Performance Numbers for Nitro Javascript Engine in IOS 4.3

TLDR: In summary, the original post is entirely accurate. Javascript running in web apps in Mobile Safari are roughly 2x faster than running in fullscreen mode via saving a web page to the home screen. Additionally, javascript is marginally faster in a custom UIWebView running in fullscreen, but still much slower than Mobile Safari.

There was a post on Hacker News earlier today that demonstrated the new Nitro javascript engine for Mobile Safari only appears to be used when a web app is running in Mobile Safari, but not when that page has been saved as a home screen object and then runs in fullscreen mode.

The post is here: IOS 4.3 Nitro JS engine disabled for full screen apps and uiwebview and the Hacker News post is here:

I’ve run some numbers using the page from the HN post. The test embeds v0.9.1 of the Sunspider javascript test, which can then be run from the device.

I ran the following tests using a GSM iPhone 4 and iPad v1 32gb w/ 3G, both upgraded to IOS 4.3.

My tests included 3 uninterrupted runs of Sunspider in each of the following situations:

  1. Mobile Safari, native browser
  2. Page saved as home screen icon, full screen
  3. Custom iPhone app using a UIWebView that directly loads the Sunspider test linked to originally


ipad v1 (browser):
page1: 8145.2
page2: 8149.6
page3: 8166.3
avg: 8153.7ms
iPad v1 (fullscreen):
page1: 8383.7
page2: 8374.0
page3: 8201.7
avg: 8319.8ms
iPhone 4 (browser):
page1: 3981.3
page2: 4110.1
page3: 4087.5
iPhone 4 (fullscreen):
page1: 10383.4
page2: 10594.6
page3: 10572.7
avg: 10416.9
iPhone 4 (fullscreen, custom UIWebView app)
page1: 9400.0
page2: 9422.8
page3: 9431.4
avg: 9417.6666

iPad v1 (browser):

  • page1: 3320.3
  • page2: 3248.5
  • page3: 3241.8
  • AVG: 3270.2 ms

iPad v1 (fullscreen):

  • page1: 8383.8
  • page2: 8375.4
  • page3: 8397.2
  • AVG: 8385.4666 ms

iPad (fullscreen, custom UIWebView app)

  • page1: 7689.7
  • page2: 7656.7
  • page3: 7703.9
  • AVG: 7683.4333 ms

iPhone 4 (browser):

  • page1: 3981.3
  • page2: 4110.1
  • page3: 4087.5
  • AVG: 4059.33333 ms

iPhone 4 (fullscreen):

  • page1: 10383.4
  • page2: 10594.6
  • page3: 10572.7
  • AVG: 10416.9 ms

iPhone 4 (fullscreen, custom UIWebView app)

  • page1: 9400.0
  • page2: 9422.8
  • page3: 9431.4
  • AVG: 9417.6666 ms

Finally my original tests were incorrect for the iPad. I had started the upgrade from IOS 4.2 to 4.3 but it had not completed. So, the following numbers are recorded for the iPad v1 using 4.2. Basically, in Mobile Safari javascript is more than 2x as fast javascript run in fullscreen mode.

iPad v1 4.2 (browser):

  • page1: 8145.2
  • page2: 8149.6
  • page3: 8166.3
  • AVG: 8153.7ms

iPad v1 4.2 (fullscreen):

  • page1: 8383.7
  • page2: 8374.0
  • page3: 8201.7
  • AVG: 8319.8ms

How to run a web server from Virtual Box

VirtualBox is a free, lightweight virtual machine simulator from Sun. The current version is 3.0.10.

One of the uses of VirtualBox is to run a web server or other application from a virtual operating system on your computer, whether it be Windows, Linux, or Mac.

So, the point of this short post is to describe how to access your web server from your host machine. For whatever odd reason, I simply could not find this documented *anywhere* that was simple. This requires no installation of extra software or configuration of anything on your computer or on your virtual server.

Ok, I’m assuming that you already have your server installed.

