perf: ts parser O(n^2) performance bug. (#6035)

This caused high cpu usage when the ts file segments are large.
shaka-project · Jan 8, 2024 · dd50028 · dd50028
1 parent a70136d
commit dd50028
Showing 1 changed file with 15 additions and 16 deletions.
diff --git a/lib/util/ts_parser.js b/lib/util/ts_parser.js
@@ -32,7 +32,7 @@ shaka.util.TsParser = class {
     /** @private {?string} */
     this.videoCodec_ = null;
 
-    /** @private {!Array.<Uint8Array>} */
+    /** @private {!Array.<!Array.<Uint8Array>>} */
     this.videoData_ = [];
 
     /** @private {!Array.<shaka.extern.MPEG_PES>} */
@@ -44,7 +44,7 @@ shaka.util.TsParser = class {
     /** @private {?string} */
     this.audioCodec_ = null;
 
-    /** @private {!Array.<Uint8Array>} */
+    /** @private {!Array.<!Array.<Uint8Array>>} */
     this.audioData_ = [];
 
     /** @private {!Array.<shaka.extern.MPEG_PES>} */
@@ -53,7 +53,7 @@ shaka.util.TsParser = class {
     /** @private {?number} */
     this.id3Pid_ = null;
 
-    /** @private {!Array.<Uint8Array>} */
+    /** @private {!Array.<!Array.<Uint8Array>>} */
     this.id3Data_ = [];
   }
 
@@ -79,7 +79,6 @@ shaka.util.TsParser = class {
    */
   parse(data) {
     const packetLength = shaka.util.TsParser.PacketLength_;
-    const Uint8ArrayUtils = shaka.util.Uint8ArrayUtils;
 
     // A TS fragment should contain at least 3 TS packets, a PAT, a PMT, and
     // one PID.
@@ -162,38 +161,35 @@ shaka.util.TsParser = class {
           case this.videoPid_: {
             const videoData = data.subarray(offset, start + packetLength);
             if (payloadUnitStartIndicator) {
-              this.videoData_.push(videoData);
+              this.videoData_.push([videoData]);
             } else if (this.videoData_.length) {
               const prevVideoData = this.videoData_[this.videoData_.length - 1];
               if (prevVideoData) {
-                this.videoData_[this.videoData_.length - 1] =
-                    Uint8ArrayUtils.concat(prevVideoData, videoData);
+                this.videoData_[this.videoData_.length - 1].push(videoData);
               }
             }
             break;
           }
           case this.audioPid_: {
             const audioData = data.subarray(offset, start + packetLength);
             if (payloadUnitStartIndicator) {
-              this.audioData_.push(audioData);
+              this.audioData_.push([audioData]);
             } else if (this.audioData_.length) {
               const prevAudioData = this.audioData_[this.audioData_.length - 1];
               if (prevAudioData) {
-                this.audioData_[this.audioData_.length - 1] =
-                    Uint8ArrayUtils.concat(prevAudioData, audioData);
+                this.audioData_[this.audioData_.length - 1].push(audioData);
               }
             }
             break;
           }
           case this.id3Pid_: {
             const id3Data = data.subarray(offset, start + packetLength);
             if (payloadUnitStartIndicator) {
-              this.id3Data_.push(id3Data);
+              this.id3Data_.push([id3Data]);
             } else if (this.id3Data_.length) {
               const prevId3Data = this.id3Data_[this.id3Data_.length - 1];
               if (prevId3Data) {
-                this.id3Data_[this.id3Data_.length - 1] =
-                    Uint8ArrayUtils.concat(prevId3Data, id3Data);
+                this.id3Data_[this.id3Data_.length - 1].push(id3Data);
               }
             }
             break;
@@ -588,7 +584,8 @@ shaka.util.TsParser = class {
   getMetadata() {
     const timescale = shaka.util.TsParser.Timescale;
     const metadata = [];
-    for (const id3Data of this.id3Data_) {
+    for (const id3DataArray of this.id3Data_) {
+      const id3Data = shaka.util.Uint8ArrayUtils.concat(...id3DataArray);
       const pes = this.parsePES_(id3Data);
       if (pes) {
         metadata.push({
@@ -612,7 +609,8 @@ shaka.util.TsParser = class {
   getAudioData() {
     if (this.audioData_.length && !this.audioPes_.length) {
       let sort = false;
-      for (const audioData of this.audioData_) {
+      for (const audioDataArray of this.audioData_) {
+        const audioData = shaka.util.Uint8ArrayUtils.concat(...audioDataArray);
         const pes = this.parsePES_(audioData);
         let previousPes = this.audioPes_.length ?
             this.audioPes_[this.audioPes_.length - 1] : null;
@@ -654,7 +652,8 @@ shaka.util.TsParser = class {
   getVideoData(naluProcessing = true) {
     if (this.videoData_.length && !this.videoPes_.length) {
       let sort = false;
-      for (const videoData of this.videoData_) {
+      for (const videoDataArray of this.videoData_) {
+        const videoData = shaka.util.Uint8ArrayUtils.concat(...videoDataArray);
         const pes = this.parsePES_(videoData);
         let previousPes = this.videoPes_.length ?
             this.videoPes_[this.videoPes_.length - 1] : null;