Track input/output cleanup.

- Remove special DefaultTrackOutput.sampleData method, and have
  SingleSampleMediaChunk use the regular one instead.
- Make DummyTrackOutput behave correctly is allowEndOfInput is
  false.
- Simplify progress tracking in ExtractorSampleSource.
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=117808659

library/src/main/java/com/google/android/exoplayer/chunk/SingleSampleMediaChunk.java

@@ -18,6 +18,8 @@ package com.google.android.exoplayer.chunk;
 import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.Format;
 import com.google.android.exoplayer.drm.DrmInitData;
+import com.google.android.exoplayer.extractor.DefaultExtractorInput;
+import com.google.android.exoplayer.extractor.ExtractorInput;
 import com.google.android.exoplayer.upstream.DataSource;
 import com.google.android.exoplayer.upstream.DataSpec;
 import com.google.android.exoplayer.util.Util;
@@ -90,12 +92,16 @@ public final class SingleSampleMediaChunk extends BaseMediaChunk {
     DataSpec loadDataSpec = Util.getRemainderDataSpec(dataSpec, bytesLoaded);
     try {
       // Create and open the input.
-      dataSource.open(loadDataSpec);
+      long length = dataSource.open(loadDataSpec);
+      if (length != C.LENGTH_UNBOUNDED) {
+        length += bytesLoaded;
+      }
+      ExtractorInput extractorInput = new DefaultExtractorInput(dataSource, bytesLoaded, length);
       // Load the sample data.
       int result = 0;
       while (result != C.RESULT_END_OF_INPUT) {
         bytesLoaded += result;
-        result = getOutput().sampleData(dataSource, Integer.MAX_VALUE, true);
+        result = getOutput().sampleData(extractorInput, Integer.MAX_VALUE, true);
       }
       int sampleSize = bytesLoaded;
       getOutput().sampleMetadata(startTimeUs, C.SAMPLE_FLAG_SYNC, sampleSize, 0, null);

library/src/main/java/com/google/android/exoplayer/extractor/DefaultTrackOutput.java

@@ -15,14 +15,11 @@
  */
 package com.google.android.exoplayer.extractor;
 
-import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.Format;
 import com.google.android.exoplayer.SampleHolder;
 import com.google.android.exoplayer.upstream.Allocator;
-import com.google.android.exoplayer.upstream.DataSource;
 import com.google.android.exoplayer.util.ParsableByteArray;
 
-import java.io.EOFException;
 import java.io.IOException;
 
 /**
@@ -225,24 +222,6 @@ public class DefaultTrackOutput implements TrackOutput {
     return true;
   }
 
-  // Called by the loading thread.
-
-  /**
-   * Invoked to write sample data to the output.
-   *
-   * @param dataSource A {@link DataSource} from which to read the sample data.
-   * @param length The maximum length to read from the input.
-   * @param allowEndOfInput True if encountering the end of the input having read no data is
-   *     allowed, and should result in {@link C#RESULT_END_OF_INPUT} being returned. False if it
-   *     should be considered an error, causing an {@link EOFException} to be thrown.
-   * @return The number of bytes appended.
-   * @throws IOException If an error occurred reading from the input.
-   */
-  public int sampleData(DataSource dataSource, int length, boolean allowEndOfInput)
-      throws IOException {
-    return rollingBuffer.appendData(dataSource, length, allowEndOfInput);
-  }
-
   // TrackOutput implementation. Called by the loading thread.
 
   @Override

library/src/main/java/com/google/android/exoplayer/extractor/DummyTrackOutput.java

@@ -15,9 +15,11 @@
  */
 package com.google.android.exoplayer.extractor;
 
+import com.google.android.exoplayer.C;
 import com.google.android.exoplayer.Format;
 import com.google.android.exoplayer.util.ParsableByteArray;
 
+import java.io.EOFException;
 import java.io.IOException;
 
 /**
@@ -33,7 +35,14 @@ public final class DummyTrackOutput implements TrackOutput {
   @Override
   public int sampleData(ExtractorInput input, int length, boolean allowEndOfInput)
       throws IOException, InterruptedException {
-    return input.skip(length);
+    int bytesSkipped = input.skip(length);
+    if (bytesSkipped == C.RESULT_END_OF_INPUT) {
+      if (allowEndOfInput) {
+        return C.RESULT_END_OF_INPUT;
+      }
+      throw new EOFException();
+    }
+    return bytesSkipped;
   }
 
   @Override

library/src/main/java/com/google/android/exoplayer/extractor/ExtractorSampleSource.java

@@ -219,14 +219,11 @@ public final class ExtractorSampleSource implements SampleSource, ExtractorOutpu
   private Loader loader;
   private ExtractingLoadable loadable;
   private IOException currentLoadableException;
-  // TODO: Set this back to 0 in the correct place (some place indicative of making progress).
   private int currentLoadableExceptionCount;
   private long currentLoadableExceptionTimestamp;
+  private boolean currentLoadableExtractedSamples;
   private boolean loadingFinished;
 
-  private int extractedSampleCount;
-  private int extractedSampleCountAtStartOfLoad;
-
   /**
    * @param uri The {@link Uri} of the media stream.
    * @param dataSource A data source to read the media stream.
@@ -550,7 +547,7 @@ public final class ExtractorSampleSource implements SampleSource, ExtractorOutpu
   @Override
   public void onLoadError(Loadable ignored, IOException e) {
     currentLoadableException = e;
-    currentLoadableExceptionCount = extractedSampleCount > extractedSampleCountAtStartOfLoad ? 1
+    currentLoadableExceptionCount = currentLoadableExtractedSamples ? 1
         : currentLoadableExceptionCount + 1;
     currentLoadableExceptionTimestamp = SystemClock.elapsedRealtime();
     notifyLoadError(e);
@@ -635,7 +632,7 @@ public final class ExtractorSampleSource implements SampleSource, ExtractorOutpu
           // We're playing a seekable on-demand stream. Resume the current loadable, which will
           // request data starting from the point it left off.
         }
-        extractedSampleCountAtStartOfLoad = extractedSampleCount;
+        currentLoadableExtractedSamples = false;
         loader.startLoading(loadable, this);
       }
       return;
@@ -659,7 +656,7 @@ public final class ExtractorSampleSource implements SampleSource, ExtractorOutpu
       loadable = createLoadableFromPositionUs(pendingResetPositionUs);
       pendingResetPositionUs = NO_RESET_PENDING;
     }
-    extractedSampleCountAtStartOfLoad = extractedSampleCount;
+    currentLoadableExtractedSamples = false;
     loader.startLoading(loadable, this);
   }
 
@@ -765,7 +762,7 @@ public final class ExtractorSampleSource implements SampleSource, ExtractorOutpu
     @Override
     public void sampleMetadata(long timeUs, int flags, int size, int offset, byte[] encryptionKey) {
       super.sampleMetadata(timeUs, flags, size, offset, encryptionKey);
-      extractedSampleCount++;
+      currentLoadableExtractedSamples = true;
     }
 
   }