fix(hls): limit preload across buffered islands

packages/xgplayer-hls/__tests__/hls.spec.js

@@ -228,6 +228,58 @@ describe('Hls', () => {
     expect(removeAllListeners).toHaveBeenCalled()
   })
 
+  test('vod stops preloading when discontinuous buffered islands exceed preloadTime', async () => {
+    const hls = new Hls({ media, url: 'url', preloadTime: 30 })
+    const loadSegmentDirect = jest.spyOn(hls, '_loadSegmentDirect').mockImplementation(() => Promise.resolve())
+    const tryEos = jest.spyOn(hls, '_tryEos').mockImplementation(() => {})
+    hls._playlist.nextSegment = { sn: 4, start: 37.4, end: 46.6 }
+    hls._playlist.lastSegment = { duration: 9.2 }
+    Buffer.info = () => ({
+      start: 0,
+      end: 9.2,
+      index: 0,
+      nextStart: 9.4,
+      remaining: 9.2,
+      buffers: [
+        [0, 9.2],
+        [9.4, 18.6],
+        [18.8, 27.9],
+        [28.1, 37.3]
+      ]
+    })
+
+    await hls._loadSegment()
+
+    expect(tryEos).toHaveBeenCalled()
+    expect(loadSegmentDirect).not.toHaveBeenCalled()
+  })
+
+  test('vod keeps loading when next segment starts at the next buffered island', async () => {
+    const hls = new Hls({ media, url: 'url', preloadTime: 30 })
+    const loadSegmentDirect = jest.spyOn(hls, '_loadSegmentDirect').mockImplementation(() => Promise.resolve())
+    const tryEos = jest.spyOn(hls, '_tryEos').mockImplementation(() => {})
+    hls._playlist.nextSegment = { sn: 1, start: 9.4, end: 18.6 }
+    hls._playlist.lastSegment = { duration: 9.2 }
+    Buffer.info = () => ({
+      start: 0,
+      end: 9.2,
+      index: 0,
+      nextStart: 9.4,
+      remaining: 9.2,
+      buffers: [
+        [0, 9.2],
+        [9.4, 18.6],
+        [18.8, 27.9],
+        [28.1, 37.3]
+      ]
+    })
+
+    await hls._loadSegment()
+
+    expect(tryEos).not.toHaveBeenCalled()
+    expect(loadSegmentDirect).toHaveBeenCalled()
+  })
+
   test('switchStream', async () => {
     const hls = new Hls({ media })
 

packages/xgplayer-hls/src/hls/index.js

@@ -117,6 +117,23 @@ export class Hls extends EventEmitter {
     return Buffer.info(Buffer.get(this.media), this.media?.currentTime, maxHole)
   }
 
+  _getPreloadBufferLength (bInfo, nextSegment) {
+    const remaining = bInfo?.remaining || 0
+    const buffers = bInfo?.buffers
+    const nextStart = bInfo?.nextStart
+    if (!buffers?.length || !nextSegment || !nextStart || nextSegment.start <= nextStart) return remaining
+
+    let fullBufferLength = remaining
+    const bufferedIndex = bInfo.end ? bInfo.index : -1
+    for (let i = buffers.length - 1; i > bufferedIndex; i--) {
+      const item = buffers[i]
+      if (item[0] < nextSegment.start) {
+        fullBufferLength += item[1] - item[0]
+      }
+    }
+    return fullBufferLength
+  }
+
   /**
    * @returns {Stats}
    */
@@ -520,8 +537,9 @@ export class Hls extends EventEmitter {
         bInfo = this.bufferInfo(bInfo.nextStart || 0.5)
       }
       const bufferThroughout = Math.abs(bInfo.end - this.media.duration) < maxBufferThroughout
+      const preloadBufferLength = this._getPreloadBufferLength(bInfo, nextSegment)
       // Only stop loading if we've buffered enough preload time or reached end AND all segments are loaded
-      if (bInfo.remaining >= config.preloadTime || (bufferThroughout && !nextSegment)) {
+      if (preloadBufferLength >= config.preloadTime || (bufferThroughout && !nextSegment)) {
         this._tryEos()
         return
       }