fix: Manually order key for decodingInfo cache

shaka-project · Dec 6, 2022 · b446633 · b446633
1 parent 68f10a1
commit b446633
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Showing 2 changed files with 41 additions and 6 deletions.
diff --git a/lib/util/stream_utils.js b/lib/util/stream_utils.js
@@ -510,10 +510,45 @@ shaka.util.StreamUtils = class {
    * @private
    */
   static async getDecodingInfosForVariant_(variant, decodingConfig) {
+    // Construct a key for that decoding config. By using this instead of plain
+    // JSON.stringify, we ensure that the keys are always in a consistent order.
+    const cacheKeyAr = [decodingConfig.type];
+    if (decodingConfig.video) {
+      cacheKeyAr.push(decodingConfig.video.contentType);
+      cacheKeyAr.push(decodingConfig.video.width);
+      cacheKeyAr.push(decodingConfig.video.height);
+      cacheKeyAr.push(decodingConfig.video.bitrate);
+      cacheKeyAr.push(decodingConfig.video.framerate);
+      cacheKeyAr.push(decodingConfig.video.transferFunction);
+    }
+    if (decodingConfig.audio) {
+      cacheKeyAr.push(decodingConfig.audio.contentType);
+      cacheKeyAr.push(decodingConfig.audio.channels);
+      cacheKeyAr.push(decodingConfig.audio.bitrate);
+      cacheKeyAr.push(decodingConfig.audio.samplerate);
+      cacheKeyAr.push(decodingConfig.audio.spatialRendering);
+    }
+    if (decodingConfig.keySystemConfiguration) {
+      const keyConfig = decodingConfig.keySystemConfiguration;
+      cacheKeyAr.push(keyConfig.keySystem);
+      cacheKeyAr.push(keyConfig.initDataType);
+      cacheKeyAr.push(keyConfig.persistentState);
+      cacheKeyAr.push(keyConfig.distinctiveIdentifier);
+      cacheKeyAr.push(keyConfig.sessionTypes.join(','));
+      if (keyConfig.audio) {
+        cacheKeyAr.push(keyConfig.audio.robustness);
+      }
+      if (keyConfig.video) {
+        cacheKeyAr.push(keyConfig.video.robustness);
+      }
+    }
+    const cacheKey = cacheKeyAr.map((term) => `{${term}}`).join('');
+
     try {
-      const cacheKey = JSON.stringify(decodingConfig);
-      const cache = shaka.util.StreamUtils.decodingConfigCache;
+      const cache = shaka.util.StreamUtils.decodingConfigCache_;
       if (cache[cacheKey]) {
+        shaka.log.v2('Using cached results of mediaCapabilities.decodingInfo',
+            'for key', cacheKey);
         variant.decodingInfos.push(cache[cacheKey]);
       } else {
         const result =
@@ -1601,9 +1636,9 @@ shaka.util.StreamUtils = class {
  * (stringified) decodingConfig.
  *
  * @type {Object.<(!string), (!MediaCapabilitiesDecodingInfo)>}
- * @export
+ * @private
  */
-shaka.util.StreamUtils.decodingConfigCache = {};
+shaka.util.StreamUtils.decodingConfigCache_ = {};
 
 
 /** @private {number} */

diff --git a/test/test/boot.js b/test/test/boot.js
@@ -332,8 +332,8 @@ function configureJasmineEnvironment() {
   }
 
   // Reset decoding config cache after each test.
-  afterEach(() => {
-    shaka.util.StreamUtils.decodingConfigCache = {};
+  afterEach(/** @suppress {accessControls} */ () => {
+    shaka.util.StreamUtils.decodingConfigCache_ = {};
   });
 
   // Code in karma-jasmine's adapter will malform test failures when the