Move utility methods to DashUtil class

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=148647040

library/src/main/java/com/google/android/exoplayer2/drm/OfflineLicenseHelper.java

@@ -17,7 +17,6 @@
 package com.google.android.exoplayer2.drm;
 
 import android.media.MediaDrm;
-import android.net.Uri;
 import android.os.ConditionVariable;
 import android.os.Handler;
 import android.os.HandlerThread;
@@ -27,24 +26,14 @@ import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.drm.DefaultDrmSessionManager.EventListener;
 import com.google.android.exoplayer2.drm.DefaultDrmSessionManager.Mode;
 import com.google.android.exoplayer2.drm.DrmSession.DrmSessionException;
-import com.google.android.exoplayer2.extractor.Extractor;
+import com.google.android.exoplayer2.source.dash.DashUtil;
-import com.google.android.exoplayer2.extractor.mkv.MatroskaExtractor;
-import com.google.android.exoplayer2.extractor.mp4.FragmentedMp4Extractor;
-import com.google.android.exoplayer2.source.chunk.ChunkExtractorWrapper;
-import com.google.android.exoplayer2.source.chunk.InitializationChunk;
 import com.google.android.exoplayer2.source.dash.manifest.AdaptationSet;
 import com.google.android.exoplayer2.source.dash.manifest.DashManifest;
-import com.google.android.exoplayer2.source.dash.manifest.DashManifestParser;
 import com.google.android.exoplayer2.source.dash.manifest.Period;
-import com.google.android.exoplayer2.source.dash.manifest.RangedUri;
 import com.google.android.exoplayer2.source.dash.manifest.Representation;
-import com.google.android.exoplayer2.upstream.DataSource;
-import com.google.android.exoplayer2.upstream.DataSourceInputStream;
-import com.google.android.exoplayer2.upstream.DataSpec;
 import com.google.android.exoplayer2.upstream.HttpDataSource;
 import com.google.android.exoplayer2.upstream.HttpDataSource.Factory;
 import com.google.android.exoplayer2.util.Assertions;
-import com.google.android.exoplayer2.util.MimeTypes;
 import java.io.IOException;
 import java.util.HashMap;
 
@@ -58,28 +47,6 @@ public final class OfflineLicenseHelper<T extends ExoMediaCrypto> {
   private final DefaultDrmSessionManager<T> drmSessionManager;
   private final HandlerThread handlerThread;
 
-  /**
-   * Helper method to download a DASH manifest.
-   *
-   * @param dataSource The {@link HttpDataSource} from which the manifest should be read.
-   * @param manifestUriString The URI of the manifest to be read.
-   * @return An instance of {@link DashManifest}.
-   * @throws IOException If an error occurs reading data from the stream.
-   * @see DashManifestParser
-   */
-  public static DashManifest downloadManifest(HttpDataSource dataSource, String manifestUriString)
-      throws IOException {
-    DataSourceInputStream inputStream = new DataSourceInputStream(
-        dataSource, new DataSpec(Uri.parse(manifestUriString)));
-    try {
-      inputStream.open();
-      DashManifestParser parser = new DashManifestParser();
-      return parser.parse(dataSource.getUri(), inputStream);
-    } finally {
-      inputStream.close();
-    }
-  }
-
   /**
    * Instantiates a new instance which uses Widevine CDM. Call {@link #releaseResources()} when
    * you're done with the helper instance.
@@ -174,7 +141,7 @@ public final class OfflineLicenseHelper<T extends ExoMediaCrypto> {
    */
   public byte[] download(HttpDataSource dataSource, String manifestUriString)
       throws IOException, InterruptedException, DrmSessionException {
-    return download(dataSource, downloadManifest(dataSource, manifestUriString));
+    return download(dataSource, DashUtil.loadManifest(dataSource, manifestUriString));
   }
 
   /**
@@ -210,14 +177,8 @@ public final class OfflineLicenseHelper<T extends ExoMediaCrypto> {
     Representation representation = adaptationSet.representations.get(0);
     DrmInitData drmInitData = representation.format.drmInitData;
     if (drmInitData == null) {
-      ChunkExtractorWrapper extractorWrapper = newWrappedExtractor(representation.format,
+      Format sampleFormat = DashUtil.loadSampleFormat(dataSource, representation,
           adaptationSet.type);
-      InitializationChunk initializationChunk = loadInitializationChunk(dataSource, representation,
-          extractorWrapper);
-      if (initializationChunk == null) {
-        return null;
-      }
-      Format sampleFormat = extractorWrapper.getSampleFormat();
       if (sampleFormat != null) {
         drmInitData = sampleFormat.drmInitData;
       }
@@ -291,28 +252,4 @@ public final class OfflineLicenseHelper<T extends ExoMediaCrypto> {
     return session;
   }
 
