Add structure to ExoPlaybackException.

- Add a top level failure type (source/renderer/unexpected),
  and convenience methods for retrieving the underlying cause
  without needing to cast.
- Also add renderer index in the case of renderer failures.
- setIndex/getIndex is a little . . . unclean, but alternatives
  involve either having the top line of the stack trace be a
  non-interesting line, or loads of try/catch blocks in
  ExoPlayerImplInternal.

Issue: #777
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=114763073

library/src/main/java/com/google/android/exoplayer/ExoPlaybackException.java

@@ -15,37 +15,85 @@
  */
 package com.google.android.exoplayer;
 
+import com.google.android.exoplayer.util.Assertions;
+
+import java.io.IOException;
+
 /**
  * Thrown when a non-recoverable playback failure occurs.
- * <p>
- * Where possible, the cause returned by {@link #getCause()} will indicate the reason for failure.
  */
 public final class ExoPlaybackException extends Exception {
 
   /**
-   * True if the cause (i.e. the {@link Throwable} returned by {@link #getCause()}) was only caught
+   * The error occurred loading data from a {@link SampleSource}.
-   * by a fail-safe at the top level of the player. False otherwise.
+   * <p>
+   * Call {@link #getSourceException()} to retrieve the underlying cause.
    */
-  public final boolean caughtAtTopLevel;
+  public static final int TYPE_SOURCE = 0;
+  /**
+   * The error occurred in a {@link TrackRenderer}.
+   * <p>
+   * Call {@link #getRendererException()} to retrieve the underlying cause.
+   */
+  public static final int TYPE_RENDERER = 1;
+  /**
+   * The error was an unexpected {@link RuntimeException}.
+   * <p>
+   * Call {@link #getUnexpectedException()} to retrieve the underlying cause.
+   */
+  public static final int TYPE_UNEXPECTED = 2;
 
-  public ExoPlaybackException(String message) {
+  /**
-    super(message);
+   * The type of the playback failure. One of {@link #TYPE_SOURCE}, {@link #TYPE_RENDERER} and
-    caughtAtTopLevel = false;
+   * {@link #TYPE_UNEXPECTED}.
+   */
+  public final int type;
+
+  /**
+   * If {@link #type} is {@link #TYPE_RENDERER}, this is the index of the renderer.
+   */
+  public final int rendererIndex;
+
+  public static ExoPlaybackException createForRenderer(Exception cause, int rendererIndex) {
+    return new ExoPlaybackException(TYPE_RENDERER, null, cause, rendererIndex);
   }
 
-  public ExoPlaybackException(Throwable cause) {
+  public static ExoPlaybackException createForSource(IOException cause) {
-    super(cause);
+    return new ExoPlaybackException(TYPE_SOURCE, null, cause, -1);
-    caughtAtTopLevel = false;
   }
 
-  public ExoPlaybackException(String message, Throwable cause) {
+  /* package */ static ExoPlaybackException createForUnexpected(RuntimeException cause) {
+    return new ExoPlaybackException(TYPE_UNEXPECTED, null, cause, -1);
+  }
+
+  private ExoPlaybackException(int type, String message, Throwable cause, int rendererIndex) {
     super(message, cause);
-    caughtAtTopLevel = false;
+    this.type = type;
+    this.rendererIndex = rendererIndex;
   }
 
-  /* package */ ExoPlaybackException(Throwable cause, boolean caughtAtTopLevel) {
+  /**
-    super(cause);
+   * Retrieves the underlying error when {@link #type} is {@link #TYPE_SOURCE}.
-    this.caughtAtTopLevel = caughtAtTopLevel;
+   */
+  public IOException getSourceException() {
+    Assertions.checkState(type == TYPE_SOURCE);
+    return (IOException) getCause();
+  }
+
+  /**
+   * Retrieves the underlying error when {@link #type} is {@link #TYPE_RENDERER}.
+   */
+  public Exception getRendererException() {
+    Assertions.checkState(type == TYPE_RENDERER);
+    return (Exception) getCause();
+  }
+
+  /**
+   * Retrieves the underlying error when {@link #type} is {@link #TYPE_UNEXPECTED}.
+   */
+  public RuntimeException getUnexpectedException() {
+    Assertions.checkState(type == TYPE_UNEXPECTED);
+    return (RuntimeException) getCause();
   }
 
