This is a huge job, probably impossible: * Chrome has a sandboxing architecture that separates the renderers and the browsers. The renderer is the unsafe part of the browser that works on web-site provided data. This is where compilation of JS code takes place. The browser is what handles the caches. If you take compiled code from a renderer and put it in a cache then you are transporting data from an untrusted to a trusted part of the browser. And if you then give the compiled data to a different renderer you are violating the isolation of tabs. This would be OK if compiled data was in a simple, verifiable data format that could be checked for correctness, but as you say it's arbitrary machine code. * When the top level JS code runs (and creates 'classes', functions, etc.) it can do anything. It's JS code so it can change the intrinsic functions with monkey patching, it can make references to DOM objects (C++ heap allocated objects) and can make other changes to the native heap of the browser. Capturing all these changes in a serialized form that you can call 'the compiled code' is very difficult. Perhaps you can detect the presence of some changes and disallow serializations in some cases, but it's a non-trivial task, and if you get it wrong you have probably made a security issue of some sort.
So it's not completely impossible. Objection number 2 does not apply to as large an extent to Dart, so perhaps in that language something is possible. Objection number 1 is perhaps something that extensive auditing, persuasion and hard work could fix. As for node.js I don't see the VM being started up so often in node.js applications so as far as I can see the compile time is not a big issue. I'm not sure there is a real issue to fix there. On Thu, Sep 20, 2012 at 11:47 PM, riadh chtara <[email protected]> wrote: > Hi > Javascript is today used in browser,server (node.js), mobile apps, firefox > os, webapps. and I really love it and I want to help making it better and > faster. > I think that one of the reasons that javascript is slow (despite the great > improvement done with modern engine such v8) , is that that javascript code > is compiled every time it used. > In v8, javascript is translated to machine code and then executed. And I > think it would be good idea to save generated code to reduce the time needed > for running javascript (in chrome for example, we save the generated files > instead of .js files) > If this new feature would be implement, v8 will gain a lot of speed, with > webapp, and website. > This enhancement will be also available for node.js. > what do you think about my idea? > And how much time do you think it would take to be done? > Cheers > Riadh > > -- > v8-dev mailing list > [email protected] > http://groups.google.com/group/v8-dev -- Erik Corry, Software Engineer Google Denmark ApS - Frederiksborggade 20B, 1 sal, 1360 København K - Denmark - CVR nr. 28 86 69 84 -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev
