Create the ProgresiveMediaExtractor interface

- Which abstracts ProgressiveMediaPeriod from the Extraction
  implementation.
- Will allow us to depend on MediaParser.

PiperOrigin-RevId: 297330623

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

@@ -29,8 +29,11 @@ import com.google.android.exoplayer2.util.Util;
 import java.io.EOFException;
 import java.io.IOException;
 
-/** Stores a list of extractors and a selected extractor when the format has been detected. */
-/* package */ final class ExtractorHolder {
+/**
+ * {@link ProgressiveMediaExtractor} built on top of {@link Extractor} instances, whose
+ * implementation classes are bundled in the app.
+ */
+/* package */ final class BundledExtractorsAdapter implements ProgressiveMediaExtractor {
 
   private final Extractor[] extractors;
 
@@ -42,33 +45,11 @@ import java.io.IOException;
    *
    * @param extractors One or more extractors to choose from.
    */
-  public ExtractorHolder(Extractor[] extractors) {
+  public BundledExtractorsAdapter(Extractor[] extractors) {
     this.extractors = extractors;
   }
 
-  /**
-   * Disables seeking in MP3 streams.
-   *
-   * <p>MP3 live streams commonly have seekable metadata, despite being unseekable.
-   */
-  public void disableSeekingOnMp3Streams() {
-    if (extractor instanceof Mp3Extractor) {
-      ((Mp3Extractor) extractor).disableSeeking();
-    }
-  }
-
-  /**
-   * Initializes any necessary resources for extraction.
-   *
-   * @param dataSource The {@link DataSource} from which data should be read.
-   * @param position The initial position of the {@code dataSource} in the stream.
-   * @param length The length of the stream, or {@link C#LENGTH_UNSET} if it is unknown.
-   * @param output The {@link ExtractorOutput} that will be used to initialize the selected
-   *     extractor.
-   * @throws UnrecognizedInputFormatException Thrown if the input format could not be detected.
-   * @throws IOException Thrown if the input could not be read.
-   * @throws InterruptedException Thrown if the thread was interrupted.
-   */
+  @Override
   public void init(DataSource dataSource, long position, long length, ExtractorOutput output)
       throws IOException, InterruptedException {
     extractorInput = new DefaultExtractorInput(dataSource, position, length);
@@ -101,39 +82,7 @@ import java.io.IOException;
     extractor.init(output);
   }
 
-  /**
-   * Returns the current read position in the input stream, or {@link C#POSITION_UNSET} if no input
-   * is available.
-   */
-  public long getCurrentInputPosition() {
-    return extractorInput != null ? extractorInput.getPosition() : C.POSITION_UNSET;
-  }
-
-  /**
-   * Notifies the underlying extractor that a seek has occurred.
-   *
-   * @param position The byte offset in the stream from which data will be provided.
-   * @param seekTimeUs The seek time in microseconds.
-   */
-  public void seek(long position, long seekTimeUs) {
-    Assertions.checkNotNull(extractor).seek(position, seekTimeUs);
-  }
-
-  /**
-   * Extracts data starting at the current input stream position.
-   *
-   * @param positionHolder If {@link Extractor#RESULT_SEEK} is returned, this holder is updated to
-   *     hold the position of the required data.
-   * @return One of the {@link Extractor}{@code .RESULT_*} values.
-   * @throws IOException If an error occurred reading from the input.
-   * @throws InterruptedException If the thread was interrupted.
-   */
-  public int read(PositionHolder positionHolder) throws IOException, InterruptedException {
-    return Assertions.checkNotNull(extractor)
-        .read(Assertions.checkNotNull(extractorInput), positionHolder);
-  }
-
-  /** Releases any held resources. */
+  @Override
   public void release() {
     if (extractor != null) {
       extractor.release();
@@ -141,4 +90,27 @@ import java.io.IOException;
     }
     extractorInput = null;
   }
+
+  @Override
+  public void disableSeekingOnMp3Streams() {
+    if (extractor instanceof Mp3Extractor) {
+      ((Mp3Extractor) extractor).disableSeeking();
+    }
+  }
+
+  @Override
+  public long getCurrentInputPosition() {
+    return extractorInput != null ? extractorInput.getPosition() : C.POSITION_UNSET;
+  }
+
+  @Override
+  public void seek(long position, long seekTimeUs) {
+    Assertions.checkNotNull(extractor).seek(position, seekTimeUs);
+  }
+
+  @Override
+  public int read(PositionHolder positionHolder) throws IOException, InterruptedException {
+    return Assertions.checkNotNull(extractor)
+        .read(Assertions.checkNotNull(extractorInput), positionHolder);
+  }
 }

