Allow injection of DataSource's per type of data

This allows the client to define what data source is used for
media chunks, encryption chunks and playlists.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=149537766

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

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2017 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.hls;
+
+import com.google.android.exoplayer2.upstream.DataSource;
+
+/**
+ * Default implementation of {@link HlsDataSourceFactory}.
+ */
+public final class DefaultHlsDataSourceFactory implements HlsDataSourceFactory {
+
+  private final DataSource.Factory dataSourceFactory;
+
+  /**
+   * @param dataSourceFactory The {@link DataSource.Factory} to use for all data types.
+   */
+  public DefaultHlsDataSourceFactory(DataSource.Factory dataSourceFactory) {
+    this.dataSourceFactory = dataSourceFactory;
+  }
+
+  @Override
+  public DataSource createDataSource(int dataType) {
+    return dataSourceFactory.createDataSource();
+  }
+
+}

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

@@ -81,7 +81,8 @@ import java.util.Locale;
 
   }
 
-  private final DataSource dataSource;
+  private final DataSource mediaDataSource;
+  private final DataSource encryptionDataSource;
   private final TimestampAdjusterProvider timestampAdjusterProvider;
   private final HlsUrl[] variants;
   private final HlsPlaylistTracker playlistTracker;
@@ -105,18 +106,18 @@ import java.util.Locale;
   /**
    * @param playlistTracker The {@link HlsPlaylistTracker} from which to obtain media playlists.
    * @param variants The available variants.
-   * @param dataSource A {@link DataSource} suitable for loading the media data.
+   * @param dataSourceFactory An {@link HlsDataSourceFactory} to create {@link DataSource}s for the
+   *     chunks.
    * @param timestampAdjusterProvider A provider of {@link TimestampAdjuster} instances. If
    *     multiple {@link HlsChunkSource}s are used for a single playback, they should all share the
    *     same provider.
    * @param muxedCaptionFormats List of muxed caption {@link Format}s.
    */
   public HlsChunkSource(HlsPlaylistTracker playlistTracker, HlsUrl[] variants,
-      DataSource dataSource, TimestampAdjusterProvider timestampAdjusterProvider,
+      HlsDataSourceFactory dataSourceFactory, TimestampAdjusterProvider timestampAdjusterProvider,
       List<Format> muxedCaptionFormats) {
     this.playlistTracker = playlistTracker;
     this.variants = variants;
-    this.dataSource = dataSource;
     this.timestampAdjusterProvider = timestampAdjusterProvider;
     this.muxedCaptionFormats = muxedCaptionFormats;
     Format[] variantFormats = new Format[variants.length];
@@ -125,6 +126,8 @@ import java.util.Locale;
       variantFormats[i] = variants[i].format;
       initialTrackSelection[i] = i;
     }
+    mediaDataSource = dataSourceFactory.createDataSource(C.DATA_TYPE_MEDIA);
+    encryptionDataSource = dataSourceFactory.createDataSource(C.DATA_TYPE_DRM);
     trackGroup = new TrackGroup(variantFormats);
     trackSelection = new InitializationTrackSelection(trackGroup, initialTrackSelection);
   }
@@ -285,7 +288,7 @@ import java.util.Locale;
     Uri chunkUri = UriUtil.resolveToUri(mediaPlaylist.baseUri, segment.url);
     DataSpec dataSpec = new DataSpec(chunkUri, segment.byterangeOffset, segment.byterangeLength,
         null);
-    out.chunk = new HlsMediaChunk(dataSource, dataSpec, initDataSpec, selectedUrl,
+    out.chunk = new HlsMediaChunk(mediaDataSource, dataSpec, initDataSpec, selectedUrl,
         muxedCaptionFormats, trackSelection.getSelectionReason(), trackSelection.getSelectionData(),
         startTimeUs, startTimeUs + segment.durationUs, chunkMediaSequence, discontinuitySequence,
         isTimestampMaster, timestampAdjuster, previous, encryptionKey, encryptionIv);
@@ -341,7 +344,7 @@ import java.util.Locale;
   private EncryptionKeyChunk newEncryptionKeyChunk(Uri keyUri, String iv, int variantIndex,
       int trackSelectionReason, Object trackSelectionData) {
     DataSpec dataSpec = new DataSpec(keyUri, 0, C.LENGTH_UNSET, null, DataSpec.FLAG_ALLOW_GZIP);
-    return new EncryptionKeyChunk(dataSource, dataSpec, variants[variantIndex].format,
+    return new EncryptionKeyChunk(encryptionDataSource, dataSpec, variants[variantIndex].format,
         trackSelectionReason, trackSelectionData, scratchSpace, iv);
   }
 

