fix(MSS): Fix playback of some MSS streams (shaka-project#7517)

fix(DASH): Fix playback of some DASH with multiple period (shaka-project#7516)

With this change, closeSegmentIndex() of stream removed of a period are defered in StreamingEngine.onUpdate_()

Fixes shaka-project#7517

lib/dash/dash_parser.js

@@ -1491,6 +1491,16 @@ shaka.dash.DashParser = class {
     }
   }
 
+  /**
+   * Handles deferred releases of old SegmentIndexes
+   * content type from a previous update.
+   */
+  handleDeferredCloseSegmentIndexes() {
+    if (this.periodCombiner_) {
+      this.periodCombiner_.handleDeferredCloseSegmentIndexes_();
+    }
+  }
+
   /**
    * Clean StreamMap Object to remove reference of deleted Stream Object
    * @private

lib/media/segment_index.js

@@ -308,6 +308,19 @@ shaka.media.SegmentIndex = class {
     this.numEvicted_ += diff;
   }
 
+  /**
+   * Removes all SegmentReferences that end before the given time.
+   *
+   * @param {number} time The time in seconds.
+   * @export
+   */
+  evictAll() {
+    if (this.references.length) {
+      this.numEvicted_ += this.references.length;
+      this.references = [];
+    }
+  }
+
 
   /**
    * Drops references that start after windowEnd, or end before windowStart,

lib/media/streaming_engine.js

@@ -148,6 +148,13 @@ shaka.media.StreamingEngine = class {
 
     /** @private {?shaka.media.StreamingEngine.MediaState_} */
     this.lastTextMediaStateBeforeUnload_ = null;
+
+    /**
+     * Defered closedSegmentIndex of the periodCombiner.
+     *
+     * @private {function}
+     */
+    this.periodCombinerDeferredCloseSegmentIndexesFunction_ = null;
   }
 
   /** @override */
@@ -182,6 +189,7 @@ shaka.media.StreamingEngine = class {
     this.playerInterface_ = null;
     this.manifest_ = null;
     this.config_ = null;
+    this.periodCombinerDeferredCloseSegmentIndexesFunction_ = null;
   }
 
   /**
@@ -269,6 +277,14 @@ shaka.media.StreamingEngine = class {
     }
   }
 
+  /**
+   * Provide function for releases of old SegmentIndexes of the PeriodCombiner
+   * @param {function} extraDeferredCloseSegmentIndexes
+   */
+  setExtraDeferredCloseSegmentIndexesFunction(deferredCloseSegmentIndexesFunction)
+  {
+    this.periodCombinerDeferredCloseSegmentIndexesFunction_ = deferredCloseSegmentIndexesFunction;
+  }
 
   /**
    * Applies a playback range. This will only affect non-live content.
@@ -1255,6 +1271,12 @@ shaka.media.StreamingEngine = class {
         }
         return;
       }
+
+      if (this.periodCombinerDeferredCloseSegmentIndexesFunction_)
+      {   
+        this.periodCombinerDeferredCloseSegmentIndexesFunction_();
+      }
+
     }
 
     // Update the MediaState.

lib/player.js

@@ -2570,6 +2570,8 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
 
     this.streamingEngine_ = this.createStreamingEngine();
     this.streamingEngine_.configure(this.config_.streaming);
+    if (this.parser_.handleDeferredCloseSegmentIndexes)
+        this.streamingEngine_.setExtraDeferredCloseSegmentIndexesFunction(this.parser_.handleDeferredCloseSegmentIndexes)
 
     // Set the load mode to "loaded with media source" as late as possible so
     // that public methods won't try to access internal components until

lib/util/periods.js

@@ -56,6 +56,14 @@ shaka.util.PeriodCombiner = class {
      * @private {!Set.<string>}
      */
     this.usedPeriodIds_ = new Set();
+
+    /**
+     * Retains a reference to the function used to close SegmentIndex objects
+     * for streams which were switched away from during an ongoing update_() 
+     * just after the period removal.
+     * @private {!Map.<string, !function()>}
+     */
+    this.deferredCloseSegmentIndex_ = new Map();
   }
 
   /** @override */
@@ -69,6 +77,7 @@ shaka.util.PeriodCombiner = class {
         stream.segmentIndex.release();
       }
     }
+    this.handleDeferredCloseSegmentIndexes_();
 
     this.audioStreams_ = [];
     this.videoStreams_ = [];
@@ -110,6 +119,21 @@ shaka.util.PeriodCombiner = class {
     return this.imageStreams_;
   }
 
+
+  /**
+   * Handles deferred releases of old SegmentIndexes
+   * content type from a previous update.
+   * @private
+   */
+  handleDeferredCloseSegmentIndexes_() {
+    for (const [key, value] of this.deferredCloseSegmentIndex_.entries()) {
+      const streamId = /** @type {string} */ (key);
+      const closeSegmentIndex = /** @type {!function()} */ (value);
+      closeSegmentIndex();
+      this.deferredCloseSegmentIndex_.delete(streamId);
+    }
+  }
+
   /**
    * Deletes a stream from matchedStreams because it is no longer needed
    *
@@ -154,9 +178,24 @@ shaka.util.PeriodCombiner = class {
         });
       }
     }
-    if (stream.segmentIndex) {
-      stream.closeSegmentIndex();
+
+    if (stream.segmentIndex && !this.deferredCloseSegmentIndex_.has(stream.id)) {
+      const originalcloseSegmentIndex = stream.closeSegmentIndex;
+      stream.closeSegmentIndex = () => {
+        if(stream.segmentIndex)
+        {
+          /**
+           * as the closure of the segmentIndex is defered
+           * update the number of evicted references in case or
+           * than 2 of more period are removed.
+           */ 
+          stream.segmentIndex.evictAll();
+        }
+        originalcloseSegmentIndex();
+      }
+      this.deferredCloseSegmentIndex_.set(stream.id, stream.closeSegmentIndex);
     }
+
     this.usedPeriodIds_.delete(periodId);
   }