Allow configuration of the Loader retry delay

Issue:#3370

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=201996109

RELEASENOTES.md

@@ -13,6 +13,9 @@
   ([#3972](https://github.com/google/ExoPlayer/issues/3972)).
 * Pass `BandwidthMeter` to `TrackSelection.Factory` which can be used to obtain
   bandwidth estimates in the future. Always null at the moment.
+* Error handling:
+  * Allow configuration of the Loader retry delay
+    ([#3370](https://github.com/google/ExoPlayer/issues/3370)).
 * HLS:
   * Allow injection of custom playlist trackers.
   * Pass HTTP response headers to `HlsExtractorFactory.createExtractor`.

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

@@ -38,6 +38,7 @@ import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
 import com.google.android.exoplayer2.upstream.Loader;
+import com.google.android.exoplayer2.upstream.Loader.LoadErrorAction;
 import com.google.android.exoplayer2.upstream.Loader.Loadable;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.ConditionVariable;
@@ -532,7 +533,7 @@ import java.util.Arrays;
   }
 
   @Override
-  public @Loader.RetryAction int onLoadError(
+  public LoadErrorAction onLoadError(
       ExtractingLoadable loadable, long elapsedRealtimeMs, long loadDurationMs, IOException error) {
     boolean isErrorFatal = isLoadableExceptionFatal(error);
     eventDispatcher.loadError(

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

@@ -25,6 +25,7 @@ import com.google.android.exoplayer2.trackselection.TrackSelection;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
 import com.google.android.exoplayer2.upstream.Loader;
+import com.google.android.exoplayer2.upstream.Loader.LoadErrorAction;
 import com.google.android.exoplayer2.upstream.Loader.Loadable;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
@@ -228,7 +229,7 @@ import java.util.Arrays;
   }
 
   @Override
-  public @Loader.RetryAction int onLoadError(
+  public LoadErrorAction onLoadError(
       SourceLoadable loadable, long elapsedRealtimeMs, long loadDurationMs, IOException error) {
     errorCount++;
     boolean cancel = treatLoadErrorsAsEndOfStream && errorCount >= minLoadableRetryCount;

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

@@ -28,6 +28,7 @@ import com.google.android.exoplayer2.source.SampleStream;
 import com.google.android.exoplayer2.source.SequenceableLoader;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.Loader;
+import com.google.android.exoplayer2.upstream.Loader.LoadErrorAction;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import java.io.IOException;
@@ -409,7 +410,7 @@ public class ChunkSampleStream<T extends ChunkSource> implements SampleStream, S
   }
 
   @Override
-  public @Loader.RetryAction int onLoadError(
+  public LoadErrorAction onLoadError(
       Chunk loadable, long elapsedRealtimeMs, long loadDurationMs, IOException error) {
     long bytesLoaded = loadable.bytesLoaded();
     boolean isMediaChunk = isMediaChunk(loadable);

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

@@ -23,6 +23,7 @@ import android.os.SystemClock;
 import android.support.annotation.IntDef;
 import android.support.annotation.Nullable;
 import android.util.Log;
+import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.TraceUtil;
 import com.google.android.exoplayer2.util.Util;
@@ -110,12 +111,12 @@ public final class Loader implements LoaderErrorThrower {
      * @param elapsedRealtimeMs {@link SystemClock#elapsedRealtime} when the error occurred.
      * @param loadDurationMs The duration of the load up to the point at which the error occurred.
      * @param error The load error.
-     * @return The desired retry action. One of {@link Loader#RETRY}, {@link
+     * @return The desired error handling action. One of {@link Loader#RETRY}, {@link
-     *     Loader#RETRY_RESET_ERROR_COUNT}, {@link Loader#DONT_RETRY} and {@link
+     *     Loader#RETRY_RESET_ERROR_COUNT}, {@link Loader#DONT_RETRY}, {@link
-     *     Loader#DONT_RETRY_FATAL}.
+     *     Loader#DONT_RETRY_FATAL} or a retry action created by {@link #createRetryAction}.
      */
-    @RetryAction
+    LoadErrorAction onLoadError(
-    int onLoadError(T loadable, long elapsedRealtimeMs, long loadDurationMs, IOException error);
+        T loadable, long elapsedRealtimeMs, long loadDurationMs, IOException error);
   }
 
   /**
@@ -130,15 +131,51 @@ public final class Loader implements LoaderErrorThrower {
 
