stark raving finkle

One of the common types of feedback we get about Firefox for Android is that it’s slow. Other browsers get the same feedback and it’s an ongoing struggle. I mean, is anything ever really fast enough?

We tend to separate performance into three categories: Startup, Page Load and UX Responsiveness. Lately, we have been focusing on the Page Load performance. We separate further into Objective (real timing) and Subjective (perceived timing). If something “feels” slow it can be just as bad as something that is measurably slow. We have a few testing frameworks that help us track objective and subjective performance. We also use Java, JavaScript and C++ profiling to look for slow code.

To start, we have been focusing on anything that is not directly part of the Gecko networking stack. This means we are looking at all the code that executes while Gecko is loading a page. In general, we want to reduce this code as much as possible. Some of the things we turned up include:

• Writing extra and/or redundant page information to the history database
• Saving session restore information too frequently
• Looking up Android system proxy information was slow
• Drawing unused view backgrounds
• Animating the pageload spinner consumed a lot of CPU cycles
• Extra messaging between the Java UI and Gecko
• Opportunities for predictive networking hints

Some of these were small improvements, while others, like the proxy lookups, were significant for “desktop” pages. I’d like to expand on two of the improvements:

Predictive Networking Hints
Gecko networking has a feature called Speculative Connections, where it’s possible for the networking system to start opening TCP connections and even begin the SSL handshake, when needed. We use this feature when we have a pretty good idea that a connection might be opened. We now use the feature in three cases:

• When a touch occurs on a link in web content, we speculatively connect to the HREF. Technically, we need to wait before really opening the link to make sure you didn’t really start panning the page or start a double-tap.
• When starting to type a URL in the titlebar, we load the current set of search engines. We speculative connect to the default search engine, since it’s somewhat probable that you will perform a search.
• When typing into the titlebar, Firefox tries to use domain autocompletion and searches your history for recent URLs. Both the current auto-completed URL and the top-most search result are speculatively connected.

Animating the Page Load Spinner
Firefox for Android has used the animated spinner as a page load indicator for a long time. We use the Android animation framework to “spin” an image. Keeping the spinner moving smoothly is pretty important for perceived performance. A stuck spinner doesn’t look good. Profiling showed a lot of time was being taken to keep the animation moving, so we did a test and removed it. Our performance testing frameworks showed a variety of improvements in both objective and perceived tests.

We decided to move to a progressbar, but not a real progressbar widget. We wanted to control the rendering. We did not want the same animation rendering issues to happen again. We also use only a handful of “trigger” points, since listening to true network progress is also time consuming. The result is an objective page load improvement the ranges from ~5% on multi-core, faster devices to ~20% on single-core, slower devices.

The progressbar is currently allowed to “stall” during a page load, which can be disconcerting to some people. We will experiment with ways to improve this too.

Install Firefox for Android Nightly and let us know what you think of the page load improvements.

Last week, the Firefox for Android team, and some friends, had a team meetup at the Mozilla Toronto office. As is typical for Mozilla, the team is quite distributed so getting together, face to face, is refreshing. The agenda for the week was fairly simple: Brainstorm new feature ideas, discuss ways to make our workflow better, and provide some time for fun hacking.

We spent most of our time brainstorming, first at a high level, then we picked a few ideas/concepts to drill into. The high level list ended up with over 150 ideas. These ranged from blue-sky features, building on existing features, performance and UX improvements, and removing technical debt. Some of the areas where we had deeper discussions included:

• Sharing: We talked about ways to improve the current Quick Share system by making it more context-aware, adding support for default providers and supporting Quick Share from more than the main menu. We also discussed adding support for more explicit sharing with integrated services. This would allow more control than Android’s Intent system supports by itself.
• Cloud Services: We found that there are plenty of ways we can integrate with cloud services. Whether it’s a way to backup parts of your profile, pull external search results into the Awesomescreen, or use other services as a source for the Reading List. Lots of project ideas were created from this concept.
• Focused UX: There were a lot of discussions around how specific types of users could benefit from new features. We ended up grouping some of these together around commonalities, which include: Privacy oriented features, parental control and child web-safety features, and hardening the application by reducing ways to corrupt the state and providing ways to rollback to a good state. While these ideas might fall into common groups, we decided that many of the details would benefit all users.

We also took some time to examine our workflow. We found some rough edges we intend to smooth out. We also ended up with a better understanding of our current, somewhat organic, workflow. Look for more write-ups from the team on this as we pull the information together. One technical outcome of the the discussions was a critical examination of our automated testing situation. We decided that we depend entirely too much on Robotium for testing our Java UI and non-UI code. Plans are underway to add some JUnit test support for the non-UI code.

The Android team is very committed to working with contributors and have been doing a great job attracting and mentoring code contributors. Last week they started discussing how to attract other types of contributors, focusing on bug triage as the next possible area. Desktop Firefox has had some great bug triage support from the community, so it seems like a natural candidate. Look for more information about that effort coming soon.