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

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2017 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.hls;
+
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.upstream.DataSource;
+
+/**
+ * Creates {@link DataSource}s for HLS playlists, encryption and media chunks.
+ */
+public interface HlsDataSourceFactory {
+
+  /**
+   * Creates a {@link DataSource} for the given data type.
+   *
+   * @param dataType The data type for which the {@link DataSource} will be used. One of {@link C}
+   *     {@code .DATA_TYPE_*} constants.
+   * @return A {@link DataSource} for the given data type.
+   */
+  DataSource createDataSource(int dataType);
+
+}

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

@@ -30,7 +30,6 @@ import com.google.android.exoplayer2.source.hls.playlist.HlsMasterPlaylist.HlsUr
 import com.google.android.exoplayer2.source.hls.playlist.HlsPlaylistTracker;
 import com.google.android.exoplayer2.trackselection.TrackSelection;
 import com.google.android.exoplayer2.upstream.Allocator;
-import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.util.Assertions;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -44,7 +43,7 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
     HlsPlaylistTracker.PlaylistEventListener {
 
   private final HlsPlaylistTracker playlistTracker;
-  private final DataSource.Factory dataSourceFactory;
+  private final HlsDataSourceFactory dataSourceFactory;
   private final int minLoadableRetryCount;
   private final EventDispatcher eventDispatcher;
   private final Allocator allocator;
@@ -61,7 +60,7 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
   private HlsSampleStreamWrapper[] enabledSampleStreamWrappers;
   private CompositeSequenceableLoader sequenceableLoader;
 
-  public HlsMediaPeriod(HlsPlaylistTracker playlistTracker, DataSource.Factory dataSourceFactory,
+  public HlsMediaPeriod(HlsPlaylistTracker playlistTracker, HlsDataSourceFactory dataSourceFactory,
       int minLoadableRetryCount, EventDispatcher eventDispatcher, Allocator allocator,
       long positionUs) {
     this.playlistTracker = playlistTracker;
@@ -349,9 +348,8 @@ public final class HlsMediaPeriod implements MediaPeriod, HlsSampleStreamWrapper
 
   private HlsSampleStreamWrapper buildSampleStreamWrapper(int trackType, HlsUrl[] variants,
       Format muxedAudioFormat, List<Format> muxedCaptionFormats) {
-    DataSource dataSource = dataSourceFactory.createDataSource();
+    HlsChunkSource defaultChunkSource = new HlsChunkSource(playlistTracker, variants,
-    HlsChunkSource defaultChunkSource = new HlsChunkSource(playlistTracker, variants, dataSource,
+        dataSourceFactory, timestampAdjusterProvider, muxedCaptionFormats);
-        timestampAdjusterProvider, muxedCaptionFormats);
     return new HlsSampleStreamWrapper(trackType, this, defaultChunkSource, allocator,
         preparePositionUs, muxedAudioFormat, minLoadableRetryCount, eventDispatcher);
   }

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

@@ -44,7 +44,7 @@ public final class HlsMediaSource implements MediaSource,
   public static final int DEFAULT_MIN_LOADABLE_RETRY_COUNT = 3;
 
   private final Uri manifestUri;
-  private final DataSource.Factory dataSourceFactory;
+  private final HlsDataSourceFactory dataSourceFactory;
   private final int minLoadableRetryCount;
   private final EventDispatcher eventDispatcher;
 
@@ -60,6 +60,13 @@ public final class HlsMediaSource implements MediaSource,
   public HlsMediaSource(Uri manifestUri, DataSource.Factory dataSourceFactory,
       int minLoadableRetryCount, Handler eventHandler,
       AdaptiveMediaSourceEventListener eventListener) {
+    this(manifestUri, new DefaultHlsDataSourceFactory(dataSourceFactory), minLoadableRetryCount,
+        eventHandler, eventListener);
+  }
+
+  public HlsMediaSource(Uri manifestUri, HlsDataSourceFactory dataSourceFactory,
+      int minLoadableRetryCount, Handler eventHandler,
+      AdaptiveMediaSourceEventListener eventListener) {
     this.manifestUri = manifestUri;
     this.dataSourceFactory = dataSourceFactory;
     this.minLoadableRetryCount = minLoadableRetryCount;

