Back and forth in Google Chrome will be much faster with bfcache

Google Chrome is the most popular web browser in the world, both on mobile devices and on computers. Over the years, he has faced his fair share of criticism by being more memory-intensive than it needs to be and swelling in terms of size and features, but has also been praised for its speed and usability in the real world. Now Google has announced that it is working on a new feature to improve browser back-forward navigation using bfcache (backward forward cache).

Google claims that a back / forward cache (bfcache) caches entire pages, including the JavaScript heap, when browsing out of a page. This is done so that the complete state of the page can be restored when the user navigates back. The company gives an analogy of pausing a page when the user leaves it and plays it when the user returns. It will work by navigating back and navigating to a page you've previously accessed.

Google notes that this feature will not help when you visit new sites. That does not mean it will not be useful, though. According to the company, accounts for 19% of pages viewed on Google Chrome for Android and 10% on Chrome for PC are accounted for. Bfcache will make this navigation "extremely fast," according to Google. It's definitely not a trivial effort to implement, the company notes.

Mozilla Firefox and Apple Safari have subtly different implementations of this cache technology, Google notes. Chrome, however, is choosing not to use the Webkit bfcache implementation because of incompatibility with the multi-threaded architecture of Chrome.

Addy Osmani, engineering manager for the Chrome team, said CNET that the tricky part of Chrome is to rewrite some parts of the browser to protect privacy and security. The Google web browser must prevent Web-based JavaScript programs from being displayed, even if they are hung in their memory. He acknowledged that running JavaScript on pages that are not there from a user's perspective is "a major potential privacy issue," and so the company will change the Chrome architecture to ensure that the privacy issue does not occur.

The disadvantage? Bfcache will not be available on Chrome any time soon. Google expects to test bfcache in 2019 and turn it into Chrome by 2020, according to Osmani.

Another constraint is that saving the status of web pages for possible later use consumes memory, which is already one of the main problems faced by Chrome. Osmani said that Google is still trying to figure out the best rules for deciding which pages to keep around when dumping them from memory. He also said that the feature could help in other situations, such as better performance of the guides that need to be paused while they are in the background, especially in the mobile. Such a situation usually leads to saved memory, but it also has a major disadvantage, since pages need to be reloaded upon return to them.

The bfcache in Chrome definitely looks promising, but it's in the early stages so far. We look forward to learning more in the coming months.

---

Source: GoogleVia: CNET