 }

library/src/main/java/com/google/android/exoplayer/ExoPlayerImplInternal.java

@@ -42,7 +42,6 @@ import java.util.concurrent.atomic.AtomicInteger;
  */
 // TODO[REFACTOR]: Make sure renderer errors that will prevent prepare from being called again are
 // always propagated properly.
-// TODO[REFACTOR]: Distinguish source and renderer errors in ExoPlaybackException.
 /* package */ final class ExoPlayerImplInternal implements Handler.Callback {
 
   private static final String TAG = "ExoPlayerImplInternal";
@@ -113,6 +112,7 @@ import java.util.concurrent.atomic.AtomicInteger;
     MediaClock rendererMediaClock = null;
     TrackRenderer rendererMediaClockSource = null;
     for (int i = 0; i < renderers.length; i++) {
+      renderers[i].setIndex(i);
       MediaClock mediaClock = renderers[i].getMediaClock();
       if (mediaClock != null) {
         Assertions.checkState(rendererMediaClock == null);
@@ -266,12 +266,13 @@ import java.util.concurrent.atomic.AtomicInteger;
       return true;
     } catch (IOException e) {
       Log.e(TAG, "Source track renderer error.", e);
-      eventHandler.obtainMessage(MSG_ERROR, new ExoPlaybackException(e)).sendToTarget();
+      eventHandler.obtainMessage(MSG_ERROR, ExoPlaybackException.createForSource(e)).sendToTarget();
       stopInternal();
       return true;
     } catch (RuntimeException e) {
       Log.e(TAG, "Internal runtime error.", e);
-      eventHandler.obtainMessage(MSG_ERROR, new ExoPlaybackException(e, true)).sendToTarget();
+      eventHandler.obtainMessage(MSG_ERROR, ExoPlaybackException.createForUnexpected(e))
+          .sendToTarget();
       stopInternal();
       return true;
     }

library/src/main/java/com/google/android/exoplayer/MediaCodecAudioTrackRenderer.java

@@ -353,7 +353,7 @@ public class MediaCodecAudioTrackRenderer extends MediaCodecTrackRenderer implem
         audioTrackHasData = false;
       } catch (AudioTrack.InitializationException e) {
         notifyAudioTrackInitializationError(e);
-        throw new ExoPlaybackException(e);
+        throw ExoPlaybackException.createForRenderer(e, getIndex());
       }
       if (getState() == TrackRenderer.STATE_STARTED) {
         audioTrack.play();
@@ -377,7 +377,7 @@ public class MediaCodecAudioTrackRenderer extends MediaCodecTrackRenderer implem
       lastFeedElapsedRealtimeMs = SystemClock.elapsedRealtime();
     } catch (AudioTrack.WriteException e) {
       notifyAudioTrackWriteError(e);
-      throw new ExoPlaybackException(e);
+      throw ExoPlaybackException.createForRenderer(e, getIndex());
     }
 
     // If we are out of sync, allow currentPositionUs to jump backwards.

library/src/main/java/com/google/android/exoplayer/MediaCodecTrackRenderer.java

@@ -273,7 +273,7 @@ public abstract class MediaCodecTrackRenderer extends SampleSourceTrackRenderer
       return decoderInfo != null && decoderInfo.adaptive ? TrackRenderer.ADAPTIVE_SEAMLESS
           : TrackRenderer.ADAPTIVE_NOT_SEAMLESS;
     } catch (DecoderQueryException e) {
-      throw new ExoPlaybackException(e);
+      throw ExoPlaybackException.createForRenderer(e, getIndex());
     }
   }
 
@@ -282,7 +282,7 @@ public abstract class MediaCodecTrackRenderer extends SampleSourceTrackRenderer
     try {
       return supportsFormat(mediaCodecSelector, format);
     } catch (DecoderQueryException e) {
-      throw new ExoPlaybackException(e);
+      throw ExoPlaybackException.createForRenderer(e, getIndex());
     }
   }
 
