fix: browser freezes when using shaka on long live streams

Novage · Jan 17, 2025 · 02af012 · 02af012
1 parent 113119f
commit 02af012
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Showing 3 changed files with 42 additions and 31 deletions.
diff --git a/packages/p2p-media-loader-shaka/src/manifest-parser-decorator.ts b/packages/p2p-media-loader-shaka/src/manifest-parser-decorator.ts
@@ -136,9 +136,13 @@ export class ManifestParserDecorator implements shaka.extern.ManifestParser {
 
         segmentIndex.get = originalGet;
         try {
-          const references = [...segmentIndex];
-          const firstItemReference = references[0];
-          const lastItemReference = references[references.length - 1];
+          const referencesCount = segmentIndex.getNumReferences();
+          const firstItemReference = segmentIndex.get(0);
+          const lastItemReference = segmentIndex.get(referencesCount - 1);
+
+          if (!firstItemReference || !lastItemReference) {
+            return reference;
+          }
 
           if (
             firstItemReference === prevFirstItemReference &&
@@ -150,7 +154,7 @@ export class ManifestParserDecorator implements shaka.extern.ManifestParser {
           prevLastItemReference = lastItemReference;
 
           // Segment index have been updated
-          segmentManager.updateStreamSegments(stream, references);
+          segmentManager.updateStreamSegments(stream);
           stream.isSegmentIndexAlreadyRead = true;
           this.debug(`Stream ${stream.id} is updated`);
         } catch {

diff --git a/packages/p2p-media-loader-shaka/src/segment-manager.ts b/packages/p2p-media-loader-shaka/src/segment-manager.ts
@@ -32,37 +32,26 @@ export class SegmentManager {
     if (shakaStream.segmentIndex) this.updateStreamSegments(shakaStream);
   }
 
-  updateStreamSegments(
-    shakaStream: HookedStream,
-    segmentReferences?: shaka.media.SegmentReference[],
-  ) {
+  updateStreamSegments(shakaStream: HookedStream) {
     const stream = this.core.getStream(shakaStream.id.toString());
     if (!stream) return;
 
-    const { segmentIndex } = stream.shakaStream;
-    if (!segmentReferences && segmentIndex) {
-      try {
-        segmentReferences = [...segmentIndex];
-      } catch {
-        return;
-      }
-    }
-    if (!segmentReferences) return;
-
     if (this.streamInfo.protocol === "hls") {
-      this.processHlsSegmentReferences(stream, segmentReferences);
+      this.processHlsSegmentReferences(stream);
     } else {
-      this.processDashSegmentReferences(stream, segmentReferences);
+      this.processDashSegmentReferences(stream);
     }
   }
 
   private processDashSegmentReferences(
     managerStream: StreamWithReadonlySegments,
-    segmentReferences: shaka.media.SegmentReference[],
   ) {
+    const { segmentIndex } = managerStream.shakaStream;
+    if (!segmentIndex) return;
+
     const staleSegmentsIds = new Set(managerStream.segments.keys());
     const newSegments: Segment[] = [];
-    for (const reference of segmentReferences) {
+    for (const reference of segmentIndex) {
       const externalId = Math.trunc(
         reference.getStartTime() / SEGMENT_ID_RESOLUTION_IN_SECONDS,
       );
@@ -89,22 +78,30 @@ export class SegmentManager {
 
   private processHlsSegmentReferences(
     managerStream: StreamWithReadonlySegments,
-    segmentReferences: shaka.media.SegmentReference[],
   ) {
+    const { segmentIndex } = managerStream.shakaStream;
     const { segments } = managerStream;
+
+    if (!segmentIndex) return;
+
     const lastMediaSequence = Utils.getStreamLastMediaSequence(managerStream);
+    const segmentRefsCount = segmentIndex.getNumReferences();
 
     const newSegments: Segment[] = [];
     if (segments.size === 0) {
       const firstReferenceMediaSequence =
         lastMediaSequence === undefined
           ? 0
-          : lastMediaSequence - segmentReferences.length + 1;
+          : lastMediaSequence - segmentRefsCount + 1;
+
+      for (let i = 0; i < segmentRefsCount; i++) {
+        const reference = segmentIndex.get(i);
+
+        if (!reference) continue;
 
-      for (const [index, reference] of segmentReferences.entries()) {
         const segment = Utils.createSegment({
           segmentReference: reference,
-          externalId: firstReferenceMediaSequence + index,
+          externalId: firstReferenceMediaSequence + i,
         });
         newSegments.push(segment);
       }
@@ -115,9 +112,13 @@ export class SegmentManager {
     if (!lastMediaSequence) return;
     let mediaSequence = lastMediaSequence;
 
-    for (const reference of itemsBackwards(segmentReferences)) {
+    for (let i = segmentRefsCount - 1; i >= 0; i--) {
+      const reference = segmentIndex.get(i);
+      if (!reference) continue;
+
       const runtimeId = Utils.getSegmentRuntimeIdFromReference(reference);
       if (segments.has(runtimeId)) break;
+
       const segment = Utils.createSegment({
         runtimeId,
         segmentReference: reference,
@@ -143,10 +144,6 @@ export class SegmentManager {
   }
 }
 
-function* itemsBackwards<T>(items: T[]) {
-  for (let i = items.length - 1; i >= 0; i--) yield items[i];
-}
-
 function* nSegmentsBackwards(
   segments: ReadonlyMap<string, Segment>,
   count: number,

diff --git a/packages/p2p-media-loader-shaka/src/types.ts b/packages/p2p-media-loader-shaka/src/types.ts
@@ -43,3 +43,13 @@ export type HookedNetworkingEngine = shaka.net.NetworkingEngine & {
 export type StreamWithReadonlySegments = Stream & {
   segments: ReadonlyMap<string, SegmentWithStream>;
 };
+
+declare global {
+  // eslint-disable-next-line @typescript-eslint/no-namespace
+  namespace shaka.media {
+    interface SegmentIndex {
+      get(position: number): shaka.media.SegmentReference | null;
+      getNumReferences(): number;
+    }
+  }
+}