There was also some time for hacking on code. Some of the hacking was pure fun stuff. I saw a twitterbot and an IRCbot created. There was also a lot of discussion and hacking on add-on APIs that provide more integration hooks for add-on developers into the Java UI. Of course there is usually a fire that needs to be put out, and we had one this time as well. The front-end team quickly pulled together to implement a late-breaking design change to the new Home page. It’s been baking on Nightly for a few days now and will start getting uplifted to Aurora by the end of the week.

All in all, it was a great week. I’m looking forward to seeing what happens next!

Firefox on desktop has nice support for previewing and subscribing to syndication feeds (RSS and Atom). There is even support for creating Live Bookmarks. Firefox for Android does not support anything related to syndication feeds… until now.

We just landed basic support for subscribing to feeds discovered on a web page. This is only initial support, so many things are not supported.

How it works:

• If feeds are discovered on a page, Firefox will enable a menu action on the URLBar long-tap menu. Yes, we have a URLBar long-tap menu!
• Tap the “Subscribe to Page” menu action.
• If there is more than one advertised feed, choose the feed you want.
• Pick the online web service where you want to add the subscription. The choices really depend on the locale, but initially Google Reader (but not for long) and Yahoo are supported.

The limitations:

• We only support online web services right now. We are looking into local application support too, but have not seen a universal way of listing feed reader applications. We are working on a proposal and want to get support from native feed reader apps like Feedly and Newsblur.
• No support for feed previews. No plan to add support
• No support for adding new web service handlers. We are working to add this support.
• No support for Live Bookmarks. No plan to add support.

In pictures:

Long-tap on the URLBar

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Choose “Subscribe to Page”

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Choose the feed

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Choose the web service

On The Web

If you want to stay up to date on any new developments in Firefox for Android (Fennec), check out the new Tumblr and Twitter stream. Lots of updates on what’s landing in Fennec Nightly, tips and tricks and summaries of the Mobile Engineering Team meetings.

Mailing List

We have a new mailing list at mobile-dev-firefox@mozilla.org. The newsgroup at mozilla.dev.platforms.mobile is being closed. Use the new mailing list to following along and give feedback on topics being discussed, or post your own ideas.

On IRC

As always, you can jump on Mozilla IRC and talk directly to the Mobile team in the #mobile channel. This is great if you want to start working on the code, need help writing an add-on, want to help investigate a bug or just rant about some design decision.

Intel and Lenovo launched the first Android device based on the Intel Atom processor in 2012 at CES. Some of the current Android x86 devices include the Lenovo K800, the Orange San Diego, the ZTE Grand X IN, and the Motorola RAZR i.

Mozilla has been internally testing Android x86 builds of Firefox. Firefox runs really well on the Motorola RAZR i. Once we get Android x86 nightly builds stood up and running automated tests, we’ll start planning for a release.

In the meantime, you can try a developer build of Firefox for Android x86 yourself. Just like the ARM version, Firefox runs on Android 2.2 or higher. It should run fine on the Lenovo K800, which shipped with Android 2.3.7 (Gingerbread).

WARNING: This is not an officially released version of Firefox. It will only run on Intel-based (x86) Android devices.

If you don’t have an Android x86 device, you can still try the build using the Android x86 emulator. It’s the same as standard ARM emulator, but since it’s x86, it runs a lot better on your PC. Just make sure you update your Android SDK so it has the latest AVD images, and make an AVD using the x86 image. Also make sure you enable Use Host GPU as well:

Please let us know how the build works on your Android x86 devices and remember to file bugs.

I already blogged about support for remote debugging in Firefox for Android. Now we have support for remote Web Console too!

The remote console, like remote debugging, requires using Desktop Firefox to connect to Mobile Firefox over USB using ADB. Remote console is supported in Firefox 19 and newer releases. Here’s a quick guide to getting started:

1. USB Connection: Connect your Android device running Firefox to a host machine running desktop Firefox using USB. In a terminal, forward the TCP connection using: adb forward tcp:6000 tcp:6000
2. Firefox Desktop: Use about:config to enable remote debugging. Set the “devtools.debugger.remote-enabled” pref to true. Restart. You should see a “Tools > Web Developer > Remote Web Console” menu.
3. Firefox for Android: Use about:config to enable remote debugging. Set the “devtools.debugger.remote-enabled” pref to true. Restart.
4. Firefox Desktop: Choose “Tools > Web Developer > Remote Web Console” and a Remote Connection dialog should open. If you changed none of the other remote debugging preferences, just use the defaults. Press OK.
   
5. Firefox for Android: You should see a remote connection prompt appear. Press OK to initialize the connection. You have 20 seconds, by default, to accept the connection. You can retry 3 times.
   
6. Firefox Desktop: Once the connection is accepted, you should see a scope prompt. The prompt is used to pick the tab, or global, scope you want to attach to the web console.
   
7. Firefox Desktop: After picking a scope, you should see a Web Console window appear.
   

Once you have the Web Console up and running, you can do pretty much everything the desktop version can do. For example, you can load a web page and monitor the network activity, including viewing the network request details:

You can also use the JS console to execute JS code in the scope of the web page running on the Android device! Pretty cool!

A big thanks goes out to Mihai Sucan, who did a mountain of work to get the Web Console remoted. Mihai also blogged about the remote Web Console and you can find some of the underlying details on the remoting API on MDN.

Happy (remote) Debugging!