   }
 
-  /** Actions that can be taken in response to a load error. */
+  /** Types of action that can be taken in response to a load error. */
   @Retention(RetentionPolicy.SOURCE)
-  @IntDef({RETRY, RETRY_RESET_ERROR_COUNT, DONT_RETRY, DONT_RETRY_FATAL})
+  @IntDef({
-  public @interface RetryAction {}
+    ACTION_TYPE_RETRY,
+    ACTION_TYPE_RETRY_AND_RESET_ERROR_COUNT,
+    ACTION_TYPE_DONT_RETRY,
+    ACTION_TYPE_DONT_RETRY_FATAL
+  })
+  private @interface RetryActionType {}
 
-  public static final int RETRY = 0;
+  private static final int ACTION_TYPE_RETRY = 0;
-  public static final int RETRY_RESET_ERROR_COUNT = 1;
+  private static final int ACTION_TYPE_RETRY_AND_RESET_ERROR_COUNT = 1;
-  public static final int DONT_RETRY = 2;
+  private static final int ACTION_TYPE_DONT_RETRY = 2;
-  public static final int DONT_RETRY_FATAL = 3;
+  private static final int ACTION_TYPE_DONT_RETRY_FATAL = 3;
+
+  /** Retries the load using the default delay. */
+  public static final LoadErrorAction RETRY =
+      createRetryAction(/* resetErrorCount= */ false, C.TIME_UNSET);
+  /** Retries the load using the default delay and resets the error count. */
+  public static final LoadErrorAction RETRY_RESET_ERROR_COUNT =
+      createRetryAction(/* resetErrorCount= */ true, C.TIME_UNSET);
+  /** Discards the failed loading task and ignores any errors that have occurred. */
+  public static final LoadErrorAction DONT_RETRY =
+      new LoadErrorAction(ACTION_TYPE_DONT_RETRY, C.TIME_UNSET);
+  /**
+   * Discards the failed load. The next call to {@link #maybeThrowError()} will throw the last load
+   * error.
+   */
+  public static final LoadErrorAction DONT_RETRY_FATAL =
+      new LoadErrorAction(ACTION_TYPE_DONT_RETRY_FATAL, C.TIME_UNSET);
+
+  /**
+   * Action that can be taken in response to {@link Callback#onLoadError(Loadable, long, long,
+   * IOException)}.
+   */
+  public static final class LoadErrorAction {
+
+    private final @RetryActionType int type;
+    private final long retryDelayMillis;
+
+    private LoadErrorAction(@RetryActionType int type, long retryDelayMillis) {
+      this.type = type;
+      this.retryDelayMillis = retryDelayMillis;
+    }
+  }
 
   private final ExecutorService downloadExecutorService;
 
@@ -152,6 +189,19 @@ public final class Loader implements LoaderErrorThrower {
     this.downloadExecutorService = Util.newSingleThreadExecutor(threadName);
   }
 
+  /**
+   * Creates a {@link LoadErrorAction} for retrying with the given parameters.
+   *
+   * @param resetErrorCount Whether the previous error count should be set to zero.
+   * @param retryDelayMillis The number of milliseconds to wait before retrying.
+   * @return A {@link LoadErrorAction} for retrying with the given parameters.
+   */
+  public static LoadErrorAction createRetryAction(boolean resetErrorCount, long retryDelayMillis) {
+    return new LoadErrorAction(
+        resetErrorCount ? ACTION_TYPE_RETRY_AND_RESET_ERROR_COUNT : ACTION_TYPE_RETRY,
+        retryDelayMillis);
+  }
+
   /**
    * Starts loading a {@link Loadable}.
    *
@@ -395,12 +445,16 @@ public final class Loader implements LoaderErrorThrower {
           break;
         case MSG_IO_EXCEPTION:
           currentError = (IOException) msg.obj;
-          int retryAction = callback.onLoadError(loadable, nowMs, durationMs, currentError);
+          LoadErrorAction action = callback.onLoadError(loadable, nowMs, durationMs, currentError);
-          if (retryAction == DONT_RETRY_FATAL) {
+          if (action.type == ACTION_TYPE_DONT_RETRY_FATAL) {
             fatalError = currentError;
-          } else if (retryAction != DONT_RETRY) {
+          } else if (action.type != ACTION_TYPE_DONT_RETRY) {
-            errorCount = retryAction == RETRY_RESET_ERROR_COUNT ? 1 : errorCount + 1;
+            errorCount =
-            start(getRetryDelayMillis());
+                action.type == ACTION_TYPE_RETRY_AND_RESET_ERROR_COUNT ? 1 : errorCount + 1;
+            start(
+                action.retryDelayMillis != C.TIME_UNSET
+                    ? action.retryDelayMillis
+                    : getRetryDelayMillis());
           }
           break;
         default:

