From 5c0745cedff6a0c2f373ff63a787780dcf491607 Mon Sep 17 00:00:00 2001
From: Oliver Woodman <olly@google.com>
Date: Mon, 7 Sep 2015 13:59:55 +0100
Subject: [PATCH] Add some generally useful error propagation logic for HLS.

Issue #765
---
 .../android/exoplayer/hls/HlsChunkSource.java | 23 +++++++++++++++++++
 .../exoplayer/hls/HlsSampleSource.java        |  3 +++
 2 files changed, 26 insertions(+)

diff --git a/library/src/main/java/com/google/android/exoplayer/hls/HlsChunkSource.java b/library/src/main/java/com/google/android/exoplayer/hls/HlsChunkSource.java
index aa89804e9d..23659a5baf 100644
--- a/library/src/main/java/com/google/android/exoplayer/hls/HlsChunkSource.java
+++ b/library/src/main/java/com/google/android/exoplayer/hls/HlsChunkSource.java
@@ -138,6 +138,7 @@ public class HlsChunkSource {
   private byte[] scratchSpace;
   private boolean live;
   private long durationUs;
+  private IOException fatalError;
 
   private Uri encryptionKeyUri;
   private byte[] encryptionKey;
@@ -223,6 +224,18 @@ public class HlsChunkSource {
     return live ? C.UNKNOWN_TIME_US : durationUs;
   }
 
+  /**
+   * If the source is currently having difficulty providing chunks, then this method throws the
+   * underlying error. Otherwise does nothing.
+   *
+   * @throws IOException The underlying error.
+   */
+  public void maybeThrowError() throws IOException {
+    if (fatalError != null) {
+      throw fatalError;
+    }
+  }
+
   /**
    * Returns the next {@link Chunk} that should be loaded.
    *
@@ -262,9 +275,15 @@ public class HlsChunkSource {
         chunkMediaSequence = switchingVariantSpliced
             ? previousTsChunk.chunkIndex : previousTsChunk.chunkIndex + 1;
         if (chunkMediaSequence < mediaPlaylist.mediaSequence) {
+          // TODO: Decide what we want to do with: https://github.com/google/ExoPlayer/issues/765
+          // if (allowSkipAhead) {
           // If the chunk is no longer in the playlist. Skip ahead and start again.
           chunkMediaSequence = getLiveStartChunkMediaSequence(nextVariantIndex);
           liveDiscontinuity = true;
+          // } else {
+          //   fatalError = new BehindLiveWindowException();
+          //   return null;
+          // }
         }
       }
     } else {
@@ -414,6 +433,10 @@ public class HlsChunkSource {
     return false;
   }
 
+  public void reset() {
+    fatalError = null;
+  }
+
   private int getNextVariantIndex(TsChunk previousTsChunk, long playbackPositionUs) {
     clearStaleBlacklistedVariants();
     long bitrateEstimate = bandwidthMeter.getBitrateEstimate();
diff --git a/library/src/main/java/com/google/android/exoplayer/hls/HlsSampleSource.java b/library/src/main/java/com/google/android/exoplayer/hls/HlsSampleSource.java
index 1d30242465..e75d48fb0b 100644
--- a/library/src/main/java/com/google/android/exoplayer/hls/HlsSampleSource.java
+++ b/library/src/main/java/com/google/android/exoplayer/hls/HlsSampleSource.java
@@ -206,6 +206,7 @@ public final class HlsSampleSource implements SampleSource, SampleSourceReader,
     enabledTrackCount--;
     trackEnabledStates[track] = false;
     if (enabledTrackCount == 0) {
+      chunkSource.reset();
       downstreamPositionUs = Long.MIN_VALUE;
       if (loadControlRegistered) {
         loadControl.unregister(this);
@@ -317,6 +318,8 @@ public final class HlsSampleSource implements SampleSource, SampleSourceReader,
   public void maybeThrowError() throws IOException {
     if (currentLoadableException != null && currentLoadableExceptionCount > minLoadableRetryCount) {
       throw currentLoadableException;
+    } else if (currentLoadable == null) {
+      chunkSource.maybeThrowError();
     }
   }