feat(HLS): Improve HLS parsing time (shaka-project#5264)

Related to shaka-project#5261 This PR delays the creation of the final urls of the segments so that they are not calculated in each media playlist parsing.
theodab · Jun 8, 2023 · 2ca7d0b · 2ca7d0b
1 parent 5a5a7ac
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Showing 4 changed files with 57 additions and 26 deletions.
diff --git a/lib/hls/hls_classes.js b/lib/hls/hls_classes.js
@@ -11,6 +11,7 @@ goog.provide('shaka.hls.Segment');
 goog.provide('shaka.hls.Tag');
 
 goog.require('goog.asserts');
+goog.require('shaka.hls.Utils');
 goog.require('shaka.util.Error');
 
 
@@ -202,24 +203,48 @@ shaka.hls.Segment = class {
   /**
    * Creates an HLS segment object.
    *
-   * @param {string} absoluteUri An absolute URI.
+   * @param {string} absoluteMediaPlaylistUri An absolute Media Playlist URI.
+   * @param {string} verbatimSegmentUri verbatim segment URI.
    * @param {!Array.<shaka.hls.Tag>} tags
    * @param {!Array.<shaka.hls.Tag>=} partialSegments
    */
-  constructor(absoluteUri, tags, partialSegments=[]) {
+  constructor(absoluteMediaPlaylistUri, verbatimSegmentUri, tags,
+      partialSegments=[]) {
     /** @const {!Array.<shaka.hls.Tag>} */
     this.tags = tags;
 
-    /**
-     * An absolute URI.
-     *
-     * @const {string}
-     */
-    this.absoluteUri = absoluteUri;
+    /** @type {?string} */
+    this.absoluteUri_ = null;
+
+    /** @type {?string} */
+    this.absoluteMediaPlaylistUri_ = absoluteMediaPlaylistUri;
+
+    /** @type {?string} */
+    this.verbatimSegmentUri_ = verbatimSegmentUri;
 
     /** @type {!Array.<shaka.hls.Tag>} */
     this.partialSegments = partialSegments;
   }
+
+  /**
+   * Returns an absolute URI.
+   *
+   * @return {string}
+   */
+  get absoluteUri() {
+    if (!this.absoluteUri_ &&
+        this.absoluteMediaPlaylistUri_ && this.verbatimSegmentUri_) {
+      goog.asserts.assert(this.absoluteMediaPlaylistUri_,
+          'An absolute Media Playlist URI should be defined!');
+      goog.asserts.assert(this.verbatimSegmentUri_,
+          'An verbatim segment URI should be defined!');
+      this.absoluteUri_ = shaka.hls.Utils.constructAbsoluteUri(
+          this.absoluteMediaPlaylistUri_, this.verbatimSegmentUri_);
+      this.absoluteMediaPlaylistUri_ = null;
+      this.verbatimSegmentUri_ = null;
+    }
+    return this.absoluteUri_ || '';
+  }
 };
 
 

diff --git a/lib/hls/manifest_text_parser.js b/lib/hls/manifest_text_parser.js
@@ -172,15 +172,13 @@ shaka.hls.ManifestTextParser = class {
         // Skip comments.
       } else {
         const verbatimSegmentUri = line.trim();
-        const absoluteSegmentUri = shaka.hls.Utils.constructAbsoluteUri(
-            absoluteMediaPlaylistUri, verbatimSegmentUri);
         // Attach the last parsed EXT-X-MAP tag to the segment.
         if (currentMapTag) {
           segmentTags.push(currentMapTag);
         }
         // The URI appears after all of the tags describing the segment.
-        const segment = new shaka.hls.Segment(absoluteSegmentUri, segmentTags,
-            partialSegmentTags);
+        const segment = new shaka.hls.Segment(absoluteMediaPlaylistUri,
+            verbatimSegmentUri, segmentTags, partialSegmentTags);
         segments.push(segment);
         segmentTags = [];
         partialSegmentTags = [];
@@ -195,7 +193,7 @@ shaka.hls.ManifestTextParser = class {
       if (currentMapTag) {
         segmentTags.push(currentMapTag);
       }
-      const segment = new shaka.hls.Segment('', segmentTags,
+      const segment = new shaka.hls.Segment('', '', segmentTags,
           partialSegmentTags);
       segments.push(segment);
     }

diff --git a/lib/util/manifest_parser_utils.js b/lib/util/manifest_parser_utils.js
@@ -19,6 +19,9 @@ shaka.util.ManifestParserUtils = class {
    * Resolves an array of relative URIs to the given base URIs. This will result
    * in M*N number of URIs.
    *
+   * Note: This method is slow in SmartTVs and Consoles. It should only be
+   * called when necessary.
+   *
    * @param {!Array.<string>} baseUris
    * @param {!Array.<string>} relativeUris
    * @return {!Array.<string>}