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

@@ -22,6 +22,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ParserException;
 import com.google.android.exoplayer2.source.AdaptiveMediaSourceEventListener.EventDispatcher;
 import com.google.android.exoplayer2.source.chunk.ChunkedTrackBlacklistUtil;
+import com.google.android.exoplayer2.source.hls.HlsDataSourceFactory;
 import com.google.android.exoplayer2.source.hls.playlist.HlsMasterPlaylist.HlsUrl;
 import com.google.android.exoplayer2.source.hls.playlist.HlsMediaPlaylist.Segment;
 import com.google.android.exoplayer2.upstream.DataSource;
@@ -81,7 +82,7 @@ public final class HlsPlaylistTracker implements Loader.Callback<ParsingLoadable
   private static final long PRIMARY_URL_KEEPALIVE_MS = 15000;
 
   private final Uri initialPlaylistUri;
-  private final DataSource.Factory dataSourceFactory;
+  private final HlsDataSourceFactory dataSourceFactory;
   private final HlsPlaylistParser playlistParser;
   private final int minRetryCount;
   private final IdentityHashMap<HlsUrl, MediaPlaylistBundle> playlistBundles;
@@ -105,7 +106,7 @@ public final class HlsPlaylistTracker implements Loader.Callback<ParsingLoadable
    *     playlist.
    * @param primaryPlaylistListener A callback for the primary playlist change events.
    */
-  public HlsPlaylistTracker(Uri initialPlaylistUri, DataSource.Factory dataSourceFactory,
+  public HlsPlaylistTracker(Uri initialPlaylistUri, HlsDataSourceFactory dataSourceFactory,
       EventDispatcher eventDispatcher, int minRetryCount,
       PrimaryPlaylistListener primaryPlaylistListener) {
     this.initialPlaylistUri = initialPlaylistUri;
@@ -143,8 +144,8 @@ public final class HlsPlaylistTracker implements Loader.Callback<ParsingLoadable
    */
   public void start() {
     ParsingLoadable<HlsPlaylist> masterPlaylistLoadable = new ParsingLoadable<>(
-        dataSourceFactory.createDataSource(), initialPlaylistUri, C.DATA_TYPE_MANIFEST,
+        dataSourceFactory.createDataSource(C.DATA_TYPE_MANIFEST), initialPlaylistUri,
-        playlistParser);
+        C.DATA_TYPE_MANIFEST, playlistParser);
     initialPlaylistLoader.startLoading(masterPlaylistLoadable, this, minRetryCount);
   }
 
@@ -436,7 +437,8 @@ public final class HlsPlaylistTracker implements Loader.Callback<ParsingLoadable
       this.playlistUrl = playlistUrl;
       lastSnapshotAccessTimeMs = initialLastSnapshotAccessTimeMs;
       mediaPlaylistLoader = new Loader("HlsPlaylistTracker:MediaPlaylist");
-      mediaPlaylistLoadable = new ParsingLoadable<>(dataSourceFactory.createDataSource(),
+      mediaPlaylistLoadable = new ParsingLoadable<>(
+          dataSourceFactory.createDataSource(C.DATA_TYPE_MANIFEST),
           UriUtil.resolveToUri(masterPlaylist.baseUri, playlistUrl.url), C.DATA_TYPE_MANIFEST,
           playlistParser);
     }

library/src/main/java/com/google/android/exoplayer2/upstream/DataSpec.java

@@ -47,7 +47,9 @@ public final class DataSpec {
    */
   public static final int FLAG_ALLOW_GZIP = 1 << 0;
 
-  /** Permits content to be cached even if its length can not be resolved. */
+  /**
+   * Permits content to be cached even if its length can not be resolved.
+   */
   public static final int FLAG_ALLOW_CACHING_UNKNOWN_LENGTH = 1 << 1;
 
   /**