Fix: Set watermark-cache params for dash segments (#422)

In theory, if a content-url-template is given with watermark-cache
(cache-busting) params from the server, all dash requests should carry
those cache-busting params. They did not however, because the
content-url-template is only used to construct the URL of the manifest -
the segment URLs are constructed by shaka-player itself, based on the
manifest url, but ignores all query-params on the manifest. This is why
we have a requestFilter function, but watermark-cache busting parameters
weren't taken into account. This commit adds a watermark cache-busting
parameter to every segment request, if the file is watermarked.

src/lib/viewers/media/DashViewer.js

@@ -1,7 +1,7 @@
 import autobind from 'autobind-decorator';
 import VideoBaseViewer from './VideoBaseViewer';
 import fullscreen from '../../Fullscreen';
-import { get } from '../../util';
+import { appendQueryParams, get } from '../../util';
 import { getRepresentation } from '../../file';
 import { MEDIA_STATIC_ASSETS_VERSION } from '../../constants';
 import './Dash.scss';
@@ -78,6 +78,7 @@ class DashViewer extends VideoBaseViewer {
     load() {
         this.setup();
         this.mediaUrl = this.options.representation.content.url_template;
+        this.watermarkCacheBust = Date.now();
         this.mediaEl.addEventListener('loadeddata', this.loadeddataHandler);
 
         return Promise.all([this.loadAssets(this.getJSAssets()), this.getRepStatus().getPromise()])
@@ -164,7 +165,13 @@ class DashViewer extends VideoBaseViewer {
     requestFilter(type, request) {
         const asset = type === shaka.net.NetworkingEngine.RequestType.MANIFEST ? MANIFEST : undefined;
         /* eslint-disable no-param-reassign */
-        request.uris = request.uris.map((uri) => this.createContentUrlWithAuthParams(uri, asset));
+        request.uris = request.uris.map((uri) => {
+            let newUri = this.createContentUrlWithAuthParams(uri, asset);
+            if (asset !== MANIFEST && this.options.file.watermark_info.is_watermarked) {
+                newUri = appendQueryParams(newUri, { 'watermark-cache': this.watermarkCacheBust });
+            }
+            return newUri;
+        });
         /* eslint-enable no-param-reassign */
     }
 

src/lib/viewers/media/__tests__/DashViewer-test.js

@@ -215,10 +215,47 @@ describe('lib/viewers/media/DashViewer', () => {
         it('should append representation URLs with tokens', () => {
             stubs.createUrl = sandbox.stub(dash, 'createContentUrlWithAuthParams').returns('auth_url');
             stubs.req = { uris: ['uri'] };
+            dash.options = {
+                file: {
+                    watermark_info: {
+                        is_watermarked: false
+                    },
+                    representations: {
+                        entries: [
+                            { representation: 'dash' },
+                        ]
+                    }
+                }
+            }
+
             dash.requestFilter('', stubs.req);
+
             expect(stubs.createUrl).to.be.calledOnce;
             expect(stubs.req.uris).to.deep.equal(['auth_url']);
         });
+
+        it('should append watermark cache-busting query params if file is watermarked', () => {
+            stubs.createUrl = sandbox.stub(dash, 'createContentUrlWithAuthParams').returns('www.authed.com/?foo=bar');
+            stubs.req = { uris: ['uri'] };
+            dash.watermarkCacheBust = '123'
+            dash.options = {
+                file: {
+                    watermark_info: {
+                        is_watermarked: true
+                    },
+                    representations: {
+                        entries: [
+                            { representation: 'dash' },
+                        ]
+                    }
+                }
+            }
+
+            dash.requestFilter('', stubs.req);
+
+            expect(stubs.createUrl).to.be.calledOnce;
+            expect(stubs.req.uris).to.deep.equal(['www.authed.com/?foo=bar&watermark-cache=123']);
+        });
     });
 
     describe('getActiveTrack()', () => {