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

@@ -43,6 +43,7 @@ import com.google.android.exoplayer2.source.dash.manifest.UtcTimingElement;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.Loader;
+import com.google.android.exoplayer2.upstream.Loader.LoadErrorAction;
 import com.google.android.exoplayer2.upstream.LoaderErrorThrower;
 import com.google.android.exoplayer2.upstream.ParsingLoadable;
 import com.google.android.exoplayer2.util.Assertions;
@@ -716,8 +717,7 @@ public final class DashMediaSource extends BaseMediaSource {
     }
   }
 
-  /* package */ @Loader.RetryAction
+  /* package */ LoadErrorAction onManifestLoadError(
-  int onManifestLoadError(
       ParsingLoadable<DashManifest> loadable,
       long elapsedRealtimeMs,
       long loadDurationMs,
@@ -745,8 +745,7 @@ public final class DashMediaSource extends BaseMediaSource {
     onUtcTimestampResolved(loadable.getResult() - elapsedRealtimeMs);
   }
 
-  /* package */ @Loader.RetryAction
+  /* package */ LoadErrorAction onUtcTimestampLoadError(
-  int onUtcTimestampLoadError(
       ParsingLoadable<Long> loadable,
       long elapsedRealtimeMs,
       long loadDurationMs,
@@ -1172,7 +1171,7 @@ public final class DashMediaSource extends BaseMediaSource {
     }
 
     @Override
-    public @Loader.RetryAction int onLoadError(
+    public LoadErrorAction onLoadError(
         ParsingLoadable<DashManifest> loadable,
         long elapsedRealtimeMs,
         long loadDurationMs,
@@ -1197,7 +1196,7 @@ public final class DashMediaSource extends BaseMediaSource {
     }
 
     @Override
-    public @Loader.RetryAction int onLoadError(
+    public LoadErrorAction onLoadError(
         ParsingLoadable<Long> loadable,
         long elapsedRealtimeMs,
         long loadDurationMs,

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

@@ -40,6 +40,7 @@ import com.google.android.exoplayer2.source.hls.playlist.HlsMasterPlaylist.HlsUr
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.Loader;
+import com.google.android.exoplayer2.upstream.Loader.LoadErrorAction;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
@@ -602,7 +603,7 @@ import java.util.Arrays;
   }
 
   @Override
-  public @Loader.RetryAction int onLoadError(
+  public LoadErrorAction onLoadError(
       Chunk loadable, long elapsedRealtimeMs, long loadDurationMs, IOException error) {
     long bytesLoaded = loadable.bytesLoaded();
     boolean isMediaChunk = isMediaChunk(loadable);

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

@@ -27,6 +27,7 @@ import com.google.android.exoplayer2.source.hls.playlist.HlsMasterPlaylist.HlsUr
 import com.google.android.exoplayer2.source.hls.playlist.HlsMediaPlaylist.Segment;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.Loader;
+import com.google.android.exoplayer2.upstream.Loader.LoadErrorAction;
 import com.google.android.exoplayer2.upstream.ParsingLoadable;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.UriUtil;
@@ -229,7 +230,7 @@ public final class DefaultHlsPlaylistTracker
   }
 
   @Override
-  public @Loader.RetryAction int onLoadError(
+  public LoadErrorAction onLoadError(
       ParsingLoadable<HlsPlaylist> loadable,
       long elapsedRealtimeMs,
       long loadDurationMs,
@@ -485,7 +486,7 @@ public final class DefaultHlsPlaylistTracker
     }
 
     @Override
-    public @Loader.RetryAction int onLoadError(
+    public LoadErrorAction onLoadError(
         ParsingLoadable<HlsPlaylist> loadable,
         long elapsedRealtimeMs,
         long loadDurationMs,

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

@@ -41,6 +41,7 @@ import com.google.android.exoplayer2.source.smoothstreaming.manifest.SsUtil;
 import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.Loader;
+import com.google.android.exoplayer2.upstream.Loader.LoadErrorAction;
 import com.google.android.exoplayer2.upstream.LoaderErrorThrower;
 import com.google.android.exoplayer2.upstream.ParsingLoadable;
 import com.google.android.exoplayer2.util.Assertions;
@@ -540,7 +541,7 @@ public final class SsMediaSource extends BaseMediaSource
   }
 
   @Override
-  public @Loader.RetryAction int onLoadError(
+  public LoadErrorAction onLoadError(
       ParsingLoadable<SsManifest> loadable,
       long elapsedRealtimeMs,
       long loadDurationMs,