Use identical cache keys for downloading and playing DASH segments

Issue: #9370 PiperOrigin-RevId: 395429794

Use identical cache keys for downloading and playing DASH segments
Issue: #9370 PiperOrigin-RevId: 395429794
69c75fb5 · bachinger · Christos Tsilopoulos · ee2ef1c3 · 69c75fb5 · 69c75fb5
Commit 69c75fb5 authored Sep 08, 2021 by bachinger Committed by Christos Tsilopoulos Sep 16, 2021
Showing with 89 additions and 30 deletions
RELEASENOTES.md
library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashUtil.java
library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DefaultDashChunkSource.java
library/dash/src/main/java/com/google/android/exoplayer2/source/dash/offline/DashDownloader.java
library/dash/src/test/java/com/google/android/exoplayer2/source/dash/DashUtilTest.java
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -23,6 +23,9 @@
        thrown from `Requirements.isInternetConnectivityValidated` on devices
        running Android 11
        ([#9002](https://github.com/google/ExoPlayer/issues/9002)).
+*   DASH:
+    *   Use identical cache keys for downloading and playing DASH segments
+        ([#9370](https://github.com/google/ExoPlayer/issues/9370)).
 *   RTSP:
    *   Handle when additional spaces are in SDP's RTPMAP atrribute
        ([#9379](https://github.com/google/ExoPlayer/issues/9379)).

--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashUtil.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashUtil.java
@@ -46,20 +46,20 @@ public final class DashUtil {
  /**
   * Builds a {@link DataSpec} for a given {@link RangedUri} belonging to {@link Representation}.
   *
+   * @param representation The {@link Representation} to which the request belongs.
   * @param baseUrl The base url with which to resolve the request URI.
   * @param requestUri The {@link RangedUri} of the data to request.
-   * @param cacheKey An optional cache key.
   * @param flags Flags to be set on the returned {@link DataSpec}. See {@link
   *     DataSpec.Builder#setFlags(int)}.
   * @return The {@link DataSpec}.
   */
  public static DataSpec buildDataSpec(
-      String baseUrl, RangedUri requestUri, @Nullable String cacheKey, int flags) {
+      Representation representation, String baseUrl, RangedUri requestUri, int flags) {
    return new DataSpec.Builder()
        .setUri(requestUri.resolveUri(baseUrl))
        .setPosition(requestUri.start)
        .setLength(requestUri.length)
-        .setKey(cacheKey)
+        .setKey(resolveCacheKey(representation, requestUri))
        .setFlags(flags)
        .build();
  }
@@ -77,8 +77,7 @@ public final class DashUtil {
   */
  public static DataSpec buildDataSpec(
      Representation representation, RangedUri requestUri, int flags) {
-    return buildDataSpec(
+    return buildDataSpec(representation, representation.baseUrls.get(0).url, requestUri, flags);
-        representation.baseUrls.get(0).url, requestUri, representation.getCacheKey(), flags);
  }
  /**
@@ -289,9 +288,9 @@ public final class DashUtil {
      throws IOException {
    DataSpec dataSpec =
        DashUtil.buildDataSpec(
+            representation,
            representation.baseUrls.get(baseUrlIndex).url,
            requestUri,
-            representation.getCacheKey(),
            /* flags= */ 0);
    InitializationChunk initializationChunk =
        new InitializationChunk(
@@ -304,6 +303,21 @@ public final class DashUtil {
    initializationChunk.load();
  }
+  /**
+   * Resolves the cache key to be used when requesting the given ranged URI for the given {@link
+   * Representation}.
+   *
+   * @param representation The {@link Representation} to which the URI belongs to.
+   * @param rangedUri The URI for which to resolve the cache key.
+   * @return The cache key.
+   */
+  public static String resolveCacheKey(Representation representation, RangedUri rangedUri) {
+    @Nullable String cacheKey = representation.getCacheKey();
+    return cacheKey != null
+        ? cacheKey
+        : rangedUri.resolveUri(representation.baseUrls.get(0).url).toString();
+  }
  private static ChunkExtractor newChunkExtractor(int trackType, Format format) {
    String mimeType = format.containerMimeType;
    boolean isWebm =

