fix: Replace Loader.getResponseHeader() with Loader.getCacheAge().

api-extractor/report/hls.js.api.md

@@ -1555,8 +1555,7 @@ export interface Loader<T extends LoaderContext> {
     context: T;
     // (undocumented)
     destroy(): void;
-    // (undocumented)
-    getResponseHeader(name: string): string | null;
+    getCacheAge?: () => number | null;
     // (undocumented)
     load(context: LoaderContext, config: LoaderConfiguration, callbacks: LoaderCallbacks<T>): void;
     // (undocumented)

src/loader/playlist-loader.ts

@@ -684,8 +684,12 @@ class PlaylistLoader {
     }
 
     if (levelDetails.live) {
-      const ageHeader = loader.getResponseHeader('age');
-      levelDetails.ageHeader = ageHeader ? parseFloat(ageHeader) : 0;
+      if (loader.getCacheAge) {
+        levelDetails.ageHeader = loader.getCacheAge() || 0;
+      }
+      if (!loader.getCacheAge || isNaN(levelDetails.ageHeader)) {
+        levelDetails.ageHeader = 0;
+      }
     }
 
     switch (type) {

src/types/loader.ts

@@ -120,7 +120,16 @@ export interface Loader<T extends LoaderContext> {
     config: LoaderConfiguration,
     callbacks: LoaderCallbacks<T>
   ): void;
-  getResponseHeader(name: string): string | null;
+  /**
+   * `getCacheAge()` is called by hls.js to get the duration that a given object
+   * has been sitting in a cache proxy when playing live.  If implemented,
+   * this should return a value in seconds.
+   *
+   * For HTTP based loaders, this should return the contents of the "age" header.
+   *
+   * @returns time object being lodaded
+   */
+  getCacheAge?: () => number | null;
   context: T;
   loader: any;
   stats: LoaderStats;

src/utils/fetch-loader.ts

@@ -160,15 +160,13 @@ class FetchLoader implements Loader<LoaderContext> {
       });
   }
 
-  getResponseHeader(name: string): string | null {
+  getCacheAge(): number | null {
+    let result: number | null = null;
     if (this.response) {
-      try {
-        return this.response.headers.get(name);
-      } catch (error) {
-        /* Could not get header */
-      }
+      const ageHeader = this.response.headers.get('age');
+      result = ageHeader ? parseFloat(ageHeader) : null;
     }
-    return null;
+    return result;
   }
 
   private loadProgressively(

src/utils/xhr-loader.ts

@@ -249,11 +249,16 @@ class XhrLoader implements Loader<LoaderContext> {
     }
   }
 
-  getResponseHeader(name: string): string | null {
-    if (this.loader && this.loader.getAllResponseHeaders().indexOf(name) >= 0) {
-      return this.loader.getResponseHeader(name);
+  getCacheAge(): number | null {
+    let result: number | null = null;
+    if (
+      this.loader &&
+      this.loader.getAllResponseHeaders().indexOf('age') >= 0
+    ) {
+      const ageHeader = this.loader.getResponseHeader('age');
+      result = ageHeader ? parseFloat(ageHeader) : null;
     }
-    return null;
+    return result;
   }
 }
 

tests/unit/loader/fragment-loader.ts

@@ -36,9 +36,6 @@ class MockXhr implements Loader<LoaderContext> {
 
   abort() {}
   destroy(): void {}
-  getResponseHeader(name: string): string | null {
-    return null;
-  }
 }
 
 describe('FragmentLoader tests', function () {