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src/loader/level-details.ts

  1. import { Part } from './fragment';
  2. import type { Fragment } from './fragment';
  3. import type { AttrList } from '../utils/attr-list';
  4.  
  5. const DEFAULT_TARGET_DURATION = 10;
  6.  
  7. export class LevelDetails {
  8.   public PTSKnown: boolean = false;
  9.   public alignedSliding: boolean = false;
  10.   public averagetargetduration?: number;
  11.   public endCC: number = 0;
  12.   public endSN: number = 0;
  13.   public fragments: Fragment[];
  14.   public fragmentHint?: Fragment;
  15.   public partList: Part[] | null = null;
  16.   public initSegment: Fragment | null = null;
  17.   public live: boolean = true;
  18.   public ageHeader: number = 0;
  19.   public advancedDateTime?: number;
  20.   public updated: boolean = true;
  21.   public advanced: boolean = true;
  22.   public availabilityDelay?: number; // Manifest reload synchronization
  23.   public misses: number = 0;
  24.   public needSidxRanges: boolean = false;
  25.   public startCC: number = 0;
  26.   public startSN: number = 0;
  27.   public startTimeOffset: number | null = null;
  28.   public targetduration: number = 0;
  29.   public totalduration: number = 0;
  30.   public type: string | null = null;
  31.   public url: string;
  32.   public m3u8: string = '';
  33.   public version: number | null = null;
  34.   public canBlockReload: boolean = false;
  35.   public canSkipUntil: number = 0;
  36.   public canSkipDateRanges: boolean = false;
  37.   public skippedSegments: number = 0;
  38.   public recentlyRemovedDateranges?: string[];
  39.   public partHoldBack: number = 0;
  40.   public holdBack: number = 0;
  41.   public partTarget: number = 0;
  42.   public preloadHint?: AttrList;
  43.   public renditionReports?: AttrList[];
  44.   public tuneInGoal: number = 0;
  45.   public deltaUpdateFailed?: boolean;
  46.  
  47.   constructor(baseUrl) {
  48.     this.fragments = [];
  49.     this.url = baseUrl;
  50.   }
  51.  
  52.   reloaded(previous: LevelDetails | undefined) {
  53.     if (!previous) {
  54.       this.advanced = true;
  55.       this.updated = true;
  56.       return;
  57.     }
  58.     const partSnDiff = this.lastPartSn - previous.lastPartSn;
  59.     const partIndexDiff = this.lastPartIndex - previous.lastPartIndex;
  60.     this.updated =
  61.       this.endSN !== previous.endSN || !!partIndexDiff || !!partSnDiff;
  62.     this.advanced =
  63.       this.endSN > previous.endSN ||
  64.       partSnDiff > 0 ||
  65.       (partSnDiff === 0 && partIndexDiff > 0);
  66.     if (this.updated || this.advanced) {
  67.       this.misses = Math.floor(previous.misses * 0.6);
  68.     } else {
  69.       this.misses = previous.misses + 1;
  70.     }
  71.     this.availabilityDelay = previous.availabilityDelay;
  72.   }
  73.  
  74.   get hasProgramDateTime(): boolean {
  75.     if (this.fragments.length) {
  76.       return Number.isFinite(
  77.         this.fragments[this.fragments.length - 1].programDateTime as number
  78.       );
  79.     }
  80.     return false;
  81.   }
  82.  
  83.   get levelTargetDuration(): number {
  84.     return (
  85.       this.averagetargetduration ||
  86.       this.targetduration ||
  87.       DEFAULT_TARGET_DURATION
  88.     );
  89.   }
  90.  
  91.   get edge(): number {
  92.     return this.partEnd || this.fragmentEnd;
  93.   }
  94.  
  95.   get partEnd(): number {
  96.     if (this.partList?.length) {
  97.       return this.partList[this.partList.length - 1].end;
  98.     }
  99.     return this.fragmentEnd;
  100.   }
  101.  
  102.   get fragmentEnd(): number {
  103.     if (this.fragments?.length) {
  104.       return this.fragments[this.fragments.length - 1].end;
  105.     }
  106.     return 0;
  107.   }
  108.  
  109.   get age(): number {
  110.     if (this.advancedDateTime) {
  111.       return Math.max(Date.now() - this.advancedDateTime, 0) / 1000;
  112.     }
  113.     return 0;
  114.   }
  115.  
  116.   get lastPartIndex(): number {
  117.     if (this.partList?.length) {
  118.       return this.partList[this.partList.length - 1].index;
  119.     }
  120.     return -1;
  121.   }
  122.  
  123.   get lastPartSn(): number {
  124.     if (this.partList?.length) {
  125.       return this.partList[this.partList.length - 1].fragment.sn as number;
  126.     }
  127.     return this.endSN;
  128.   }
  129. }