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

@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.android.exoplayer2.source;
+
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.extractor.Extractor;
+import com.google.android.exoplayer2.extractor.ExtractorOutput;
+import com.google.android.exoplayer2.extractor.PositionHolder;
+import com.google.android.exoplayer2.upstream.DataSource;
+import java.io.IOException;
+
+/** Extracts the contents of a container file from a progressive media stream. */
+/* package */ interface ProgressiveMediaExtractor {
+
+  /**
+   * Initializes the underlying infrastructure for reading from the input.
+   *
+   * @param dataSource The {@link DataSource} from which data should be read.
+   * @param position The initial position of the {@code dataSource} in the stream.
+   * @param length The length of the stream, or {@link C#LENGTH_UNSET} if length is unknown.
+   * @param output The {@link ExtractorOutput} that will be used to initialize the selected
+   *     extractor.
+   * @throws UnrecognizedInputFormatException Thrown if the input format could not be detected.
+   * @throws IOException Thrown if the input could not be read.
+   * @throws InterruptedException Thrown if the thread was interrupted.
+   */
+  void init(DataSource dataSource, long position, long length, ExtractorOutput output)
+      throws IOException, InterruptedException;
+
+  /** Releases any held resources. */
+  void release();
+
+  /**
+   * Disables seeking in MP3 streams.
+   *
+   * <p>MP3 live streams commonly have seekable metadata, despite being unseekable.
+   */
+  void disableSeekingOnMp3Streams();
+
+  /**
+   * Returns the current read position in the input stream, or {@link C#POSITION_UNSET} if no input
+   * is available.
+   */
+  long getCurrentInputPosition();
+
+  /**
+   * Notifies the extracting infrastructure that a seek has occurred.
+   *
+   * @param position The byte offset in the stream from which data will be provided.
+   * @param seekTimeUs The seek time in microseconds.
+   */
+  void seek(long position, long seekTimeUs);
+
+  /**
+   * Extracts data starting at the current input stream position.
+   *
+   * @param positionHolder If {@link Extractor#RESULT_SEEK} is returned, this holder is updated to
+   *     hold the position of the required data.
+   * @return One of the {@link Extractor}{@code .RESULT_*} values.
+   * @throws IOException If an error occurred reading from the input.
+   * @throws InterruptedException If the thread was interrupted.
+   */
+  int read(PositionHolder positionHolder) throws IOException, InterruptedException;
+}

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

@@ -103,7 +103,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
   @Nullable private final String customCacheKey;
   private final long continueLoadingCheckIntervalBytes;
   private final Loader loader;
-  private final ExtractorHolder extractorHolder;
+  private final ProgressiveMediaExtractor progressiveMediaExtractor;
   private final ConditionVariable loadCondition;
   private final Runnable maybeFinishPrepareRunnable;
   private final Runnable onContinueLoadingRequestedRunnable;
@@ -175,7 +175,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     this.customCacheKey = customCacheKey;
     this.continueLoadingCheckIntervalBytes = continueLoadingCheckIntervalBytes;
     loader = new Loader("Loader:ProgressiveMediaPeriod");
-    extractorHolder = new ExtractorHolder(extractors);
+    progressiveMediaExtractor = new BundledExtractorsAdapter(extractors);
     loadCondition = new ConditionVariable();
     maybeFinishPrepareRunnable = this::maybeFinishPrepare;
     onContinueLoadingRequestedRunnable =
@@ -215,7 +215,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     for (SampleQueue sampleQueue : sampleQueues) {
       sampleQueue.release();
     }
-    extractorHolder.release();
+    progressiveMediaExtractor.release();
   }
 
   @Override
@@ -756,7 +756,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
   private void startLoading() {
     ExtractingLoadable loadable =
         new ExtractingLoadable(
-            uri, dataSource, extractorHolder, /* extractorOutput= */ this, loadCondition);
+            uri, dataSource, progressiveMediaExtractor, /* extractorOutput= */ this, loadCondition);
     if (preparedState != null) {
       SeekMap seekMap = preparedState.seekMap;
       Assertions.checkState(isPendingReset());
@@ -909,7 +909,7 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
     private final Uri uri;
     private final StatsDataSource dataSource;
-    private final ExtractorHolder extractorHolder;
+    private final ProgressiveMediaExtractor progressiveMediaExtractor;
     private final ExtractorOutput extractorOutput;
     private final ConditionVariable loadCondition;
     private final PositionHolder positionHolder;
@@ -927,12 +927,12 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
     public ExtractingLoadable(
         Uri uri,
         DataSource dataSource,
-        ExtractorHolder extractorHolder,
+        ProgressiveMediaExtractor progressiveMediaExtractor,
         ExtractorOutput extractorOutput,
         ConditionVariable loadCondition) {
       this.uri = uri;
       this.dataSource = new StatsDataSource(dataSource);
-      this.extractorHolder = extractorHolder;
+      this.progressiveMediaExtractor = progressiveMediaExtractor;
       this.extractorOutput = extractorOutput;
       this.loadCondition = loadCondition;
       this.positionHolder = new PositionHolder();
@@ -966,20 +966,20 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
             icyTrackOutput = icyTrack();
             icyTrackOutput.format(ICY_FORMAT);
           }
-          extractorHolder.init(extractorDataSource, position, length, extractorOutput);
+          progressiveMediaExtractor.init(extractorDataSource, position, length, extractorOutput);
 
           if (icyHeaders != null) {
-            extractorHolder.disableSeekingOnMp3Streams();
+            progressiveMediaExtractor.disableSeekingOnMp3Streams();
           }
 
           if (pendingExtractorSeek) {
-            extractorHolder.seek(position, seekTimeUs);
+            progressiveMediaExtractor.seek(position, seekTimeUs);
             pendingExtractorSeek = false;
           }
           while (result == Extractor.RESULT_CONTINUE && !loadCanceled) {
             loadCondition.block();
-            result = extractorHolder.read(positionHolder);
-            long currentInputPosition = extractorHolder.getCurrentInputPosition();
+            result = progressiveMediaExtractor.read(positionHolder);
+            long currentInputPosition = progressiveMediaExtractor.getCurrentInputPosition();
             if (currentInputPosition > position + continueLoadingCheckIntervalBytes) {
               position = currentInputPosition;
               loadCondition.close();
@@ -989,8 +989,8 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
         } finally {
           if (result == Extractor.RESULT_SEEK) {
             result = Extractor.RESULT_CONTINUE;
-          } else if (extractorHolder.getCurrentInputPosition() != C.POSITION_UNSET) {
-            positionHolder.position = extractorHolder.getCurrentInputPosition();
+          } else if (progressiveMediaExtractor.getCurrentInputPosition() != C.POSITION_UNSET) {
+            positionHolder.position = progressiveMediaExtractor.getCurrentInputPosition();
           }
           Util.closeQuietly(dataSource);
         }