  1. Shut it down if its running.
  2. Open up Virtual Box. In the left panel, select your VM and then click the yellow Settings button above it.
  3. In the new view, click on the Network button off to the right along the top.
  4. By default, Adapter 1 should already be selected. If not select it, or if you are configuring a different adapter, select that one.
  5. You should see menus called Adapter Type, Attached To, and Name. Name is probably greyed out.
  6. Under Attached To, select Bridged Adapter. The Name menu should now be clickable.
  7. Under the Name menu, select the network adapter that your computer is using for its internet connection. I am on a Mac on wireless, so my network adapter is en1: Airport. Yours might be one of the others if you are connected via ethernet.
  8. Hit OK, and this window will go away.
  9. Now start your VM image and log in.
  10. Once it is started up, you have to find the IP address that the VM is now using.
  11. If you are running a Linux server like Ubuntu, type “ifconfig” on the command line. Look for “eth0” and the “ifnet addr” near it. In my case, it is
  12. If you are running Windows, open your command prompt and type “ipconfig”. Look for a similar type of IP address.
  13. The IP address you found will be the one that you use to contact your virtual web server.
  14. Open a browser and type that number in as the address. If your server is up and running, you should now see a web page from it.

As an added bonus, its easy to configure a local name that points to this IP address and makes it easy to access your web page in the future. The steps are nearly identical for Mac, Linux, and Windows users. Since I am on a Mac, I will describe the process for us. For Windows users, do a quick search on where to find your Hosts file. The information I describe here applies, but your hosts file is in a different location.

  1. Mac users: Open a terminal.
  2. Type ‘sudo pico /etc/hosts’ and enter.
  3. Somewhere at the end of the file, add something like “localubuntu”. Of course, “localubuntu” is the address I want to use. Feel free to name it whatever you like. Also, the IP address has to match the one that you found in the earlier steps with “ifconfig” or “ipconfig”.
  4. Hit control-o and enter to save the changes. Closing the terminal window will save the changes system wide. No reboot should be necessary.
  5. Now go back to a browser and try going to “localubuntu” or whatever you named yours and you should now be hitting your web server.

Feel free to leave comments, suggestions, or questions about any of this.

Quick tips on UTF-8 encoding on a Mac running Java & Tomcat6

I ran into a problem today with UTF-8 encoding on my Mac(10.5.8), running a Java/Tomcat6 environment. It took a while to figure out, so I’m posting here in the hopes it helps others in the future.

Mac OS uses its own variant of the Java SDK. The default character encoding is MacRoman. (Read this page, scroll to “Character Encoding”). This can cause problems, such as my situation, where we are consuming a service that encodes its data as UTF-8, operates or transforms the data within our application, then outputs it again as UTF-8. The original UTF-8 data was being converted to MacRoman and then back out to UTF-8. Corruption ensued.

Depending on exactly what your problem is, I identified 2 general fixes. I only needed the first one, but I want to document the 2nd as well.

  1. Add URIEncoding to both the Java HTTP and AJP Connectors
  2. Add “-Dfile.encoding=UTF-8” to your JAVA_OPTS environment variable.

Fix #1:

  1. Edit your server.xml file. This is typically in /apache-tomcat/conf/server.xml.
  2. Look for the HTTP Connector, mine looks like this: <Connector port=”8080″ protocol=”HTTP/1.1″ connectionTimeout=”20000″ redirectPort=”8443″ useBodyEncodingForURI=”true”/>
  3. Add the uriencoding to it: <Connector port=”8080″ protocol=”HTTP/1.1″ connectionTimeout=”20000″ redirectPort=”8443″ useBodyEncodingForURI=”true” uriencoding=”UTF-8″/>
  4. Look for the AJP Connector: <Connector port=”8009″ protocol=”AJP/1.3″ redirectPort=”8443″/>
  5. Add the uriencoding to it: <Connector port=”8009″ protocol=”AJP/1.3″ redirectPort=”8443″ uriencoding=”UTF-8″/>

Fix #2:

  1. In my setup, I have added my JAVA_OPTS and other environment variables to my ~/.bash_profile. I am assuming that you already have your dev environment setup and know where your JAVA_OPTS are. This is my setup.
  2. From the terminal: sudo pico ~/.bash_profile and find the line with your JAVA_OPTS. Again, this is my config line and yours may be different.
  3. Add “-Dfile.encoding=UTF-8” to it: export JAVA_OPTS=”-Xmx768m -XX:MaxPermSize=256m -Djava.awt.headless=true -Dfile.encoding=UTF-8″

It took me a few hours of searching around and it seems like these are the general settings that most people recommend. For me, it was the combination of both Connectors that made it work. It will probably be different for other people depending on your setup.

