Bug 1093869 - Migrate indexedDB reader mode cache. r=bnicholson

mobile/android/base/tests/testReadingListCache.js

@@ -73,6 +73,47 @@ add_task(function* test_parse_articles() {
   }
 });
 
+add_task(function* test_migrate_cache() {
+  // Store an article in the old indexedDB reader mode cache.
+  let cacheDB = yield new Promise((resolve, reject) => {
+    let win = Services.wm.getMostRecentWindow("navigator:browser");
+    let request = win.indexedDB.open("about:reader", 1);
+    request.onerror = event => reject(request.error);
+
+    // This will always happen because there is no pre-existing data store.
+    request.onupgradeneeded = event => {
+      let cacheDB = event.target.result;
+      cacheDB.createObjectStore("articles", { keyPath: "url" });
+    };
+
+    request.onsuccess = event => resolve(event.target.result);
+  });
+
+  yield new Promise((resolve, reject) => {
+    let transaction = cacheDB.transaction(["articles"], "readwrite");
+    let store = transaction.objectStore("articles");
+
+    let request = store.add({
+      url: TEST_PAGES[0].url,
+      content: "Lorem ipsum",
+      title: TEST_PAGES[0].expected.title,
+      byline: TEST_PAGES[0].expected.byline,
+      excerpt: TEST_PAGES[0].expected.excerpt,
+      length: TEST_PAGES[0].expected.length
+    });
+    request.onerror = event => reject(request.error);
+    request.onsuccess = event => resolve();
+  });
+
+  // Migrate the cache.
+  yield Reader.migrateCache();
+
+  // Check to make sure the article made it into the new cache.
+  let uri = Services.io.newURI(TEST_PAGES[0].url, null, null);
+  let article = yield Reader.getArticleFromCache(uri);
+  checkArticle(article, TEST_PAGES[0]);
+});
+
 function checkArticle(article, testcase) {
   if (testcase.expected == null) {
     do_check_eq(article, null);

mobile/android/chrome/content/Reader.js

@@ -419,5 +419,49 @@ let Reader = {
         return OS.File.makeDir(dir);
       }
     });
-  }
+  },
+
+  /**
+   * Migrates old indexedDB reader mode cache to new JSON cache.
+   */
+  migrateCache: Task.async(function* () {
+    let cacheDB = yield new Promise((resolve, reject) => {
+      let request = window.indexedDB.open("about:reader", 1);
+      request.onsuccess = event => resolve(event.target.result);
+      request.onerror = event => reject(request.error);
+
+      // If there is no DB to migrate, don't do anything.
+      request.onupgradeneeded = event => resolve(null);
+    });
+
+    if (!cacheDB) {
+      return;
+    }
+
+    let articles = yield new Promise((resolve, reject) => {
+      let articles = [];
+
+      let transaction = cacheDB.transaction(cacheDB.objectStoreNames);
+      let store = transaction.objectStore(cacheDB.objectStoreNames[0]);
+
+      let request = store.openCursor();
+      request.onsuccess = event => {
+        let cursor = event.target.result;
+        if (!cursor) {
+          resolve(articles);
+        } else {
+          articles.push(cursor.value);
+          cursor.continue();
+        }
+      };
+      request.onerror = event => reject(request.error);
+    });
+
+    for (let article of articles) {
+      yield this.storeArticleInCache(article);
+    }
+
+    // Delete the database.
+    window.indexedDB.deleteDatabase("about:reader");
+  }),
 };

mobile/android/chrome/content/browser.js

@@ -870,6 +870,10 @@ var BrowserApp = {
       Services.prefs.setBoolPref("searchActivity.default.migrated", true);
       SearchEngines.migrateSearchActivityDefaultPref();
     }
+
+    if (this._startupStatus === "upgrade") {
+      Reader.migrateCache().catch(e => Cu.reportError("Error migrating Reader cache: " + e));
+    }
   },
 
   // This function returns false during periods where the browser displayed document is