refactor: Add segment categories in clear logic

This commit optimizes the segment memory storage by introducing segment storage categories. The new SegmentCategories type is added to classify segments into different categories such as obsolete, beyondHalfHttpWindowBehind, behindPlayback, and aheadHttpWindow. The segment removal logic is updated to use these categories for better organization and efficiency.

Author: DimaDemchenko

packages/p2p-media-loader-core/src/segment-storage/segment-memory-storage.ts

@@ -23,6 +23,12 @@ type LastRequestedSegmentInfo = {
   endTime: number;
 };
 
+type SegmentCategories = {
+  obsolete: string[];
+  beyondHalfHttpWindowBehind: string[];
+  behindPlayback: string[];
+  aheadHttpWindow: string[];
+};
 const getStorageItemId = (streamId: string, segmentId: number) =>
   `${streamId}|${segmentId}`;
 
@@ -236,10 +242,12 @@ export class SegmentMemoryStorage implements SegmentStorage {
       return [];
     }
 
-    const segmentsToRemove: string[] = [];
-    const halfSegmentsBehindPlayback: string[] = [];
-    const allSegmentsBehindPlayback: string[] = [];
-    const segmentsAheadOfPlayback: string[] = [];
+    const segmentIds: SegmentCategories = {
+      obsolete: [],
+      beyondHalfHttpWindowBehind: [],
+      behindPlayback: [],
+      aheadHttpWindow: [],
+    };
 
     const currentPlayback = this.currentPlayback.position;
 
@@ -255,31 +263,31 @@ export class SegmentMemoryStorage implements SegmentStorage {
       );
 
       if (isLiveStream && currentPlayback > highDemandTimeWindow + endTime) {
-        segmentsToRemove.push(storageId);
+        segmentIds.obsolete.push(storageId);
         continue;
       }
 
       if (currentPlayback > endTime + httpDownloadTimeWindow * 0.95) {
-        segmentsToRemove.push(storageId);
+        segmentIds.obsolete.push(storageId);
       }
       if (currentPlayback > endTime + httpDownloadTimeWindow * 0.5) {
-        halfSegmentsBehindPlayback.push(storageId);
+        segmentIds.beyondHalfHttpWindowBehind.push(storageId);
       }
       if (currentPlayback > endTime) {
-        allSegmentsBehindPlayback.push(storageId);
+        segmentIds.behindPlayback.push(storageId);
       }
       if (endTime > currentPlayback + httpDownloadTimeWindow) {
-        segmentsAheadOfPlayback.push(storageId);
+        segmentIds.aheadHttpWindow.push(storageId);
       }
     }
 
-    if (isLiveStream) return segmentsToRemove;
-    if (segmentsToRemove.length > 0) return segmentsToRemove;
+    if (isLiveStream) return segmentIds.obsolete;
+    if (segmentIds.obsolete.length > 0) return segmentIds.obsolete;
 
     return firstNonEmpty(
-      halfSegmentsBehindPlayback,
-      allSegmentsBehindPlayback,
-      segmentsAheadOfPlayback,
+      segmentIds.beyondHalfHttpWindowBehind,
+      segmentIds.behindPlayback,
+      segmentIds.aheadHttpWindow,
     );
   }