For extra info, visit these links for more info:

Tomcat and UTF-8

Apple’s Java Docs

Install Google Page Speed into Firefox 3.5 Beta

The Goal – Get Page Speed Running on Firefox3.5 Beta I’ve been using Firefox3.5b as my primary browser more frequently because its just damned faster than FF3.0. I’m also a front-end engineer and my life online isn’t complete without Firebug. So I installed that, and on a whim wanted to install Google’s Page Speed Firebug extension. Except it wouldn’t. You probably aren’t reading this unless you know what Page Speed is already, but if you don’t and want to know more visit Needless to say, I got this running. Kinda. Page Speed has some “bugs” in FF3.5 right now. This is simply a write-up on how to get it installed right now. This document will likely be out of date in a couple months.

Also, I am not providing a download for my modified Page Speed extension because:

  1. It will be out of date soon.
  2. I don’t want to deal with hosting it.
  3. And I don’t want to deal with comments from people who just install it and get any of the errors that result. This is just a how-to.

What’s Needed

You need Firefox 3.5 Beta. Go here.

You need Firebug 1.4 Beta. Go here.

You need Page Speed. Go here.

Install the Firefox 3.5 Beta. When you get that going, install the Firebug 1.4 Beta extension.


The Problem – Page Speed Isn’t Designed For Firefox 3.5 Beta

After I got this going, Page Speed was giving some errors. Basically, it looks like the page performance tab works just fine, but the page speed activity tab doesn’t. And it produces some errors. Oh well, lets continue.

What we’re doing is increasing the “maxVersion” value in the page-speed.xpi extension to allow FF3.5 to install it.


  1. Download the page-speed.xpi and save it locally on your machine. Direct Link
  2. Rename the file from “page-speed.xpi” to “”.
  3. Un-archive the zip, aka unzip. This creates a directory called “page-speed”.
  4. Navigate to “page-speed” directory.
  5. Edit “install.rd” with your favorite text editor.
  6. Search for “3.0.*”
  7. Change to “3.5.*”
  8. Save the “install.rdf” file.
  9. On a Mac, select all of the contents of the page-speed directory, right-click and choose “Compress 6 items”. This creates “” in the page-speed directory.
  10. Are you on Windows? I’m sure the steps are similar. You really should just get a Mac, because “I’m a Megan”, not a piece of under-performing commodity hardware with an over-priced OS and no quality pre-installed software.
  11. Rename “” to “page-speed.xpi”.
  12. Drag the new “page-speed.xpi” into any open Firefox 3.5 Beta window and you should get the extension install dialogs. A restart of the browser is required after installation.

If you get an error like: “Error: Firefox could not install the file at because: Install script not found -204″ its because you created the archive wrong. See notes from above.

After Installation

Assuming everything went well, you should now have Page Speed available in Firebug. In my testing, the Page Speed tab works great. However, the Page Speed Activity tab generates some errors and won’t run. I have no idea or ambition to fix this particular problem. Maybe someone more outgoing than I am can come up with a fix for this.

How to Use Multiple Twitter Accounts on One Gmail Account

There are many times when you might want multiple Twitter accounts. You might have one for your personal use and one for your company.

Twitter restricts accounts to one per unique email address. Who wants to manage multiple email accounts unnecessarily?

Add Some Variety to Your Gmail Address

Gmail has a cool feature that’s been around for many years. You can extend your email address by applying “+uniquetext” to the end of your address before the @ symbol.

For example, my personal Twitter account is I also have another one I just started for Javascript conferences,

For my personal account, I signed up with ‘’. For jsconferences, I used ‘’. Twitter recognizes each as a unique email address, and Gmail nicely delivers mail to both addresses to my one email account.

Keeping Organized: Apply Labels Automatically

If you’re running multiple Twitter accounts, all of those notification emails could get confusing. Lets filter them into their own labels in Gmail.

If you’re new to labels, just think of them as versatile folders. Also, Gmail offers “filters”, which are similar to “Rules” in a mail program like Outlook.

Ok, there’s 2 steps.

  1. 1) Make the label(s).
  2. 2) Setup the filter(s).

Make the Label

Go to your inbox and at the top look for the Labels drop down button. Click on “Manage Labels” at the bottom of the menu.

On the Settings screen that appears, at the very bottom create a new label. For me, I’m adding “jsconferences”. Click the Create button to make it so.

Setup the Filter

Click the Filters tab, then click “Create a New Filter”. In the To: field, put your email address with the “+uniquetext” you used to register your Twitter account. For me, this is

Click the “Next Step” button.