--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DefaultDashChunkSource.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DefaultDashChunkSource.java
@@ -628,10 +628,7 @@ public class DefaultDashChunkSource implements DashChunkSource {
    }
    DataSpec dataSpec =
        DashUtil.buildDataSpec(
-            representationHolder.selectedBaseUrl.url,
+            representation, representationHolder.selectedBaseUrl.url, requestUri, /* flags= */ 0);
-            requestUri,
-            representation.getCacheKey(),
-            /* flags= */ 0);
    return new InitializationChunk(
        dataSource,
        dataSpec,
@@ -664,10 +661,7 @@ public class DefaultDashChunkSource implements DashChunkSource {
              : DataSpec.FLAG_MIGHT_NOT_USE_FULL_NETWORK_SPEED;
      DataSpec dataSpec =
          DashUtil.buildDataSpec(
-              representationHolder.selectedBaseUrl.url,
+              representation, representationHolder.selectedBaseUrl.url, segmentUri, flags);
-              segmentUri,
-              representation.getCacheKey(),
-              flags);
      return new SingleSampleMediaChunk(
          dataSource,
          dataSpec,
@@ -706,10 +700,7 @@ public class DefaultDashChunkSource implements DashChunkSource {
              : DataSpec.FLAG_MIGHT_NOT_USE_FULL_NETWORK_SPEED;
      DataSpec dataSpec =
          DashUtil.buildDataSpec(
-              representationHolder.selectedBaseUrl.url,
+              representation, representationHolder.selectedBaseUrl.url, segmentUri, flags);
-              segmentUri,
-              representation.getCacheKey(),
-              flags);
      long sampleOffsetUs = -representation.presentationTimeOffsetUs;
      return new ContainerMediaChunk(
          dataSource,
@@ -765,9 +756,9 @@ public class DefaultDashChunkSource implements DashChunkSource {
              ? 0
              : DataSpec.FLAG_MIGHT_NOT_USE_FULL_NETWORK_SPEED;
      return DashUtil.buildDataSpec(
+          representationHolder.representation,
          representationHolder.selectedBaseUrl.url,
          segmentUri,
-          representationHolder.representation.getCacheKey(),
          flags);
    }

--- a/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/offline/DashDownloader.java
+++ b/library/dash/src/main/java/com/google/android/exoplayer2/source/dash/offline/DashDownloader.java
@@ -15,12 +15,15 @@
 */
 package com.google.android.exoplayer2.source.dash.offline;
+import static com.google.android.exoplayer2.util.Util.castNonNull;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.MediaItem;
 import com.google.android.exoplayer2.extractor.ChunkIndex;
 import com.google.android.exoplayer2.offline.DownloadException;
 import com.google.android.exoplayer2.offline.SegmentDownloader;
+import com.google.android.exoplayer2.source.dash.BaseUrlExclusionList;
 import com.google.android.exoplayer2.source.dash.DashSegmentIndex;
 import com.google.android.exoplayer2.source.dash.DashUtil;
 import com.google.android.exoplayer2.source.dash.DashWrappingSegmentIndex;
@@ -70,6 +73,8 @@ import org.checkerframework.checker.nullness.compatqual.NullableType;
 */
 public final class DashDownloader extends SegmentDownloader<DashManifest> {
+  private final BaseUrlExclusionList baseUrlExclusionList;
  /**
   * Creates a new instance.
   *
@@ -113,6 +118,7 @@ public final class DashDownloader extends SegmentDownloader<DashManifest> {
      CacheDataSource.Factory cacheDataSourceFactory,
      Executor executor) {
    super(mediaItem, manifestParser, cacheDataSourceFactory, executor);
+    baseUrlExclusionList = new BaseUrlExclusionList();
  }
  @Override
@@ -163,28 +169,32 @@ public final class DashDownloader extends SegmentDownloader<DashManifest> {
        throw new DownloadException("Unbounded segment index");
      }
-      String baseUrl = representation.baseUrls.get(0).url;
+      String baseUrl = castNonNull(baseUrlExclusionList.selectBaseUrl(representation.baseUrls)).url;
-      RangedUri initializationUri = representation.getInitializationUri();
+      @Nullable RangedUri initializationUri = representation.getInitializationUri();
      if (initializationUri != null) {
-        addSegment(periodStartUs, baseUrl, initializationUri, out);
+        out.add(createSegment(representation, baseUrl, periodStartUs, initializationUri));
      }
-      RangedUri indexUri = representation.getIndexUri();
+      @Nullable RangedUri indexUri = representation.getIndexUri();
      if (indexUri != null) {
-        addSegment(periodStartUs, baseUrl, indexUri, out);
+        out.add(createSegment(representation, baseUrl, periodStartUs, indexUri));
      }
      long firstSegmentNum = index.getFirstSegmentNum();
      long lastSegmentNum = firstSegmentNum + segmentCount - 1;
      for (long j = firstSegmentNum; j <= lastSegmentNum; j++) {
-        addSegment(periodStartUs + index.getTimeUs(j), baseUrl, index.getSegmentUrl(j), out);
+        out.add(
+            createSegment(
+                representation,
+                baseUrl,
+                periodStartUs + index.getTimeUs(j),
+                index.getSegmentUrl(j)));
      }
    }
  }
-  private static void addSegment(
+  private Segment createSegment(
-      long startTimeUs, String baseUrl, RangedUri rangedUri, ArrayList<Segment> out) {
+      Representation representation, String baseUrl, long startTimeUs, RangedUri rangedUri) {
-    DataSpec dataSpec =
+    DataSpec dataSpec = DashUtil.buildDataSpec(representation, baseUrl, rangedUri, /* flags= */ 0);
-        new DataSpec(rangedUri.resolveUri(baseUrl), rangedUri.start, rangedUri.length);
+    return new Segment(startTimeUs, dataSpec);
-    out.add(new Segment(startTimeUs, dataSpec));
  }
  @Nullable