-  private static InitializationChunk loadInitializationChunk(DataSource dataSource,
-      Representation representation, ChunkExtractorWrapper extractorWrapper)
-      throws IOException, InterruptedException {
-    RangedUri rangedUri = representation.getInitializationUri();
-    if (rangedUri == null) {
-      return null;
-    }
-    DataSpec dataSpec = new DataSpec(rangedUri.resolveUri(representation.baseUrl), rangedUri.start,
-        rangedUri.length, representation.getCacheKey());
-    InitializationChunk initializationChunk = new InitializationChunk(dataSource, dataSpec,
-        representation.format, C.SELECTION_REASON_UNKNOWN, null /* trackSelectionData */,
-        extractorWrapper);
-    initializationChunk.load();
-    return initializationChunk;
-  }
-
-  private static ChunkExtractorWrapper newWrappedExtractor(Format format, int trackType) {
-    final String mimeType = format.containerMimeType;
-    final boolean isWebm = mimeType.startsWith(MimeTypes.VIDEO_WEBM)
-        || mimeType.startsWith(MimeTypes.AUDIO_WEBM);
-    final Extractor extractor = isWebm ? new MatroskaExtractor() : new FragmentedMp4Extractor();
-    return new ChunkExtractorWrapper(extractor, format, trackType);
-  }
-
 }