Check the box “Apply the label” and the label you created a minute ago from the list. When you’re ready, click the “Create Filter” button. You’re done!


Send an email to your email address with the “+uniquetext” text. When it is received back in your inbox, it should now have the label.

That’s it. Twitter on!

Detecting Technological Advancement in Alien Civilizations

Here in the U.S. we are converting all of our tv broadcast signals from analog to digital for the first time since people started broadcasting television signals. It indicates an advancement that is potentially detected far beyond our own blue marble. It prompted a thought about SETI’s search for an alien civilization’s broadcast signal over the years, and how we might be able to detect their rough level of advancement if we listened long enough.

There’s some hypothetical assumptions we have to make to illustrate this idea. First, that we have detected an alien civilization’s broadcast signals and have been listening for a while. Second, that we have been able to get more information from the signal beyond the fact that it exists. It not only has to be strong enough to be detectable, it must still be carrying information we can decode.

A fact that has been widely talked about over the years is that since people started broadcasting radio in the early 20th century, there has been an ever-expanding envelope of radio signals emanating from the earth and into surrounding space. By now, its possible that our earliest radio and tv signals have spread across a volume of space almost 90 light years in all directions. There are thousands of stars in this small region of space, and a sufficiently advanced civilization living out there could have been listening to us for decades.

In our scenario, lets switch roles. We have detected a civilization that isn’t too far away and have been recording their broadcasts for a number of decades. Over the years, we’ve seen their signals get stronger and more sophisticated. If we are able to interpret their broadcasts, we could get a lot more information about their societies that would add to our estimates of their development. Depending on the rate of change over time, we can make rough estimates about their level of technological advancement.

  1. If the change has been slow, we might assume they have are advancing at a slower rate than we are.
  2. Alternatively, we might deduce they are advancing more quickly than us.
  3. If we detect a variable level of complexity in their signals over a long period of time it could indicate a civilization-wide war, natural disaster, or even economic collapse has occurred that set them back.
  4. Finally, if their signals stop suddenly and never return it might indicate either a complete collapse or it could be an indicator that they have gone through their own Singularity.

Point 4 has some special meaning. If the complexity of another civilization’s signals have steadily increased over the years and then suddenly stopped or drastically altered in a short amount of time, this could be interpreted as a very good indicator of a Singularity event. Depending on the civilization’s distance from our own and how long the delay is between when it was broadcast and when it was received, this could be an early warning indicator that we could be on the receiving end of first contact in a short amount of time. It might be our only warning before we encounter whatever came out the other end of their Singularity. A short review of human history teaches good lessons for what happens to the less-developed in situations like that.

We should look at our own progress over the last 100 years and imagine what another species nearby might be seeing.

Quick tip to save a lot of memory on your iPhone

There’s a great app called FreeMemory that quickly frees up a lot of memory. It’s definitely worth the $0.99.

The last update adds a great feature that let’s you see all of the processes running on your phone.

Last night I started noticing that sometimes MobileSafari stays running as a background process. This only seems to occur if you close Safari with a web page open.

In these screenshots, you can see what I mean. The quick tip to save a lot of memory is to close any open pages before you quit Safari. I didn’t use the free memory button on this. I just closed the page between uses in Safari

Twitter "protects" API user status call… but doesn't

John Resig alerting about the authentication change

UPDATE 2/24/09: Twitter has changed their API and this technique no longer works.

For the last week or so, there’s been a lot of commentary about how you could detect if a Twitter user was visiting your site based on the response of a public, non-authenticated API call. It was documented at Ajaxian.

John Resig was one of the first to notice earlier today that Twitter has placed the API call in question behind http authentication. Indeed, the link he provides to Venture Hacks issues a login alert when you visit the page.

However, this does absolutely nothing to prevent a 3rd party from still accessing this information. Twitter is likely to fix this soon, but here’s how to use it in the mean time.

Basically, the API url that is now issuing the authentication requirement was this:

By simply changing the query string slightly, you bypass authentication and retrieve the user’s status data again if they are logged in. This works without the “/?callback=” part, but this is needed to have have Twitter wrap the json object so that it can be used in the browser, ala jsonp.

If you use jQuery, the simple bit of code that returns this is:

dataType: 'jsonp',
data: '',
jsonp: 'callback',
url: '',
success: function(jsondata) {

To use this to determine if a visitor is logged into Twitter or not, use the methods described in the Ajaxian article and just change the link. Happy hacking!