChanged(format));
+        handler.post(() -> castNonNull(listener).onVideoInputFormatChanged(format));
       }
     }
 
     /** Invokes {@link VideoRendererEventListener#onDroppedFrames(int, long)}. */
     public void droppedFrames(int droppedFrameCount, long elapsedMs) {
-      if (listener != null) {
+      if (handler != null) {
-        handler.post(() -> listener.onDroppedFrames(droppedFrameCount, elapsedMs));
+        handler.post(() -> castNonNull(listener).onDroppedFrames(droppedFrameCount, elapsedMs));
       }
     }
 
@@ -162,29 +165,30 @@ public interface VideoRendererEventListener {
         int height,
         final int unappliedRotationDegrees,
         final float pixelWidthHeightRatio) {
-      if (listener != null) {
+      if (handler != null) {
         handler.post(
             () ->
-                listener.onVideoSizeChanged(
+                castNonNull(listener)
+                    .onVideoSizeChanged(
                         width, height, unappliedRotationDegrees, pixelWidthHeightRatio));
       }
     }
 
     /** Invokes {@link VideoRendererEventListener#onRenderedFirstFrame(Surface)}. */
     public void renderedFirstFrame(@Nullable Surface surface) {
-      if (listener != null) {
+      if (handler != null) {
-        handler.post(() -> listener.onRenderedFirstFrame(surface));
+        handler.post(() -> castNonNull(listener).onRenderedFirstFrame(surface));
       }
     }
 
     /** Invokes {@link VideoRendererEventListener#onVideoDisabled(DecoderCounters)}. */
     public void disabled(DecoderCounters counters) {
       counters.ensureUpdated();
-      if (listener != null) {
+      if (handler != null) {
         handler.post(
             () -> {
               counters.ensureUpdated();
-              listener.onVideoDisabled(counters);
+              castNonNull(listener).onVideoDisabled(counters);
             });
       }
     }