fix(offline): offline downloads are slow

shaka-project · Apr 27, 2022 · 82f3f76 · 82f3f76
1 parent feefd7b
commit 82f3f76
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Showing 8 changed files with 32 additions and 3 deletions.
diff --git a/demo/common/message_ids.js b/demo/common/message_ids.js
@@ -223,6 +223,7 @@ shakaDemo.MessageIds = {
   NUMBER_INTEGER_WARNING: 'DEMO_NUMBER_INTEGER_WARNING',
   NUMBER_NONZERO_DECIMAL_WARNING: 'DEMO_NUMBER_NONZERO_DECIMAL_WARNING',
   NUMBER_NONZERO_INTEGER_WARNING: 'DEMO_NUMBER_NONZERO_INTEGER_WARNING',
+  NUMBER_OF_PARALLEL_SEGMENTS_BY_STREAM: 'DEMO_NUMBER_OF_PARALLEL_SEGMENTS_BY_STREAM',
   OFFLINE_SECTION_HEADER: 'DEMO_OFFLINE_SECTION_HEADER',
   PREFER_FORCED_SUBS: 'DEMO_PREFER_FORCED_SUBS',
   PREFER_NATIVE_HLS: 'DEMO_PREFER_NATIVE_HLS',

diff --git a/demo/config.js b/demo/config.js
@@ -341,7 +341,9 @@ shakaDemo.Config = class {
     const docLink = this.resolveExternLink_('.OfflineConfiguration');
     this.addSection_(MessageIds.OFFLINE_SECTION_HEADER, docLink)
         .addBoolInput_(MessageIds.USE_PERSISTENT_LICENSES,
-            'offline.usePersistentLicense');
+            'offline.usePersistentLicense')
+        .addNumberInput_(MessageIds.NUMBER_OF_PARALLEL_SEGMENTS_BY_STREAM,
+            'offline.numberOfParallelSegmentsByStream');
   }
 
   /** @private */

diff --git a/demo/locales/en.json b/demo/locales/en.json
@@ -159,6 +159,7 @@
   "DEMO_NUMBER_INTEGER_WARNING": "Must be a positive integer.",
   "DEMO_NUMBER_NONZERO_DECIMAL_WARNING": "Must be a positive, nonzero number.",
   "DEMO_NUMBER_NONZERO_INTEGER_WARNING": "Must be a positive, nonzero integer.",
+  "DEMO_NUMBER_OF_PARALLEL_SEGMENTS_BY_STREAM": "Number of parallel segments by stream",
   "DEMO_OBSERVE_QUALITY_CHANGES": "Observe media quality changes",
   "DEMO_OFFLINE": "Downloadable",
   "DEMO_OFFLINE_SEARCH": "Filters for assets that can be stored offline.",

diff --git a/demo/locales/source.json b/demo/locales/source.json
@@ -639,6 +639,10 @@
     "description": "A warning on number inputs, telling the user what the expected input format is.",
     "message": "Must be a positive, nonzero integer."
   },
+  "DEMO_NUMBER_OF_PARALLEL_SEGMENTS_BY_STREAM": {
+    "description": "The name of a configuration value.",
+    "message": "Number of parallel segments by stream."
+  },
   "DEMO_OBSERVE_QUALITY_CHANGES": {
     "description": "The name of a configuration value.",
     "message": "Observe media quality changes"

diff --git a/demo/main.js b/demo/main.js
@@ -582,7 +582,10 @@ shakaDemo.Main = class {
         };
         asset.storedProgress = 0;
         this.dispatchEventWithName_('shaka-main-offline-progress');
+        const start = Date.now();
         const stored = await storage.store(asset.manifestUri, metadata).promise;
+        const end = Date.now();
+        console.log('Download time:', end - start);
         asset.storedContent = stored;
       } catch (error) {
         this.onError_(/** @type {!shaka.util.Error} */ (error));

diff --git a/externs/shaka/player.js b/externs/shaka/player.js
@@ -1075,7 +1075,8 @@ shaka.extern.CmcdConfiguration;
  *       function(shaka.extern.TrackList):!Promise<shaka.extern.TrackList>,
  *   downloadSizeCallback: function(number):!Promise<boolean>,
  *   progressCallback: function(shaka.extern.StoredContent,number),
- *   usePersistentLicense: boolean
+ *   usePersistentLicense: boolean,
+ *   numberOfParallelSegmentsByStream: number
  * }}
  *
  * @property {function(shaka.extern.TrackList):!Promise<shaka.extern.TrackList>}
@@ -1098,6 +1099,12 @@ shaka.extern.CmcdConfiguration;
  *   license.  A network will be required to retrieve a temporary license to
  *   view.
  *   Defaults to <code>true</code>.
+ * @property {number} numberOfParallelSegmentsByStream
+ *   Number of parallel segments by stream. Putting a number other than the
+ *   default can help reduce download time.
+ *   Note: normally browsers limit to 5 request in parallel, so putting a
+ *   number higher than this will not help it download faster.
+ *   Defaults to <code>1</code>.
  * @exportDoc
  */
 shaka.extern.OfflineConfiguration;

diff --git a/lib/offline/storage.js b/lib/offline/storage.js
@@ -1334,10 +1334,19 @@ shaka.offline.Storage = class {
       if (!toDownload.has(pendingSegmentRefId)) {
         const estimateId = downloader.addDownloadEstimate(
             estimator.getSegmentEstimate(stream.id, segment));
+        let groupId = stream.id;
+        const numberOfParallelSegmentsByStream =
+            config.offline.numberOfParallelSegmentsByStream;
+        if (numberOfParallelSegmentsByStream > 1) {
+          // Note: 1000 is a random number to not coincide with other groups
+          // of other streams
+          groupId += 1000 + Math.floor(Math.random() *
+              numberOfParallelSegmentsByStream);
+        }
         const segmentDownload = new shaka.offline.DownloadInfo(
             segment,
             estimateId,
-            stream.id,
+            groupId,
             /* isInitSegment= */ false);
         toDownload.set(pendingSegmentRefId, segmentDownload);
       }

diff --git a/lib/util/player_configuration.js b/lib/util/player_configuration.js
@@ -222,6 +222,8 @@ shaka.util.PlayerConfiguration = class {
       // unexpected behaviours when someone tries to plays downloaded content
       // without a persistent license.
       usePersistentLicense: true,
+
+      numberOfParallelSegmentsByStream: 1,
     };
 
     const abr = {