perf: Improve times of probeSupport (#7889)

Fixes to #7449

Backported to v4.9.x

Author: avelad

lib/media/drm_engine.js

@@ -1947,17 +1947,47 @@ shaka.media.DrmEngine = class {
       support.set(keySystem, null);
     }
 
+    const checkKeySystem = (keySystem) => {
+      // Our Polyfill will reject anything apart com.apple.fps key systems.
+      // It seems the Safari modern EME API will allow to request a
+      // MediaKeySystemAccess for the ClearKey CDM, create and update a key
+      // session but playback will never start
+      // Safari bug: https://bugs.webkit.org/show_bug.cgi?id=231006
+      if (shaka.util.DrmUtils.isClearKeySystem(keySystem) &&
+          shaka.util.Platform.isSafari()) {
+        return false;
+      }
+      // FairPlay is a proprietary DRM from Apple and will never work on
+      // Windows.
+      if (shaka.util.DrmUtils.isFairPlayKeySystem(keySystem) &&
+          shaka.util.Platform.isWindows()) {
+        return false;
+      }
+      // PlayReady is a proprietary DRM from Microsoft and will never work on
+      // Apple platforms
+      if (shaka.util.DrmUtils.isPlayReadyKeySystem(keySystem) &&
+          (shaka.util.Platform.isMac() || shaka.util.Platform.isApple())) {
+        return false;
+      }
+      // Mozilla has no intention of supporting PlayReady according to
+      // comments posted on Bugzilla.
+      if (shaka.util.DrmUtils.isPlayReadyKeySystem(keySystem) &&
+          shaka.util.Platform.isFirefox()) {
+        return false;
+      }
+      // We are sure that WisePlay is not supported on Windows or macOS.
+      if (shaka.util.DrmUtils.isWisePlayKeySystem(keySystem) &&
+          (shaka.util.Platform.isWindows() || shaka.util.Platform.isMac())) {
+        return false;
+      }
+      return true;
+    };
+
     // Test each key system and encryption scheme.
     const tests = [];
     for (const encryptionScheme of testEncryptionSchemes) {
       for (const keySystem of testKeySystems) {
-        // Our Polyfill will reject anything apart com.apple.fps key systems.
-        // It seems the Safari modern EME API will allow to request a
-        // MediaKeySystemAccess for the ClearKey CDM, create and update a key
-        // session but playback will never start
-        // Safari bug: https://bugs.webkit.org/show_bug.cgi?id=231006
-        if (keySystem === 'org.w3.clearkey' &&
-            shaka.util.Platform.isSafari()) {
+        if (!checkKeySystem(keySystem)) {
           continue;
         }
         tests.push(testSystemEme(keySystem, encryptionScheme, '', ''));
@@ -1967,6 +1997,9 @@ shaka.media.DrmEngine = class {
 
     for (const keySystem of testKeySystems) {
       for (const robustness of (testRobustness[keySystem] || [])) {
+        if (!checkKeySystem(keySystem)) {
+          continue;
+        }
         tests.push(testSystemEme(keySystem, null, robustness, ''));
         tests.push(testSystemEme(keySystem, null, '', robustness));
         tests.push(testSystemMcap(keySystem, null, robustness, ''));

lib/util/drm_utils.js

@@ -157,6 +157,14 @@ shaka.util.DrmUtils = class {
     return false;
   }
 
+  /**
+   * @param {?string} keySystem
+   * @return {boolean}
+   */
+  static isWisePlayKeySystem(keySystem) {
+    return keySystem === 'com.huawei.wiseplay';
+  }
+
   /**
    * A method for generating a key for the MediaKeySystemAccessRequests cache.
    *

test/util/drm_utils_unit.js

@@ -212,4 +212,20 @@ describe('DrmUtils', () => {
           'com.abc.playready')).toBe(false);
     });
   });
+
+  describe('isWisePlayKeySystem', () => {
+    it('should return true for WisePlay', () => {
+      expect(shaka.util.DrmUtils.isWisePlayKeySystem(
+          'com.huawei.wiseplay')).toBe(true);
+    });
+
+    it('should return false for non-WisePlay key systems', () => {
+      expect(shaka.util.DrmUtils.isWisePlayKeySystem(
+          'com.widevine.alpha')).toBe(false);
+      expect(shaka.util.DrmUtils.isWisePlayKeySystem(
+          'com.microsoft.playready')).toBe(false);
+      expect(shaka.util.DrmUtils.isWisePlayKeySystem(
+          'com.apple.fps')).toBe(false);
+    });
+  });
 });