diff --git a/test/hls/manifest_text_parser_unit.js b/test/hls/manifest_text_parser_unit.js
@@ -307,7 +307,7 @@ describe('ManifestTextParser', () => {
               new shaka.hls.Tag(/* id= */ 0, 'EXT-X-MEDIA-SEQUENCE', [], '1'),
             ],
             segments: [
-              new shaka.hls.Segment('https://test/test.mp4',
+              new shaka.hls.Segment('https://test/manifest.m3u8', 'https://test/test.mp4',
                   [
                     new shaka.hls.Tag(/* id= */ 2, 'EXTINF', [], '5.99467'),
                   ]),
@@ -332,7 +332,7 @@ describe('ManifestTextParser', () => {
               new shaka.hls.Tag(/* id= */ 0, 'EXT-X-MEDIA-SEQUENCE', [], '1'),
             ],
             segments: [
-              new shaka.hls.Segment('https://test/test.mp4', [
+              new shaka.hls.Segment('https://test/manifest.m3u8', 'https://test/test.mp4', [
                 new shaka.hls.Tag(
                     /* id= */ 2,
                     'EXTINF',
@@ -360,7 +360,7 @@ describe('ManifestTextParser', () => {
               new shaka.hls.Tag(/* id= */ 2, 'EXT-X-TARGETDURATION', [], '6'),
             ],
             segments: [
-              new shaka.hls.Segment('https://test/test.mp4',
+              new shaka.hls.Segment('https://test/manifest.m3u8', 'https://test/test.mp4',
                   [
                     new shaka.hls.Tag(/* id= */ 1, 'EXT-X-KEY',
                         [
@@ -393,7 +393,7 @@ describe('ManifestTextParser', () => {
               new shaka.hls.Tag(/* id= */ 0, 'EXT-X-MEDIA-SEQUENCE', [], '1'),
             ],
             segments: [
-              new shaka.hls.Segment('https://test/test.mp4',
+              new shaka.hls.Segment('https://test/manifest.m3u8', 'test.mp4',
                   [
                     new shaka.hls.Tag(/* id= */ 2, 'EXTINF', [], '5.99467'),
                   ]),
@@ -427,9 +427,9 @@ describe('ManifestTextParser', () => {
               new shaka.hls.Tag(/* id= */ 0, 'EXT-X-TARGETDURATION', [], '6'),
             ],
             segments: [
-              new shaka.hls.Segment('https://test/uri',
+              new shaka.hls.Segment('https://test/manifest.m3u8', 'uri',
                   [new shaka.hls.Tag(2, 'EXTINF', [], '5')]),
-              new shaka.hls.Segment('https://test/uri2',
+              new shaka.hls.Segment('https://test/manifest.m3u8', 'uri2',
                   [new shaka.hls.Tag(3, 'EXTINF', [], '4')]),
             ],
           },
@@ -449,9 +449,9 @@ describe('ManifestTextParser', () => {
               new shaka.hls.Tag(/* id= */ 4, 'EXT-X-ENDLIST', []),
             ],
             segments: [
-              new shaka.hls.Segment('https://test/uri',
+              new shaka.hls.Segment('https://test/manifest.m3u8', 'uri',
                   [new shaka.hls.Tag(2, 'EXTINF', [], '5')]),
-              new shaka.hls.Segment('https://test/uri2',
+              new shaka.hls.Segment('https://test/manifest.m3u8', 'uri2',
                   [new shaka.hls.Tag(3, 'EXTINF', [], '4')]),
             ],
           },
@@ -508,20 +508,23 @@ describe('ManifestTextParser', () => {
             ],
             segments: [
               new shaka.hls.Segment(
-                  /* absoluteUri= */ 'https://test/uri',
+                  /* absoluteMediaPlaylistUri= */ 'https://test/manifest.m3u8',
+                  /* verbatimSegmentUri= */ 'uri',
                   /* tags= */ [
                     new shaka.hls.Tag(3, 'EXTINF', [], '5'),
                     mapTag,
                   ]),
               new shaka.hls.Segment(
-                  /* absoluteUri= */ 'https://test/uri2',
+                  /* absoluteMediaPlaylistUri= */ 'https://test/manifest.m3u8',
+                  /* verbatimSegmentUri= */ 'uri2',
                   /* tags= */ [
                     new shaka.hls.Tag(6, 'EXTINF', [], '2'),
                     mapTag,
                   ],
                   /* partialSegments= */ partialSegments1),
               new shaka.hls.Segment(
-                  /* absoluteUri= */ '',
+                  /* absoluteMediaPlaylistUri= */ '',
+                  /* verbatimSegmentUri= */ '',
                   /* tags= */ [mapTag],
                   /* partialSegments= */ partialSegments2),
             ],
@@ -574,13 +577,15 @@ describe('ManifestTextParser', () => {
             ],
             segments: [
               new shaka.hls.Segment(
-                  /* absoluteUri= */ 'https://test/uri',
+                  /* absoluteMediaPlaylistUri= */ 'https://test/manifest.m3u8',
+                  /* verbatimSegmentUri= */ 'uri',
                   /* tags= */ [
                     new shaka.hls.Tag(3, 'EXTINF', [], '5'),
                     mapTag,
                   ]),
               new shaka.hls.Segment(
-                  /* absoluteUri= */ '',
+                  /* absoluteMediaPlaylistUri= */ '',
+                  /* verbatimSegmentUri= */ '',
                   /* tags= */ [preloadMapTag],
                   /* partialSegments= */ preloadSegment),
             ],