--- a/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/DashUtilTest.java
+++ b/library/dash/src/test/java/com/google/android/exoplayer2/source/dash/DashUtilTest.java
@@ -25,6 +25,7 @@ import com.google.android.exoplayer2.drm.DrmInitData.SchemeData;
 import com.google.android.exoplayer2.source.dash.manifest.AdaptationSet;
 import com.google.android.exoplayer2.source.dash.manifest.BaseUrl;
 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.source.dash.manifest.SegmentBase.SingleSegmentBase;
 import com.google.android.exoplayer2.upstream.DummyDataSource;
@@ -69,6 +70,46 @@ public final class DashUtilTest {
    assertThat(format).isNull();
  }
+  @Test
+  public void resolveCacheKey_representationCacheKeyIsNull_resolvesRangedUriWithFirstBaseUrl() {
+    ImmutableList<BaseUrl> baseUrls =
+        ImmutableList.of(new BaseUrl("http://www.google.com"), new BaseUrl("http://www.foo.com"));
+    Representation.SingleSegmentRepresentation representation =
+        new Representation.SingleSegmentRepresentation(
+            /* revisionId= */ 1L,
+            new Format.Builder().build(),
+            baseUrls,
+            new SingleSegmentBase(),
+            /* inbandEventStreams= */ null,
+            /* cacheKey= */ null,
+            /* contentLength= */ 1);
+    RangedUri rangedUri = new RangedUri("path/to/resource", /* start= */ 0, /* length= */ 1);
+    String cacheKey = DashUtil.resolveCacheKey(representation, rangedUri);
+    assertThat(cacheKey).isEqualTo("http://www.google.com/path/to/resource");
+  }
+  @Test
+  public void resolveCacheKey_representationCacheKeyDefined_usesRepresentationCacheKey() {
+    ImmutableList<BaseUrl> baseUrls =
+        ImmutableList.of(new BaseUrl("http://www.google.com"), new BaseUrl("http://www.foo.com"));
+    Representation.SingleSegmentRepresentation representation =
+        new Representation.SingleSegmentRepresentation(
+            /* revisionId= */ 1L,
+            new Format.Builder().build(),
+            baseUrls,
+            new SingleSegmentBase(),
+            /* inbandEventStreams= */ null,
+            "cacheKey",
+            /* contentLength= */ 1);
+    RangedUri rangedUri = new RangedUri("path/to/resource", /* start= */ 0, /* length= */ 1);
+    String cacheKey = DashUtil.resolveCacheKey(representation, rangedUri);
+    assertThat(cacheKey).isEqualTo("cacheKey");
+  }
  private static Period newPeriod(AdaptationSet... adaptationSets) {
    return new Period("", 0, Arrays.asList(adaptationSets));
  }