library/src/main/java/com/google/android/exoplayer2/source/dash/DashUtil.java

@@ -0,0 +1,166 @@
+/*
+ * 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.dash;
+
+import android.net.Uri;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.extractor.ChunkIndex;
+import com.google.android.exoplayer2.extractor.Extractor;
+import com.google.android.exoplayer2.extractor.mkv.MatroskaExtractor;
+import com.google.android.exoplayer2.extractor.mp4.FragmentedMp4Extractor;
+import com.google.android.exoplayer2.source.chunk.ChunkExtractorWrapper;
+import com.google.android.exoplayer2.source.chunk.InitializationChunk;
+import com.google.android.exoplayer2.source.dash.manifest.DashManifest;
+import com.google.android.exoplayer2.source.dash.manifest.DashManifestParser;
+import com.google.android.exoplayer2.source.dash.manifest.RangedUri;
+import com.google.android.exoplayer2.source.dash.manifest.Representation;
+import com.google.android.exoplayer2.upstream.DataSource;
+import com.google.android.exoplayer2.upstream.DataSourceInputStream;
+import com.google.android.exoplayer2.upstream.DataSpec;
+import com.google.android.exoplayer2.upstream.HttpDataSource;
+import com.google.android.exoplayer2.util.MimeTypes;
+import java.io.IOException;
+
+/**
+ * Utility methods for DASH streams.
+ */
+public final class DashUtil {
+
+  /**
+   * Loads a DASH manifest.
+   *
+   * @param dataSource The {@link HttpDataSource} from which the manifest should be read.
+   * @param manifestUriString The URI of the manifest to be read.
+   * @return An instance of {@link DashManifest}.
+   * @throws IOException If an error occurs reading data from the stream.
+   * @see DashManifestParser
+   */
+  public static DashManifest loadManifest(DataSource dataSource, String manifestUriString)
+      throws IOException {
+    DataSourceInputStream inputStream = new DataSourceInputStream(dataSource,
+        new DataSpec(Uri.parse(manifestUriString), DataSpec.FLAG_ALLOW_CACHING_UNKNOWN_LENGTH));
+    try {
+      inputStream.open();
+      DashManifestParser parser = new DashManifestParser();
+      return parser.parse(dataSource.getUri(), inputStream);
+    } finally {
+      inputStream.close();
+    }
+  }
+
+  /**
+   * Loads initialization data for the {@code representation} and returns the sample {@link
+   * Format}.
+   *
+   * @param dataSource The source from which the data should be loaded.
+   * @param representation The representation which initialization chunk belongs to.
+   * @param type The type of the primary track. Typically one of the {@link C} {@code TRACK_TYPE_*}
+   *     constants.
+   * @return the sample {@link Format} of the given representation.
+   * @throws IOException Thrown when there is an error while loading.
+   * @throws InterruptedException Thrown if the thread was interrupted.
+   */
+  public static Format loadSampleFormat(DataSource dataSource, Representation representation,
+      int type) throws IOException, InterruptedException {
+    ChunkExtractorWrapper extractorWrapper = loadInitializationData(dataSource, representation,
+        type, false);
+    return extractorWrapper == null ? null : extractorWrapper.getSampleFormat();
+  }
+
+  /**
+   * Loads initialization and index data for the {@code representation} and returns the {@link
+   * ChunkIndex}.
+   *
+   * @param dataSource The source from which the data should be loaded.
+   * @param representation The representation which initialization chunk belongs to.
+   * @param type The type of the primary track. Typically one of the {@link C} {@code TRACK_TYPE_*}
+   *     constants.
+   * @return {@link ChunkIndex} of the given representation.
+   * @throws IOException Thrown when there is an error while loading.
+   * @throws InterruptedException Thrown if the thread was interrupted.
+   */
+  public static ChunkIndex loadChunkIndex(DataSource dataSource, Representation representation,
+      int type) throws IOException, InterruptedException {
+    ChunkExtractorWrapper extractorWrapper = loadInitializationData(dataSource, representation,
+        type, true);
+    return extractorWrapper == null ? null : (ChunkIndex) extractorWrapper.getSeekMap();
+  }
+
+  /**
+   * Loads initialization data for the {@code representation} and optionally index data then
+   * returns a {@link ChunkExtractorWrapper} which contains the output.
+   *
+   * @param dataSource The source from which the data should be loaded.
+   * @param representation The representation which initialization chunk belongs to.
+   * @param type The type of the primary track. Typically one of the {@link C} {@code TRACK_TYPE_*}
+   *     constants.
+   * @param loadIndex Whether to load index data too.
+   * @return A {@link ChunkExtractorWrapper} for the {@code representation}, or null if no
+   *     initialization or (if requested) index data exists.
+   * @throws IOException Thrown when there is an error while loading.
+   * @throws InterruptedException Thrown if the thread was interrupted.
+   */
+  private static ChunkExtractorWrapper loadInitializationData(DataSource dataSource,
+      Representation representation, int type, boolean loadIndex)
+      throws IOException, InterruptedException {
+    RangedUri initializationUri = representation.getInitializationUri();
+    if (initializationUri == null) {
+      return null;
+    }
+    ChunkExtractorWrapper extractorWrapper = newWrappedExtractor(representation.format, type);
+    RangedUri requestUri;
+    if (loadIndex) {
+      RangedUri indexUri = representation.getIndexUri();
+      if (indexUri == null) {
+        return null;
+      }
+      // It's common for initialization and index data to be stored adjacently. Attempt to merge
+      // the two requests together to request both at once.
+      requestUri = initializationUri.attemptMerge(indexUri, representation.baseUrl);
+      if (requestUri == null) {
+        loadInitializationData(dataSource, representation, extractorWrapper, initializationUri);
+        requestUri = indexUri;
+      }
+    } else {
+      requestUri = initializationUri;
+    }
+    loadInitializationData(dataSource, representation, extractorWrapper, requestUri);
+    return extractorWrapper;
+  }
+
+  private static void loadInitializationData(DataSource dataSource,
+      Representation representation, ChunkExtractorWrapper extractorWrapper, RangedUri requestUri)
+      throws IOException, InterruptedException {
+    DataSpec dataSpec = new DataSpec(requestUri.resolveUri(representation.baseUrl),
+        requestUri.start, requestUri.length, representation.getCacheKey());
+    InitializationChunk initializationChunk = new InitializationChunk(dataSource, dataSpec,
+        representation.format, C.SELECTION_REASON_UNKNOWN, null /* trackSelectionData */,
+        extractorWrapper);
+    initializationChunk.load();
+  }
+
+  private static ChunkExtractorWrapper newWrappedExtractor(Format format, int trackType) {
+    String mimeType = format.containerMimeType;
+    boolean isWebm = mimeType.startsWith(MimeTypes.VIDEO_WEBM)
+        || mimeType.startsWith(MimeTypes.AUDIO_WEBM);
+    Extractor extractor = isWebm ? new MatroskaExtractor() : new FragmentedMp4Extractor();
+    return new ChunkExtractorWrapper(extractor, format, trackType);
+  }
+
+  private DashUtil() {}
+
+}