Examining Chrome's Source Code

An anonymous reader writes "Chrome is open source, and there's clearly still some work to be done on it. In this article, Neil McAllister decided to take a peek under Chrome's hood and view it through the eyes of the developers who will improve and maintain it in the coming years. It seems Google's open source browser currently has much to offer prospective hackers — provided they use Windows. Quoting: 'The Chromium site explains how to download the source code for Linux, Mac OS X, or Windows. Unfortunately, if you're eagerly awaiting a Mac version of Chrome, you shouldn't hold your breath. As the Mac OS X area of the Chromium developer site explains, "Right now, the Mac build is a work in progress that is much closer to the start than the finish." In fact, according to the latest status report, the Chrome developers have yet to get even the browser core running under Mac OS X. Rendering actual Web pages is still a long way off, to say nothing of a usable Aqua GUI. Then again, the Linux version is in arguably even worse shape.'"

Comments

What I don't get...

[Angstroem]

So they want to develop a cross-platform browser.

Why exactly is it then tied that tightly to a platform that porting it over to other platforms seems to basically mean starting all over again? After all, it's not like all 3 platforms would be completely alien in the backend -- they are POSIX compliant. Then the GUI: it's not like there aren't any cross-platform widget sets out there. But even if you want to go for individual approaches for each platform, then you still can separate functionality from the GUI.

So why again is the Mac port "closer to start than finish" (especially when reminding that Chrome is based on Webkit) and the Linux port "even worse"?

Re:What I don't get...

[anon mouse-cow-aard]

mod-parent up. QT is the native toolkit for KDE.
IT isn't some artificial toolkit people only use for cross platform work, wxwindows or tk. It's a real native toolkit on Linux.

Heck, there's a windows port of KDE4.x in the works.
I mean come on...

Re:What I don't get...

[kollivier]

There can't be a grand unified HIG, but you're thinking about the problem backwards. Instead of trying to unify the HIGs, just have classes that abstract out the differences. For example, wxPython actually handles much of this already - the SizedControls library gives controls HIG-compliant borders and spacing on Win/Mac/GTK, while wxStdDialogButtonSizer (long name, I know ;-) will take your OK and Cancel button and make sure they appear in the right order on each platform. The platform-specific code is all built into the library - you don't need to deal with it yourself.

The reason most cross-platform apps don't follow HIGs too well is that rather than use a library like this, they hand-code spacing, positioning, etc., usually doing the whole thing on one platform first. So then when they decide to make it cross-platform, going through and making a huge preferences window, for example, follow HIGs is a massive task.

Re:It's not over for Mozilla after all

[dotancohen]

They still have a near monopoly on the entire Linux desktop market!

Truth is, I don't really care if Chrome runs under Linux or not. What _is_ important is that there is a lot of buzz about a non-IE browser out there, and that will help Linux users no matter which browser they use. Chrome will get the attention of at least some PHBs and Frontpa^w webdevs who code IE-only websites. I have been complaining about this for years but now there finally is a product that they will have a hard time ignoring. Firefox was close, but was only talked about by gearheads. Even my mother-in-law asked me about Chrome. Which is too bad, as she's on Ubuntu and feels left out...

Tracemonkey vs. V8

[Anik315]

Chrome is currently faster than Firefox at most things even when Tracemonkey is enabled. I mostly work with browser based math/finance apps, and one of the most intensive things that can be done is a numerical integral. No other browser even comes close to Chrome in terms of speed. The only drawback is that it isn't cross platform yet. From what I hear, Tracemonkey is working really well on different processors so it will be an interesting match up. Try pasting this code into JavaScript Shell from Chrome and Firefox for a comparison.