@@ -335,7 +335,8 @@ public abstract class MediaCodecTrackRenderer extends SampleSourceTrackRenderer
     boolean requiresSecureDecoder = false;
     if (drmInitData != null) {
       if (drmSessionManager == null) {
-        throw new ExoPlaybackException("Media requires a DrmSessionManager");
+        throw ExoPlaybackException.createForRenderer(
+            new IllegalStateException("Media requires a DrmSessionManager"), getIndex());
       }
       if (!openedDrmSession) {
         drmSessionManager.open(drmInitData);
@@ -343,7 +344,7 @@ public abstract class MediaCodecTrackRenderer extends SampleSourceTrackRenderer
       }
       int drmSessionState = drmSessionManager.getState();
       if (drmSessionState == DrmSessionManager.STATE_ERROR) {
-        throw new ExoPlaybackException(drmSessionManager.getError());
+        throw ExoPlaybackException.createForRenderer(drmSessionManager.getError(), getIndex());
       } else if (drmSessionState == DrmSessionManager.STATE_OPENED
           || drmSessionState == DrmSessionManager.STATE_OPENED_WITH_KEYS) {
         mediaCrypto = drmSessionManager.getMediaCrypto();
@@ -403,7 +404,7 @@ public abstract class MediaCodecTrackRenderer extends SampleSourceTrackRenderer
   private void notifyAndThrowDecoderInitError(DecoderInitializationException e)
       throws ExoPlaybackException {
     notifyDecoderInitializationError(e);
-    throw new ExoPlaybackException(e);
+    throw ExoPlaybackException.createForRenderer(e, getIndex());
   }
 
   protected boolean shouldInitCodec() {
@@ -636,7 +637,7 @@ public abstract class MediaCodecTrackRenderer extends SampleSourceTrackRenderer
         }
       } catch (CryptoException e) {
         notifyCryptoError(e);
-        throw new ExoPlaybackException(e);
+        throw ExoPlaybackException.createForRenderer(e, getIndex());
       }
       return false;
     }
@@ -678,7 +679,7 @@ public abstract class MediaCodecTrackRenderer extends SampleSourceTrackRenderer
       codecReconfigurationState = RECONFIGURATION_STATE_NONE;
     } catch (CryptoException e) {
       notifyCryptoError(e);
-      throw new ExoPlaybackException(e);
+      throw ExoPlaybackException.createForRenderer(e, getIndex());
     }
     return true;
   }
@@ -705,7 +706,7 @@ public abstract class MediaCodecTrackRenderer extends SampleSourceTrackRenderer
     }
     int drmManagerState = drmSessionManager.getState();
     if (drmManagerState == DrmSessionManager.STATE_ERROR) {
-      throw new ExoPlaybackException(drmSessionManager.getError());
+      throw ExoPlaybackException.createForRenderer(drmSessionManager.getError(), getIndex());
     }
     if (drmManagerState != DrmSessionManager.STATE_OPENED_WITH_KEYS &&
         (sampleEncrypted || !playClearSamplesWithoutKeys)) {

library/src/main/java/com/google/android/exoplayer/TrackRenderer.java

@@ -88,8 +88,27 @@ public abstract class TrackRenderer implements ExoPlayerComponent {
    */
   protected static final int STATE_STARTED = 2;
 
+  private int index;
   private int state;
 
+  /**
+   * Sets the index of this renderer within the player.
+   *
+   * @param index The renderer index.
+   */
+  /* package */ final void setIndex(int index) {
+    this.index = index;
+  }
+
+  /**
+   * Returns the index of the renderer within the player.
+   *
+   * @return The index of the renderer within the player.
+   */
+  protected final int getIndex() {
+    return index;
+  }
+
   /**
    * If the renderer advances its own playback position then this method returns a corresponding
    * {@link MediaClock}. If provided, the player will use the returned {@link MediaClock} as its

library/src/main/java/com/google/android/exoplayer/metadata/MetadataTrackRenderer.java

@@ -108,7 +108,7 @@ public final class MetadataTrackRenderer<T> extends SampleSourceTrackRenderer im
         try {
           pendingMetadata = metadataParser.parse(sampleHolder.data.array(), sampleHolder.size);
         } catch (IOException e) {
-          throw new ExoPlaybackException(e);
+          throw ExoPlaybackException.createForRenderer(e, getIndex());
         }
       } else if (result == TrackStream.END_OF_STREAM) {
         inputStreamEnded = true;

library/src/main/java/com/google/android/exoplayer/text/TextTrackRenderer.java

@@ -188,7 +188,7 @@ public final class TextTrackRenderer extends SampleSourceTrackRenderer implement
       try {
         nextSubtitle = parserHelper.getAndClearResult();
       } catch (IOException e) {
-        throw new ExoPlaybackException(e);
+        throw ExoPlaybackException.createForRenderer(e, getIndex());
       }
     }