Math.precision=function (x, eps) { var dec = Math.pow(10, Math.floor(Math.log(1 / eps) * Math.LOG10E)); return Math.round(dec * x) / dec; };function asr(f, a, b, eps) { var c = (a + b) / 2; var h = (b - a) / 6; var fa = f(a); var fb = f(b); var fc = f(c); return Math.precision(recursive_asr(f, a, b, c, eps, h * (fa + fb + 4 * fc), fa, fb, fc), eps); };function recursive_asr(f, a, b, c, eps, sum, fa, fb, fc) { var cl = (a + c) / 2; var cr = (c + b) / 2; var h = (c - a) / 6; var fcr = f(cr); var fcl = f(cl); var left = (fa + 4 * fcl + fc) * h; var right = (fc + 4 * fcr + fb) * h; if (Math.abs(left + right - sum) <= 15 * eps) { return left + right + (left + right - sum) / 15; } return recursive_asr(f, a, c, cl, eps / 2, left, fa, fc, fcl) + recursive_asr(f, c, b, cr, eps / 2, right, fc, fb, fcr); };asr(Math.sin,0,100,1e-15);

Re:the core not even running under mac?

[maxume]

It uses webkit for layout, but it uses a (sort of) homegrown library for rendering:

http://gigaom.com/2008/09/02/google-open-sources-skia-graphics-engine/
http://src.chromium.org/viewvc/chrome/trunk/src/skia/

Re:It's not over for Mozilla after all

[sznupi]

Unfortunatelly, Firefox wasn't close at all; it simply shifted the mindset in most places from "we support only IE" to "we support only IE and Firefox".

It was noticeable when you use something else, like Opera... (luckily not on sites originating in my area of the world, since Opera here has from 5 to 25 percent, depending on the country; and since Firefox has over 40% in most of them, aiming sites for duopoly doesn't work)

Seems like three major browsers is a minimum needed for them to start noticing _true_ interoperability...

the great irony

[Anonymous Coward]

The great irony of all of this is that Chrome (also Safari) directly owe the KDE and Qt projectÅ credit for constructing the base on which this is built. And now they are primarily targeting windows. When discussing either Safari or Chrome, I never ever even see mention of the F/OSS projectÅ to which they owe their existence. More than a pity, itÅ a crying shame. Do no evil my ass.

Re:It's going to have maintainability problems.

[skeeto]

And, yuck, they checked in a whole bunch of binaries. If you so a checkout of the Subversion repository (weighing in at 1.5G for the single revision checkout, 8G or so to build!) it is a huge mess. I don't think Chrome is going anywhere for a long time due to these maintainability problems you mentioned, and you won't find hackers poking around Chromium with the mess that the codebase is in. Plus, it's all tied very closely to Windows, and who wants to hack in the hacker-unfriendly Windows?

Once I saw this, I sort-of forgot all about Chrome/Chromium. It's all hype for now.

Re:It's not over for Mozilla after all

[kripkenstein]

And google is really happy with that. They don't need to target the linux market because Mozilla is already working for them here.

The target is obviously internet explorer.

I disagree for two reasons.

First, we can only presume Google wants Chrome to run on Android, Google's handset OS. Which is based on Linux. So clearly Google has a direct and powerful motivation to target Linux with Chrome. (In fact a much stronger motivation than to get Chrome running on OS X - I wouldn't be surprised to see the Android/Linux version out earlier.)

Second, one of the best ways to weaken IE is to weaken Windows - the less people running Windows, the less run IE. But if Chrome is Windows-only, that just strengthens Windows as the only platform able to run the 'best' browser ('best' at least in Google's eyes and those that like Chrome).

In other words, every IE convert to Chrome is still locked in to Windows. Whereas Google's long-term goal is to make the OS irrelevant so long as it can access Google's web services.

Re:It's not over for Mozilla after all

[Fumus]

If a large enough subgroup of "the blue e takes me to the internet" group starts thinking that google=internet, then a convenient "Download chrome! Make your google experience even better." link on every search page can easily convert them.

Re:the core not even running under mac?

[Dolda2000]

What a weird question to ask. WebKit is a just a library for HTML rendering. It's like asking why Windows games don't run on Linux; after all, they're written in C, known to be a cross-platform language.

Chrome naturally consists of many other components as well, such as the actual user interface, all the glue code to actually read and write files (like the cache), doing network connections, DNS lookups, checking SSL certificates, handling its famous sandbox processes, loading plugins and all sorts of other things.

Re:the core not even running under mac?

[Vexorian]

I'd say that under google's perspective, the core is the Javascript VM.

Re:Not open source!

[emiraga]

There are some theories on the internet of what RLZ.DLL is doing, no one is 100% sure. The problem is that google can change RLZ.dll via GoogleUpdate at any time and it can potentially do anything.